An actuator includes an electric motor, an output shaft and a speed reducer. The speed reducer includes at least one metal gear which has a plurality of teeth made of metal. The speed reducer is configured to transmit rotation, which is outputted from the electric motor, to the output shaft after reducing a rotational speed of the rotation. The actuator includes a housing that receives the electric motor and the speed reducer. The actuator includes a plate member that is configured to limit scattering of a scattering object, which is generated in response to an operation of the speed reducer and is scattered from the at least one metal gear.

Transmission system for a vehicle having an input arranged for connection to a drive source, and an output arranged for connection to a load. The transmission includes a transmission. The transmission includes first input shaft, a first output shaft connected to the output, and a first speed transforming gear connecting the first input shaft and the first output shaft, and a second input shaft, a second output shaft connected to the output, and a second speed transforming gear connecting the second input shaft and the second output shaft. The transmission includes a first coupling member, arranged for coupling the input to the first input shaft at a first speed ratio and a second coupling member, arranged for coupling the input to the second input shaft at a second speed ratio. The first and second speed transforming gears together include a plurality of transmission gears, wherein the transmission gears are arranged such that successive shifting through respective first, second, third, fourth, fifth and sixth gears is effected by alternatingly engaging the first coupling member and the second coupling member.

A driving device includes a motor, a wave gear device including a wave generator having first thickness, a flex spline, and a circular spline having thickness larger than the first thickness, a housing functioning as a housing of the motor and including a flange, and an oil seal fixed to the inner side of the flange and extending along the outer circumference of the shaft. The wave generator is set closer to the opposite direction of the flange to configure an internal space with the members. When the internal space is filled with grease, a distance between the oil seal and the wave generator is set smaller than distances among the other members.

A driving device includes a motor, a wave gear device including a wave generator having first thickness, a flex spline, and a circular spline having thickness larger than the first thickness, a housing functioning as a housing of the motor and including a flange, and an oil seal fixed to the inner side of the flange and extending along the outer circumference of the shaft. The wave generator is set closer to the opposite direction of the flange to configure an internal space with the members. When the internal space is filled with grease, a distance between the oil seal and the wave generator is set smaller than distances among the other members.

According to one embodiment, a grease filling method for a ball screw device includes the steps of covering an outer periphery of a screw shaft protruding from one end portion of a nut with a covering member, supplying grease to a portion between a nut inner peripheral surface on one end portion side of the nut and the screw shaft, inserting the protruding screw shaft into a nut inner side while being covered with the covering member by relatively rotating the screw shaft and the nut, bringing a tip of the covering member in an insertion direction closer to an end portion of an infinite circulation path on the one end portion side of the nut, and sending the grease supplied to the nut inner side to a region of the infinite circulation path, pulling out the covering member together with the screw shaft from the one end portion of the nut by relatively rotating the screw shaft and the nut in an opposite direction, and taking out the covering member from the screw shaft.

A planetary gear device includes a bearing inner cylinder including an internal gear on the inner circumferential side, a bearing fitted on the outer circumference of the bearing inner cylinder, an output shaft outer cylinder fitted on the outer circumference of the bearing, and an output shaft end plate that fixedly supports the planetary carrier and transmits a rotation thereof to the output shaft outer cylinder. A wheel is fitted onto the outer circumference of the output shaft outer cylinder so as to prevent relative rotation. The bearing inner cylinder is fixed to a support frame. A drive motor is fixed coaxially with the planetary gear device on the side of the support frame opposite to the bearing inner cylinder, and a rotation shaft is coupled to the sun gear.

A reduction in the amount of filled grease and a reduction in weight are achieved, and an excessive rise in the internal pressure is suppressed. Provided is a gearbox including: a plurality of gears that are rotated by a motor; a housing that has a sealed interior space for rotatably accommodating the respective gears; and a spacer that is disposed in the interior space of the housing and that partially occupies the interior space, wherein the spacer has a lower density than grease and is elastically deformable so as to change the volume thereof according to the internal pressure of the interior space.

Transmission system for a vehicle having an input arranged for connection to a drive source, and an output arranged for connection to a load. The transmission includes a transmission. The transmission includes first input shaft, a first output shaft connected to the output, and a first speed transforming gear connecting the first input shaft and the first output shaft, and a second input shaft, a second output shaft connected to the output, and a second speed transforming gear connecting the second input shaft and the second output shaft. The transmission includes a first coupling member, arranged for coupling the input to the first input shaft at a first speed ratio and a second coupling member, arranged for coupling the input to the second input shaft at a second speed ratio. The first and second speed transforming gears together include a plurality of transmission gears, wherein the transmission gears are arranged such that successive shifting through respective first, second, third, fourth, fifth and sixth gears is effected by alternatingly engaging the first coupling member and the second coupling member.

A planetary gear device includes a bearing inner cylinder including an internal gear on the inner circumferential side, a bearing fitted on the outer circumference of the bearing inner cylinder, an output shaft outer cylinder fitted on the outer circumference of the bearing, and an output shaft end plate that fixedly supports the planetary carrier and transmits a rotation thereof to the output shaft outer cylinder. A wheel is fitted onto the outer circumference of the output shaft outer cylinder so as to prevent relative rotation. The bearing inner cylinder is fixed to a support frame. A drive motor is fixed coaxially with the planetary gear device on the side of the support frame opposite to the bearing inner cylinder, and a rotation shaft is coupled to the sun gear.

A fluid containing component is provided having a structure and a sump for storing a fluid. A gear baffle is disposed between the rotatable component and the structure. The gear baffle includes a first side end and a second side defining a gear cavity therebetween. The fluid displaced by rotation of a gear positioned within the gear baffle collects on inner surfaces of the gear baffle and is directed out of the gear baffle through at least one flow port of the baffle.