A device for testing a needle roller bearing of a planet gear set consists of two identical helical planet gear sets, a piston, an end cover, a spindle, and can simulate the actual operating condition of a needle roller bearing of the planet gear set; the rotating speed difference between an inner raceway and an outer raceway of the needle roller bearing is determined by adjusting the rotating speed of a sun gear and a planet carrier; the load on the needle roller bearing includes a centrifugal load and a radial load, and the centrifugal acceleration and the centrifugal load are determined by adjusting the rotating speed of the planet carrier; a method of determining the radial load by adjusting the hydraulic pressure difference of hydraulic chambers at both ends of the piston, generating a tangential force to load the planet gear, and balancing the radial load of the bearing.

A hollow reducer for high precision control includes a pin wheel housing and two-stage reduction components disposed in the pin wheel housing. A first-stage reduction component includes a driving wheel on a servo motor, a dual gear, and a planet wheel; and a second-stage reduction component includes 2-3 eccentric shafts distributed uniformly, cycloidal gears, a pin, rigid disks, and bearings, wherein two eccentric sections of the eccentric shaft support the cycloidal gears by means of the bearings, shaft extensions on two sides of the eccentric section of the eccentric shaft are supported on the left and right rigid disks by the bearings, and the rigid disks are supported on two sides of the pin wheel housing by the bearings.

The present disclosure relates to gearboxes for aircraft gas turbine engines, in particular to arrangements for journal bearings such gearboxes, and to related methods of operating such gearboxes and gas turbine engines. Example embodiments include a gearbox for an aircraft gas turbine engine, the gearbox comprising: a sun gear; a plurality of planet gears surrounding and engaged with the sun gear; and a ring gear surrounding and engaged with the plurality of planet gears, each of the plurality of planet gears being rotatably mounted around a pin of a planet gear carrier with a journal bearing having an internal sliding surface on the planet gear and an external sliding surface on the pin.

Methods and systems for an electric drive axle of a vehicle are provided. An electric drive axle system includes, in one example, a gear train configured to rotationally attach to an electric motor-generator. The gear train includes an output shaft rotationally coupled to a first planetary gear assembly axially offset from an input shaft rotationally coupled to the electric motor-generator, the first planetary gear assembly configured to removably couple to a differential arranged co-axial with an axle.

A planetary gear apparatus for a power transmission apparatus including a transmission housing includes a sun gear provided on a first shaft, first and second planet carriers rotatably supporting pinion gears gear-engaged with the sun gear, and a ring gear gear-engaged with the pinion gears, where an internal circumference of the sun gear is spline-engaged with an external circumference of the first shaft, where first and second support shafts are fixed to first and second side surfaces of the ring gear, respectively, where the first support shaft is rotatably supported by a supporting frame fixed to the transmission housing, interposing a first bearing, where the second support shaft is rotatably supported by the transmission housing, interposing a second bearing, where the first planet carrier is rotatably supported by the first support shaft interposing a third bearing, and where the second planet carrier is fixedly connected to a connection end portion of a second shaft.

A gearbox comprises a differential gear train. The differential gear train comprises a ring gear assembly, a sun gear assembly, and a planetary carrier assembly connected to a planetary gear mechanism. The planetary carrier assembly comprises side plates. The side plates combine with gears to form high-pressure volume units and low-pressure volume units, and a throttle channel is connected between two volume units. The high-pressure volume unit is constructed in a meshing zone of the gears. All high-pressure volume units are connected and communicated with each other by means of a high-pressure oil channel on the planetary carrier assembly. The gearbox can reduce the volume of the high-pressure volume unit, simplify the structure and process, and improve the transmission efficiency and reliability

A bending meshing type gear device includes a wave generator; an external gear that is disposed on an outer periphery of the wave generator, and is bendably deformed as the wave generator rotates; a first internal gear meshing with the external gear; a second internal gear that is disposed on one side in an axial direction of the first internal gear to mesh with the external gear; and a wave generator bearing that is disposed between the external gear and the wave generator in a state where movement in the axial direction of the wave generator bearing is restricted. The external gear includes a protrusion on an inner periphery of the external gear. The protrusion engages with the wave generator bearing to restrict movement in the axial direction of the external gear.

A mechanical reduction gear for turbomachine, in particular for aircraft. The reduction gear includes a sun gear having an axis of rotation, a ring gear which extends around the sun gear, planet gears which are meshed with the sun gear and the ring gear and which each includes a first toothing and a second toothing each including two series of teeth located on either side of a median plane, each of the planet gears being centred and guided in rotation by bearings, including an upstream bearing interposed axially between the series of upstream teeth of the second toothing and the plane, and a downstream bearing interposed axially between the series of downstream teeth of the second toothing and the plane.

A coupling structure includes a shaft, a tube, and a connection assembly. An end of the shaft is formed with a plurality of axial insertion troughs extended in an axial direction and arranged in an alternate manner. The tube includes a penetration-axle hole formed in a center thereof and corresponding to the penetration-axle section of the shaft. A plurality of radial insertion troughs, in the form of a recessed surface, are formed in an inner circumferential surface of the penetration-axle hole of the tube. The connection assembly includes a coupling block that has an outer circumference formed with a plurality of radial insertion blocks corresponding to the radial insertion troughs of the tube and a plurality of axial insertion blocks corresponding to the axial insertion troughs of the shaft, so that a fastening member may be used to selectively fasten the coupling block between the shaft and the tube.

A floating spacer assembly for a gear mounted on a shaft, such as a planet gear mounted to a planet carrier, is disclosed. The gear may be mounted on the shaft with a pair of roller bearings with inner races and bearing rollers, and a gear bore having a gear groove defined therein functioning as the outer races of the roller bearings. The floating spacer assembly may include an annular spacer ring having one or more sector slots circumferentially spaced around the spacer ring, and a spacer sector disposed within each of the sector slots and extending radially outward from the spacer ring and into the gear groove when the floating spacer assembly is installed between the roller bearings. The spacer sectors may engage surfaces of the gear groove and the spacer ring may engage the bearing rollers to limit axial movement of the gear relative to the shaft.