CPM Hydraulic Motors

The CPM Series hydraulic motors are characterized by the following key features:

• Spool valve design with gerotor: Proven and reliable technology
• Compact design: Ideal for confined installation spaces
• Internal check valve: Enables operation without a case drain line
• High-pressure shaft seal: Standard up to 150 bar, optional up to 200 bar
• Versatile applications: Suitable for various hydraulic applications

The CPM motors offer a wide range of performance data:

• Displacement: 36 cm³/rev to 486.5 cm³/rev
• Maximum speed (continuous): 120 rpm (CPM 500) to 1500 rpm (CPM 36)
• Maximum torque (continuous): 5.5 daNm (CPM 36) to 56.0 daNm (CPM (1) 250)
• Peak torque: Up to 78.7 daNm (CPM (1) 400)
• Maximum output power (continuous): 4.6 kW to 10.3 kW

The CPM motors are designed for different pressure ranges:

Maximum operating pressure:

• Continuous: 160 bar
• Intermittent: 175 bar
• Peak: 210 bar

Maximum return pressure without case drain line:

• Continuous: 160 bar
• Intermittent: 175 bar
• Peak: 210 bar

With case drain line, the maximum return pressure is speed-dependent: from 150 bar at 0–100 rpm to 100 bar at 300–1000 rpm.

For maximum flexibility, various mounting and port options are available:

Flange types:

• Oval 2-bolt flange (SAE A)
• 4-bolt magneto flange
• Square 4-bolt flange
• Wheel flange

Port types:

• Side ports
• End ports

Thread types:

• BSPP (British Standard Pipe Parallel)
• Metric
• SAE-UNF (Society of Automotive Engineers – Unified Fine)
• SAE-NPTF (National Pipe Thread Fuel)

A variety of shaft designs are available with different torque transmission capacities:

Parallel keyed shafts:

• Ø25 mm: up to 34 daNm
• Ø25.4 mm: various torque capacities
• Ø31.75 mm: for higher loads
• Ø32 mm: heavy-duty design

Spline shafts:

• Ø31.75 mm, 14 teeth, DP 12/24
• Ø25.32 mm, SAE 6B: up to 77 daNm

Tapered shafts:

• 1:8 SAE J501: up to 77 daNm
• 1:10: for special applications

The different modes of operation allow for varying load levels:

• Continuous operation: Continuous running without time limit
• Intermittent operation: Maximum operating duration of 6 seconds per minute
• Peak operation: Maximum load duration of 0.6 seconds per minute

These modes allow for higher speeds, torque, power output, and pressure differentials compared to continuous operation, but only for short periods to avoid reducing the motor’s service life.

The permissible radial shaft load (Prad) is calculated based on several factors:

Calculation formula: Prad = [ ]n X800 25000 95+L daN

Influencing factors:

• Distance L: Between the point of force application and the flange mounting surface
• Speed: Affects maximum load capacity
• Flange type: Determines the maximum point load (Pmax)

Maximum point load (Pmax):

• Oval flange: 150 daN (with needle bearing)
• Square flange: 200 daN (with needle bearing)

For CPMW models, specific diagrams are available with limit values at various speeds (e.g., 50, 200, 800 rpm).

Customers can customize the CPM motors to meet their specific requirements:

Painting options:

• Unpainted 
• Standard grey paint
• Specific RAL color as requested by the customer

Rotation options:

• Standard rotation: Viewed from the shaft end
• Clockwise: when port A is pressurized
• Counterclockwise: when port B is pressurized
• Reverse rotation: Available as a special option

The internal check valve offers several key advantages:

• Operation without case drain line: Simplifies installation and reduces connections
• System safety: Prevents uncontrolled reverse movements
• Compact design: Fewer external components required
• Cost savings: Reduced installation costs due to fewer lines
• Increased reliability: Fewer potential leakage points
• Ease of maintenance: Fewer connections mean less maintenance effort

The selection of the right CPM motor is based on several criteria:

Performance requirements:

• Required torque (5.5 to 78.7 daNm)
• Required speed (120 to 1500 rpm)
• Displacement (36 to 486.5 cm³/rev)
• Mode of operation (continuous, intermittent, or peak)

Installation conditions:

• Available installation space (compact design)
• Flange type and mounting position
• Port orientation (side or end ports)
• Shaft design and torque transmission

System integration:

• System pressure and return pressure
• Rotation requirements
• Case drain management (with or without case drain line)