A pump housing structure of a three-axis multi-stage Roots pump is provided, comprising a first-stage pump housing, a second-stage pump housing and a third-stage pump housing, wherein the first-stage pump housing is provided with a first center axial hole, a first left axial hole and a first right axial hole; a fixed bearing end cover is mounted on the side of the first-stage pump housing, three fixed bearing chambers are provided on the surface of the fixed bearing end cover; the second-stage pump housing is provided with a second center axial hole, a second left axial hole and a second right axial hole, the third-stage pump housing is provided with a third center axial hole, a third left axial hole and a third right axial hole, and the end surface at the outer side of the third-stage pump housing is fixedly mounted with a non-driving end bearing end cover. The present invention can accommodate and fix three axes through three fixed bearing chambers, respectively. Moreover, since the sum of the axial lengths of the second-stage pump housing and the third-stage pump housing is equal to the axial length of the first-stage pump housing, it not only can strengthen the center stiffness of the three axes of the Roots pump, but also can ensure that the total axial expansion is evenly divided, reducing the cumulated amount of thermal expansion at the end of the axis.

Oil pump and oil pump-integrated balancer device each have a pump housing formed by housing body 31 and cover member 32, pump shaft 33 having driven side helical gear 43 at which thrust force occurs when transmitting rotation force and rotating a rotor by the rotation force provided from drive side helical gear 13 that is engaged with driven side helical gear 43, first and second thrust receiving portions 47, 46 formed close to hole edges of bearing holes 32a, 31a of the cover member and the housing body, and first and second thrust limiting portions 49, 48 provided at the driven side helical gear and the pump shaft, contacting the thrust receiving portions from axis direction and limiting thrust movement of the pump shaft. With this configuration, oil pump and oil pump-integrated balancer device which are capable of securing stable support of the pump shaft are provided.

A driving structure of a three-axis multi-stage Roots pump comprises a pump body, wherein a gear end cover is mounted at one side of the pump body, an air outlet end moving bearing air sealing unit is mounted on the other side of the pump body, and the bearing end cover is mounted on the pump at the side of the pump body; a driving axis, a first driven axis and a second driven axis are further provided inside the pump body, and the driving axis is connected with the first driven axis and the second driven axis through the gear, respectively; and both ends of the driving axis, the first driven axis and the second driven axis are movably connected to an air inlet end gear mechanical seal driving unit and an air outlet end moving bearing air sealing unit, respectively. The present invention overcomes the deficiencies of the prior art, a fixed bearing limiting unit not only plays a radial supporting role, strengthens the rigidity of an independent axis, but also reduces the diameter of the axis, and at the same time, evenly distributes to the two axial ends in the axial deformation process, avoiding deformation in a single direction, reducing the amount of displacement by nearly half, and also improving the sealing efficiency of the system.

A pump technology that provides for more effective and efficient transfer of liquids, such as petroleum products and components, to and through pipelines. Such a technology can comprise a type of external gear pump that creates higher flow, resulting in higher pressures in the pipeline, to move the liquids, while providing for longer pump life, simpler and less maintenance, and fewer undesired conditions, with a smaller footprint, in a cost-effective system. Further, one or more portions of the pump can be configured to be easily replaceable to provide for maintenance in place, and provide for longer pump life. Additionally, one or more portions of the pump can be constructed with or coated with abrasive resistant material that extends the life of the external gear pump. Such material can also reduce the friction between surfaces and improve the life of the external gear pump under poor feeding conditions.

A rotor unit for an eccentric screw pump, comprising a drive shaft which is drivable by means of a drive element of the eccentric screw pump, a helical rotor, and a flex shaft connecting the drive shaft to the rotor, wherein the flex shaft is at least in part accommodated within in the drive shaft, and wherein between the flex shaft and the drive shaft a gap extending around the flex shaft is provided, which allows for a radial movement of the flex shaft within the drive shaft.

A rotary fluid transmission device contains: a rotor, a drive shaft, a first holder, and a second holder. The first holder includes a circular bush and an annular chamber. The rotor includes a C-shaped piston which has an external face and an internal face. In addition, the annular chamber has a first reservoir defined between the internal face and the circular bush, and the annular chamber has a second reservoir defined between the external face and the inner fringe. The circular seat includes two clamp arms, and a respective clamp arm is rotatably engaged with a blade. The blade includes two abutting faces, and the C-shaped piston has two edge faces. The first holder includes two first conduits and two second conduits, the two first conduits are in communication with the first reservoir, and the two second conduits are in communication with the second reservoir.

A vane pump has a pump flange, a cam ring, a pressure plate and at least one pin extending axially through the pump flange, the cam ring and the pressure plate, the pin being preloaded in an axial direction thereof by means of at least one spring element.

A sliding vane pump includes a fixed housing defining inlet and outlet ports and a sliding housing defining a cylindrical cavity and configured to slide within the fixed housing. The fixed housing and the sliding housing define a gap therebetween. A rotor is configured to rotate within the cylindrical cavity and has a plurality of vanes configured to seal against an inner circumferential wall of the cylindrical cavity to define a plurality of pumping chambers. A seal is located in the gap disposed between the fixed housing and the sliding housing to split the gap into first and second compensation chambers. The first chamber is fluidly connected to a first pumping chamber of the plurality of pumping chambers and the second chamber is connected to a second pumping chamber of the plurality of pumping chambers.

A cartridge vane pump includes: a side plate brought into contact with first end surfaces of the rotor and the cam ring; a cover brought into contact with second end surfaces of the rotor and the cam ring, the cover attached to the body; and an O-ring provided in an outer circumference of the side plate, the O-ring being configured to seal a gap between the outer circumference of the side plate and an inner circumference of the body. The side plate has: a first flange portion configured to restrict movement of the O-ring towards the rotor side; a second flange portion configured to restrict movement of the O-ring towards an opposite side from the rotor. The first flange portion is formed to be able to compress the O-ring with the body in an axial direction of the driving shaft.

A variable displacement rotary vane pump. The pump has a pump body, a rotor with vanes that rotates inside the pump body around a rotation axis, an oscillating stator arranged in an eccentric position around the rotor, a fulcrum for the rotation of the oscillating stator with respect to the pump body, and adjusting means for adjusting the displacement of the pump. The adjusting means act on the oscillating stator to move it with respect to the rotor and the pump body. The fulcrum is integrally formed with the oscillating stator and is housed in a recess formed in the pump body. The pump has a sliding element between the fulcrum and the recess. The sliding element is at least partially free to rotate within the recess.