Abstract: A scroll fluid machine is capable of readily providing a back-pressure chamber having an increased pressure-receiving area and yet capable of being reduced in size. A fixed scroll member is secured to a casing. An orbiting scroll member is provided at a position facing the fixed scroll member. A holder is provided at the back of the orbiting scroll member, and a coupling member is provided to face the orbiting scroll member across the holder. The coupling member couples together the orbiting scroll member and a driving shaft and performs an orbiting motion together with the orbiting scroll member. A back-pressure plate is provided at the back of the orbiting scroll member, and a back-pressure chamber is formed between the back-pressure plate and the holder.

Abstract: A scroll type fluid machine having a driving system including a counter weight and a sub weight, in which an efficiency of an assembling operation is enhanced by simplifying an assembling structure of the driving system. In the fluid machine, a sub weight (17) is provided on a rotary shaft (16) and a counter weight (20) is provided on a driving bush (19) . The driving bush (19) is attached to the rotary shaft (16) by an attachment bolt (23) to prevent relative rotation between the rotary shaft and the driving bush. The rotary shaft (16) supported by a main bearing (18) and is driven in rotation by a motor (9), with the result that an orbiting scroll (4) performs an orbiting motion with respect to a fixed scroll (2).

Abstract: In order to make a displacement type compressor be able to reliably start without increasing an outside diameter dimension of the compressor while using a self-start synchronous motor having high energy efficiency, the displacement type compressor according to the invention includes the self-start synchronous motor which starts as an induction-motor and performs synchronous operation by performing synchronization pull-in almost at a synchronous rotational frequency, a compression part having a compression chamber which compresses a working fluid, and a hermetic container which houses the self-start synchronous motor and the compression part. The displacement type compressor is provided with a start load reducing means which reduces a load of the compression part at startup and is-placed at the compression part in the hermetic container.

Abstract: A scroll machine is powered by a brushless permanent magnet motor. The rotor for the motor includes a rotor body formed by a plurality of laminations and an upper and lower counterweight made of zinc and located at opposite ends of the rotor body. An attachment member extends through the counterweights and the rotor body to secure the counterweights and the plurality of laminations. The counterweights include steel inserts which cooperate with the attachment member to provide a metal to metal clamping for the rotor body with a steel connection being maintained through the rotor.

Abstract: The object is to provide a scroll fluid machine in which relative revolving motion is produced between two scrolls engaging with each other without using conventional Oldham coupling or pin crank type mechanism which has sliding parts. The scroll compressor 50 comprises a stationary scroll 58 fixed to a scroll casing 60, a revolving scroll 52, a rotation shaft 86 having an offset portion 100 for revolving the revolving scroll 52, and plate springs 110a 110b that connect the stationary scroll to the revolving scroll in a state surrounding the scroll laps of the scrolls.

Abstract: A scroll compressor may include a shell, a bearing housing, first and second scroll members, and a ring member. The bearing housing may be supported within the shell and may include at least three axially extending arms. The first scroll member may be supported on the bearing housing and may include a circumferential outer surface. The second scroll member may be supported on the bearing housing and may be meshingly engaged with the first scroll member. The second scroll member may be disposed between the first scroll member and the bearing housing. The ring member may include an open center portion surrounding the circumferential outer surface of the first scroll member therein. A portion of the ring member may be disposed between the arms of the bearing housing and the circumferential outer surface of the first scroll member.

Abstract: A balancing system for different compressors utilizes a counterweight having a common exterior configuration. The mass of the counterweight is optimized for each compressor by changing the size of a recess located in the counterweight. In one embodiment, the recess is an arcuately shaped recess; and in another embodiment, the recess is a plurality of holes.

Abstract: A scroll compressor has a moving scroll and a stationary scroll in contact with each other. A seal ring for defining a back pressure space at a rear side of the moving scroll is provided and its position is adjusted between a sealing position and a leakage position with respect to an end plate of the moving scroll.

Abstract: An oil discharge preventing apparatus of a scroll compressor comprises: a balance weight coupled to a rotor of a driving motor so as to offset an unbalance generated when an orbiting scroll performs an orbiting motion by receiving a rotation force of the driving motor; and a lower fixed oil guide fixedly coupled between the balance weight and the rotor, for preventing oil from being spread in a casing and guiding the oil downwardly to a bottom of the casing, whereby an oil leakage to the outside of the casing can be minimized, the number of construction components can be reduced, and assembling processes can be simplified.

Abstract: An apparatus for varying the capacity of a scroll compressor is disclosed. The apparatus for varying the capacity of a scroll compressor includes a bypass passage for connecting a compression pocket under intermediate pressure among compression pockets formed by a wrap of a fixed scroll and a wrap of a orbiting scroll and a suction side through which refrigerant is inhaled into the compression pocket to each other, an opening and closing device for opening and closing the bypass passage, and an elastic opening and closing device mounted in the bypass passage to open and close the bypass passage by the pressure of the compression pocket and the pressure and elasticity of the suction side according as the bypass passage is opened and closed by the opening and closing device. Therefore, it is possible to simplify the structure of varying the capacity of a compressor such that it is possible to reduce the size of the apparatus for varying the capacity of a scroll compressor and to thus reduce the number of parts.

Abstract: A sealed type motor-driven compressor includes a cylindrical motor housing and an annular stator core fastened to the interior of the motor housing. A method of assembling the compressor includes fastening the stator core to the motor housing by mechanically deforming at least one of the motor housing and the stator core. It is thus possible to set the fastening interference between the motor housing and the stator core to a sufficiently great level for suppressing loosening of the stator core with respect to the motor housing, which may otherwise be caused by a relatively high pressure produced by refrigerant gas.

Abstract: A scroll type compressor with an enhanced sealing arrangement includes two sealing rings, mounted one between a first part of a gliding block and a first chamber of a fixed scroll and another one between a second part of the gliding block and a second chamber of the fixed scroll, respectively. The sealing ring has a U-shape cross section characterized in having a center depth smaller than half of a total height of the cross section. By providing such sealing rings, damage in mounting the sealing rings can be reduced to a minimum, possible leakage from the damage can be avoided, the assembly process in producing the compressor can be improved, and the compressor can be successfully merchandized.

Abstract: In a scroll fluid machine, a stationary scroll fixed to a housing engages with an orbiting scroll to form a sealed chamber between the orbiting and stationary scrolls. Fluid in the sealed chamber is compressed or decompressed with revolution of the orbiting scroll with respect to the stationary scroll. A plurality of self-rotation preventing devices are provided on the orbiting scroll to prevent the orbiting scroll from rotating on its own axis. The self-rotation preventing device comprises an eccentric tube connected to a main shaft fitting in the housing, and an eccentric shaft fitted in a bearing plate. The eccentric tube is eccentrically revolved with respect to the main shaft thereby allowing engagement of the orbiting scroll with the stationary scroll to be adjusted.

Abstract: There is provided a scroll compressor having high overall adiabatic efficiency and reliability in a wide pressure operating range. A backside excess-suction-pressure region is provided such that pressure higher than suction pressure by a constant value is applied to a backside of scroll members to produce an attractive force to attract both scroll members. A control bypass is also provided for communicating compression chambers with a discharge system only when pressure in the compression chambers is high.

Abstract: After the tooth portion 102b of the stationary scroll 102 and the tooth portion 103b of the revolving scroll 103 have contacted each other on one contact face 121 in the central portion of the scroll (shown in FIG. 5A), when this contact face 121 is shifted to two sliding contact portions 122, 123, the operating chamber V is formed between the two sliding contact portions 122, 123 (shown in FIG. 5B), and the refrigerant introducing port 105a is open to the region on the contact face 121. Accordingly, the operating chamber can be instantaneously changed over while the sealing property is ensured. Due to the above structure, the sealing property for suppressing leakage from the high pressure side at the time of the expansion mode can be compatible with the smoothing property for smoothing a change-over of the scroll operating chamber successively formed.

Abstract: A scroll compressor includes a first scroll and a second scroll. The first scroll has a step portion that separates an elevated portion and a recessed portion of a surface of the first scroll. A spiral wall of the second scroll has a step that separates an elevated portion and a recessed portion of the wall. A first bypass hole is provided in the elevated portion of the surface of the first scroll. A second bypass hole is provided in the recessed portion of the surface of the first scroll. The second bypass hole is within 360 degrees toward a center of the spiral of the first scroll from an outer end of the spiral. The first bypass hole is within 360 degrees from the second bypass hole toward the center of the spiral.

Abstract: A scroll compressor includes an orbiting scroll having a compressor chamber in an upper portion thereof and a bypass passage formed through upper and lower ends of a body thereof, a fixed scroll that allows the orbiting scroll to orbit therein to compress a coolant, an Oldham ring on which the orbiting scroll is seated, the Oldham ring having an upper chamber formed on an upper surface thereof with predetermined width and depth and a lower chamber formed on a lower surface thereof with predetermined width and depth, and a main frame on which the Oldham ring is seated.

Abstract: A scroll machine utilizes a floating seal to isolate pressurized fluid to provide axial biasing. The floating seal is designed as a single piece plate with inner and outer annular seals. The inner and outer annular seals can be U-shaped, V-shaped or L-shaped and each configuration is oriented to provide pressure actuation of the seal. Additional embodiments add a discharge valve, a high temperature protection system or a high pressure protection system to the floating seal.

Abstract: A scroll compressor is provided with spaced grooves in a base of one of the two scroll members. A recess is formed in a wrap tip of the other scroll member. The recess in the wrap tip bridges a space between the grooves of the other scroll member. This bridging equalizes pressure between two parallel intermediate compression chambers. Pressure equalization between the chambers improves compressor efficiency.

Abstract: There is provided, at a low cost, a small-size and lightweight scroll compressor capable of preventing a decrease in compression efficiency by utilizing a medium pressure between a suction pressure and a discharge pressure as a back pressure. An independent minute gap in the axial direction is provided between a main frame 3 and a thrust ring 8. This minute gap is used as a second back pressure chamber C2, and the medium pressure between the suction pressure and the discharge pressure is introduced into the second back pressure chamber C2.

Abstract: The present invention discloses an apparatus for varying a capacity of a scroll compressor. The apparatus comprises: a pressure control mechanism for controlling a pressure applied to the back of a orbiting scroll orbiting engaged with a fixed scroll; and a sealing varying mechanism for changing a sealing region of a orbiting scroll wrap and a sealing region of a fixed scroll wrap according to a change in the pressure applied to the back of the orbiting scroll. By this, the capacity of a refrigerant compressed by the fixed scroll and orbiting scroll using a high pressure in a casing can be varied to thus minimize the power consumption.

Abstract: A scroll compressor includes a compression mechanism contained within a shell. A non-orbiting scroll is supported for axial displacement relative the shell, and includes an end plate having a wrap extending therefrom and a flange having a bore extending therethrough. A guide member is axially fixed relative the shell and extends through the bore in the flange. A first portion of the guide member is disposed within and generally abuts a first circumferential portion of the bore. A second portion of the guide member is disposed within and generally spaced apart from a second circumferential portion of the bore.

Abstract: A scroll compressor, which allows refrigerant in a compressor chamber to be partially discharged so that frictions generated in frictional surfaces between an orbiting scroll and an Oldham ring and between the Oldham ring and a main frame may be decreased. Also, an upper chamber may be formed on an upper surface thereof and a lower chamber may be formed on a lower surface thereof. An oil supply structure may be provided in a main frame such that lubrication is smoothly performed. Additionally, at least one key may be provided protruding from the lower surface of the Oldham ring. Further, the main frame may include at least one key groove configured to receive the at least one key of the Oldham ring. Additionally, the oil supply groove may be provided separately from and in communication with the at least one key groove.

Abstract: A scroll compressor is provided with a cavity in its back pressure chamber to increase a volume of the back pressure chamber. In this manner, at start-up, the back pressure chamber will not be effective to bias the two scroll members together until this enlarged volume is filled with a compressed refrigerant. This reduces the load on the electric motor at start-up.

Abstract: There is provided a scroll compressor in which reliability and durability is increased by preventing peeling of a coating layer applied to a thrust plate, to maintain a desired level of lubrication for a long period of time. A scroll compressor 1 comprises a thrust plate 51, a coating which is applied to a surface of the thrust plate, a housing 3 having a thrust bearing face 5B to which the thrust plate 51 is attached, an orbiting scroll member 27 having a slide face 61 which is supported by the thrust plate 51 and which orbits while sliding, and a peeling prevention part which reduces a sliding pressure acting on an edge portion 51C of the thrust plate 51 from the slide face 61.

Abstract: Disclosed herein is a back pressure apparatus for orbiting vane compressors that is capable of reducing excessive axial force applied to an orbiting vane due to high-pressure refrigerant gas introduced to the lower surface of a vane plate of the orbiting vane. The back pressure apparatus comprises a back pressure chamber formed at the upper surface of a main frame, which is brought into tight contact with the lower surface of a vane plate of an orbiting vane, and a low-pressure gas communication part for allowing the back pressure chamber and an inlet port to communicate with each other therethrough. Consequently, the present invention has the effect of preventing excessive friction between the orbiting vane and the inner surface of a cylinder, preventing damage to the orbiting vane compressor due to the friction, and preventing deterioration of performance of the orbiting vane compressor due to the frictional loss.

Abstract: A scroll machine includes a shell and a pair of scroll members. At least one of the scroll members disposed in the shell is mounted for axial movement with respect to the other scroll member disposed in the scroll. The amount of axial movement of at least one scroll member is accurately controlled by providing a stop. The stop is defined by the contact of the end plate of the at least one scroll member with another member of the scroll machine which is accurately positioned within the shell of the scroll machine. The member can be either the shell or another component which engages the shell.

Abstract: A scroll compressor has a stop on its eccentric pin to selectively engage a notch in a slider block, and prevent the slider block from moving upwardly and contacting a rear surface of the orbiting scroll. The present invention prevents this unwanted contact, and the resultant wear.

Abstract: Scroll compressors are provided with vapor injection or by-pass ports that will allow greater flow of refrigerant through the port than was the case in the prior art. The prior art has typically utilized a single injection port having a diameter equal to or slightly larger than the thickness of the scroll wrap. In this way, the scroll wrap is able to prevent or restrict cross-flow leakage from the port from passing between the two compression chambers. However, this single port has also limited the amount of refrigerant that can be returned. In one embodiment, the present invention utilizes a plurality of ports generally spaced along the length of the wrap such that cross-flow can still be prevented while providing a greater cross-sectional flow area into or out of the compression chambers. In another embodiment, the several ports may be replaced by a single elongated port.

Abstract: A scroll fluid machine comprises compression chambers defined with an orbiting scroll orbiting relative to a fixed scroll, and a back pressure chamber provided on the face opposite from a wrap of the orbiting scroll. A back pressure port is provided, which is formed in an end-plate of the orbiting scroll and connects from a compression chamber side opening opened to a compression chamber side and to a back pressure chamber side opening opened to a back pressure chamber side. The compression chamber side opening is opened and closed by an end-plate of the fixed scroll according as the orbiting motion of the orbiting scroll to perform connection and blockage of the back pressure port. The flow resistance of fluid flowing in and out between the back pressure chamber and the compression chamber is reduced and the compression efficiency and reliability are improved.

Abstract: A displacement type compressor includes a compressing mechanism section for performing a compression, a motor for driving the compressing mechanism section, and a crankshaft adapted to be driven in rotation by the motor to rotate the compressing mechanism section. The motor includes stator cores and having claw-type magnetic poles formed of a magnetic powder and circumferentially arranged in alternately meshed states, and annular coils and wound in a toric shape around the claw-type magnetic poles. Thus, the displacement type compressor is capable of being at a high speed and has a reduced size.

Abstract: A scroll apparatus with an axial gap control function is described. The scroll apparatus is capable of controlling the axial gap between its fixed scroll and orbiting scroll. The scroll apparatus has a frame with a pair of indentations installed in the casing of the scroll apparatus, a pair of flexible elements installed at the lateral side top of the frame and spanning the pair of indentations for defining a suspended flexible segment at the span, a sidewall having a positioning ring with a downward protruding body corresponding to the indentation, in which the protruding body of the positioning ring is fixed to the flexible segment of the flexible element, a fixed scroll suspended at the positioning ring, and an orbiting scroll for orbiting into the fixed scroll.

Abstract: A coupling structure of an eccentric bush of a scroll compressor, comprising: an orbiting scroll; a rotary shaft provided with an eccentric part and transferring rotary power of a driving motor to the orbiting scroll; and an eccentric bush coupled between the orbiting scroll and the eccentric part of the rotary shaft, wherein an insertion hole provided with two plane contact portions having predetermined areas is formed at the eccentric bush, a cutting surface surface-contacting the plane contact portions of the eccentric bush is formed at the eccentric part of the rotary shaft, and the eccentric part is inserted into the insertion hole of the eccentric bush. Accordingly, damage to the eccentric bush or the rotary shaft can be prevented by dispersing the power applied to the rotary shaft and the eccentric bush.

Abstract: A slider block for a scroll compressor has a recess formed in a wall between a flat portion on the outer surface and a chamfer formed on the inner surface. The recess eliminates a high stress area of the prior art, and reduces cracks originating from this area of the slider block.

Abstract: A scroll compressor assembly includes a shaft having an eccentric pin that orbits a first scroll member relative to a second scroll member. The eccentric pin has a length extending from a base end to a distal end, which defines a contact area having a slight crown that engages a slider block. The contact area is moved toward the distal end of the eccentric pin to improve the stability of at least one of the first and second scroll members.

Abstract: A scroll compressor is provided. The scroll compressor includes a fixed scroll and an orbiting scroll, each with a wrap extending from a plate. The wrap or the plate may have different heights so as to prevent a gap from forming between the end of one of the wraps and the opposite plate. Accordingly, performance of the compressor may be enhanced even if manufacturing tolerances are not precisely controlled or the compressor operates for an extended period of time. Furthermore, frictional loss due to increased frictional area of an edge of the plate may be prevented, and refrigerant leakage due to separation between the wrap and the plate may be prevented.

Abstract: A motor accommodating chamber accommodates an electric motor such that a rotation axis of the motor is substantially horizontal. The pressure in the motor accommodating chamber is equal to the pressure in a suction chamber. A connecting passage connects a bottom portion of the motor accommodating chamber with the suction chamber. Therefore, mixture of liquids having a lowered insulating property is prevented from staying in a motor accommodating chamber.

Abstract: A scroll fluid machine comprises a driving shaft having an eccentric axial portion at one end; a fixed scroll having a fixed wrap; and an orbiting scroll having an orbiting wrap and rotatably mounted to the eccentric axial portion of the driving shaft. A gas introduced through an inlet on the outer circumference of the fixed scroll is compressed by a compression chamber between the fixed and orbiting wraps towards the center and discharged through an outlet close to the center. Between the eccentric axial portion and the innermost winding portion of the fixed wrap, an adiabatic expansion chamber is formed thereby cooling the compressed gas right before discharging.

Abstract: A scroll compressor has a novel slider block with an upper surface that extends for a greater extent than the prior art. By extending this upper surface, the upper surface is better able to withstand wear on the slider block during the life of the scroll compressor.

Abstract: A surface of a fixed scroll which is opposed to a end plate of an orbiting scroll existing outside of a lap of the fixed scroll is formed with: a substantially annular seal portion which extends such as to have an outer wall surface of the fixed scroll outwardly extending from an inner wall surface of outermost periphery of the lap substantially along the inner wall surface, and which comes into slide contact with the end plate of the orbiting scroll; a substantially annular recess located outside of the substantially annular seal portion; and a recess which is brought into communication with an intake port of the fixed scroll independently from the substantially annular recess. With this, back pressure of the orbiting scroll is increased, and turning-over phenomenon of the orbiting scroll can be suppressed.

Abstract: A compressor for suppressing leakage of lubricating oil has a casing, a motor and a scroll mechanism coupled to the motor by a drive shaft. The drive shaft is rotatably supported by a bearing. The lubricating oil is supplied between the drive shaft and the bearing. An oil collecting portion is formed at an end portion in the axis direction of a bearing portion. The bearing portion is constituted of an outer peripheral surface of the drive shaft and an inner peripheral surface of the bearing. The oil collecting portion includes an oil groove formed in the periphery direction of the drive shaft. An oil passage is formed to conduct the lubricating oil into the oil collecting portion.

Abstract: A scroll fluid machine has a low-pressure stage compression part for compressing a fluid sucked in from the outside between mutually overlapping wrap portions of two scroll members performing a relative orbiting motion and a high-pressure stage compression part for compressing the fluid sucked in from the low-pressure stage compression part between mutually overlapping wrap portions of two scroll members performing a relative orbiting motion. The scroll members in the low-pressure stage compression part have a larger radial gap between the wrap portions than that of the scroll members in the high-pressure stage compression part.

Abstract: A scroll type compressor includes a housing defining a discharge pressure region, a fixed scroll member having a fixed base plate and a fixed scroll wall, a movable scroll member having a movable base plate and a movable scroll wall, a fixed wall slidably supporting the movable scroll member, a back pressure chamber defined on a back surface side of the movable base plate. A supply passage connects the back pressure chamber to the discharge pressure region and passes through a sliding portion between the movable scroll member and the fixed wall. A clearance at the sliding portion varies in response to a position of the movable scroll member in a direction in which the movable scroll member approaches to or leaves from the fixed wall, whereby cross-sectional area of the clearance where gas passes is varied to adjust pressure in the back pressure chamber.

Abstract: In a scroll fluid machine, an orbiting scroll is eccentrically revolved with respect to a stationary scroll so that fluid in a sealed chamber between the stationary and orbiting scrolls may be compressed toward a center. A first magnet is mounted on the stationary scroll and a second magnet is mounted on the orbiting scroll so that the same poles of the first and second scrolls may be opposite to each other thereby preventing the orbiting scroll from pressing the stationary scroll excessively.

Abstract: A scroll compressor having a vacuum preventing structure includes: a casing forming a receiving space therein; a fixed scroll fixed to a main frame installed in the casing, and including a back pressure passage at an outer side surface thereof, a discharge pressure hole formed at one side of the back pressure passage such that the back pressure passage and a discharge pressure space of the casing can communicate with each other, a middle pressure hole formed at another side of the back pressure passage such that the back pressure passage and a compression space of the casing can communicate with each other, and a suction pressure hole formed at still another side of the back pressure passage such that the back pressure passage and a suction pressure space can communicate with each other; an orbiting scroll positioned between the fixed scroll and the main frame and forming a compression space by being coupled with the fixed scroll; a piston slidably installed in the back pressure passage, for opening or closin

Abstract: An eccentric coupling device in a radial compliance scroll compressor includes a crank pin that is eccentrically arranged at an upper end of a crankshaft and provided with a vertically-extending flat surface at one side thereof. A bush is provided with a crank pin hole, overlapped by a stopper hole, for receiving the crank pin. A stopper is fitted in the stopper hole such that the stopper radially protrudes into the crank pin hole toward the flat surface to selectively come into contact with the flat surface in accordance with a rotation of the bush. An elevating preventing device is adapted to elastically support the bush, while connecting the stopper and the crank pin via a spring wire, preventing an elevation of the bush.

Abstract: A scroll compressor has a movable auxiliary member provided by mounting it between a frame member and a circling scroll member. The movable auxiliary member has a stopper portion for causing a contact plane to contact a pane of a fixed scroll member and a ring portion having an opposed plane annularly formed to face the pane of the circling scroll member, is further supported elastically by an elastic support in a state of being energized in a direction of the circling scroll member, has the contact plane of the stopper portion caused to contact the pane in this elastic support state to keep a limit position with the opposed plane facing the pane of the circling scroll member, and goes back elastically to the frame member side when the circling scroll member goes back to the frame member side and the pane is pressed to contact the opposed plane.

Abstract: An eccentric coupling device in a radial compliance scroll compressor including a crank pin eccentrically arranged at an upper end of a crankshaft included in the scroll compressor, and provided with a vertically-extending cut surface at one side thereof, a bush fitted around the crank pin, and provided with a crank pin hole and a stopper hole, a stopper fitted in the stopper hole, and an engagement jaw adapted to prevent a vertical movement of the stopper, thereby preventing a vertical movement of the bush, the engagement jaw being provided at an upper end of the crank pin. The bush is arranged such that an upper end thereof is flush with an upper end of the crank pin. The stopper hole overlaps with the crank pin hole so that the stopper selectively comes into contact with the cut surface in accordance with a rotation of the crank pin. The stopper has a length shorter than that of the stopper hole.

Abstract: A scroll-type machine is disclosed which is particularly well suited for use as a compressor in refrigeration and air conditioning systems and incorporates a unique arrangement for modulating the capacity thereof. In one group of embodiments the capacity of the scroll-type machine is modulated by relative axial movement between the scroll members so as to form a leakage path across the wrap tips and opposed end plates. In another group of embodiments, modulation is achieved by reducing the orbital radius of one of the scroll members to thereby form a leakage path across the flank surfaces of the wraps. Both types of scroll separation may be accomplished in a time pulsed manner to thereby enable a full range of modulation with the duration of the loading and unloading periods being selected to maximize the efficiency of the overall system.

Abstract: A scroll-type machine is disclosed which is particularly well suited for use as a compressor in refrigeration and air conditioning systems and incorporates a unique arrangement for modulating the capacity thereof. In one group of embodiments the capacity of the scroll-type machine is modulated by relative axial movement between the scroll members so as to form a leakage path across the wrap tips and opposed end plates. In another group of embodiments, modulation is achieved by reducing the orbital radius of one of the scroll members to thereby form a leakage path across the flank surfaces of the wraps. In the second group, a plurality of pin members are moveable from a first and second positions. In a first position the plurality of pin members operably enable the scroll members to orbit and in a second position the pin members restrict the orbiting motion of the first scroll members.