Torque motor

Abstract

The present invention relates to a torque motor comprising a long tubular housing, a piston (3), which is mounted in said housing in an axially displaceable manner and can be axially driven by being subjected to a pressure fluid in a pressure chamber, and at least one shaft (6) that is mounted in an axially fixed manner inside the housing and is configured so as to rotate about an axis of rotation. The piston comprises a recess at the shaft hole, thereby allowing the piston to be axially displaceable on the shaft. According to the invention, the shaft forms a camshaft whose rotating axis (7) is offset relative to the recess at the shaft hole. The shaft part that extends slidably through the respective recess at the shaft hole has a lever arm relative to the axis of rotation of the shaft, thereby converting the radial force produced by the axial displacement of the piston and the pitch of the helical engagement path between the shaft and the piston and/or between the piston and the housing during the engagement of shaft and piston into a rotational movement of the shaft relative to the housing (1) or vice versa. According to the invention, the recess at the shaft hole is arranged approximately in the center of the piston in relation to the piston cross-section, a rotational locking of the piston not being required.

Description

technical field [0001] The invention relates to a torque motor, preferably a rotary drive for construction machines, elevators, trucks and such devices, comprising: an elongated tubular housing; at least one piston accommodated axially displaceable in the housing, which is driven axially by loading a pressure medium into the pressure chamber; and at least one shaft which is fixed axially and accommodated in the housing rotatably about an axis of rotation, wherein the piston has a shaft through-cut, by means of which the piston can be moved axially on the shaft move. Background technique [0002] In such a torque motor, an axial movement of the piston, which is acted upon by the pressure medium of the pressure chamber, can be converted into a twist of the shaft relative to the housing or of the housing relative to the shaft. For this purpose, the shaft is usually in screw engagement with the piston, which in turn is guided in a rotationally fixed manner relative to the housi...

AI Technical Summary

Problems solved by technology

[0004] Furthermore, the achievable efficiency of the known torque motors with helical toothing is very poor, because of the high losses due to the very high pressure per unit area and frictional surfaces

The fields of application of such torque motors have thus far been limited to lubricant-related pressure media

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