Apparatus and method for aligning scroll compressor

Abstract

Alignment is performed in a short time without reducing aligning accuracy. In performing the determination of the relative positions (alignment) of a fixed scroll and an orbiting scroll, both revolution compensation and translation compensation are performed by one measurement operation.

Description

TECHNICAL FIELD

The present invention relates to an apparatus for aligning a scroll compressor and, more particularly, to a technique capable of performing alignment in a short time without reducing aligning accuracy.

BACKGROUND ART

In a scroll compressor, scroll wraps formed in spiral shape on end plates of a fixed scroll and an orbiting scroll are brought into mesh with each other thereby to internally form a hermetically closed working chamber and the orbiting scroll is caused to perform an orbital motion, whereby a crescent-shaped space formed between the scroll wraps moves from the periphery to the center while reducing its volume, and a cooling medium is compressed by utilizing this phenomenon.

Incidentally, in the above-described scroll compressor, the positional relationship of the fixed scroll and the orbiting scroll in a meshed condition, i.e., an assembly accuracy of a wrap clearance between the scroll wrap of the fixed scroll and the scroll wrap of the orbiting scroll or the like has a great effect on the compression performance and durability of a cooling medium.

Therefore, it is necessary to align the fixed scroll and the orbiting scroll in an optimum position (alignment). Usually, in the aligning work of a scroll compressor, a dedicated aligning apparatus is often used. An example of this aligning apparatus is described in Patent Document 1 (the Japanese Patent Application Publication No. 2002-70763), for example.

The aligning apparatus of the scroll compressor of Patent Document 1 is provided with fixed scroll moving means which moves a fixed scroll in the X-Y direction, θ revolving means which revolves a main frame in a θ direction, a driving section which revolves and drives an orbiting scroll via a driving shaft, and a displacement sensor which measures an X-Y displacement of the fixed scroll.

First, while the orbiting scroll is being revolved by the driving section via the driving shaft, the main frame is revolved by the θ rotating means through a prescribed angle of θ°, the displacement is read by use of the displacement sensor, and positioning of a relative revolution direction (θ revolution compensation) of the fixed scroll and orbiting scroll is performed. After that, the fixed scroll is forcedly moved in the X-Y direction by use of the fixed scroll moving means, variations in displacement are measured by use of the displacement sensor, and a minimum displacement value of the fixed scroll in the X-Y direction is determined (translation compensation), whereby the determination of the relative position (alignment) of the fixed scroll and the orbiting scroll is performed.

However, in conventional aligning apparatus, the measurement of displacements in the directions of the X axis and Y axis is performed in each of the steps of θ rotation compensation and translation compensation in order to ensure high aligning accuracy, thereby requiring time to calculate a position for positioning. For this reason, production efficiency is low and this poses a problem in mass production.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made to solve the above-described problem and has as its object the provision of an apparatus and a method for aligning a scroll compressor which can perform both θ revolution compensation and translation compensation on the basis of a moving displacement obtained by one measurement operation.

To achieve the above object, the present invention provides an apparatus for aligning a scroll compressor, which has a compression section which is internally formed a hermetically closed working chamber by bringing scroll wraps of a fixed scroll and an orbiting scroll into mesh with each other, a main frame which supports the compression section, and a crank shaft which is connected to the orbiting scroll at a top end thereof, and performs positioning of the scroll wraps of the scroll compressor including a driving shaft held by the main frame while revolving the orbiting scroll via the driving shaft. This aligning apparatus comprises: X-Y moving means which is restricted in revolutions in a θ direction around a Z axis and supports the main frame or the fixed scroll so as to be movable in directions of an X axis and a Y axis; θ revolution compensation means which is restricted in movements in the directions of the X axis and the Y axis and supports the orbiting scroll or the fixed scroll via the main frame so as to be revolvable in the θ direction around the Z axis; orbiting scroll driving means which is connected to the driving shaft and drives the orbiting scroll; X-Y displacement measuring means which detects a moving displacement of the fixed scroll or the main frame in the directions of the X axis and the Y axis, which result from an orbital motion of the orbiting scroll; and control means which controls at least the X-Y moving means, the θ revolution compensation means, the orbiting scroll driving means and the X-Y displacement measuring means. In this aligning apparatus, the control means measures a moving displacement of the fixed scroll or the main frame, which results from the revolutions of the driving shaft, by use of the X-Y displacement measuring means by revolving and driving the driving shaft by use of the orbiting scroll driving means and by revolving the orbiting scroll or the fixed scroll in increments of a prescribed angle of θ° by use of the θ revolution compensation means each time the driving shaft performs a prescribed revolution, performs revolution compensation from obtained measured values by controlling the θ revolution compensation means so that the moving displacement of the fixed scroll or the main frame becomes a minimum, and performs translation compensation by determining an optimum position of the fixed scroll or the main frame from the measured values on the basis of displacement components in the directions of the X axis and the Y axis and by moving the fixed scroll or the main frame to the optimum position.

As a result of this, both the alignment of the orbiting scroll and the fixed scroll in a relative revolution direction (θ revolution compensation) and the alignment in the directions of the X axis and the Y axis (translation compensation) can be adjusted at a time on the basis of a moving displacement measured during θ revolution compensation.

Also, the control means performs arithmetic processing as stated in Formula 1, determines an optimum position (Xc, Yc) of the fixed scroll or the main frame and performs translation compensation on the basis of the optimum position,
[Formula 1] $\begin{array}{cc}\left(X_C,Y_C\right)=\left\{\frac{\left(X_{\max }+X_{\min }\right)}{2},\frac{\left(Y_{\max }+Y_{\min }\right)}{2}\right\}& \mathrm{Formula}1\end{array}$
where a maximum point and a minimum point of a locus of the fixed scroll or the main frame in the direction of the X axis which are obtained when the driving shaft performs one revolution are denoted respectively by Xmax and Xmin, and a maximum point and a minimum point of the locus in the direction of the Y axis are denoted respectively by Ymax and Ymin.

As a result of this, the center position for positioning (Xc, Yc) can be calculated as the center position of a maximum displacement value and a minimum displacement value in each of the directions of the X axis and the Y axis.

Furthermore, the control means performs arithmetic processing as stated in Formula 2, determines an optimum position (Xc, Yc) of the fixed scroll or the main frame and performs translation compensation on the basis of the optimum position,
[Formula 2] $\begin{array}{cc}\left(X_c,Y_c\right)=\left\{\frac{\sum _{i=1}^n{X}_i}{n},\frac{\sum _{i=1}^{n}Y}{n}\right\}& \mathrm{Formula}2\end{array}$
where the number of all samplings of a locus of the fixed scroll or the main frame in the directions of the X axis and Y axis which are obtained when the driving shaft performs one revolution is denoted by n.

As a result of this, the center of coordinate points of all sampling number n is averaged by integral calculation and this center is regarded as the optimum position (Xc, Yc) of the fixed scroll (or the main frame). Therefore, even when exceptional data by sampling errors is included, more stable positioning can be performed because leveling is performed by integration.

Furthermore, the control means performs arithmetic processing as stated in Formula 3, determines an optimum position (Xc, Yc) of the fixed scroll or the main frame and performs translation compensation on the basis of the optimum position,
[Formula 3] $\begin{array}{cc}\left(X_c,Y_c\right)=\left\{\frac{X_{\mathrm{C1}}+X_{\mathrm{C2}}}{2},\frac{Y_{\mathrm{C1}}+Y_{\mathrm{C2}}}{2}\right\}& \mathrm{Formula}3\end{array}$
where an optimum compensation angle of the orbiting scroll or the fixed scroll is denoted by θc, a maximum displacement difference when the revolution angle of the orbiting scroll or the fixed scroll is θ1 is denoted by GAP1, the center of the locus in the directions of the X axis and the Y axis at this time is denoted by (X_c1, Y_c1), a maximum displacement difference when the revolution angle is θ2 is denoted by GAP2, with the optimum compensation angle θc being intermediate between θ1 and θ2, the center of the locus in the directions of the X axis and the Y axis at this time is denoted by (X_c2, Y_c2), and the relationship GAP1 £ GAP2 holds in the maximum displacement difference.

As a result of this, when a minimum point of the fixed scroll (the orbiting scroll) is an optimum compensation angle θc, an optimum position (Xc, Yc) of the fixed scroll 1 is found from the center of a locus of revolution angles θ1, θ2, which provide almost the same displacement difference on a quadratic curve which appears symmetrically. Therefore, stable positioning can be performed.

As a more preferable mode, it is preferred that abnormality detection means which is connected to the driving shaft and detects an abnormality in the orbiting scroll driving means which drives the orbiting scroll be further provided.

As a result of this, it is possible to prevent an abnormal load from being applied to a work during aligning work and the work from being broken and it is also possible to positively prevent the aligning apparatus itself from being broken.

A method for aligning the scroll compressor is also included in the present invention. That is, the present invention provides a method for aligning a scroll compressor, which uses a compression section which is internally formed a hermetically closed working chamber by bringing scroll wraps of a fixed scroll and an orbiting scroll into mesh with each other, a main frame which supports the compression section, and a crank shaft which is connected to the orbiting scroll at a top end thereof, and performs positioning of the scroll wraps of the scroll compressor including a driving shaft held by the main frame while revolving the orbiting scroll via the driving shaft. This method uses: X-Y moving means which is restricted in revolutions in a θ direction around a Z axis and supports the main frame or the fixed scroll so as to be movable in directions of an X axis and a Y axis; θ revolution compensation means which is restricted in movements in the directions of the X axis and the Y axis and supports the orbiting scroll or the fixed scroll via the main frame so as to be revolvable in the θ direction around the Z axis; orbiting scroll driving means which is connected to the driving shaft and drives the orbiting scroll; X-Y displacement measuring means which detects a moving displacement of the fixed scroll or the main frame in the directions of the X axis and the Y axis, which result from an orbital motion of the orbiting scroll; and control means which controls at least the X-Y moving means, the θ revolution compensation means, the orbiting scroll driving means and the X-Y displacement measuring means. And this method comprises: a displacement measuring step of measuring a moving displacement of the fixed scroll or the main frame, which results from the revolutions of the driving shaft, by use of the X-Y displacement measuring means by revolving and driving the driving shaft by use of the orbiting scroll driving means and by revolving the orbiting scroll or the fixed scroll in increments of a prescribed angle of θ° by use of the θ revolution compensation means each time the driving shaft performs a prescribed revolution, a revolution compensation step of performing revolution compensation from obtained measured values by controlling the θ revolution compensation means so that the moving displacement of the fixed scroll or the main frame becomes a minimum and a translation compensation step of performing translation compensation by determining an optimum position of the fixed scroll or the main frame from the measured values on the basis of displacement components in the directions of the X axis and the Y axis and by moving the fixed scroll or the main frame to the optimum position.

As a result of this, it is possible to perform both the relative alignment (θ revolution compensation) of the orbiting scroll and the fixed scroll and the alignment in the directions of the X axis and the Y axis by measuring only one moving displacement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view which shows an apparatus for aligning a scroll compressor in an embodiment of the present invention;

FIG. 2 is a schematic diagram which shows the internal structure of a compression section;

FIG. 3 is a flowchart to explain the flow of aligning work;

FIG. 4A is a displacement-time graph of a fixed scroll in the directions of an X axis and a Y axis;

FIG. 4B is a displacement-feed angle graph of a fixed scroll in the directions of an X axis and a Y axis;

FIG. 5 is a schematic diagram which schematically shows a variation example of a displacement difference;

FIG. 6 is a graph which shows plots of displacement amount of a fixed scroll in the directions of an X axis and a Y axis; and

FIG. 7 is an explanatory diagram to explain a method of calculating an optimum position for translation compensation.

DETAILED DESCRIPTION

Next, an embodiment of the present invention will be described with reference to the drawings. Incidentally, in the present invention, the axial direction of the driving shaft is a Z axis, an X axis and a Y axis are of an arbitrary orthogonal coordinate system which is orthogonal to the Z axis, and the direction of revolution around the Z axis is θ.

As shown in FIG. 1, an aligning apparatus 100 of the present invention is provided with a base 200 having a rigid frame structure of metal etc., and the base 200 is constituted by a base stand 201 which is installed on a horizontal plane such as a floor and an L-shaped support frame 202 which is provided almost perpendicularly in a standing manner from one end of the base stand 201.

To a side wall surface of the support frame 202 is fixed a support plate 310 which supports fixed scroll moving means 300, which will be described later. Furthermore, a second Z axis linear rail 205 which moves assembly means 700 in the direction of the Z axis is provided at a leading end of the support frame 202. Incidentally, in addition to the linear rail, a usual hydraulic actuator or the like may be used.

The support frame 202 is further provided with a control console 4 (control means) which measures, calculates and outputs detection data fed from each detection means. A display monitor, various operation panels and the like are integrally built in the control console 4, and aligning accuracy, time, etc. can be set by inputting various set values.

In this embodiment, the control console 4 takes charge of not only data processing of detection data, but also the whole command system related to the aligning apparatus of the present invention, such as the control of various kinds of means and the control of switches. In this example, the control console 4 is a computer in which dedicated aligning control software is installed.

Next, a compression section 1 will be described. As shown in FIG. 2, the compression section 1 is provided with a fixed scroll 11 and an orbiting scroll 12, scroll wraps of the two being in mesh with each other, and the orbiting scroll 12 is held within a main frame 13 via an Oldham's ring 14 for preventing revolutions on its axis.

In the main frame 13, a bearing part 13a which supports a driving shaft 2 for causing the orbiting scroll 12 to perform an orbital motion is provided in the middle. The driving shaft 2 is such that, with this bearing part 13a sandwiched, a crank shaft 21 of the driving shaft 2 is drawn out to the support surface side (the top surface side in FIG. 2) of the orbiting scroll 12 of the main frame 13 and a main shaft 22 of the driving shaft 2 is drawn out to the back surface side (the bottom surface side in FIG. 2) v of the main frame 13.

As shown in FIG. 2, positioning holes 111, 131 for positioning a relative initial position of the fixed scroll 11 and the main frame 13 are provided respectively in the fixed scroll 11 and the main frame 13.

The positioning hole 111 on the fixed scroll 11 side is a round hole which pierces through end plates of the fixed scroll 11 along an axial direction. The positioning hole 131 on the main frame 13 side is a round hole and female screw threads with a specified pitch are formed on the inside diameter of the positioning hole 131.

The positioning holes 111, 131 are each provided in multiple places at prescribed intervals (in this example, in three places at intervals of 120°) along the circumference direction, and a temporary lock pin 15 is inserted, with each of the positioning holes 111, 131 coaxially arranged.

Referring to FIGS. 1 and 2, a work table 206 for substantially performing the aligning work of the compression section 1 is provided on the base stand 201 at a prescribed height by support posts 206a, 206b. The work table 206 is provided with an insertion hole 207 through which the main shaft 22, which is drawn out of the back surface side of the main frame 13, is drawn out to the lower side of the work table 206.

The support posts 206a, 206b are provided with lifting and lowering means 203 which vertically moves the work bench and the compression section 1 between an attaching position and an aligning position. The lifting and lowering means 203 is formed from a hydraulic actuator, for example, and controlled by the control console 4. Although in this example the lifting and lowering means 203 is provided, for example, a rotary column or the like may be provided in part of the support frame 202.

Upon the work table 206 is provided orbiting scroll revolution compensation means 400 as θ revolution compensation means which supports the main frame 13 of the compression section 1 so as to be revolvable in the θ direction and revolves the orbiting scroll 12 in the θ direction via the main frame 13 according to a command from the control console 4.

In this example, the θ revolution compensation means revolves the orbiting scroll 12 in the θ direction via the main frame 13. Conversely, however, the fixed scroll 11 side may be caused to revolve. In this case, θ revolutions around the Z axis of the main frame 13 are restricted.

Upon the base stand 201 is provided a motor 3 which is selectively connected to the driving shaft 2 of the orbiting scroll 12 via coupling means 500. In this embodiment, the motor 3 is connected to the control console 4 via a signal line and controlled according to a command from the control console 4.

The motor 3 is provided with abnormality detection means 31 which detects an abnormality in alignment when an abnormal torque is applied to the driving shaft 2 connected via the coupling means 500 due to, for example, contact of the scroll wraps with each other. Similarly, this abnormality detection means 31 is also connected to the control console 4 via a signal line and sends measurement signals to the control console 4.

Again referring to FIG. 1, the fixed scroll moving means 300 is provided with the support plate 310, X-Y moving means 320 and Z axis movement allowing support means 330, and at a leading end of the Z axis movement allowing support means 330 is provided fixed scroll fixing means 340 which fixes the fixed scroll 11 by coming into substantial contact therewith.

Incidentally, the fixed scroll moving means 300 is restricted in θ revolutions around the Z axis and can arbitrarily move the fixed scroll 11 in the directions of the X axis, Y axis and the Z axis.

Although in this embodiment the X-Y moving means 320 and the Z axis movement allowing support means 330 are provided so as to move the fixed scroll 11, the two may be provided so as to move the main frame 13. In this case, the movement of the fixed scroll 11 in the X-Y direction is restricted.

The support plate 310 is fabricated from an L-shaped frame an end of which is fixed to the support frame 202, and in part of the support plate 310 are provided the X-Y moving means 320 and the Z axis movement allowing support means 330. Although in this example the support plate 310 is integrally fixed to the support frame 202, the support plate 310 may vertically lift and lower the X-Y moving means 320 and the Z axis movement allowing support means 330, for example, via lifting and lowering means, which is not shown.

The X-Y moving means 320 is provided with an X axis support plate 321 which moves the fixed scroll 11 only in the direction of the X axis, and a Y axis support plate 322 which moves the fixed scroll 11 only in the direction of the Y axis.

The X axis support plate 321 is slidably attached by a linear guide rail (not shown) formed between the support plate 310 and the X axis support plate 321 and is driven according to a command from the control console 4.

The Y axis support plate 322 is slidably attached by a linear guide rail (not shown) formed between the X axis support plate 321 and the Y axis support plate 322 and is similarly driven according to a command from the control console 4.

A support stay 323 is provided on the top surface side of the Y axis support plate 322, and a Z axis free rail 330 is provided on the leading end side of the support stay 323. The Z axis free rail 330 has what is called a free rail mechanism capable of constantly moving in the direction of the Z axis and functions as the Z axis movement allowing means which allows movements of the fixed scroll 11 in the direction of the Z axis.

The fixed scroll fixing means 340 is integrally provided on the bottom end side of the Z axis free rail 330 and is attached so as to cover the top side of the fixed scroll 11. A clamper 341 for fixing the fixed scroll 11 is provided in the fixed scroll fixing means 340 in three places at intervals of 120° in this embodiment, and each of the clampers 341 clamps and fixes the fixed scroll 11 by use of driving means, which is not shown.

Although in this embodiment the fixed scroll fixing means 340 fixes the fixed scroll 11 by a clamping mechanism which uses the clamper 341, fixing by adsorption by use of an electromagnet etc. may be adopted and any mechanism can be arbitrarily selected so long as it can restrict the movement of the fixed scroll 11.

The support plate 310 is further provided with fixed scroll pushing means 350 which fixes the fixed scroll 11 by pushing the fixed scroll 11 from the direction of the Z axis. The fixed scroll pushing means 350 has two fixing cylinders 351 which are arranged parallel in the direction of the X axis, and fixes the fixed scroll 11 by ensuring that the leading end of the fixed cylinder 351 appears toward the top surface of the fixed scroll 11. Also this fixing cylinder 351 is controlled by the control console 4.

As shown in FIGS. 1 and 2, the orbiting scroll revolution compensation means 400 is provided with a main frame holding part 410 which holds the main frame 13 and θ revolving means 420 capable of revolving this main frame holding part 410 in the θ direction around the Z axis. Both the main frame holding part 410 and the θ revolving means 420 are installed on the work table 206.

The orbiting scroll revolution compensation means 400 is restricted in movements in the directions of the X axis and the Y axis and can revolve only in the direction of θ revolution. The θ revolving means 420 is connected to the control console 4 via a signal line and driven according to a command from the control console 4.

Driving means such as a motor is generally used as the θ revolving means 420, and more preferably, a rotary actuator is used. If a rotary actuator is used, high resolution and high moving speeds are obtained and there occurs no functional harm even when an insertion hole 421 through which the driving shaft 2 is inserted is formed in the middle.

On the surface of the main frame holding part 410 on which the main frame is provided (the top surface in FIG. 1), there is provided a clamp part 430 for fixing the main frame 13. The clamp part 430 is formed in multiple places at intervals of a prescribed angle around the Z axis, in three places at intervals of 120° in this embodiment.

In one clamp part 430 out of the three, a cylinder 431 which is pushed hydraulically, pneumatically or by use of a solenoid is provided. Because the main frame 13 is pushed against other clamp parts 430 by the appearing of the cylinder 431, movements can be restricted.

The support plate 310 and the clamp part 340 are further provided respectively with displacement sensors 610, 620 for measuring moving displacements of the fixed scroll 11 in the directions of the X axis and the Y axis.

Each of the displacement sensors 610, 620 is connected to the control console 4 each via a signal line, and detection data detected by each of the displacement sensors 610, 620 is outputted to the control console 4. It is preferred that the displacement sensors 610, 620 be contactless displacement sensors, and as a more preferred mode, a distance sensor which measures moving displacements of the fixed scroll 11 by use of a laser displacement meter or an eddy current displacement meter can be mentioned.

Furthermore, it is possible to adopt a method by which the number of linear steps of the X-Y moving means 320 in the directions of the X axis and the Y axis are counted and displacements are measured on the basis of the count numbers.

Coupling means 500 is connecting means which coaxially connects the output shaft of the motor 3 and the main shaft 22 of the driving shaft 2, and collet chuck type coupling means is provided in this embodiment. Incidentally, because in the present invention a concrete structure of the coupling means 500 is arbitrary, its description is omitted.

Again referring to FIG. 1, assembly means 700 for assembling the compression section 1 which has been aligned is mounted on the aligning apparatus 100 of the present invention. The assembly means 700 is attached so as to be able to vertically lift and lower along the second Z axis linear guide rail 205.

The assembly means 700 is provided with a Z axis linear guide 710 which is attached so as to be movable along the Z axis linear guide rail 205 and a support plate 720 which is integrally provided so as to extend from this Z axis linear guide 710, and tightening means 730 which integrally tightens the fixed scroll 1 and the main frame 13 is mounted on the support plate 720.

The Z axis linear guide 710, which is what is called lifting and lowering means which vertically moves the whole assembly means 700 along the Z axis, is connected to the control console 4 via a signal line and driven according to a command from the control console 4.

The tightening means 730 is provided with three tightening cylinders 731, which are provided on the top surface side of the support plate 720 in a protruding manner, and the tightening cylinders 731 are provided in three places at intervals of 120° around the Z axis. Although lightening jig supply means and the like which are not shown are built in each of the tightening cylinders 731, their concrete descriptions are omitted, because the assembly means is an arbitrary component element in the present invention.

Next, a concrete aligning method by the aligning apparatus 100 of the present invention will be described with reference to the flowchart shown in FIG. 3.

First, before the start of substantial aligning work, at Step ST1, the compression section 1 is installed in the aligning apparatus 100. After the placing of the compression section 1 on the work table 206 in the initial position shown in FIG. 1, a set button which is not shown is depressed. As a result of this, the work table 206 is moved up via the lifting and lowering means 203 of the support posts 206a, 206b and lifted to the initial position of aligning work.

When a start signal is sent from an input section which is not shown after the completion of the setting, the control console 4 initializes the whole system (Step ST2).

After the initialization, the control console 4 issues a command to the fixed scroll pushing means 350, and the fixed scroll pushing means 350 receives this command and lowers the fixing cylinder 351, thereby depressing the top surface of the fixed scroll 11 (Step ST3).

Next, the control console 4 issues a command to the clamp part 430, the clamp part 430 receives this command and causes the clamper 431 to protrude, and the clamper 31 fixes the main frame 13 (MF) to the main frame holding part 410, whereby the main frame 13 is restricted in revolutions in the X-Y direction and the θ direction (Step ST4).

Furthermore, the control console 4 issues a command to the fixed scroll fixing means 340, the fixed scroll fixing means 340 receives this command and drives each of the clampers 341, and the clampers 341 fix the fixed scroll 11 from sides and connect the fixed scroll 11 to the X-Y moving means 320 (Step ST5). After these preprocessing steps, the control console 4 starts aligning steps.

After the fixing of the compression section 1, the control console 4 issues a command to the coupling means 500, and the coupling means 500 which has received this command is lifted to the driving shaft 2 by use of lifting and lowering means which is not shown and chucks the driving shaft 2 (Step ST6). With this, the installation of the compression section 1 in the aligning apparatus 100 is completed.

After the completion of the installation, the worker depresses a work restart button which is not shown and the aligning work is restarted. In the aligning work, first, the control console 4 issues a command to the motor 3. The motor 3 receives this command and starts revolution and driving and the orbiting scroll 12 starts to rotate via the driving shaft 2 (Step ST7).

Immediately after the start of the revolution of the driving shaft, errors between the scroll wraps and those of the bearing part are apt enter the data. At Step ST9, therefore, the control console 4 counts the number of revolutions of the motor 3, i.e., the number of revolutions (n) of the driving shaft 2, and after at least the n-th revolutions (n>3: n is a positive number) of the driving shaft 2, the control console 4 starts regular sampling of measured values sent from the displacement sensors 610, 620 (Step ST8). In this embodiment, the sampling of measured values is performed from the beginning of revolutions.

Aligning is performed in two stages of revolution compensation and translation compensation. First, revolution correction of rotation for compensating for a relative angle of the fixed scroll 11 and the orbiting scroll 12 is performed.

When the driving shaft 2 has finished the third revolution and the instant the driving shaft 2 starts the fourth revolution, the control console 4 issues a command to the orbiting scroll revolution compensation means 400, and the orbiting scroll revolution compensation means 400, which has received this command, revolves in increments of Δθ° and causes the orbiting scroll 12 to revolve (Step ST10). Incidentally, an ideal relative angle of the fixed scroll 11 and the orbiting scroll 12 is 180°.

As shown in FIG. 4A, in the initial condition, a relative angle of the fixed scroll 11 and the orbiting scroll 12 deviate greatly from an ideal one. Therefore, the scroll wraps interfere with each other as a result of an orbital motion of the orbiting scroll 12 and the center of the fixed scroll 11 moves (revolves), with the result that displacements in the directions of the X axis and the Y axis increase.

Therefore, in the revolution compensation, the X-Y moving means 320 is first brought into an off condition (a free rail condition) and the orbiting scroll 12 is revolved in increments of Δθ° in Step ST10, whereby as shown in FIG. 4B, the displacement in the X-Y direction (the displacement difference) begins to converge gradually and the displacement becomes a minimum at an optimum compensation angle θc (a feed angle of 1.0°in FIG. 4B). When the revolutions are further continued in increments of Δθ°, the relative angles begin to deviate from each other and the displacement difference begins to increase again.

Therefore, the control console 4 judges whether an optimum compensation angle θc can be calculated on the basis of the sampling data obtained at Step ST11. When the control console 4 has judged that an optimum compensation angle θc can be calculated from the sampling data, the processing proceeds to the next Step ST12. The control console 4 judges that the origin of a quadratic curve shown in FIG. 4B is an optimum compensation angle θc and revolves and moves the orbiting scroll 12 to the position of an optimum compensation angle θc via the main frame 13 by driving the orbiting scroll revolution compensation means 400, whereby the revolution compensation is finished (Step ST13). Incidentally, when the control console 4 judges that an optimum compensation angle θc cannot be calculated, the processing returns to Step ST7 and sampling is repeatedly performed until data permitting calculation is obtained. In this example, the main frame 13 is revolved in increments of 0.1 Δθ° and the revolution compensation is stopped in a position where the displacement difference becomes not less than 40 μm.

Incidentally, although in this embodiment, the origin of a quadratic curve representing displacements is recognized as an optimum compensation angle θc, as shown in FIG. 5 there is also a case where the bottom of a quadratic curve representing displacements appears flat like a ship bottom. In such a case, the control console 4 may find two points θ1, θ2 at which the displacements in the directions of the X axis and the Y axis are equal, calculate an average value of the revolution angle as θc=(θ1+θ2)/2 and judge that this average angle is an optimum compensation angle θc. At Step ST11, the control console 4 selects any of the methods of calculating an optimum compensation angle θc according to obtained sampling data.

Next, the translation compensation is performed. In the present invention, the translation compensation is performed by using sampling data obtained in the above-described revolution compensation. When displacements of the fixed scroll 11 in the directions of the X axis and the Y axis obtained while the driving shaft performs one revolution are plotted, the plotted displacements appear in annular form as shown in FIG. 6.

As a result of this, displacements are still large when the feed angle is θa and the plot shape is a large annulus. Next, when the feed angle is θb, displacements converge a little but the plot shape is still a large annulus. When the feed angle is θc, the plot shape is a small annulus because displacements shrink most and become small.

Therefore, at Step ST14, the control console 4 performs arithmetic processing as stated in Formula 1 below and determines an optimum position (Xc, Yc) of the fixed scroll,
[Formula 1] $\begin{array}{cc}\left(X_C,Y_C\right)=\left\{\frac{\left(X_{\max }+X_{\min }\right)}{2},\frac{\left(Y_{\max }+Y_{\min }\right)}{2}\right\}& \mathrm{Formula}1\end{array}$
where a maximum point and a minimum point of a locus of the fixed scroll 11 in the direction of the X axis are denoted respectively by Xmax and Xmin, and a maximum point and a minimum point of the locus in the direction of the Y axis are denoted respectively by Ymax and Ymin.

As s result of this, an optimum position (Xc, Yc) of each of the scrolls 11, 12 can be easily calculated by finding a center position of sampling data and center accuracy is high. Incidentally, sampling data obtained when the feed angle is θc at which displacements converge most is the best. However, sampling data obtained when the feed angle is θa or θb may also be used.

In some measurement data, displacements do not always converge as when the feed angle is θc. Therefore, as the second measurement method, the control console 4 performs arithmetic processing as stated in Formula 2 below and determines an optimum position (Xc, Yc) of the fixed scroll,
[Formula 2] $\begin{array}{cc}\left(X_c,Y_c\right)=\left\{\frac{\sum _{i=1}^n{X}_i}{n},\frac{\sum _{i=1}^{n}Y}{n}\right\}& \mathrm{Formula}2\end{array}$
where the number of all samplings of a locus of the fixed scroll 11 in the directions of the X axis and Y axis which are obtained when the driving shaft 2 performs one revolution is denoted by n.

As a result of this, the center of coordinate points of all sampling number n is averaged by integral calculation and this center is regarded as the optimum position (Xc, Yc) of the fixed scroll. Therefore, even when exceptional data by sampling errors is included, more stable positioning can be performed because leveling is performed by integration.

Furthermore, as the third method, as shown in FIG. 7, the control console 4 performs arithmetic processing as stated in Formula 3 below and determines an optimum position (Xc, Yc) of the fixed scroll 11,
[Formula 3] $\begin{array}{cc}\left(X_c,Y_c\right)=\left\{\frac{X_{\mathrm{C1}}+X_{\mathrm{C2}}}{2},\frac{Y_{\mathrm{C1}}+Y_{\mathrm{C2}}}{2}\right\}& \mathrm{Formula}3\end{array}$
where an optimum compensation angle of the orbiting scroll 12 is denoted by θc, a maximum displacement difference when the revolution angle of the orbiting scroll 12 is θ1 is denoted by GAP1, centers of the locus in the directions of the X axis and the Y axis at this time are denoted by (X_c1, Y_c1), a maximum displacement difference when the revolution angle is θ2 is denoted by GAP2, with the optimum compensation angle θc being intermediate between θ1 and θ2, the center of the locus in the directions of the X axis and the Y axis at this time is denoted by (X_c2, Y_c2), and the relationship GAP1 £ GAP2 holds in the maximum displacement difference.

As a result of this, when a minimum point of the orbiting scroll 12 is an optimum compensation angle θc, an optimum position (Xc, Yc) of the fixed scroll 1 is found from the center of a locus of revolution angles θ1, θ2, which provide almost the same displacement difference on a quadratic curve which appears symmetrically. Therefore, stable positioning can be performed.

At Step ST11, the control console 4 selects an optimum calculating method from the above-described first and third calculating methods in consideration of the condition of sampling data and performs the translation compensation.

After the establishment of an optimum position (Xc, Yc) of the translation compensation, at Step ST15 the control console 4 issues a command to the X-Y moving means 320, and the X-Y moving means 320 which has received this command forcedly moves the fixed scroll 11 to the optimum position (Xc, Yc). With the above processing, the aligning work is completed.

Next, the control console 4 issues a command to the assembly means 700 and the Z axis linear guide 710. First, the Z axis linear guide 710 which has received this command starts lowering and descends to immediately above the fixed scroll 11.

Next, the assembly means 700 lowers a guide cylinder of the tightening means (not shown) mounted in the assembly means 700 and supplies screw bolts to the fixing holes of the fixed scroll 11. After that, the assembly means 700 causes a tightening jig (not shown) to tighten the screw bolts. At this time, the control console 4 issues a command to the fixed scroll fixing means 340 to ensure that by further increasing a depressing force applied to the fixed scroll 11, the position of the fixed scroll 11 does not change during the tightening of the bolts. Incidentally, because in the present invention the assembling procedure of the assembly means 700 is arbitrary, its concrete description is omitted.

Lastly, by revolving and driving the compression section 1 in an assembled condition, whether there is an abnormality in the revolving and driven condition (for example, torque, vibration, etc.) is checked by the abnormality detection means 31. If there is no problem, the motor 3 is stopped and the aligning work is finished (Step ST17). In the case of an abnormality, the motor 3 is stopped similarly and alarm display which indicates that the abnormality has occurred is performed on the display part of the control console 4 (Step ST18). Incidentally, programming may be performed in such a manner that the aligning work is temporarily stopped when the abnormality detection means 31 detects an abnormality during the aligning work. With the above processing, all the aligning work and assembling work are finished.

In this embodiment, the aligning apparatus 100 is an apparatus which can perform the aligning work and the assembling work from first to last. However, for example, a preassembling apparatus which includes a basic assembling and supply step of the compression section 10 may be further built in the aligning apparatus 100, or the aligning apparatus 100 may be integrally built in a packing apparatus or an assembling apparatus which includes a step of packing the compression section 10 after the completion of alignment and an assembling step as a scroll compressor.

As described above, according to the present invention, alignment can be performed in a short time without reducing aligning accuracy by performing the determination of a relative position (alignment) of a fixed scroll and an orbiting scroll by revolution compensation and translation compensation and at the same time, by performing the translation compensation by use of measured values obtained in the revolution compensation.

The present application is based on, and claims priority from, Japanese Application Serial Number JP2005-008591, filed Jan. 17, 2005, the disclosure of which is hereby incorporated by reference herein in its entirety.

Claims

1. An apparatus for aligning a scroll compressor, which has a compression section which is internally formed a hermetically closed working chamber by bringing scroll wraps of a fixed scroll and an orbiting scroll into mesh with each other, a main frame which supports the compression section, and a crank shaft which is connected to the orbiting scroll at a top end thereof, and performs positioning of the scroll wraps of the scroll compressor including a driving shaft held by the main frame while revolving the orbiting scroll via the driving shaft, comprising:

X-Y moving means which is restricted in revolutions in a θ direction around a Z axis and supports the main frame or the fixed scroll so as to be movable in directions of an X axis and a Y axis;

θ revolution compensation means which is restricted in movements in the directions of the X axis and the Y axis and supports the orbiting scroll or the fixed scroll via the main frame so as to be revolvable in the θ direction around the Z axis;

orbiting scroll driving means which is connected to the driving shaft and drives the orbiting scroll;

X-Y displacement measuring means which detects a moving displacement of the fixed scroll or the main frame in the directions of the X axis and the Y axis, which result from an orbital motion of the orbiting scroll; and

control means which controls at least the X-Y moving means, the θ revolution compensation means, the orbiting scroll driving means and the X-Y displacement measuring means,

wherein the control means measures a moving displacement of the fixed scroll or the main frame, which results from the revolutions of the driving shaft, by use of the X-Y displacement measuring means by revolving and driving the driving shaft by use of the orbiting scroll driving means and by revolving the orbiting scroll or the fixed scroll in increments of a prescribed angle of θ° by use of the θ revolution compensation means each time the driving shaft performs a prescribed revolution,

performs revolution compensation from obtained measured values by controlling the θ revolution compensation means so that the moving displacement of the fixed scroll or the main frame becomes a minimum, and

performs translation compensation by determining an optimum position of the fixed scroll or the main frame from the measured values on the basis of displacement components in the directions of the X axis and the Y axis and by moving the fixed scroll or the main frame to the optimum position.

2. The apparatus for aligning a scroll compressor according to claim 1, wherein the control means performs arithmetic processing as stated in Formula 1 below, determines an optimum position (Xc, Yc) of the fixed scroll or the main frame and performs translation compensation on the basis of the optimum position, [Formula 1] ( X C, Y C ) = { ( X max + X min ) 2, ( Y max + Y min ) 2 } Formula ⁢   ⁢ 1 where a maximum point and a minimum point of a locus of the fixed scroll or the main frame in the direction of the X axis which are obtained when the driving shaft performs one revolution are denoted respectively by Xmax and Xmin, and a maximum point and a minimum point of the locus in the direction of the Y axis are denoted respectively by Ymax and Ymin.

3. The apparatus for aligning a scroll compressor according to claim 1, wherein the control means performs arithmetic processing as stated in Formula 2 below, determines an optimum position (Xc, Yc) of the fixed scroll or the main frame and performs translation compensation on the basis of the optimum position, [Formula 2] ( X c, Y c ) = { ∑ i = 1 n ⁢ X i n, ∑ i = 1 n ⁢ Y n } Formula ⁢   ⁢ 2 where the number of all samplings of a locus of the fixed scroll or the main frame in the directions of the X axis and Y axis which are obtained when the driving shaft performs one revolution is denoted by n.

4. The apparatus for aligning a scroll compressor according to claim 1, wherein the control means performs arithmetic processing as stated in Formula 3 below, determines an optimum position (Xc, Yc) of the fixed scroll or the main frame and performs translation compensation on the basis of the optimum position, [Formula 3] ( X c, Y c ) = { X C1 + X C2 2, Y C1 + Y C2 2 } Formula ⁢   ⁢ 3 where an optimum compensation angle of the orbiting scroll or the fixed scroll is denoted by θc, a maximum displacement difference when the revolution angle of the orbiting scroll or the fixed scroll is θ1 is denoted by GAP1, the center of the locus in the directions of the X axis and the Y axis at this time is denoted by (Xc1, Yc1), a maximum displacement difference when the revolution angle is θ2 is denoted by GAP2, with the optimum compensation angle θc being intermediate between θ1 and θ2, the center of the locus in the directions of the X axis and the Y axis at this time is denoted by (Xc2, Yc2), and the relationship GAP1 £≈GAP2 holds in the maximum displacement difference.

5. The apparatus for aligning a scroll compressor according to claim 1, wherein the apparatus for aligning a scroll compressor further comprises abnormality detecting means which is connected to the driving shaft and detects an abnormality in the orbiting scroll driving means which drives the orbiting scroll.

6. A method for aligning a scroll compressor, which uses a compression section which is internally formed a hermetically closed working chamber by bringing scroll wraps of a fixed scroll and an orbiting scroll into mesh with each other, a main frame which supports the compression section, and a crank shaft which is connected to the orbiting scroll at a top end thereof, and performs positioning of the scroll wraps of the scroll compressor including a driving shaft held by the main frame while revolving the orbiting scroll via the driving shaft, wherein the method uses:

X-Y moving means which is restricted in revolutions in a θ direction around a Z axis and supports the main frame or the fixed scroll so as to be movable in directions of an X axis and a Y axis;

θ revolution compensation means which is restricted in movements in the directions of the X axis and the Y axis and supports the orbiting scroll or the fixed scroll via the main frame so as to be revolvable in the θ direction around the Z axis;

orbiting scroll driving means which is connected to the driving shaft and drives the orbiting scroll;

X-Y displacement measuring means which detects a moving displacement of the fixed scroll or the main frame in the directions of the X axis and the Y axis, which result from an orbital motion of the orbiting scroll; and

control means which controls at least the X-Y moving means, the θ revolution compensation means, the orbiting scroll driving means and the X-Y displacement measuring means,

and wherein the method comprises:

a displacement measuring step of measuring a moving displacement of the fixed scroll or the main frame, which results from the revolutions of the driving shaft, by use of the X-Y displacement measuring means by revolving and driving the driving shaft by use of the orbiting scroll driving means and by revolving the orbiting scroll or the fixed scroll in increments of a prescribed angle of θ° by use of the θ revolution compensation means each time the driving shaft performs a prescribed revolution,

a revolution compensation step of performing revolution compensation from obtained measured values by controlling the θ revolution compensation means so that the moving displacement of the fixed scroll or the main frame becomes a minimum and

a translation compensation step of performing translation compensation by determining an optimum position of the fixed scroll or the main frame from the measured values on the basis of displacement components in the directions of the X axis and the Y axis and by moving the fixed scroll or the main frame to the optimum position.