A plurality of shape memory alloy tubes (SMTs) of one or more shape memory alloy (SMA) types is configured as an element in a rotary actuator system in a nested manner. In various configurations, the nested SMTs provide one or more modes of multiplication (torque output or angular displacement), rotation reversibility and bias loading. The innovation provides for leveraging the modes for reductions in the rotary actuator system size, weight, or complexity or combinations thereof, or providing improved and more stable actuation capabilities in a given envelope.

A plurality of shape memory alloy tubes (SMTs) of one or more shape memory alloy (SMA) types is configured as an element in a rotary actuator system in a nested manner. In various configurations, the nested SMTs provide one or more modes of multiplication (torque output or angular displacement), rotation reversibility and bias loading. The innovation provides for leveraging the modes for reductions in the rotary actuator system size, weight, or complexity or combinations thereof, or providing improved and more stable actuation capabilities in a given envelope.

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 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 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 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 system and method for preventing back-drive in a braking system for a rotary actuator. The braking system comprises a housing and split cam design. A driving cam located within the housing is associated with an upstream side of the braking system. The driving cam is configured to rotate when a torque is applied to the upstream side. The braking system has a wedging cam and a plurality of cylindrical rollers. The wedging cam located within the housing and is associated with a downstream side of the braking system. The wedging cam is configured to react and prevent back-drive motion when torque is applied to the downstream side. The plurality of cylindrical rollers is positioned between the wedging cam and the housing. The plurality of cylindrical rollers is configured to wedge between a surface of the wedging cam and the housing when the torque is applied to the downstream side.

A phaser system is provided. The system includes a first gear connected to a first plate, and a second gear connected to a second plate. A phaser assembly includes at least one piston plate, and axial displacement of the at least one piston plate is configured to adjust a phase between the first gear and the second gear. A hydraulic fluid actuator assembly is also provided that includes a hydraulic fluid circuit including an advance chamber defined on a first side of the at least one piston plate and a retard chamber defined on a second side of the at least one piston plate. A valve selectively pressurizes the advance chamber or the retard chamber such that the at least one piston plate is axially displaced.