Accessories for hydraulic motors

Oil expansion tank with oil level control

Coaxial or angular gear units must be completely filled with oil when installed vertically.

During filling, an air bubble may form in the upper part at the level of the shaft seal, which must be eliminated to prevent insufficient lubrication. Since the oil volume increases as the temperature rises, an expansion tank with oil level control and breather filter must be installed to compensate and prevent harmful excess pressure inside the gear unit.

Torque supports

Shaft-mounted gear units are attached to the input shaft with shrink discs. They are not rigidly flange-mounted, but are "soft-mounted" with the aid of torque arms. This means that no angular misalignment occurs, which leads to additional bending moments and increased stress on the gear unit. The anchoring point of the torque arm should be able to move freely in the longitudinal direction of the shaft. In the tangential direction, damping elements should reduce the impact load.

Shrink discs

Shrink discs are among the detachable shaft-hub connections. They are used in slip-on gearmotors. They are insensitive to dirt, have no moving parts and are therefore not subject to wear. Shrink discs offer the advantage of absolute freedom from backlash, especially in reversing operation.

Rotary encoder

Incremental encoders, rotary pulse encoders or absolute encoders are sensors for detecting changes in position which can detect both the angle of rotation and the direction of rotation. Incremental encoders have a measuring standard with a repeating, periodic counting track. The measurement is based on a determination of direction and a count.

The encoders are usually mounted on the measuring shaft side of the hydraulic motor with a mounting bell and a flexible coupling. For particularly narrow spatial conditions, there are rotary encoders in slip-on design with a type of torque support in compact design.