An exhaust gas recirculation pump for an internal combustion engine that includes an electric motor assembly having an electric motor disposed within an electric motor housing. A roots device is coupled to the electric motor. The roots device includes a housing defining an internal volume. Rotors are disposed in the internal volume and connected to the electric motor. A bearing plate is attached to the housing wherein the bearing plate and an outer cover attached to the bearing plate defines an oil cavity. A transmission assembly is positioned on an opposing side of the housing relative to the electric motor and in the oil cavity.

Provided are: a displacement expanding apparatus, which uses environmentally friendly electrical energy to generate rotational power; and an engine including the displacement expanding apparatus, the novel engine having improved performance and a long lifespan. Also, to realize a novel engine, provided is a novel engine which is environmentally friendly and has a long lifespan.

A transmission structure of motor connection of roots pump comprises a shaft sleeve, a motor shaft cavity is opened inside the shaft sleeve, and the inner circle of the motor shaft cavity is concentrically meshed with the excircle of the motor shaft; a fixed bolt mounting cavity is opened on the outer surface of the shaft sleeve, a bolt through-hole is opened in the fixed bolt mounting cavity, the shaft sleeve is fixedly connected with the gear seat through a hexagon bolt, and the gear seat and the shaft sleeve rotate synchronously at the same shaft center; a gear is fixedly connected with the gear seat with a bolt, the gear seat is fixed to the pump shaft through a first keyway under the fitting between the first keyway and a first shaft key, and the pump shaft and the motor shaft are coaxially arranged at the center. The utility model overcomes the disadvantages of the prior art, which is convenient to install without wearing parts, not affected by temperature, pressure and external dust; and the structure is simple with compound seal and oil protection function; and when a motor with a motor shaft is selected, only the diameter and keyway of the motor shaft cavity of the part are required to fit the new motor.

A scroll-type fluid machine includes a motor unit and a main body. The motor unit includes a rotor, a stator, a shaft provided with an eccentric portion at a distal end of the shaft and configured to rotate integrally with the rotor, a main bearing configured to support the shaft, and a motor cover configured to house the rotor and the stator. The main bearing is fixed to an inside of the motor cover by a fixing flange. The main bearing supports the shaft and is located between the fixing flange and an end bracket on an opposite side of the main body unit with respect to the fixing flange.

A rotary compressor is provided that may include a casing, a cylinder having an inner circumferential surface in an annular shape, a roller rotatably disposed in a compression space of the cylinder, a rotational shaft coupled to an inner circumference of the roller, main and sub bearings defining surfaces of the compression space, and a sub bearing cover coupled to the sub bearing to cover one end of the sub bearing and defining a discharge chamber with the sub bearing to communicate with the compression space so as to accommodate compressed refrigerant to be discharged. The sub bearing or the sub bearing cover may include a first barrier rib that protrudes from a surface thereof located inside of the discharge chamber. The first barrier rib may be spaced apart from a surface opposite to the surface within the discharge chamber by a predetermined distance.

A scroll fluid machine includes a main body and a motor unit. The main body unit configured to compress a fluid. The motor unit configured to drive the main body unit. The main body unit and the motor unit are connected via the eccentric portion. The main body casing and the motor cover are fastened with a fastening member. The motor unit includes a main bearing that is fixed to an inside of the motor cover by a flange. The main bearing is configured to support the shaft and is located between the flange and an end bracket on an opposite side of the main body unit with respect to the flange.

An all-metal conical combined screw pump suitable for petroleum field includes: a stator, a rotor (2), a sleeve (3) and a sucker rod (4), wherein the internal threaded curved surface and the external threaded curved surface are both tapered The spiral structure and the taper are the same, and the end of the inner threaded surface and the outer threaded surface with the larger radial size is adjacent to the sucker rod; the all-metal conical combined screw pump further comprises an elastic telescopic component, wherein the elastic telescopic component comprises a movable part, a fixed part and a elastic part, the movable part is fixedly connected to the rotor, the fixed part is fixedly connected to the sucker rod, the movable part and the fixed part are slidly fitted in the up and down directions and can be To transmit torque to the sucker rod and the rotor, one end of the elastic member abuts against the movable part or the rotor, and the other end abuts against the fixed part or the sucker rod, the elastic member can Elastic contraction or elastic expansion along the sliding direction of the movable part.

Technologies are generally described for clearance adjustments in twin-screw pump assemblies. A twin-screw pump assembly may include a conically shaped portion of a drive shaft enveloped by a bushing. For clearance adjustment, both clamping nuts of the drive shaft, which provide pretention to the bushing and secure an axial position of a threaded screw to the drive shaft, may be removed on the flow side of the pump assembly and the bushing loosened to adjust the angularity between bushing and drive shaft. The bushing may then be pushed over the conically shaped portion and both clamping nuts re-assembled. In some examples, a clamping nut of the driven shaft may be designed and used as removal/loosening tool for the drive shaft bushing.

A rotary, self-priming, positive displacement pump is described. The pump may include a pump housing including an inlet and an outlet, a pump chamber including an upper wall, a lateral wall, and a floor, first and second rotary impellers in the pump chamber, and a pair of gears each secured to the first and second rotary impellers, and a pressure relief feature operable to relieve pressure developing in a relatively high pressure zone of the pump chamber. The gears mesh with each other to ensure that the vanes do not contact one another during rotation. The pressure relief feature may comprise one or more channels formed in the pump housing and/or the first and second rotary impellers. The channels connect the high pressure zone with another zone to redistribute pressure. The channels may include one continuous channel or alternatively, a plurality of unconnected channels.

An automotive electrical oil pump includes an oil displacement pumping unit with a pump rotor which rotates in a pump chamber so as to pump a pressurized oil to an oil recipient, an electric driving motor which drives the pump rotor of the oil displacement pumping unit, an electrical connector plug which electrically connects the electric driving motor to a power source, and a fluid connector. The fluid connector includes a pump inlet which is fluidically connected to a chamber inlet, a pump outlet which is fluidically connected to a chamber outlet, a center front opening, and a ring front opening which is arranged coaxially to the center front opening. The center front opening and the ring front opening define the pump inlet and the pump outlet.