CPMT Hydraulic motors

CPMT hydraulic motors combine a compact design with high performance, making them ideal for demanding drives in confined installation spaces. Thanks to integrated tapered roller bearings, they can withstand high axial and radial loads and achieve torques of up to 166.5 daNm at pressure drops of up to 280 bar. Learn more ...

A wide range of flange, shaft, and port options allows precise adaptation to a variety of industrial applications. These hydraulic motors are similar in design to the OMT hydraulic motor from Sauer/Danfoss.

CPMT Series Hydraulic Motors – Frequently Asked Questions

What are the main features of CPMT hydraulic motors?

CPMT hydraulic motors feature a disc valve Geroler design for low starting torque and high efficiency. They are optimized for compact installation spaces, have an internal check valve, and can be operated without a drain line. Integrated tapered roller bearings allow for high radial load capacity.

What types of CPMT hydraulic motors are available and how do their performance specifications differ?

There are eight types: CPMT 160, 200, 250, 315, 400, 500, 630, and 800. Displacements range from 161.1 cm³/rev (CPMT 160) to 801.8 cm³/rev (CPMT 800). As displacement increases, torque output increases while the maximum speed decreases. Other parameters such as power output, pressure drop, oil flow, and weight also vary.

What do the terms “Continuous”, “Intermittent” and “Peak” mean in performance data?

Continuous (Cont.): Continuous operation without interruption.
Intermittent (Int.(1)): Higher loads for a maximum of 6 s/minute.
Peak (2): Maximum loads for a maximum of 0.6 s/minute.

Each mode has its own limits for speed, torque, power, pressure drop, and inlet pressure.

What output shaft options are available for CPMT motors and how do they affect torque capacity?

Cylindrical with key (C and Co): Ø40 mm or Ø38.1 mm – max. 132.8 daNm
P.T.O (Sl): Ø34.85 mm – max. 77 daNm
Splined (SH): Ø1½", 17 teeth – max. 132.8 daNm
Tapered (k, ka): 1:10 or 1:8 – max. 210.7 daNm

How is the permissible radial shaft load determined for CPMT motors?

The load is calculated based on the distance (L) between the point of force application and the mounting flange surface. Tapered roller bearings allow for high axial and radial loads. Charts indicate maximum values (dashed) and permissible loads for 3000 h service life at 200 rpm (solid). Exceeding these limits increases the risk of shaft failure.

What is the function of the integrated check valves and the drain line on CPMT motors?

The integrated check valve protects the shaft seal by ensuring that its pressure never exceeds return pressure. Operation without a drain line is possible, but a drain line offers benefits such as cleaning, cooling, and longer seal life. Permissible return pressures depend on the presence of a drain line and the motor speed.

How is the rotation direction of a CPMT motor selected?

Standard rotation: Right-hand (clockwise) with pressure at “A”. Left-hand (counterclockwise) with pressure at “B”. When ordering under “Pos. 7 Rotation direction”, either Standard or Reverse rotation (r) can be specified.

What factors must be considered and calculated when using a CPMT motor for vehicle drive applications?

Motor speed (n): Based on vehicle speed, wheel rolling radius, gear ratio.
Rolling resistance (rr): Depends on vehicle weight and rolling resistance coefficient.
Grade resistance (Gr): Force required for climbing slopes.
Inertia force (Fa): Force required for acceleration.
Drawbar pull (dP): Additional force for towing loads.
Total tractive effort (TE): Sum of all forces + 10% air resistance.
Motor torque (M): Calculated from TE, wheel rolling radius, number of motors, gear ratio, transmission efficiency.
Wheel adhesion (MW): MW > M to avoid slip.
Radial load (Prad): Sum of drive and load forces for wheels mounted directly on the motor.

These calculations help select the appropriate motor from the catalog.