A cam transmission mechanism includes a rotary disk, a camshaft, contact members and a housing. The rotary disk has a periphery formed with equidistant projections, any two adjacent ones of which define an accommodating recess. The camshaft includes a shaft rod and a cam body that has at least one groove communicated with some of the recesses of the rotary disk. The groove and the recesses cooperate to form a plurality of confining spaces, within which the contact members are accommodated freely rollably for rotation transfer from the camshaft to the rotary disk. The housing is connected to the rotary disk for confining the contact members in the confining spaces, respectively.

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 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 coaxial gear (1), includes an axially oriented tooth system (5) with respect to a rotational axis (3) of the coaxial gear (1), a tooth carrier (7) having axially oriented guideways (9), tooth pins (11) received within the guideways (9) for engaging with the tooth system (5), wherein the tooth pins (11) are axially oriented within the guideways (9) by their respective longitudinal axes and are mounted within the guideways (9) in an axially displaceable manner, and a cam disc (15) rotatable about the rotational axis (3) for axially driving the tooth pins (11), wherein a plurality of bearing segments (17) is disposed between the cam disc (15) and the tooth pins (11) for bearing the tooth pins (11), and wherein, on a side facing the tooth pins, the bearing segments (17) have an elevation at least in sections formed as a spherical cap for bearing the respective tooth pin (11).

A clutch assembly includes a shaft, a seal plate supported by the shaft, and a cap connect to the shaft. The shaft includes a first end and a second end axially spaced from each other. The cap is disposed at the second end. The cap includes a base covering the second end, and a wall extending from the base towards the first end. The wall is configured to axially constrain the seal plate.

A transmission, including an outer shell (1), an inner shell (2), a drive disk (3), a plurality of T-shaped teeth (4), a gear (5), a tooth seat (6), an adjustable nut (7), balls (8), inner balls (9), outer balls (10), an inner protective frame (11), an outer protective frame (12), rollers (13), a first sealing ring (14), a second sealing ring (15) and a third sealing ring (16). Transmission clearance can be adjusted freely at any time, the meshing of the T-shaped tooth and the gear is a real surface meshing, and almost all the teeth participate in force transmission simultaneously. Therefore, the transmission has high precision, high mechanical properties, and long service life.

A reduction gear has pins that extend across and contact a first swing body and a second swing body and are swung by the first swing body and the second swing body. A first radial direction groove forming body has radial direction grooves formed in the same number (Za) as the pins to allow the pins to slide in a radial direction. A second radial direction groove forming body has radial direction grooves formed in the same number as the pins to allow the other ends of the pins to slide in the radial direction. A wave shape depressed portion forming body has wave shape depressed portions contacting the pins formed along a circumferential direction (Zb). Then, the difference between Za and Zb is 1.

A reduction gear has pins that extend across and contact a first swing body and a second swing body and are swung by the first swing body and the second swing body. A first radial direction groove forming body has radial direction grooves formed in the same number (Za) as the pins to allow the pins to slide in a radial direction. A second radial direction groove forming body has radial direction grooves formed in the same number as the pins to allow the other ends of the pins to slide in the radial direction. A wave shape depressed portion forming body has wave shape depressed portions contacting the pins formed along a circumferential direction (Zb). Then, the difference between Za and Zb is 1.

A harmonic ring gear system can include at least one inner gear with external toothing, the at least one inner gear defining an axis of rotation; at least one outer gear with internal toothing arranged concentrically to the at least one inner gear about the axis of rotation, the internal toothing spaced apart from the external toothing; a pin ring positioned between the at least one inner gear and the at least one outer gear, the pin ring comprising a multiplicity of pins; and a rotary transmitter configured to lift a portion of the pins of the multiplicity of pins off the external toothing and press the portion of the pins into the internal toothing.

A harmonic ring gear system can include at least one inner gear with external toothing, the at least one inner gear defining an axis of rotation; at least one outer gear with internal toothing arranged concentrically to the at least one inner gear about the axis of rotation, the internal toothing spaced apart from the external toothing; a pin ring positioned between the at least one inner gear and the at least one outer gear, the pin ring comprising a multiplicity of pins; and a rotary transmitter configured to lift a portion of the pins of the multiplicity of pins off the external toothing and press the portion of the pins into the internal toothing.