Abstract: An improved abrasion resistant rotor assembly and valve and system related thereto is disclosed. The assembly includes a rotor body defining an annular opening which surrounds a drive shaft and a plurality of vanes radially extending from the rotor body. The rotor is made up of a unitary ceramic component, such as silicon carbide. The valve also includes a body for defining a bore that receives the rotor assembly, where the body bore is likewise comprised of a hardened ceramic material. This valve may thus be used to convey abrasive particulate in an efficient manner from a supply container to a pressured line for further processing or disposal.

Abstract: Disclosed is a system for pumping of fluid by a single pump from a plurality of storage tanks in situations where some of the tanks should be pumped simultaneously at predefined, equal or unequal flow rates, and where some of the tanks should be pumped sequentially, in an orderly manner. The system needs no restrictors or valves to determine the flow rate or the sequence of pumping. In some embodiments, the rate of flow out of the pump does not change when one tank becomes empty before another.

Abstract: A discharge valve system of a scroll compressor comprises: a fixed scroll having a discharge hole and discharge bypass holes; a discharge valve assembly mounted at the fixed scroll, for opening and closing the discharge hole by a pressure difference; and an integral bypass valve assembly mounted at the fixed scroll, for opening and closing the bypass holes and interworking the discharge valve assembly. According to this, a discharge amount of gas is maximized in a low pressure ration driving of the scroll compressor thereby to enhance a discharge efficiency. Also, the number of components is greatly reduced thus to reduce a fabrication cost. Also, the number of assembly processes is greatly reduced thereby to enhance an assembly productivity.

Abstract: A hermetic compressor uses an oil pump that includes a trochoid gear. Therefore, regardless of the rotation speed of a driving motor of the compressor, a sufficient amount of oil can always be pumped. The oil pump unit may include a plurality of suction holes with openings at different heights. If the refrigerant and oil separate, at least one of the openings will admit oil into the oil pump unit, to ensure lubricating oil is supplied to the moving parts of the compressor.

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: A high-efficiency vane rotary expander is provided, which prevents a loss due to incomplete expansion or overexpansion from occurring because the volume of an operating chamber may vary. This is done by forming a plurality of discharge ports (28, 29, 48, 49, 50) in an inner wall (21a, 41a) of a cylinder in the circumferential direction, placing, among these discharge ports, the discharge port (28, 48), to which the operating chamber (25, 45) connects at the initial stage of the discharging process, at a position of {180×(1+1/n)} degrees from a small clearance (22, 42) defined between the cylinder (21, 41) and the rotor (23, 43) in the direction where a shaft rotates, and providing a valve mechanism (30a, 30b, 51a, 51b, 52a, 52b).

Abstract: A hydraulic traction system for vehicles is described. The system comprises a hydraulic vane motor mounted at each wheel of the vehicle, and equal number of identical hydraulic vane motors operated as engine driven pumps, and a control system for regulating the flow and direction of hydraulic oil during operation. The hydraulic motor is of a novel design that has a hollow non-drive shaft that accepts incoming hydraulic oil, this allows internal components of the hydraulic motor to be arranged in such a way to improve the efficiency of the hydraulic traction system.

Abstract: A scroll fluid machine comprises a housing having a fixed scroll and an orbiting scroll revolved by a driving shaft which is driven by a motor behind the housing. A blowing fan is provided between the orbiting scroll and the motor. Rotation of the fan causes decompression in the housing to allow primary external air to be sucked from the outside into the housing through a primary sucking hole. Secondary external air is introduced from a secondary sucking hole and mixed with the primary external air of the scroll fluid machine to cool the parts of the scroll fluid machine in the housing and/or the motor.

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 vane-type hydraulic motor includes a rotor (30) having a main shaft (70) and a plurality of vanes (35), a cam casing (10) having a chamber (11) for rotatably housing the rotor (30), a first port (13) and a second port (15) for supplying a working fluid into the chamber (11) and discharging the working fluid from the chamber (11). A bypass path (80) is provided for allowing the working fluid to flow from bearing portions (51, 61) supporting the main shaft (70). A drain port (17) is provided for discharging the working fluid to the exterior.

Abstract: A cylinder to a vane motor is designed to include cylindrically shaped inlet and outlet holes, an axial passage that includes a blocked upstream portion that bypasses the upstream inlet holes, spaced circumferentially slots for leading a portion of the pressurized air into the inlet holes, discharging the portion of pressurized air from the axial passage into an annular cavity to bathe the bearing in the cooler pressurized air, and recirculating the portion of pressurized air through another axial passageway to flow into all of the inlet holes. The discharge holes are judiciously oriented in a particular pattern to assure that the edge of the vanes wear uniformly. The inlet holes are spaced from the pinch point of the spindle to cylinder to permit an increased volume of pressurized air to enter the vane motor and the outlet holes are spaced to maximize the power stroke of the vane motor.

Abstract: In a Roots vacuum pump, an inlet port is located at a position n spaced by a positive displacement angle of 120° in one direction from a center of each rotational axis relative to an imaginary line m connecting rotor axes. An outlet port is located at a position o opposite to the inlet port relative to the line. An air feed port is formed at a position t on a casing wall obtained by returning by 90° from the position o to the inlet port side so that two closed spaces are defined by adjacent rotor lobes and a casing inner wall at both port sides immediately after air suction respectively. The casing has discharge grooves in an area of the inner wall so as to communicate with the outlet port. The area ranges from the position o to a position u obtained by returning by 45° from the position o to the inlet port side. The discharge grooves have a total volume ranging from 2% to 5% of a volume of one of the closed spaces.

Abstract: A seal assembly for the protection of a static seal device for use in a vacuum pump. The seal assembly comprising at least two components which are sealingly connected together, an o-ring seal, which is engaged between the two components to prevent transfer of fluid to and from the pump between these two components and a fluid channel. The fluid channel being in the plane of the o-ring and located between the o-ring seal and a process gas flow path. The fluid channel provides a path for a barrier gas to be routed when the apparatus is in use. The channel being connectable to an external source of barrier fluid and having an outlet in fluid communication with the pump swept volume.

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: 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: A rotary pump includes a stator housing and a rotor. The stator housing preferably has an oblong inner surface. The rotor, which is disposed in the stator housing, preferably has a substantially circular outer surface within which a plurality of vane slots are defined. A first chamber is defined between a first half of the oblong inner surface and the outer surface of the rotor. Similarly, a second chamber is defined between a second half of the oblong inner surface, diametrically opposite the first half, and the outer surface of the rotor. Resting within each of the plurality of vane slots is a corresponding sliding vane. A first inlet port and a first outlet port each provide access to the first chamber. Similarly, a second inlet port and a second outlet port each provide access to the second chamber. At least one of the vanes separates each of the first inlet port, the first outlet port, the second inlet port and the second outlet port from one another.

Abstract: A dual-inlet gear pump includes a drive gear and a driven gear. The invention utilizes the discovery that the drive gear will typically move a higher flow volume than does the driven gear, particularly when the fluid being moved is an air/oil mixture. The present invention takes advantage of this discovery to communicate a first higher expected flow source to the drive gear, and to separately communicate a second, relatively lower expected flow rate to the driven gear. A particular application is in a scavenging pump for a jet engine.

Abstract: The present invention relates to a vane-type rotary machine suitable for use in applications where a low-viscosity fluid such as water is used as a working fluid. According to the present invention, a vane-type rotary machine having a rotor (11) mounted with vanes and rotatably housed in a cam casing (10) includes a motor supply opening (or pump discharge opening) (30) for a working fluid, a motor return opening (or pump suction opening) (20) formed in the cam casing for a working fluid, and branch flow passages (23, 25, 33 and 35) branched from the motor supply opening (or pump discharge opening) and the motor return opening (or the pump suction opening) and communicating with vane chambers (22, 24, 32 and 34). The distances of the branch flow passages are identical to each other.

Abstract: A scroll fluid machine comprises fixed and orbiting scrolls. The fixed scroll has a fixed end plate having inner and outer fixed wraps and the orbiting scroll has an orbiting end plate having inner and outer wraps. Between the fixed and orbiting end plates, an annular partition wall is provided. The orbiting scroll is driven by an eccentric portion of a driving shat to form an inner compressing chamber in which the inner fixed wrap is engaged with the inner orbiting inside the annular partition wall and to form an outer compressing chamber in which the outer fixed wrap is engaged with the outer orbiting wrap between the annular partition wall and a housing. The inner compressing chamber communicates with a rear pressure chamber behind the orbiting end plate thereby preventing the orbiting end plate from being deformed or distorted.

Abstract: A rotary internal combustion engine has a shaft, a compression chamber, an ignition chamber, a center wall, a first rotor, and a second rotor. The shaft is fixed to the rotors while being rotatably mounted to the compression and ignition chambers. The compression chamber has an oval shaped chamber wall and receives fuel and compresses the fuel. The ignition chamber has an oval shaped chamber wall and receives compressed fuel from the compression chamber and combusts the compressed fuel. The center wall is located between the compression chamber and ignition chamber and allows passage of compressed fuel from the compression chamber to the ignition chamber. The first rotor has a circular perimeter surface and is rotatably received within the compression chamber. The second rotor has a circular perimeter surface and is rotatably received within the ignition chamber.

Abstract: A gas compressor has a cylinder in which a refrigerant gas is compressed and a side block mounted to an end surface of the cylinder. The side block has suction holes each having a first end opening to an outer surface of the side block and a second end opening into the cylinder. A front head has a suction port, an inner surface, and a hollow portion disposed in the inner surface. The front head is disposed on an outer surface of the side block so that the hollow portion and the outer surface of the side block form suction passages extending from the suction port to respective suction holes of the side block. Each of the suction passages form a main flow passage along which refrigerant gas flows from the suction port to a corresponding one of the suction holes of the side block. The hollow portion has a generally flat wall surface at a region corresponding to each of the main flow passages.

Abstract: External gear pump, comprising: a casing (3a, 3b) with a gear chamber (4), comprising an inlet (5) for a fluid on a low pressure side and an outlet (6) on a high pressure side and comprising axial and radial sealing stays (7, 8); toothed wheels (1, 2) being in toothed mesh, wherein the external toothings of the wheels (1, 2) form delivery cells (10) for the fluid which are axially sealed off by the axial sealing stays (7) and radially sealed off by the radial sealing stays (8); and at least one pressure fluid supply (15, 16) through which pressure fluid may be supplied to the low pressure side, wherein the at least one pressure fluid supply (15, 16) opens on the low pressure side into a delivery cell (10) which is radially opposed by one of the radial sealing stays (8).

Abstract: A bottom portion of an intake port is provided with a sloped bottom surface formed of a plane such that sloped bottom surface approaches the side surfaces of external teeth and internal teeth from an upstream side to a downstream side in rotational direction of two rotors. Fluid that flows in the intake port is regulated by the sloped bottom surface and smoothly guided into individual inter-teeth chambers that are expanding. Since the sloped bottom surface on the bottom portion of the intake port is formed of a plane without spiral or twisting, design and manufacturing of a gear pump is extremely easy.

Abstract: A fluid machinery includes a helical mechanism connected to a driving mechanism, which is driven via a crank shaft. The helical mechanism includes a cylinder defining an inner space, a roller disposed inside the cylinder so as to be rotated in an eccentric manner, the roller being formed with a plurality of helical grooves on an outer peripheral surface, and at least one seal ring groove between respective helical grooves, a plurality of helical blades fitted to the helical grooves so as to be disposed between as inner peripheral surface of the cylinder and the outer peripheral surface of the roller, and at least one seal ring fitted to the seal ring groove so as to tightly seal the inner space as a plurality of operation sections. Furthermore, a plurality of suction ports and a plurality of drain ports, associated with respective operation sections, communicate with each other.

Abstract: A supercharger includes multiple back flow ports which are controlled by valves. The valves regulate the timing and area for back flow of pressurized outlet air into the rotor chambers. The back flow air tends to equalize air pressure in the chambers prior to their exhausting into the outlet and thereby reduces flow back noise. The multiple ports are opened selectively or sequentially to provide noise control with improved efficiency at varying speeds.

Abstract: Disclosed is a vacuum preventing device for a scroll compressor comprising: a chamber formed at one side of a fixed scroll and having a suction hole, a compression hole, and a discharge hole at an inner circumference surface thereof; an open/close member installed in the chamber and having a seal oil groove at an outer circumference surface thereof for selectively connecting the discharge hole to the suction hole; and an elasticity member installed in the chamber for providing an elasticity force to the open/close member. The device can enhance a compression efficiency of the compressor by preventing gas leakage efficiently and reduce a fabricating cost by improving a design of a clearance and enhancing a tolerance limit range.

Abstract: A pump chamber defines a capacity increased in a first certain angle range and decreased in a second certain angle range. An intake port is open in an increase range where the pump chamber moves from a minimum capacity position to a maximum capacity position. A discharge port is open in a decrease range where the pump chamber moves from the maximum capacity position to the minimum capacity position, the discharge port being biased to the minimum capacity position. A seal land portion seals a communication between the intake port and the discharge port via the pump chamber. A reduced portion is defined between a communication portion and the pump chamber. A bypass path connects the communication portion with the discharge port. A relief valve intervened in the bypass path opens the bypass path with a pressure of the communication portion increased to or over a set pressure.

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: A roots pump has a housing, a plurality of rotary shafts, a rotor, a confluent passage and a closed space. The housing forms therein a pump chamber. The rotary shafts are supported on the housing in parallel relation to each other. The rotor is mounted on each of the rotary shafts, and the rotors on any adjacent rotary shafts are in engagement with each other. A set of the engaged rotors is accommodated in the pump chamber. The confluent passage is formed along one crossing line of paired imaginary swept peripheral surfaces in one-to-one correspondence with the paired and engaged rotors. The closed space is formed in one-to-one correspondence with each of the paired rotors between the paired rotors and paired peripheral wall surfaces which form the pump chamber. The closed space initially joins the confluent passage from a terminal end thereof with rotation of the paired rotors.

Abstract: A first fixed scroll has a first fixed wrap, and a first orbiting scroll has a first orbiting wrap. The first orbiting scroll is rotatably mounted to an eccentric portion of a driving shaft. The first fixed wrap is engaged with the first orbiting wrap to form a first compression chamber in which pressure is changed towards the center of the first orbiting scroll. A second fixed scroll has a second fixed wrap and a second orbiting scroll has a second orbiting wrap which is engaged with the second fixed wrap. The first orbiting scroll is connected to the second orbiting scroll by a pin inserted a partition wall between the first and second orbiting scrolls, thereby rotating the first orbiting scroll together with the second orbiting scroll when the first orbiting scroll is driven by the driving shaft via the eccentric portion.

Abstract: A dual chamber or double sided rotary pump includes a stator housing and a rotor. The stator housing has an oblong inner surface. The rotor, which is disposed in the stator housing, has a substantially circular outer surface within which a plurality of vane slots are defined. A first chamber is defined between a first half of the oblong inner surface and the outer surface of the rotor. Similarly, a second chamber is defined between a second half of the oblong inner surface, diametrically opposite the first half, and the outer surface of the rotor. Resting within each of the plurality of vane slots is a corresponding sliding vane. A first inlet port and a first outlet port each provide access to the first chamber. Similarly, a second inlet port and a second outlet port each provide access to the second chamber. At least one of the vanes separates each of the first inlet port, the first outlet port, the second inlet port and the second outlet port from one another.

Abstract: A so-called internal intermediate pressure multistage compression type rotary compressor makes it possible to prevent the pressure inside a roller from inconveniently increasing and also to permit smooth and reliable supply of oil into a cylinder of a second rotary compressing element by a relatively simple construction. A lubrication groove for providing communication between an oil bore and a low-pressure chamber in the cylinder is formed in a surface of an intermediate partitioner that is adjacent to the cylinder of the second rotary compressing element. Furthermore, a through bore for providing communication between a hermetically sealed vessel and the inside of the roller is formed in the intermediate partitioner.

Abstract: A supercharger includes multiple back flow ports which are controlled by valves. The valves regulate the timing and area for back flow of pressurized outlet air into the rotor chambers. The back flow air tends to equalize air pressure in the chambers prior to their exhausting into the outlet and thereby reduces flow back noise. The multiple ports are opened selectively or sequentially to provide noise control with improved efficiency at varying speeds.

Abstract: A cylinder structure for a pneumatic tool includes a cylinder, a rotor, a front lid, and a rear lid. The cylinder has an eccentric chamber which has an inner wall in a series of different curvature sections connected to form an entire inner wall. The rotor is in touch by its outer edge against the inner wall of the chamber to form a contact surface in a zero distance, and a gap between the outer edge of the rotor and the inner wall of the chamber is gradually increasing towards both sides until an opposite side of the contacting surface.

Abstract: A rotary vane pump has an open ended pump cylinder mounting a drive motor at one end and a ported end plate and sound chamber at the other end. The cylinder contains a rotor mounted to an eccentric drive shaft and having vane grooves receiving slidable vanes contacting an inner diameter of the cylinder. The end plate has an outlet port and primary and secondary inlet ports in communication with the cylinder interior, the inlet ports being in communication with an area of net expansion. The sound chamber has an intake port and an exhaust port in communication with the respective outlet and primary and secondary inlet ports of the end plate. The sound chamber is partitioned to define a number of internal cavities through which the incoming air is routed to the secondary inlet port.

Abstract: A rotary vane pump has an open ended pump cylinder mounting a drive motor at one end and a ported end plate and sound chamber at the other end. The cylinder contains a rotor mounted to an eccentric drive shaft and having vane grooves receiving slidable vanes contacting an inner diameter of the cylinder. The end plate has an outlet port and primary and secondary inlet ports in communication with the cylinder interior, the inlet ports being in communication with an area of net expansion. The sound chamber has an intake port and an exhaust port in communication with the respective outlet and primary and secondary inlet ports of the end plate. The sound chamber is partitioned to define a number of internal cavities through which the incoming air is routed to the secondary inlet port.

Abstract: A pump chamber defines a capacity increased in a first certain angle range and decreased in a second certain angle range. An intake port is open in an increase range where the pump chamber moves from a minimum capacity position to a maximum capacity position. A discharge port is open in a decrease range where the pump chamber moves from the maximum capacity position to the minimum capacity position, the discharge port being biased to the minimum capacity position. A seal land portion seals a communication between the intake port and the discharge port via the pump chamber. A reduced portion is defined between a communication portion and the pump chamber. A bypass path connects the communication portion with the discharge port. A relief valve intervened in the bypass path opens the bypass path with a pressure of the communication portion increased to or over a set pressure.

Abstract: A dry compressing vacuum pump (1) has a continuous or graduated inner compression. A gas ballast device (8) selectively adds a ballast gas to a pumped gas. The gas ballast device has an isolating valve (11), a non-return valve (12) which prevents the escape of gases from the pump through the gas ballast device to the outside, and a pressure differential valve (13).

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: A rotary internal combustion engine has a shaft, a compression chamber, an ignition chamber, a center wall, a first rotor, and a second rotor. The shaft is fixed to the rotors while being rotatably mounted to the compression and ignition chambers. The compression chamber has an oval shaped chamber wall and receives fuel and compresses the fuel. The ignition chamber has an oval shaped chamber wall and receives compressed fuel from the compression chamber and combusts the compressed fuel. The center wall is located between the compression chamber and ignition chamber and allows passage of compressed fuel from the compression chamber to the ignition chamber. The first rotor has a circular perimeter surface and is rotatably received within the compression chamber. The second rotor has a circular perimeter surface and is rotatably received within the ignition chamber.

Abstract: Two-inner gears are overlapped with each other through a partition wall and are eccentrically arranged at an inner peripheral side of an outer gear, and eccentric directions of both the inner gears are shifted from each other by 180° to the opposite side. By this, loads in an outer diameter direction due to a rise in fuel pressure affect one outer gear from the two inner gears oppositely to each other by 180°, so that an eccentric load is not generated, and sliding resistance of the outer gear to a cylindrical casing becomes small. Further, the number of teeth of the outer gear is made odd, and the number of teeth of the inner gears is made even.

Abstract: The present invention involves a gear assembly of a fuel pump for improved supply of fuel to an automotive engine from a fuel tank. The assembly includes an inner gear and an outer gear matingly cooperating with the inner gear for rotation about an axis. The assembly further includes a pump cover including a cover surface adjacent the inner and outer gears and a pump body including a body surface adjacent the inner and outer gears opposite the pump cover. The cover surface has a primary inlet porting and a secondary outlet porting formed thereon and separated between seal areas. The body surface of the pump body includes a primary outlet porting and a secondary inlet porting separated between seal areas. In use, the inlet portings and the outlet portings of the pump body and the pump cover cooperate together, respectively, such that fuel entering through the inlet portings pass therethrough at a rate at which the gear assembly moves.

Abstract: A scroll fluid machine comprises a stationary scroll that has a spiral stationary wrap, and an orbiting scroll that has a spiral orbiting wrap to form a compression chamber between the stationary and orbiting wraps. In the stationary and orbiting wraps, an outer low-pressure pressurizing portion is separated from an inner high-pressure pressurizing portion. A plurality of outlets and inlets are formed in the low-pressure and high-pressure pressurizing portions respectively. At least one of the outlets or at least one of inlets is selectively closed.

Abstract: A scroll type compressor includes a housing, a movable scroll member, a plurality of compression chambers, a discharge port, a communication passage and a relief valve. The communication passage interconnects each intermediate compression chamber with the discharge port. The communication passage has a first portion and a second portion. The first portion extends from the first intermediate compression chamber and the second portion extends from the second intermediate compression chamber. The first portion and the second portion meet at a meeting point on the way in the communication passage before reaching the discharge port. The relief valve is placed between the meeting point and the discharge port inclusive of the meeting point in the communication passage. The relief valve opens the communication passage when the pressure in the first and the second intermediate pressure chambers is higher than the pressure in the discharge port.

Abstract: A rotary displacement machine has a housing and at least two annular displacement gears arranged in the housing and supported rotatably on a stationary axle, receptively. The at least two annular displacement gears have external teeth for conveying a fluid. At least two supply channels are provided in the housing and have a supply mouth, respectively, opening toward the annular displacement gears for supplying a fluid to the annular displacement gears. The supply mouth is configured such that, upon operation of the rotary, displacement machine, a fluid exiting from the supply mouth reaches either only the teeth of a single one of the annular displacement gears or only the teeth of the annular displacement gears rotating in the same direction.

Abstract: An industrial robot including a manipulator having a control system. The manipulator includes a common gear housing having first and second inner compartments connected with a passage channel. First and second gears are arranged in the first and second inner compartments and are adapted to move the manipulator. A cooling and lubricant medium is disposed in the common gear housing and circulates between the first and second inner compartments through the passage channel.

Abstract: A scroll type compressor includes a housing, a movable scroll member, a plurality of compression chambers, a discharge port, a communication passage and a relief valve. The communication passage interconnects each intermediate compression chamber with the discharge port. The communication passage has a first portion and a second portion. The first portion extends from the first intermediate compression chamber and the second portion extends from the second intermediate compression chamber. The first portion and the second portion meet at a meeting point on the way in the communication passage before reaching the discharge port. The relief valve is placed between the meeting point and the discharge port inclusive of the meeting point in the communication passage. The relief valve opens the communication passage when the pressure in the first and the second intermediate pressure chambers is higher than the pressure in the discharge port.

Abstract: A multi-rotor screw compressor includes a compressor housing defining at least three parallel rotor housing sections, each rotor housing section containing a rotor, and adjacent rotors defining at least two compressor pairs, the housing further including a suction port and a discharge port for each of the compressor pairs, and further including at least two additional ports selected from the group consisting of first closed lobe ports, last closed lobe ports, and economizer ports, wherein at least one of the additional ports is communicated with a first pair of the at least two pairs, and another of the additional ports is communicated with a second pair of the at least two pairs whereby interaction between the additional ports is reduced.

Abstract: A screw compressor includes a compressor housing defining parallel rotor housing sections, each rotor housing section containing a rotor, and adjacent rotors defining compressor pairs, the housing further including a suction port and a discharge port for each of the compressor pairs, and further including additional ports selected from first closed lobe ports, last closed lobe ports, and economizer ports, wherein at least one of the additional ports is communicated with a first pair of the at least two pairs, and another of the additional ports is communicated with a second pair of the at least two pairs whereby interaction between the additional ports is reduced. In accordance with a further aspect of the invention, configurations are provided so that the first discharge port has a lower volume index ratio (Vi) than the second discharge port.

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.