A rotary piston and cylinder device (1) comprising: a rotor (2), comprising a rotor surface (2a), a piston (5) which extends from the rotor surface, a stator (4), a rotatable shutter (3), the rotor surface and the stator together defining an annular chamber, and the piston arranged to rotate, through the annular chamber, wherein when the chamber is viewed in axial cross-section, substantially a single surface of the stator in part defines the chamber (100).

A rotary internal combustion engine includes outer and inner housings defining an enclosure therebetween, and first and second side housings disposed on opposite sides of the outer housing. The inner housing is rotatable relative to the outer housing, at least one retractable barrier and at least one fixed barrier. The at least one retractable barrier and the at least one fixed barrier are disposed in the enclosure so as to divide the enclosure into a combustion chamber and an exhaust chamber. The at least one retractable barrier is mounted along a pivot axis and is pivotable between an extended position and a retracted position. An intake port, exhaust port, and ignition source are also provided. An exhaust duct extends from within the enclosure to outside the outer housing in a direction tangent to flow in the enclosure.

A pump device includes a rotating body, a pump housing including a suction port and a discharge port, and a relief valve. In the pump device, a fluid is sucked from the suction port and discharged from the discharge port by rotation of the rotating body. The relief valve includes a valve body and a biasing member. The discharge port includes an one end in a direction in which the discharge port extends. The one end is shallower than a middle portion of the discharge port. The pump housing includes a relief flow path through which the fluid flows when the relief valve opens. The relief flow path is provided so as to be open to a groove bottom surface of the one end of the discharge port.

A stator for a helical gear device includes a first section having first helically convoluted chamber with a set of radially inwardly extending lobes and a second section adjacent to the first section. The second section includes a stack of cutter disks. Each cutter disk includes a front surface, a rear surface, an interior surface defining a central opening extending from the front surface to the rear surface, a forward cutting edge, and a rearward cutting edge. The interior surface forms a same number of lobes for the central opening as the set of radially inwardly extending lobes in the first section. Each cutter disk is aligned along a common centerline, and each cutter disk is rotated slightly relative to each other to form a second helically convoluted chamber with a same pitch as the first helically convoluted chamber. The second helically convoluted chamber exposes, to materials passing through, portions of the forward cutting edge or the rearward cutting edge of each cutter disk.

A scroll compressor is provided which includes: a revolving scroll, a fixed scroll, an autorotation preventing mechanism, a frame, a crank shaft provided with an eccentric pin portion which is eccentric with respect to an axis, the crank shaft being provided with a flange portion at a lower portion of the eccentric pin portion, the flange portion being larger than the diameter of the eccentric pin portion, a balance weight mounted on the flange portion, a sealing member performing sealing between the revolving scroll and the flange portion, and a thrust bearing arranged between the frame and the flange portion. The scroll compressor reduces the amount of oil flowing into a back pressure chamber, thereby improving the performance of the scroll compressor.

A stator for a helical gear device includes a first section having first helically convoluted chamber with a set of radially inwardly extending lobes and a second section adjacent to the first section. The second section includes a stack of cutter disks. Each cutter disk includes a front surface, a rear surface, an interior surface defining a central opening extending from the front surface to the rear surface, a forward cutting edge, and a rearward cutting edge. The interior surface forms a same number of lobes for the central opening as the set of radially inwardly extending lobes in the first section. Each cutter disk is aligned along a common centerline, and each cutter disk is rotated slightly relative to each other to form a second helically convoluted chamber with a same pitch as the first helically convoluted chamber. The second helically convoluted chamber exposes, to materials passing through, portions of the forward cutting edge or the rearward cutting edge of each cutter disk.

The invention relates to an eccentric screw pump, comprising at least one stator (1) composed of an elastic material and a rotor (2) that can be rotated in the stator (1), the stator (1) being surrounded by a stator casing (3) at least in some regions. The stator casing (3) consists of at least two casing segments (19) as a longitudinally divided casing and forms a stator clamping device, by means of which the stator (2) can be clamped against the rotor (1) in the radial direction. The pump is characterized in that the casing segments (19) have at least one clamping flange (20) having first clamping surfaces (21) at each end of the casing segments and that one or more clamping elements (22, 23), which can be displaced in the axial direction and have second clamping surfaces (24), are placed onto the clamping flange (20), the first clamping surfaces (21) and the second clamping surfaces (24) being designed in such a way and interacting in such a way that the stator casing (3) can be clamped against the stator in the radial direction in the course of an axial displacement of the clamping elements (22, 23).

A hybrid elastomer/metal on metal motor for a helical gear device includes a rotor and stator comprising a hydraulic motor that produces work when a working fluid is pumped therethrough. The improvement involves the stator being, for part of its length, a conventional or even wall stator, using an elastomer to form a seal against the moving rotor. The stator's remaining length comprises a profiled rigid surface that forms a seal directly with the moving rotor. This gives the motor the high efficiency of the elastomer sealing against the rotor, and simultaneously provides a backup of the stator's rigid section allowing continued motor operation at reduced efficiency, if the elastomer part failed in service. The invention also includes combinations of a regular disk stack with a rubber lining, a rigid material disk stack (or unitized element) and a circular rigid sleeve which react to rotor sideloading while permitting proper rotor orbiting.

A rotary internal combustion engine including a rotor assembly where at least a first and a second of the combustion chambers have unequal theoretical volumetric ratios. Also, a rotary internal combustion engine including first and second rotor assemblies where at least one of the combustion chambers of the first rotor assembly and at least one of the combustion chambers of the second rotor assembly have unequal effective volumetric compression ratios and/or unequal effective volumetric expansion ratios.

A rotary internal combustion engine including a rotor assembly where at least a first and a second of the combustion chambers have unequal theoretical volumetric ratios. Also, a rotary internal combustion engine including first and second rotor assemblies where at least one of the combustion chambers of the first rotor assembly and at least one of the combustion chambers of the second rotor assembly have unequal effective volumetric compression ratios and/or unequal effective volumetric expansion ratios.