Device and method for enabling independent tuning of frequency and amplitude of a reverse crankshaft motor. The reverse crankshaft motor provides periodic reciprocating motion based on periodic rotational motion from a rotational motor. The reverse crankshaft motor includes a crankshaft structure having first and second frames with a third axle arranged between them and connected to them by hinges. An amplituder is affixed to the third axle and may communicate with an external device. As the first and second frames move toward or apart from each other, the third axle moves radially toward or away from a central axis of the crankshaft structure. The position of the third axle determines the amplitude of the periodic reciprocating motion of the amplituder. By adjusting the position of the first and second frames, the operator may adjust the amplitude independently from the frequency of the periodic rotational motion supplied by the rotational motor.

A valve unit includes a positioning device for converting a rotary motion into a linear motion, a valve rod, a drive unit, a drive shaft with an eccentric arranged thereon, a coupling element comprising a slot, and an output shaft arranged at the eccentric which moves in the slot of the coupling element. The valve rod is connected with the coupling element. The valve rod is linearly movable with the coupling element between an initial position where the valve is closed and an end position. The slot comprises a guide path which cooperates with the eccentric having an angle with a plane perpendicular to a direction of movement of the adjusting element. The initial position of the eccentric is a position which is located before a dead center existing for an axial movement of the output shaft. The dead center is passed during a rotational movement of the drive shaft.

A reciprocating tool includes a motor, a crank, a connecting rod, a rod, a tool bit, and a counter weight. The tool bit is mounted such that the action portion is positioned on a side opposite to a side with the rod central axis or the extended line of the rod central axis viewing from the rotational center of the crank. The first eccentric shaft and the second eccentric shaft are disposed such that at a position where the first eccentric shaft causes the rod to reach top dead center (TDC), the second eccentric shaft causes the counter weight to reach bottom dead center (BDC) or a point before the BDC, and at a position where the first eccentric shaft causes the rod to reach the BDC, the second eccentric shaft causes the counter weight to reach a point before the TDC.

A reciprocating piston mechanism comprises a crankcase and a crankshaft. The crankshaft is supported by the crankcase and rotatable with respect thereto about a crankshaft axis. The mechanism further comprises at least a connecting rod including a big end and a small end, a piston which is rotatably connected to the small end, and a crank member which is rotatably mounted on the crankpin. The crank member comprises at least a bearing portion and has an outer circumferential wall which bears the big end of the rod such that the rod is rotatably mounted on the bearing portion of the crank member via the big end. The crank member is provided with a crank member gear. The crank member gear meshes with at least an intermediate gear, which also meshes with an auxiliary gear. The auxiliary gear is fixed to an auxiliary shaft that extends concentrically through the crankshaft.

In one embodiment, a reciprocating tool includes a reciprocating plunger, the plunger including an inner wall defining a chamber portion within the plunger, a motor operably connected to the plunger, and a bushing located at least partially within the chamber and contacting the inner wall.

A crank circular slider mechanism includes a crankshaft having at least one crank pin; at least one circular slider with an eccentric hole which fits over the crank pin; at least one reciprocating element with a circular slider-receiving hole, which receives the circular slider in a rotatable manner; and at least one dynamic balance rotary block with an eccentric hole that fits over the crank pin. The dynamic balance rotary block and the adjacent circular slider are fixed together. By means of proper selection of a mounting place and a mass of the dynamic balance rotary block, the mechanism can convert reciprocating inertia of the reciprocating element into rotation inertia so as to obtain a balancing effect. An internal combustion engine and a compressor may be equipped with the crank circular slider mechanism.

A connecting rod for a reciprocating piston machine may include a hollow-cylindrical connecting rod bushing for receiving a piston pin and a hollow-cylindrical connecting rod bearing having a bearing axis running parallel to a cylinder axis of the connecting rod bushing for mounting a crank pin. An elongated shaft may extend perpendicularly to the bearing axis and be disposed between the connecting rod bushing and the connecting rod bearing for connecting the connecting rod bushing to the connecting rod bearing. The connecting rod bearing may include a connecting rod saddle which is materially connected to the shaft and a connecting rod cap which is materially separated from the shaft. A connecting rod joint may connect the connecting rod saddle to the connecting rod cap. The connecting rod joint may define a Hirth serration between the connecting rod saddle and the connecting rod cap.