The Hägglunds Hydraulic motor from Bosch Rexroth is suitable for many heavyduty applications. The CB is of the radialpiston type with a rotating cylinder block/hollow shaft and a stationary housing. The cylinder block is mounted in fixed roller bearings in the housing. An even number of pistons are radially located in bores inside the cylinder block, and the valve plate directs the incoming and outgoing oil to and from the working pistons. Each piston is working against a cam roller.
When the hydraulic pressure is acting on the pistons, the cam rollers are pushed against the slope on the cam ring that is rigidly connected to the housing, thereby producing a torque. The cam rollers transfer the reaction force to the piston which are guided in the cylinder block. Rotation therefore occurs, and the torque available is proportional to the pressure in the system.