Abstract: An engine includes a piston and a stator housing. The stator housing includes a channel in which the piston is disposed, an input port that is adapted to receive a working fluid into the channel, and an output port that is adapted to exhaust the working fluid from the channel. The channel is arranged such that the piston is able to move continuously in a single direction within the channel.

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: A scroll compressor utilizes scroll wrap profiles which are designed with a rapid compression scroll wrap profile. This profile utilizes a shorter wrap and lower vane aspect ratios during the compression process. The non-orbiting scroll member is integrated with the main bearing housing. The drive shaft extends through the main bearing housing, through the non-orbiting scroll member and through the orbiting scroll member. In one embodiment, a counterweight is disposed adjacent the orbiting scroll member. In another embodiment, and upper bearing housing is disposed adjacent the orbiting scroll member. In yet another embodiment, an upper bearing housing is disposed adjacent the orbiting scroll member with a counterweight disposed adjacent the upper bearing housing.

Abstract: The rotary-piston machine consists of two operating units. The first one comprises a horizontal operating cylinder (1) with cylindrical shaft (5), connected to the main shaft (4) and sealed with rings to the walls of the cylinder (1). The shaft (5) has a first friction element (9) pressed against the internal wall of the cylinder (1). The second unit comprises a cylindrical body (15) mounted to the main shaft (4) with a firmly connected to its circumference inner ring (16) off a bearing with an outer ring (17) provided of an articulated joint (18) connected to a frame (19) that is connected to a valve (13) which press a second friction element (14) to the shaft (5). Both units move in syncronisation.

Abstract: A vane pump includes a casing having a cylindrical inner bore and a rotor disposed in the inner bore with an eccentric relation thereto, forming a circular pump chamber between the rotor and the inner bore. The circular pump chamber is divided by vanes held in the rotor into pump chambers changing their capacities according to rotation of the rotor. A gravity center of the rotor is shifted from the rotational center of the rotor by removing or adding some weight, so that an imbalanced centrifugal force is applied to the rotor. The driving shaft and the rotor are tightly coupled to each other by the imbalanced centrifugal force even if there is a small gap or dimensional errors therebetween.

Abstract: A compressor has a compression unit for compressing gas to a desired pressure, a drive shaft and a balancer. The drive shaft is connected to the compression unit for driving the compression unit. Imbalance on the drive shaft is generated due to movement of the compression unit. The balancer is mounted on the drive shaft and includes a main portion and adjustable portion for correcting the imbalance on the drive shaft. Preferably, at least one of the weight and the shape of the adjustable portion is adjustable.

Abstract: A variable capacity rotary compressor including a housing to define therein two compression chambers having different capacities, a rotating shaft transmit ting a rotating force from a drive unit to the two compression chambers, two eccentric parts are provided on an outer surface of the rotating shaft to be placed in the two compression chambers, respectively. Two eccentric bushes, having different weights respectively fitted over the eccentric parts to rotate relative to the rotating shaft within predetermined angles, a pair of force transmission parts, provided on opposite sides of the eccentric unit, to receive the rotating force of the rotating shaft so that one of the two eccentric bushes rotates while being eccentric from the rotating shaft and a remaining one of the two eccentric bushes rotates while being released from eccentricity from the rotating shaft, according to a rotating direction of the rotating shaft.

Abstract: There is provided an efficient compressor which is simple in structure and small in torque fluctuation. The compressor comprises a compression element which comprises a cylinder having a compression space formed therein, a suction port and a discharge port which communicate with the compression space in the cylinder, a compression member which comprises continuous thick and thin parts, one surface of which inclines, which is arranged in the cylinder to rotate, and which compresses fluids sucked through the suction port and discharges the compressed fluids through the discharge port, and a vane which is arranged between the suction port and the discharge port to abut on one surface of the compression member, and which partitions the compression space of the cylinder into a low pressure chamber and a high pressure chamber.

Abstract: An eccentric bush structure in a radial compliance scroll compressor including an eccentric bush fitted around a crank pin eccentrically provided at an upper end of a crankshaft, crank pin and stopper holes provided at the eccentric bush, and a weight member adapted to increase a weight of the eccentric bush. The stopper hole overlaps with the crank pin hole such that a stopper received in the stopper hole is radially protruded into the crank pin hole toward a vertically-extending cut surface formed at the crank pin to selectively come into contact with the cut surface in accordance with a rotation of the crank pin.

Abstract: A compressor has a compression unit for compressing gas to a desired pressure, a drive shaft and a balancer. The drive shaft is connected to the compression unit for driving the compression unit. Imbalance on the drive shaft is generated due to movement of the compression unit. The balancer is mounted on the drive shaft and includes a main portion and adjustable portion for correcting the imbalance on the drive shaft. Preferably, at least one of the weight and the shape of the adjustable portion is adjustable.

Abstract: A second frame is arranged between a first frame and an orbiting scroll, and a central space and an outer peripheral space are sealed off by a seal portion, which is formed between an end surface of a shaft support of the orbiting scroll and the second frame. Also, a balance weight is arranged in a space between an underside of the second frame and the first frame. Thereby, most of an oil having lubricated respective shaft supports flows into the space below the second frame, and the oil accumulated in the space is discharged through an oil scavenge pipe into an oil reservoir in a lower portion of a closed vessel. Also, since the balance weight can be assembled from a side of the orbiting scroll in a state, in which the second frame is removed, it is possible to mount the balance weight close to the orbiting scroll.

Abstract: The invention includes a “floating scroll” mechanism for scroll type fluid displacement apparatus. The dual orbiting scroll has spiral vanes on both sides of the end plate. In a floating scroll, the orbiting scroll is dynamically well balanced, axially and radially. The scrolls are fully or semi-axially and radially compliant for maintaining minimum contacting forces between components, hence achieving good sealing for high speed, high efficiency, low friction wear and power loss. A crank shaft-sliding knuckle and/or peripheral crank handles-sliding knuckle mechanism provide the dual orbiting scroll with radial compliant capability. A synchronizer is used to synchronize the orientation of the crank handles to avoid the mechanism from jamming during operation and start up.

Abstract: The invention relates to a screw vacuum pump comprising two rotors (4, 5) which respectively have a hub (6, 7) and a thread (8, 9), additionally comprising a housing (2) wherein the rotors whose threads engage with each other are accommodated in such a way that they form, together with the housing, inlet cross sections (15, 16) on the inlet side thereof and form outlet cross sections (29) on the pressure side thereof causing gas to be conveyed from the inlet side to the pressure side during rotation of the rotors (4, 5). According to the invention, in order to improve inflow and outflow conditions, the rotors (4, 5) are provided on the inlet side with flow bodies (21, 22; 26, 27, 28; 36, 37) which are arranged upstream from the inlet cross sections (15, 16) in such a way that the inflow conditions of the gas to be transported to the inlet cross sections (15, 16) are improved.

Abstract: A hermetic compressor assembly including a compressor housing, a compression mechanism disposed in the housing, a motor disposed in the housing; and a crankshaft operatively coupling the compression mechanism and the motor and having an axis of rotation. The crankshaft includes a cylindrical eccentric and a counter eccentric lobe. The cylindrical eccentric has a central axis, defines a circular axial profile, and is located on one radial side of the axis of rotation. The counter eccentric lobe is integrally formed with the crankshaft on the opposite side of the crankshaft from the eccentric, is axially adjacent the eccentric, and is located within the circular axial profile.

Abstract: A simple, stamped counterweight is formed from a flat sheet of metal. The counterweight is attached to an uppermost portion of the end ring of the motor rotor. In this way, the counterweight requires little axial space, and is a very simple item to produce and assemble.

Abstract: A hermetic compressor assembly including a compressor housing, a compression mechanism disposed in the housing, a motor disposed in the housing; and a crankshaft operatively coupling the compression mechanism and the motor and having an axis of rotation. The crankshaft includes a cylindrical eccentric and a counter eccentric lobe. The cylindrical eccentric has a central axis, defines a circular axial profile, and is located on one radial side of the axis of rotation. The counter eccentric lobe is integrally formed with the crankshaft on the opposite side of the crankshaft from the eccentric, is axially adjacent the eccentric, and is located within the circular axial profile.

Abstract: The invention includes a “floating scroll” mechanism for scroll type fluid displacement apparatus. The dual orbiting scroll has spiral vanes on both sides of the end plate. In a floating scroll, the orbiting scroll is dynamically well balanced, axially and radially. The scrolls are fully or semi- axially and radially compliant for maintaining minimum contacting forces between components, hence achieving good sealing for high speed, high efficiency, low friction wear and power loss. A crank shaft-sliding knuckle and/or peripheral crank handles-sliding knuckle mechanism provide the dual orbiting scroll with radial compliant capability. A synchronizer is used to synchronize the orientation of the crank handles to avoid the mechanism from jamming during operation and start up.

Abstract: A compressor has a compression unit for compressing gas to a desired pressure, a drive shaft and a balancer. The drive shaft is connected to the compression unit for driving the compression unit. Imbalance on the drive shaft is generated due to movement of the compression unit. The balancer is mounted on the drive shaft and includes a main portion and adjustable portion for correcting the imbalance on the drive shaft. Preferably, at least one of the weight and the shape of the adjustable portion is adjustable.

Abstract: A single vane gas displacement apparatus comprises a stator housing with a right cylindrical bore enclosing an eccentrically mounted rotor which also has a radial slot in which is movably radially positioned a single vane. The vane is tethered to antifriction vane guide assemblies concentric with the housing bore. Then vane has a preselected center of gravity located proximate to the housing bore axis. An option is to have a port in said vane for ducting high-pressure gas to the inlet side to react against the rotor slot to reduce vane contact therewith.

Abstract: The location of center of mass of an orbiting scroll is optimized by adding or removing mass at certain strategic locations on the orbiting scroll member. The center of mass is optimized to reduce alternating torsional moment acting on Oldham coupling. Reduction in alternating torsional moment minimizes unwanted radiated sound caused by Oldham coupling chatter.

Abstract: The pressure leakage from the back pressure chamber installed at the back side of the movable scroll to the low pressure area can be prevented. An eccentric shaft (17) formed integrally to a drive shaft (14) is inserted into a bushing (19). A balance weight (18) is fixed to the bushing (19). A cylindrical portion (34) is provided so as to protrude at the back side of the movable scroll base (22), and the bushing (19) supports the cylindrical portion (34) via a needle bearing (21). A seal member (35) is interposed between the end surface of the cylindrical portion (34) and the balance weight (18). The inside of a cylinder of the cylindrical portion (34) is made to be a back pressure chamber (36).

Abstract: In prior art scroll-type compressors, a cavity is formed in the interior of the compressor of a sufficient size to allow a misplaced or extra steel spherical ball to become lodged therein and cause seizure of the compressor. The present invention modifies a plate of the counterweight assembly or adds an additional component plate on the drive shaft of the compressor to prevent the introduction of an extra or misplaced steel spherical ball into this cavity during compressor assembly or repair.

Abstract: A scroll compressor comprising paired fixed and movable scrolls, the fixed scroll of each pair having an end plate provided with a scroll body projecting from the end plate and the movable scroll of each pair having an end plate provided with a scroll body projecting from the end plate, wherein the movable scroll meshes with the fixed scroll to form a plurality of operation chambers between them and revolves relative to the fixed scroll to compress gas in the operation chambers is characterized in that two pairs of fixed and movable scrolls are disposed with back faces of the end plates of the fixed scrolls opposite each other, the movable scrolls are integrally connected with each other, a main shaft for revolving the movable scrolls passes through the two pairs of fixed and movable scrolls to operatively engage the movable scrolls, and an outlet chamber is disposed between the end plates of the fixed scrolls.

Abstract: An automotive vane pump for generating anti-centrifugal force, and more particularly to an automotive vane pump for generating anti-centrifugal force adapted to maintain constant discharge pressure and discharge amount regardless of rotating speed to prevent power loss and to improve durability via stable operation, the pump comprising: a stator housing a rotor radiately equipped with a plurality of blades variably withdrawn according to the size of centrifugal force generated by being rotated and coupled to a shaft, received in a housing having inlet/outlet structure for operation oil, in coupling with a pulley driven by an engine; a cover coupled to the housing mounted with the stator for sealing up the housing; and centrifugal force generating means corresponding to each said blade mounted at the rotor and operatively connected to each said blade for generating centrifugal force in order to pull the corresponding blade into the rotor against radial withdrawal of the blade, where each centrifugal force gene

Abstract: The moment Mo of unbalanced forces Fr of a screw rotor A1 is reduced by adjusting the number of thread leads of a threaded portion 2 of the screw rotor A1 to (an integer +0.5). The amount of unbalance for keeping a state of dynamic balance thereby decreases, and the drilling of a thread e for keeping the state of the dynamic balance is made easier.

Abstract: An automotive vane pump for generating anti-centrifugal force, and more particularly to an automotive vane pump for generating anti-centrifugal force adapted to maintain constant discharge pressure and discharge amount regardless of rotating speed to prevent power loss and to improve durability via stable operation, the pump comprising: a stator housing a rotor radiately equipped with a plurality of blades variably withdrawn according to size of centrifugal force generated by being rotated and coupled to a shaft received in a housing having inlet/outlet structure of operation oil in coupling with a pulley driven by an engine; a cover coupled to the housing mounted with the stator for sealing up the housing; and centrifugal force generating means mounted at the rotor 5 for generating centrifugal force in order to pull the blades into the rotor relative to radial withdrawal of the blades, where the centrifugal force generating means further comprises: a resilient member constituting a spring radiately formed at

Abstract: A displacement type fluid machine which is easier to machine and assemble than a scroll type fluid machine and has high performance and low cost. A displacer is revolved in a cylinder having an inside wall formed by a curve such that a planar shape is continuous, whereby a working fluid is discharged through a plurality of discharge ports, there is provided a driving unit in which the orbiting radius of the displacer is variable along the shape of a movement line contact portion of the cylinder and the displacer.

Abstract: A helical-blade fluid machine maintains a low-pressure atmosphere in a closed casing (1) and secures a proper lubrication state for a compression mechanism (9). The fluid machine has a drive mechanism (7) that is installed at an upper or lower part of the casing and consists of a stator (11) and a rotor (15). The compression mechanism is installed at the other part of the casing. The compression mechanism has a cylinder (23) and a roller (25), which is swayed with respect to the cylinder by the drive mechanism. A helical blade (39) having unequal pitches is arranged on the roller, to define compression chambers (41). This arrangement lowers the head of lubricant. An intake pipe (5) feeds gas into the casing so that a low-pressure atmosphere fills the casing.

Abstract: Counterweight size is reduced by removing material from an electric motor rotor for a machine, such as a compressor. The material is removed asymmetrically with respect to shaft centerline to provide maximum benefit. Counterweight size reduction results in decrease of compressor dimensional envelope and weight.

Abstract: An object of the present invention is to provide a multi-cylinder rotary compressor which can eliminate a number of balancers for preventing vibrations. Assuming that the mass eccentricity in a cylinder is m1×r1; the mass eccentricity in another cylinder is m2×r2; the mass eccentricity of a balancer attached to the lower side of a rotator is m3×r3; the mass eccentricity of another balancer attached to the upper side of the rotator is m4×r4; respective distances from the cylinder to another cylinder, the lower balancer and another balancer are L2, L3 and L4, when the balancing is attained with the expressions m1×r1+m4×r4=m2×r2+m3×r3, m4×r4×L4=m2×r2×L2+m3×r3×L3, and m1×r1=m2×r2, the lower balancer is eliminated and the mass eccentricity of the balancer is set to be not less than 20% and not more than 80% of m4×r4.

Abstract: A rotation balancing mechanism of an orbiting scroll of a scroll-type compressor that reduces the outer diameter of the compressor housing. A compression mechanism includes a fixed scroll and an orbiting scroll. The compression mechanism is coupled to a support frame at the front of a drive motor. A drive crankshaft is located between the drive shaft of the motor and a base plate of the orbiting scroll. The drive crankshaft causes the orbiting scroll to orbit. Follower crankshafts are located between the support frame and the base plate. The follower crankshafts permit the orbiting scroll to orbit and prevent the orbiting scroll from rotating about its own axis. A central balance weight is located on the drive crankshaft. The central balance weight opposes part of the centrifugal force that is applied to the drive crankshaft when the orbiting scroll orbits. Outer balance weights are attached to the follower crankshafts to oppose the remainder of the centrifugal force.

Abstract: A counterweight is attached to a rotating shaft by a slip fit, combined with two axially abutting surfaces to hold the counterweight. The counterweight is preferably held at one face by a ledge formed on the shaft, and at the opposed face by a portion of the motor rotor. Circumferentially spaced abutting surfaces also hold the counterweight to cause the counterweight to rotate with the rotor. The present invention eliminates the need for separately attaching the counterweight to the shaft, and thus reduces both the complexity of assembly, and also the need for precise manufacturing tolerances for the counterweight.

Abstract: A helical-blade fluid machine maintains a low-pressure atmosphere in a closed casing (1) and secures a proper lubrication state for a compression mechanism (9). The fluid machine has a drive mechanism (7) that is installed at an upper or lower part of the casing and consists of a stator (11) and a rotor (15). The compression mechanism is installed at the other part of the casing. The compression mechanism has a cylinder (23) and a roller (25), which is swayed with respect to the cylinder by the drive mechanism. A helical blade (39) having unequal pitches is arranged on the roller, to define compression chambers (41). This arrangement lowers the head of lubricant. An intake pipe (5) feeds gas into the casing so that a low-pressure atmosphere fills the casing.

Abstract: Known designs of single-thread screw rotors in single-piece cast iron constructions having wrap angles of >720 degrees with balancing cavities on the face of the screw operate with no unbalance at average rotary frequencies of (.about.3000 min.sup.-1). The use of a pump in processes having sensitive purity and maintenance requirements or working with corrosive substances or where limited space is available and quality is demanded, brings about problems for rotor designing and balancing, which the present invention solves. An uneven mass distribution is accomplished by constructing the rotors with several single parts inside the rotor, by forming cavities and/or by choosing the adequate material, which, combined with the screw length/pitch ratio, cause a static and dynamic balancing. Screw rotors designed as described offer several advantages since they are easy to assemble and have a compact and stable construction.

Abstract: A rotary engine includes a rotary shaft, a rotary piston carried by the shaft, a bearing structure supporting the shaft on one side of the rotary piston and a counterweight carried by the shaft on another side of the rotary piston. An air/fuel/oil charge is directed into a recess containing the counterweight and thereafter flows through engine components for cooling prior to combustion thereof in a combustion chamber.

Abstract: In prior art designs, single-flight cast double worms with angles of contact >720.degree. with large balance hollows at both ends and worm lengths of whole multiples of the pitch operate in the medium rotation speed ranges (.about.3000 min.sup..about.1) without imbalance. The desired use of special uncastable materials and the manufacturing complexity and the necessary dimensional stability even for extreme profile geometries pose additional problems in balancing which are solved by the present invention. Here, it is possible, by varying the angle of contact of the worm and any balance hollows and/or by altering the contour of the worms in the medium engagement region, to reduce the size of the balance hollows, sometimes to "zero", and with the possible use of additional masses. Besides the advantage of simple raw component manufacture, worms balanced in this way also permit the use of special materials and extreme worm geometries for fitting in pumps used in the chemical, medical and food sectors.

Abstract: A compressor or pump assembly including a housing, a compression mechanism disposed within the housing, a shaft operatively connecting the compression mechanism and a drive source, the shaft having an axis of rotation and first and second surfaces, the shaft axis of rotation disposed between the first and second shaft surfaces, and a counterweight disposed about the shaft and comprising first and second portions, the first counterweight portion generally U-shaped, having first and second arms, the first arm in contact with the first shaft surface, the second arm in contact with the second shaft surface, the second counterweight portion extending between the first and second arms and attached to the first counterweight portion, the shaft captured between the first and second counterweight portions, whereby rotation is imparted to the counterweight through the interface of the shaft surfaces and the arms.

Abstract: A scroll hydraulic machine has a fixed scroll and a swirling scroll performing a revolutionary swirling motion while engaging with the fixed scroll; there is also a balance weight in which a distance between a center of revolution of the swirling scroll and the center of gravity of the balance weight is changed in response to rotational speed of the swirling scroll.

Abstract: A lubrication system for a compressor has a first axially extending lubricant passage in the driveshaft located on the axis of rotation of the driveshaft. A second axially extending passage in the driveshaft is located radially outward from the first axially extending lubricant passage. An angular lubricant passage extends between the two axially extending passages. The angular lubricant passage pumps lubricant to the second axially extending passage while gas entrapped within the oil flows through the first axially extending lubricant passage.

Abstract: In a scroll compressor in which a movable scroll member (4) is eccentrically spaced from a fixed scroll member (5) and rotatably holds an eccentric bush (3) having a bush hole (30) inserted with a crank pin (110) of a crank shaft (10), the eccentric bush is movable in a radial direction of the crank pin and is guided by a guide pin (11) fixed to the eccentric bush. A pin hole (1110) is formed to penetrate the crank pin in the radial direction. The guide pin extends through the pin hole in the radial direction. Movement of the eccentric bush is guided with the guide pin being cooperated with the pin hole.

Abstract: A scroll-type fluid machine is provided, which comprises a boss provided in and projecting from a central area in a surface of the end plate of a revolving scroll; a drive bush inserted into the boss in a freely rotatable form; a rotational shaft co-rotationally coupled with the revolving scroll via a revolving-radius variable mechanism; a balance weight attached to the drive bush; and a float-protecting pin, a part of the back face of the head of the pin being in contact with the upper face of the balance weight, the shaft of this pin passing through a hole provided in the balance weight in a freely movable form, and an end part of the shaft being fixed to a larger-diameter portion at one end of the rotational shaft, said larger-diameter portion existing at the drive bush side. In the above structure, a part of the head of the pin, said part existing at the side of the drive bush, is cut.

Abstract: A scroll-type fluid displacement device has two interfitting spiral-shaped scroll members which have predetermined geometric configurations. The novel design provides a flow diverter mechanism which directs intake fluid flow to break incompressible liquid accumulated into fine droplets which can be evenly engulfed by two suction pockets formed by the scrolls. This invention also provides a multiple groove tip seal mechanism for radially sealing off the compression pockets. This invention further provides a semi-radial compliant mechanism which maintains the radial compliant function of the orbiting scroll and at the same time transfers the load caused by the centrifugal force of the orbiting scroll from the scroll elements to the crank shaft.

Abstract: A scroll compressor has a closed vessel in which a compression mechanism having orbiting and stationary scroll elements in engagement with each other is accommodated. A crankshaft is coupled with the orbiting scroll element and rotatably supported by a crank bearing. The crankshaft is rotated by an electric motor having a stator and a rotor so that the orbiting scroll element may orbit relative to the stationary scroll element. A plurality of balance weights are provided for maintaining static and dynamic balances of rotary elements including the orbiting scroll element, the crankshaft, and the rotor. The static and dynamic balances are calculated using at least a clearance between the crankshaft and the crank bearing.

Abstract: In a scroll type fluid displacement apparatus in which a drive pin (151) is connected between a large-diameter portion (15) of a main shaft (13) and a bushing (33) rotatably held to a movable scroll (26) and which a rotation of the main shaft is transmitted to the bushing through the drive pin to make the movable scroll have an orbital motion around a predetermined axis, a balance weight (331) attached to the bushing has a positioning projection (331c) which is engaged with the large-diameter portion in a rotation direction of the bushing. Therefore, the movable scroll is positioned relative to the main shaft. In addition, the movable scroll defines fluid pockets in cooperation with a fixed scroll (25) therebetween. When the orbital motion of the movable scroll is caused in dependence on rotation of the main shaft with inhibiting rotation of the movable scroll around the predetermined axis, the fluid pockets are displaced between the movable and the fixed scrolls.

Abstract: An inexpensive enclosed type rotary compressor capable of diminishing vibration. A balance weight is split into two parts. A first balance weight is formed by die casting, forging, sintering or the like to be in such a form that its end portions each having a hole for accommodating by a fixing protrusion are thinner than the remaining portion, and a second balance weight is formed as a single plate or laminated plates in plural layers and securedly sandwiched between the end ring of a rotator and the first balance weight. As a result, the balance weight can be standardized, realizing cost efficiency.

Abstract: An object of the present invention is to provide a rotor of a fluid machine in which the rotor can be made light in weight and moment of inertia of the rotor can be reduced and the rotor can be easily balanced in its rotating direction. In this rotor of a fluid machine, a fluid is compressed and pumped by a pair of rotors engaged with each other. A hollow portion is formed within a tooth stripe portion of one rotor. A thickness forming portion for a balance correction is formed in an opening portion of this hollow portion to balance the rotor in its rotating direction and is projected on an inner circumferential side of the hollow portion.

Abstract: A compressor having an oil pick-up tube which filters incoming lubricant, and increases the volumetric pumping capacity of the compressor. The oil pick-up tube is attached to the crankshaft of the compressor, and is partially disposed within an oil sump also provided in the compressor. When the motor of the compressor is energized, the crankshaft and the oil pick-up tube rotate, and oil from the oil sump is drawn into the oil pick-up tube. A passageway is provided within the motor shaft to communicate oil from the oil pick-up tube to the compressor mechanism of the compressor for lubrication purposes. A cylindrical screen is also provided within the oil pick-up tube to both filter the incoming oil and provide a surface to which the oil adheres as it migrates upward through the rotating tube and expels the oil radially outward to increase the velocity of the migrating oil. The volumetric pumping capacity of the compressor is thereby increased.

Abstract: Fixed scrolls 4, 5 are supported so to be movable axially relative to an orbiting scroll 6, so that a proper space is kept between wraps 4a, 5a and 6a to avoid an excessive load in the contacting area. Further, an end portion of an outer curve of the wrap 6a of the orbiting scroll 6 is formed to come close to or coincide to an outer edge of a panel 6f of the orbiting scroll 6 and an Oldham's coupling is accommodated in a concave groove 6e formed on an outer circumference surface of the panel 6f, so that the size of the scroll compressor is reduced.

Abstract: An oil-free type fluid machine with scrolls is disclosed, which contains a fixed scroll composed of a fixed scroll swirl, a fixed scroll base and a casing, an orbiting scroll composed of an orbiting scroll swirl, an orbiting scroll base and an orbiting scroll boss, the fixed scroll and the orbiting scroll interposed one another, a driving shaft, an eccentric driving shaft provided on the driving shaft with a predetermined eccentricity S, which penetrates the orbiting scroll boss and the fixed scroll base, the orbiting scroll performs an orbiting motion as opposed to the fixed scroll to form a compression room by the orbiting scroll and the fixed scroll, a member for preventing the orbiting scroll from rotating on the driving shaft, a first bearing for supporting the driving shaft, a second bearing for supporting the eccentric driving shaft at an end which is not adjacent to the driving shaft, a bearing shoe concentrically provided with respect to the driving shaft, around the eccentric driving shaft and insid

Abstract: A scroll type compressor comprising: a crankshaft having an eccentric shaft portion formed thereon; an orbiting scroll which is given torque by the crankshaft through the eccentric shaft portion; and bearing means for rotatably supporting the crankshaft; wherein at least one of the eccentric shaft portion and the bearing means is constituted by a rotatably engaged bushing and a curved surface portion.