Parker Hydraulic Group
SPM20 Series Two-Speed Gear Motors

Key Features

  • Tandem motor with valving to provide two-speed operation on constant input flow
  • Journal bearings for long life and good over-hung load capability
  • Buna-N Seals are standards for petroleum and glycol based fluids “Viton®E” seals are optional.
  • Pressure balanced plates for greater efficiency.

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Tandem Motor With Valving To Provide Two-Speed Operation On Constant Input Flow

Parker two-speed motors consist of two hydraulic motor units and pilot operated valving. From this unique unit either high speed or high torque can be obtained, thereby improving the efficiency of winch drives, track drives, and hydrostatic transmissions. Main features of these units are: no external pilot pressure source is necessary, shift to different speed is extremely smooth; and the motor will not hesitate during shift. Displacement of the two motors need not be equal. It utilizes one inlet and one outlet and is fully reversible.

The two motor sections are connected through valving to the common inlet/ outlet ports. For low-speed, high-torque output, the pilot port is vented to the tank. For higher-speed, lower torque,the pilot port is blocked, causing the internal valves to shift to the closed position, routing the total flow through the rear motor section. The front motor section receives lubrication oil through the valve section, and requires very little horsepower in this position, since it is only recirculating the fluid.

Description ................................................... Two-Speed Gear Motors
Flow Range ......................... To 98 GPM Per Section (370.9 LTR)
Displacements .................................. To 9.10 C.I.R. Per Section                                                                                    (149.12 cc’s/rev.)
Maximum Pressure to ................................... 2500 PSI (172 BAR)
Maximum Speed to .........................................2500 RPM
Rotation ..................................................................... Bi-Directional
Bearings .................................................................................. Journal
Construction ......................................................................... Aluminum