Rexroth is expanding its range of direct drives for compact tracked loaders and other tracked vehicles with the new MCR-T radial piston motor in frame size 10. The newly designed unit is approximately 20% shorter than conventional radial piston motors on the market and offers around 10% higher starting torque for more tractive force. For improved efficiency, especially over long distances, the MCR-T units also allow for high travel speeds at very low diesel engine rotational speeds.
The compact new design complements the MCR-T family, which was previously offered in frame sizes 5 and 6. The compact dimensions mean that the motor completely fits in the track width of compact loaders. To do this, it was necessary to shorten the overall length by a fifth, which is why Rexroth developers integrated the fail-safe, multi-disc holding brake into the outboard portion of the motor housing.
The high mechanical efficiency of the new series can also be seen in the starting torque, which has been improved by ten percent. The starting efficiency improvements will also shortly be rolled out to both of the other frame sizes, which have been produced in series since 2014.
In addition, the MCR-T can withstand higher radial forces thanks to its improved load distribution. The optimized position of the drive shaft allows for the use of a simpler sprocket in comparison to conventional radial piston motors. Larger bearings that are flushed with case oil achieve a service life that is up to 30% longer. An integrated flushing valve supports the cooling of the oil when used in closed hydraulic circuits, which therefore also lengthens the service life. The MCR-T’s improved service life lowers the total cost of ownership of the mobile working machines in which it is fitted.
MCR-T radial piston motors are designed for continuous high rotational speeds so that compact tracked loaders can also cover longer distances. Via the control valve integrated in the motor, the operator can gently and smoothly shift between travel speeds with the soft shift mode operating in both directions. The motor then runs with reduced displacement, reducing oil flow in the circuit and improving system efficiency. Additionally, the direct drive of the MCR-T results in greater efficiency and lower noise than typical gearbox-based solutions. MCR-T motors function with a differential pressure of up to 400 bar and the largest version achieves an output torque of up to 8,500 Nm. The displacement of the series ranges from 620 ccm to 1,340 ccm.