A device for converting a rotating motion into a reciprocating motion comprises a motor having a rotatable motor shaft carrying cylindrical component, an embedded cam groove of the cylindrical component, a rod component constrained to travel back and forth and forth, and a cam follower carried on the rod component. The cam follower is engaged in the embedded cam groove track of the cylindrical component so that as the rotatable motor shaft rotates, the cam follower transmits the movement dictated by the embedded cam groove track profile thereby causing the rod component to travel back and forth once for each rotation of rotatable motor shaft. There is also disclosed a mascara applicator assembly; a first electric toothbrush assembly; and a second electric toothbrush assembly comprising such a device.

A harmonic drive assembly and fluid-powered linear motors with both axial pistons are rotary piston arrangements incorporating the harmonic drive assembly are disclosed. The motors may be used in downhole drilling applications, but the drive assembly and/or motors may be used in other applications. The assembly, motors and methods use advanced harmonic drives, advanced helical drives, and combinations thereof with 1) motors with axial pistons and reciprocating linear rings to convert reciprocative axial motion to continuous rotary motion, and 2) motors with rotary pistons and reciprocating linear rings to rectify reciprocative rotary motion to continual rotary motion to improve performance over prior configurations. Axial pistons provide a robust simple solution for generating rotation; Rotational pistons provide increased torque generation as the torque generated is proportional to motor length. Since downhole drills are long, a high-torque motor can be produced using this method.

A transmission device configured to transpose a drive movement of a drive into a linear and rotating movement of a first tool part of a forming tool of a forming device, the transmission device including a shaft, including a shaft axis; a first interface; a second interface, wherein the first interface is configured to connect the shaft with the first tool part at least torque proof, and the second interface is configured to connect the shaft with the drive at least by axial fixing; and a housing supporting the shaft is rotatable about the shaft axis and displaceable on a linear path parallel to the shaft axis, wherein at least one radial recess is arranged at an outer radial circumferential surface of the shaft, and at least one radial protrusion cooperating with the at least one radial recess is arranged at least at one guide element of the housing.