An electric actuator assembly for controlling the output of a variable output drive device such as a hydraulic transaxle or pump having an output shaft connected to a swash plate for rotation thereof to control the output of the drive device. The output shaft is engaged to and driven by a control shaft of an electric actuator. The assembly includes a clamping coupler to connect and align the output shaft and the control shaft, thereby permitting use of the electric actuator with multiple drive device designs without the need to modify the control shaft of the drive device.

The shaft coupling structure includes: a male joint, and a female shaft that is coupled to male joint. The outer peripheral surface of the male joint has an outer peripheral side concave-convex portion having a concave-convex shape in the circumferential direction and an annular concave groove, and the inner peripheral surface of the female shaft has an inner peripheral side concave-convex portion having a concave-convex shape in the circumferential direction. The outer peripheral side concave-convex portion and the inner peripheral side concave-convex portion engage with a concave-convex engagement. The outer peripheral surface of the male joint and an end portion on one side of the female shaft in the axial direction are welded and fixed together, and an embossed portion provided on the inner peripheral surface of the female shaft is arranged on the inner side of the annular concave groove.

Embodiments of clamping hub are disclosed. In one embodiment, the clamping hub includes a non-circular aperture with a portion of the non-circular aperture being formed so as to be substantially flat. The clamping hub also includes a shaft securer aperture that is formed in a substantially flat wall that contributes to the substantially flat portion of the non-circular aperture.

A clamping connection includes a hollow shaft region, a shaft at least partially introduced into the hollow shaft region, a screw, and a clamping ring. The hollow shaft region has an axial slot radially extending through the hollow shaft region. The screw has a screw thread and a screw head, which is larger than the largest diameter of the screw thread. The hollow shaft region has a flattening, the screw rests at least partially against the flattening, and the screw is set apart from the shaft.

A universal joint assembly includes a yoke including a serration hole to receive an end portion of a steering column and a bolt-hole to receive a bolt which is used to restrict the steering column received in the serration hole, and a misassembly prevention member coupled to the yoke and elastically movable from a first position in which the bolt-hole is at least partially blocked to a second position in which the bolt-hole is opened, thereby preventing a misassembly of the steering column and improving safety and reliability of the universal joint assembly.

A flexible coupling for coupling a first shaft and a second shaft includes a first body and a second body. The first body includes a first end to be fixed to the first shaft, a second end to be fixed to the second shaft and a first tooth, fixed to the radially inner face. The second body is secured to the first body, and has a radially outer face and a second tooth fixed to the radially outer face. The first tooth and the second tooth come into contact when a torque is applied to the first end of the first body so as to transmit the torque to the second end of the first body by the intermediary of the second body.

An electric bicycle includes a frame assembly, wheels supporting the frame assembly, a motor assembly coupled to the frame assembly and having a motor output shaft, and a chainring assembly including a mounting portion clamped onto the motor output shaft.

A shaft coupling structure of the present invention includes a male joint and a female shaft that are coupled together. The outer peripheral surface of the male joint has an outer peripheral side concave-convex portion having a concave-convex shape in the circumferential direction and an annular concave groove, and the inner peripheral surface of the female shaft has an inner peripheral side concave-convex portion having a concave-convex shape in the circumferential direction. The outer peripheral side concave-convex portion and the inner peripheral side concave-convex portion engage with a concave-convex engagement. The outer peripheral surface of the male joint and an end portion on one side of the female shaft in the axial direction are welded and fixed together, and an embossed portion provided on the inner peripheral surface of the female shaft is arranged on the inner side of the annular concave groove.

A steering shaft assembly includes a first member having a first member inner surface and a first member outer surface. Each surface extending between a first member first end and a first member second end along an axis. A second member having a second member inner surface and a second member outer surface. Each surface extending between a second member first end and a second member second end along the axis. The first member first end arranged to be received within the second member such that the second member inner surface is disposed about a portion of the first member outer surface. Also included is a shaft extending from a third member. The shaft extending into the first member second end along the axis.

The torque transmission shaft includes: a shaft that is integrally formed and that has a yoke provided at one end portion in the axial direction and a female serration provided on the inner peripheral surface at the other end in the axial direction; and a clamp that is separate from the shaft and that is capable of reducing the diameter of the other end portion of the shaft in the axial direction; wherein the shaft and the clamp are fixed together.