The scroll compressor comprises a fixed scroll having a fixed end plate and a fixed spiral wrap extending from the fixed end plate; an orbiting scroll (9) having an orbiting end plate and an orbiting spiral wrap extending from the orbiting end plate, the fixed spiral wrap and the orbiting spiral wrap meshing with each other to form compression chambers; a vertical drive shaft (19) having a crankpin (21) at an upper end portion of the vertical drive shaft (19), the crankpin (21) including an outer circumferential surface (23) cooperating with an orbiting scroll bearing (24). The crankpin (21) includes a recess (25) formed in an axial end face (26) of the crankpin (21), the recess (25) and an upper portion (27) of the outer circumferential surface (23) defining therebetween a circumferential wall (28) extending along at least a part of the circumference of the crankpin (21), the circumferential wall (28) being deformable in a radial direction during operation of the scroll compressor.

The oil-free screw compressor includes: a screw rotor including a screw and a shaft; a bearing; a first shaft seal device disposed between the screw and the bearing, the first shaft seal device including: a first seal and a first communication section; a second shaft seal device disposed between the first shaft seal device and the bearing, the second shaft seal device including: a second seal and a second communication section; and a first seal member including a seal between the first communication section and the second communication section. The casing includes an atmosphere communication section configured to communicate the first communication section and the second communication section with an atmosphere. A sectional area in the first communication section is larger than a sectional area between the seal of the first seal member and the shaft.

According to one embodiment, a rotary shaft of a rotary compressor includes a first connection shaft and a second connection shaft. The first connection shaft has a cross-sectional shape including a first outer surface, a second outer surface, and a third outer surface. L1 represents a distance from an intersecting point located on one end side where the first outer surface and the second outer surface intersect each other to the rotation center, L2 represents a distance from an intersecting point located on an other end side where the first outer surface and the second outer surface intersect each other, to the rotation center, and L3 represents a distance from the third outer surface to the rotation center, a relationship of L1>L3L2 is satisfied.

Provided is a co-rotating scroll compressor comprising a synchronous drive mechanism that can achieve a long life. The compressor comprises a driving side scroll member (90) driven to rotate about a driving side rotation axis CL1, a driven side scroll member (70) driven to rotate about a driven side rotation axis CL2, a hollowed drive shaft (6) that is connected to the driving side scroll member (90), and driven by a motor (5) to rotate, and a driven shaft (20) that is disposed inside the drive shaft (6), and has one end connected to the drive shaft (6) via a first flexible coupling (21) and the other end connected to the driven side scroll member (70) via a second flexible coupling (22).

The disclosure herein relates to device, for example a gear pump, for pumping fluid. The gear pump comprises a motor for driving a rotatable drive shaft; a drive gear configured to be driven by the drive shaft; an idler gear which meshes with the drive gear; an annular magnet disposed coaxially with the drive shaft and configured to rotate therewith; and a sensor for sensing rotation of the annular magnet and generating an output signal corresponding to a rotational position of the drive shaft.

A pump body assembly, a compressor and an air conditioner. The pump body assembly includes: an upper flange. The upper flange includes a disc portion and a neck portion extending upward from the disc portion, an outer peripheral surface of the disc portion is connected with a housing of the compressor, a height a1 of the disc portion and a distance b1 between an upper end surface of the neck portion and a lower end surface of the disc portion satisfy: 0.3a1/b10.4, and the height a1 of the disc portion and a diameter d1 of the disc portion satisfy: 0.1a1/d10.2.

A scroll compressor includes a casing, a drive motor arranged in an inner space of the casing, a rotary shaft coupled to the drive motor to rotate, a main frame arranged under the drive motor, a fixed scroll arranged under the main frame, an orbiting scroll engaging with the orbiting scroll to make an orbiting motion, the rotary shaft being inserted into and eccentrically coupled to the orbiting scroll, a first bearing positioned between the main frame and the rotary shaft, and a second bearing positioned between the fixed scroll and the rotary shaft, where a gap between the first and second bearings and the rotary shaft varies with a vertical position. The scroll compressor may prevent the eccentric effect occurring during rotation from deteriorating performance of the bearings, thereby preventing compression performance from being lowered.

Some embodiments are directed to a positive displacement pump having an eccentric piston, comprising a tube having a first end and a second end that is terminated by a cylinder secured to a delivery zone, the tube including an intake opening and a delivery opening, a drive shaft extending between the transmission zone and the tube, a piston arranged in the delivery zone and mounted in a sliding manner at the end of the shaft, being pressed against the cylinder by an elastic presser so as to prevent fluid displacement between the tube and the delivery zone when the pump is dry, and the elastic presser is provided to press the piston against the cylinder when the pump is running under load.

The present disclosure provides a compressor and an air conditioner having the same. The compressor includes: a main shaft with a convex portion and a slip sheet; a cylinder; and an air inlet and outlet device including a disk body and an air suction port including an outer side, an inner side and a connecting side located between the outer side and the inner side, wherein the outer side is overlapped with an inner wall of the cylinder or is located on the inner side of the inner wall of the cylinder, the inner side is overlapped with an outer wall of the convex portion or is located on the outer side of the convex portion, and the connecting side is overlapped with a side wall of the slip sheet or is located on the inner side of the side wall of the slip sheet.

An internal combustion engine having at least one crankcase for defining a guide housing in which at least one crankshaft is guided in rotation about an axis of rotation and lubricated by a lubricating fluid, the at least one crankcase being of the dry-sump type. Such an internal combustion engine has at least two pumps forming a pump train of pumps on a common axis, the pump train being fitted in a cylindrical bore of the at least one crankcase.