Abstract: The present invention relates to a drive device and a method of controlling the drive device. The drive device according to the invention includes a first member, a second member, an electric actuator, and a damper. The damper is configured to drive in an enabled mode and a disabled mode, the enabled mode enables a function of mitigating an impact load applied to either one of the first member and the second member, and the disabled mode disables the function of mitigating an impact load applied to either one of the first member and the second member.

Abstract: A drive transmission device according to one embodiment of the disclosure includes: an arm having a motor that generates a rotational force; a speed reducer that is provided in the arm and has a carrier for decelerating rotation of the motor and outputting the decelerated rotation; a bucket fixed to the carrier by a reamer bolt, the reamer bolt being inserted in a bracket through hole formed in the bucket; and a resin bush provided between an internal surface of the bracket through hole and an external lateral surface of the reamer bolt. The mechanical strength of the resin bush is lower than the mechanical strength of the bucket and the mechanical strength of the reamer bolt.

Abstract: A drive transmission device according to one embodiment of the disclosure includes: an arm having a motor that generates a rotational force; a speed reducer that is provided in the arm and has a carrier for decelerating rotation of the motor and outputting the decelerated rotation; a bucket fixed to the carrier by a reamer bolt, the reamer bolt being inserted in a bracket through hole formed in the bucket; and a resin bush provided between an internal surface of the bracket through hole and an external lateral surface of the reamer bolt. The mechanical strength of the resin bush is lower than the mechanical strength of the bucket and the mechanical strength of the reamer bolt.

Abstract: The hydraulic drive system includes a hydraulic pump, a plurality of variable displacement actuators, and a control unit. The hydraulic pump discharges a hydraulic fluid. The variable displacement actuators each receive a pressure of the hydraulic fluid discharged from the hydraulic pump to operate corresponding one of a plurality of drive parts. The control unit controls displacement varying parts of the variable displacement actuators. The control unit controls the displacement varying parts of the variable displacement actuators, based on sensed pressures in fluid inflow parts of the variable displacement actuators in operation, such that the pressures in the fluid inflow parts of the variable displacement actuators in operation approach a common target pressure.

Abstract: A hydraulic device includes: a first block having internal teeth; a second block configured to rotate relative to the first block; an oscillatory rotating body having external teeth smaller in number than the internal teeth, being provided inside the first block such that it is oscillatorily rotatable, and having an inner circumferential portion; a rotation restricting shaft extending from the inner circumferential portion of the oscillatory rotating body in a direction intersecting a radial direction and coupling the oscillatory rotating body and the second block such that they are not allowed to rotate relative to each other while allowing the oscillatory rotating body to oscillatorily rotate; a first friction plate configured to rotate together with the oscillatory rotating body; a second friction plate restricted from rotating by the second or first block; and a press mechanism configured to press the first and second friction plates against each other.

Abstract: A drive transmission device of the present disclosure includes a first member and a second member, a drive source, two bracket portions, a shaft portion, a reduction unit having an output portion, and a housing portion. The first member and the second member are coupled to each other so as to be rotatable about a rotation axis. The two bracket portions are provided on the second member and are spaced apart from and opposed to each other. The shaft portion is connected to the first member and positioned between the bracket portions. The output portion is attached to the shaft portion and attached to an opposed surface of a first bracket portion. The housing portion is coupled to the shaft portion so as to be rotatable about the rotation axis, the housing portion being attached to an opposed surface of a second bracket portion.

Abstract: The drive unit according to the present disclosure includes two fluid motors serving as drive sources for generating rotational forces, and a channel member having a supply channel for supplying a pressure fluid to the two fluid motors. Each of the two fluid motors includes: a casing having a supply port and a discharge port for the pressure fluid; a drive shaft rotatably supported to the casing; and a motive power generating unit provided in the casing and configured to rotate the drive shaft with the pressure fluid, the pressure fluid being supplied through the supply port and discharged through the discharge port. The two fluid motors are arranged such that the respective drive shafts are disposed parallel to each other and oriented toward opposite sides along rotation axes of the drive shafts. The supply channel supplies the pressure fluid to the supply ports of the two fluid motors.

Abstract: Provided is a speed reducer including: a first reduction unit disposed at an input stage of a multi-stage reduction unit that decelerates a rotational driving force of an electric motor from an input stage side toward an output stage side and transmits the decelerated rotational driving force to a rotational drive unit; a first ring gear meshed with first planetary gears provided in the first reduction unit; and a third reduction unit disposed at an output stage of the multi-stage reduction unit and having a first case. The first ring gear is provided in the first case of the third reduction unit.

Abstract: Provided is a speed reducer including: a first reduction unit disposed at an input stage of a multi-stage reduction unit that decelerates a rotational driving force of an electric motor from an input stage side toward an output stage side and transmits the decelerated rotational driving force to a rotational drive unit; a first ring gear meshed with first planetary gears provided in the first reduction unit; and a third reduction unit disposed at an output stage of the multi-stage reduction unit and having a first case. The first ring gear is provided in the first case of the third reduction unit.

Abstract: A drive transmission device according to one embodiment of the disclosure includes: an arm having a motor that generates a rotational force; a speed reducer that is provided in the arm and has a carrier for decelerating rotation of the motor and outputting the decelerated rotation; a bucket fixed to the carrier by a reamer bolt, the reamer bolt being inserted in a bracket through hole formed in the bucket; and a resin bush provided between an internal surface of the bracket through hole and an external lateral surface of the reamer bolt. The mechanical strength of the resin bush is lower than the mechanical strength of the bucket and the mechanical strength of the reamer bolt.

Abstract: A crawler drive unit relating to one aspect of the present disclosure includes a speed reduction mechanism provided in a running unit for causing a vehicle body to run, where the speed reduction mechanism is configured to transmit a driving force to a crawler provided on the running unit, a transmission mechanism for transmitting the driving force to the speed reduction mechanism, and an electric motor for applying a rotational force to the transmission mechanism. A motor shaft of the electric motor is positioned higher than a rotational axis of an input shaft of the speed reduction mechanism.

Abstract: A speed reducer according to one aspect of the present disclosure includes: speed reducing units for decelerating a rotational driving force of an electric motor and transmitting the decelerated rotational driving force to a rotational driving unit; and a ring gear meshing with a gear decelerated by a speed reducing unit on the electric motor side in a direction of a rotational axis of the electric motor. The ring gear is provided with a water-cooling channel that communicates cooling water. The water-cooling channel includes a first groove having a small depth and a second groove having a larger depth and extends in a C-shape as the ring gear is viewed from the direction of the rotational axis. The ring gear is provided with a motor flange mounted to the electric motor. The motor flange is provided with an inlet port and an outlet port connected to the water-cooling channel.

Abstract: A drive transmission device in one embodiment of the disclosure includes a pair of output shafts, a differential, a clutch (power transmission unit), and a control unit. The pair of output shafts connected to a pair of speed reducers that are disposed to face each other. The differential receives a driving force from a drive source and outputs the driving force to the pair of output shafts; The clutch acts on the differential and takes a first state in which a load imbalance between the pair of output shafts is adjusted or a second state in which the pair of output shafts are rotated directly by the driving force. The control unit switches the state of the clutch based on difference information regarding a difference in rotation between the pair of speed reducers.

Abstract: A drive transmission device according to one embodiment of the disclosure includes a single differential unit to which rotation of a motor is transmitted and two speed reducers each having an operation output shaft that is coupled to the differential unit and a carrier that changes a speed of the rotation of the operation output shaft and outputs the rotation. The two speed reducers are arranged such that they are opposed to each other along a second rotation axis, and the operation output shaft and the carrier in each speed reducer are aligned in the second rotation axis direction.

Abstract: A drive transmission device includes a first member and a second member rotatably coupled about a rotation axis; a drive source generating a rotational force that drives the first member and the second member; speed reducers transmitting the rotational force from the drive source to the second member; at least two bracket portions arranged in the rotation axis direction in the second member; and a flange portion extending in a direction intersecting the rotation axis, having an overlapping region where the flange portion overlaps the bracket portion viewed from a direction along the rotation axis direction, and connecting the speed reducer and the bracket portion. A restricting member that extends in the rotation axis direction and restricts the relative rotational movement between the bracket portion and the flange portion, and a receiving portion that receives the restricting member are provided in the overlapping region.

Abstract: On a near-bottom inner surface of a tilt piston cylinder hole, only a limited part that contacts an end of a tilt piston when the tilt piston is tilted by a pressing force from a swash plate is laser-hardened along the circumferential direction of the tilt piston cylinder hole (i.e., a hardened part is formed). In the tilt piston cylinder hole, parts other than a near-opening inner surface and the near-bottom inner surface are not laser-hardened.

Abstract: The present invention relates to an extended tooth contact harmonic drive gearing apparatus for transmitting rotary motion from an input drive to an output drive through mating contact between the gear teeth of a flexspline and a rigid circular spline, the flexspline being rotated into non-circular shape by a wave generator. The profile of the flexspline teeth are generated to cause the teeth of the flexspline to contact more than one tooth of the circular spline by forming a face profile on the flexspline teeth in accordance with a predetermined equation while the flank tooth profile of the circular spline is formed of a known arc segment, such as, a circle, ellipse or parabola.