A motor includes a shaft rotatable about an axis, an engaged component engaged by the shaft, a sleeve fixed to the shaft to rotate therewith, and a seal at least partly circumscribing the shaft. The shaft includes an engagement region presenting a substantially variable outer shaft surface that at least in part engages the engaged component. The sleeve includes a first section that at least partly circumscribes and engages the engagement region of the shaft. The first section of the sleeve presents an outer seal-engaging surface and an outer bearing-engaging surface. The seal and the bearing each at least partly circumscribe the engagement region of the shaft and the first section of the sleeve to engage the seal-engaging surface and the bearing-engaging surfaces, respectively, of the sleeve.

This oil pump includes a first volume-changing part provided between an inner rotor and an outer rotor and a second volume-changing part provided in the outer rotor. A plurality of outer rotor pieces, which is annularly connected to each other, of the outer rotor is circumferentially arranged in a state where a first engaging part and a second engaging part of the outer rotor pieces being adjacent to each other engage with each other such that a distance therebetween in a circumferential direction is variable.

A screw rotor device includes a first rotor having a plurality of helical lobes about its periphery, a second rotor having a plurality of helical flutes about its periphery and a housing with a high pressure port and a low pressure port. The first and second rotors are rotatably mounted within the housing such that the lobes intermesh with the flutes for conveying, in use, a fluid between the high pressure port and the low pressure port. At least one of the rotors has a helical profile that changes along its length such that a gap is described between intermeshing lobes and flutes adjacent the high pressure port which is larger than a gap described between intermeshing lobes and flutes adjacent the low pressure port. The screw rotor device may be used for conveying a fluid.

A pair of co-operating screw rotors including a male rotor and a female rotor. The male rotor and the female rotor have helically extending lobes and intermediate grooves configured to intermesh with one another. Each groove of the female rotor has a first flank including at least three concave sections. A first section includes or is disposed immediately adjacent the radially innermost point of the groove. A second section is shaped as a circular arc with a radius having its center located outside the pitch circle. A third section is shaped as a circular arc with a radius having its center located outside the pitch circle. The radius of the third section is greater than the radius of the second section, which is greater than the radial distance between a pitch circle of the female rotor and the radially innermost point of the groove.

A gearmotor assembly includes a housing, a rotatable shaft, a bearing, a retaining member, and a seal. The housing defines a gear chamber configured to contain a lubricant. The bearing rotatably supports the shaft. The bearing is disposed between the housing and the shaft. The retaining member at least in part restricts axial shifting of the bearing. The retaining member presents a plurality of retaining member threads. The housing defines a plurality of housing threads threadably engaging the retaining member threads. The retaining member and the housing cooperatively at least in part define an interface. The interface includes a threaded portion and an additional portion. The threaded portion is cooperatively defined by the retaining member threads and the housing threads. The additional portion is fluidly interconnected to the threaded portion. The seal is disposed along the interface to prevent lubricant escaping the gear chamber past the interface.

A gear pump includes a housing, at least one gear set and a plurality of end plates. The gear set may be positioned between the end plates so that side surfaces of the gears face corresponding side surfaces of the end plates. The side surfaces of the end plates may have a plurality of spiral grooves positioned directly adjacent the side surface of the gears. The plurality of spiral grooves may have a logarithmic shape. Thus arranged, when the gears rotate, fluid in the pump is forced along the lengths of the spiral grooves, creating a local high pressure region that forces fluid between the side surfaces of the gears and the end plates, minimizing or eliminating contact therebetween. In some embodiments the plurality of spiral grooves may be positioned on bearing surfaces of the pump instead of end plates.

A rotary internal combustion engine having a cover plate, and stator plate having a bore with teeth and a primary cog that is larger than the teeth. A main rotor having a partially-circular cut-out. A gear rotor is disposed within the cut-out, having teeth that engage the teeth of the stator ring. A base plate has inlet ports for receiving fuel, air, and spark, where an ignition of the fuel and air by the spark creates a high pressure zone that drives the main rotor and the gear rotor rotationally within the stator ring, and an outlet port for exhausting spent fuel and air.

A gear wheel (10) for a hydraulic apparatus is rotatable about an axis of rotation (H-H) and comprises a plurality of teeth (11) having a sectional profile (P) and being adapted to mesh with respective teeth of another gear wheel during a rotational motion about the axis of rotation (H-H), wherein at least one tooth (11) is shaped so as to have at least one cutting edge (12) configured to remove material, in particular chips, from a body which is contacted by the cutting edge during the rotation of the gear wheel (10), wherein the cutting edge (12) is defined by at least one groove (14) which is lowered by amount from 0.2% to 5% of the height (H) of the tooth (11), said the groove (14) decreasing away from the cutting edge (12) along the profile (P).

A motor includes a housing, a shaft, a bearing, a bearing plate, and a seal. The housing includes first and second housing components directly engaging one another along a housing interface. The housing at least in part defines a sealed chamber. The shaft is at least in part received in the chamber. The bearing rotatably supports the shaft. The bearing plate is enclosed within the housing. The bearing plate supports the bearing within the housing. The seal is disposed along the housing interface. The bearing plate is spaced inwardly from the housing interface and the seal.

A motor includes a housing, a shaft, a bearing, a bearing plate, and a seal. The housing includes first and second housing components directly engaging one another along a housing interface. The housing at least in part defines a sealed chamber. The shaft is at least in part received in the chamber. The bearing rotatably supports the shaft. The bearing plate defines a bearing housing at least substantially receiving the bearing. The housing circumscribes the bearing plate such that the bearing plate is enclosed within the housing. The bearing plate is fixed to a supporting one of the housing components and directly engages the supporting one of the housing components along a bearing plate interface. The seal is disposed along at least one of the interfaces.