A rotary compressor includes a cylinder 30, an eccentric portion 31a of a shaft 31 disposed in the cylinder 30, and a piston 32 which is fitted into the eccentric portion 31a. A columnar groove 32a is formed in the piston 32, and angle of an arc of the groove 32a is greater than 180°. The rotary compressor further includes a piston 32 inserted into a slot formed in the cylinder 30, a slot 30b formed in the cylinder 30, and the groove 32a formed in the piston 32, and a columnar portion 33a having a columnar portion 33a on its one end. A compression chamber 39 is formed between the cylinder 30 and the piston 32, the columnar portion 33a is swingably fitted into the groove 32a, and the vane 33 reciprocates in the slot 30b as the shaft 31 rotates. The compression chamber 39 is divided into a high pressure-side space 39b and a low pressure-side space 39a by the vane 33. The groove 32a formed in the piston 32 is formed into a columnar shape, the groove 32a has the arc and an angle of the arc is greater than 180°. A fictitious extension La of the arc is located inside of the outer periphery fictitious line Lb of the piston 32. Gas and oil are less prone to leak from the high pressure-side space 39b to the low pressure-side space 39a of the compression chamber 39.

A roots type fluid machine includes suction and discharge ports, rotary shafts and rotors. A pair of the rotors respectively has a number n of lobe and valley portions with apex and bottom ends for engaging each other. The lobe portions are located on imaginary lines extending radially from an axis of the rotary shaft. The outer surface of the rotor is defined by an outline of the rotor including an arc and involute and envelope curves being rotated and moved in the direction of the axis. The arc has a radius R and a center located on the imaginary line. The involute curve is formed by an imaginary base circle having a radius r and a center located at the axis. The envelope curve is formed by an arc having a radius R. The number n is four or more. A torsional ange β is over 360 / n degrees.

Intended is to provide a fluid machine that can prevent wear of a rotation preventing pin. The fluid machine includes a housing 2, a fixed scroll fixed with respect to the housing 2, a turning scroll 4 that revolves around the fixed scroll, and a rotation preventing mechanism 7 that prevents the rotation of the turning scroll 4. The rotation preventing mechanism 7 includes a rotation preventing pin 71 projected from a wall surface at the housing 2 side or the turning scroll 4 side, and a restraining member 72 that restricts the position of the rotation preventing pin 71 by engaging with the rotation preventing pin 71. A projecting side end of the rotation preventing pin 71 has a taper shape, and the end of the taper shape has an R-shape.

A vane compressor comprising: a compression member whose upper surface (one surface) crossing an axial direction of a rotary shaft is inclined continuously between a top dead center and a bottom dead center and which is disposed in a cylinder to be rotated by the rotary shaft and which compresses a fluid sucked from a suction port to discharge the fluid via a discharge port; and a vane which is disposed between the suction port and the discharge port to abut on the upper surface (one surface) of the compression member and which partitions a compression space in the cylinder into a low pressure chamber and a high pressure chamber, and the upper surface of the compression member comprises: a flat surface constituted in a predetermined region centering on an intermediate point between the top dead center and the bottom dead center; and curved surfaces gradually approaching the top dead center and the bottom dead center continuously from the flat surface.

The present invention provides a rotary engine including a housing having therein N rob accommodating portions (N is a natural number equal to or greater than 3), and combustion chambers communicating with the rob accommodating portions, respectively, a rotor having N-1 robs eccentrically rotating centering on a center of the rob accommodating portions, and consecutively accommodated in the respective rob accommodating portions during the eccentric rotation, and combustion controllers provided at both sides of each combustion chamber, and configured to limit a combustion range of mixed gas, whereby an excessive emission of unburned gas caused in an existing rotary engine can be overcome, efficiency of the engine can be improved, and a rotary engine with an optimized design condition can be provided.

A rotary compressor 1 comprises a cylindrical housing 8, a cylindrical roller 10 accommodated in the housing 8, a motor shaft 13 leading through the roller 10 having a cam 14 for rolling the roller 10 along a side wall 15 of the housing 8, and a discharge port 18 leading through a bottom cover 12, wherein a height-to-radius ratio hr/rr of the roller 10 is between 1.6 and 1.2, a radius rs of the motor shaft 13 is 8.0 mm or less, a cam height hc of 14 mm or less, an area Q of the discharge port 18 of 17 mm² or more, and a thickness d of the discharge port 18 of 2.5 mm or less. For operation of the compressor 1, a top cover 19 may be put onto the top open side of the housing 8. The top cover 19 may have a bushing for the shaft 13. A heat pump P comprises the compressor 1. A household appliance H, in particular laundry care apparatus H, comprises the heat pump P.

Provided is a uniaxial eccentric screw pump which can prevent the life of a bearing sliding portion from decreasing due to a thrust load applied from a high pressure side a low pressure side. In the uniaxial eccentric screw pump 1, an external thread-like motor 2 directly coupled with a driving shaft 3 is rotated and eccentrically moved with respect to the axis of a stator 4, to deliver a fluid from a intake side to a discharge side. Further, the uniaxial eccentric screw pump 1 is provided at an end of the discharge side of the motor 4 and extends toward the discharge side in the axial direction of the stator. The uniaxial eccentric screw pump 1 includes an annular small-diameter portion 4p and a seal member 16. The external diameter of the annular small-diameter portion is smaller than the external diameter ϕB of a intake-side bearing slidingly contacting portion 4s, and the seal internal diameter pressure-receiving area of the annular small-diameter portion is larger than the area of an opening 4m of the stator 4. The seal member 16 is in a sliding contact with the outer surface of the small-diameter portion 4p, and seals the end of a sliding portion between a self-lubricating bearing 5on the discharge side and the stator 4.

A vane compressor comprising: a compression member whose upper surface (one surface) crossing an axial direction of a rotary shaft is inclined continuously between a top dead center and a bottom dead center and which is disposed in a cylinder to be rotated by the rotary shaft and which compresses a fluid sucked from a suction port to discharge the fluid via a discharge port; and a vane which is disposed between the suction port and the discharge port to abut on the upper surface (one surface) of the compression member and which partitions a compression space in the cylinder into a low pressure chamber and a high pressure chamber, and the upper surface of the compression member comprises: a flat surface constituted in a predetermined region centering on an intermediate point between the top dead center and the bottom dead center; and curved surfaces gradually approaching the top dead center and the bottom dead center continuously from the flat surface.