A system for stopping rotation of a first gear and a second gear on a shaft, The first gear and second gear are concentric and rotatable about said shaft. The first gear and the second gear are driven by the same input system and the first gear and the second gear are configured to rotate at differential speeds and independently to each other. The first gear comprises a first end stop and the second gear comprises a second end stop and the first end stop and the second end stop are configured to engage each other when the first gear and the second gear have each rotated a predetermined number of turns. Engagement of the first end stop with the second end stop is configured to prevent rotation of the first gear and the second gear and cause a stall in the system.

Various embodiments of the teachings herein include an actuating drive comprising: a drive element; an actuation element; and a restoring spring. The drive element drives the actuation element indirectly about an actuation axis. The actuation element includes a shaft portion concentric to the actuation axis and extends at least partially circumferentially. The restoring spring includes a wound flat spring providing a restoring torque on the actuation element, acting tangentially on the shaft portion, and a free spring end tangentially fastened to the shaft portion. The free spring end is radially externally disposed with respect to the spring axis and fastened tangentially to the shaft portion. The spring is mounted rotatably so the spring axis is radially spaced apart from the actuation axis and aligned parallel to the actuation axis.

A vehicle steering apparatus includes a shaft member, a moving portion, a support member, and a stop portion. The moving portion includes a first abutting surface that faces the stop portion in a circumferential direction of the shaft member. The first abutting surface is inclined with respect to an axial direction of the shaft member to face a shaft support portion side when the moving portion is viewed in a radial direction of the shaft member. The stop portion includes a first abutted surface that abuts the first abutting surface.

A gear-skipping prevention mechanism including a first gear, a second gear, and a positioning member is provided. The first gear is sleeved on an axle. The second gear meshes with the first gear and has a first guiding groove. The positioning member includes at least one body and at least one engaging portion. Each of the at least one body has a sleeving hole. The sleeving hole is sleeved on the axle, and each of the at least one engaging portion is slidably disposed in the first guiding groove to limit a relative position between the first gear and the second gear.

A driving apparatus according to an embodiment includes an arm, an operation target, and a brake unit. The arm has one end supported by a support mechanism, and includes an electric driving source. The operation target is attached to the other end of the arm, the other end being an end on the opposite side of the one end, and is enabled to be pivoted by the driving source about one rotational axis intersecting with a direction from the one end to the other end. The brake unit secures immobility of a target gear that is a gear disposed in the arm, and that is a gear being rotated as the operation target is pivoted, when the power supply to the driving source stops.

A gearhead for a handheld power tool for machining workpieces, having a housing in which an output that can be connected to a drive of a handheld power tool is accommodated, and also having a tool shaft to which a tool can be coupled, wherein a braking device that can be moved between a braking position and a release position and that acts upon the tool shaft is provided for braking of the tool shaft. A switching device is provided that can be moved between a first switching position, in which the tool shaft is connected to the output in a power transmitting manner and in which the braking device is transferred into the release position, and a second switching position, in which the tool shaft is decoupled from the output and in which the braking device is transferred into the braking position.

A rotary actuator has a stop module configured to mechanically link two gear stages travelling at different rotational speeds when an end-of-stroke travel limit is reached, thereby causing the rotary actuator to bind because relative motion between the gear stages is impeded.

A stop module for non-jamming end-of-stroke stoppage of a rotary drive actuator includes timing gears to articulate a stopping pawl, and a low inertia, deformable stopping disk arranged to safely dissipate excess rotational kinetic energy of the rotary actuator. The stop module does not rely on friction to stop and dissipate the excess kinetic energy, but instead relies on predictable deformation of a metallic stopping disk which may be provided in a stopping cartridge of the stop module. Use of a deformable element to dissipate excess energy allows the disclosed stop module to be lighter and smaller than conventional end-of-stroke stopping mechanisms.

A rotary actuator has a stop module configured to mechanically link two gear stages travelling at different rotational speeds when an end-of-stroke travel limit is reached, thereby causing the rotary actuator to bind because relative motion between the gear stages is impeded.

A speed reducer including: a first gear; an eccentric shaft joined to the first gear, the eccentric shaft has first and second supporting portions offset in a rotation radial direction with respect to a first gear rotation shaft; a fixed gear at an eccentric shaft radial direction outer side, and whose rotation is restricted; a transmitting gear supported at the first supporting portion and meshes with the fixed gear, and the transmitting gear revolves around the first gear rotation shaft and rotates around its own axis; an outputting portion rotating due to the transmitting gear revolving and rotating around its own axis; and a locking gear supported at the second supporting portion and meshes with the fixed gear, and the locking gear revolves around the first gear rotation shaft and rotates around its own axis, and rotation of the outputting portion is restricted.