A structure comprising a rotor body, the rotor body including a rotor shaft arranged on one end face of the rotor body, a sub-shaft cavity opened in the rotor shaft, and locating keyways symmetrically opened on both sides inside the sub-shaft cavity; a sub-shaft arranged on the other end face of the rotor body, and sub-shaft locating keyways symmetrically opened on both sides of the sub-shaft.

A method of operating an exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an EGR control unit lined to the EGR pump assembly; providing sensors linked to the EGR control unit; determining if a motor speed is within a predetermined target (step SI), wherein when the motor speed is within the predetermined target then; determining if a motor torque is within a predetermined target (step S2) wherein when the motor torque is within the predetermined target then; determining if a motor temperature is within a predetermined target (step S3) wherein when the motor temperature is within the predetermined target then; maintaining operation of the exhaust gas recirculation pump.

A method of operating an exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an EGR control unit lined to the EGR pump assembly; providing sensors linked to the EGR control unit; determining if a motor speed is within a predetermined target (step SI), wherein when the motor speed is within the predetermined target then; determining if a motor torque is within a predetermined target (step S2) wherein when the motor torque is within the predetermined target then; determining if a motor temperature is within a predetermined target (step S3) wherein when the motor temperature is within the predetermined target then; maintaining operation of the exhaust gas recirculation pump.

In a gear pump, a gear chamber is defined in a housing hole of a housing. A pair of gears is housed in the gear chamber. The gears are rotatably supported at support holes of a pair of side plates via support shafts. As viewed in an axial direction of the support shafts during rotation of the gears, addendum circles of the gears displaced under a differential pressure between a low-pressure chamber and a high-pressure chamber form first contact points with respect to an inner peripheral surface that defines a housing hole. As viewed in the axial direction of the support shafts during rotation of the gears, the first contact points are covered with the side plates displaced under the differential pressure.

In a gear pump, a gear chamber is defined in a housing hole of a housing. A pair of gears is housed in the gear chamber. The gears are rotatably supported at support holes of a pair of side plates via support shafts. As viewed in an axial direction of the support shafts during rotation of the gears, addendum circles of the gears displaced under a differential pressure between a low-pressure chamber and a high-pressure chamber form first contact points with respect to an inner peripheral surface that defines a housing hole. As viewed in the axial direction of the support shafts during rotation of the gears, the first contact points are covered with the side plates displaced under the differential pressure.

Disclosed herein are embodiments of magnetically controlled valve and pump systems that can be used to control and facilitate fluid flow in fluidic devices. Various types of magnetically controlled valves and pumps are described as well as methods of magnetically-controlling such valves and pumps.

Disclosed herein are embodiments of magnetically controlled valve and pump systems that can be used to control and facilitate fluid flow in fluidic devices. Various types of magnetically controlled valves and pumps are described as well as methods of magnetically-controlling such valves and pumps.

A journal bearing assembly includes a first journal bearing disposed about a longitudinal end of a gear shaft and spaced a first distance from a first axial gear face. A first fluid film location and a first hybrid pad location are annularly between an inner surface of the first journal bearing and an outer surface of the gear shaft. The first hybrid pad location circumferentially adjacent to the first fluid film location has a minimum leading edge angular location of at least about 31.0° measured relative to a first bearing flat. A first porting path provides high pressure fluid communication from a location outside the first journal bearing to the first fluid film location at or adjacent to the first hybrid pad location.

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.

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.