Concentric Gear Motors

Hydraulic Gear-Type Motors
Concentric offers one of the widest selections of gear pumps and hydraulic motors in the industry. All Concentric products are designed to provide solutions to the Customers’ application challenges. Concentric hydraulic motors are applied on turf care equipment, agricultural equipment, industrial sweepers, paving machinery, winch and fan drives on off-highway vehicles, and many other applications. They are specified by leading equipment manufacturers throughout the mobile equipment market.

Series FM20 and FM30 Motors

FM20 Series 1.410 to 5.300 in³/rev
FM30 Series 3.540 to 9.820 in³/rev

Concentric Series F20 and F30 pumps can be ordered as uni-directional hydraulic motors. These motors can be ordered with a variety of mounting options and shafts.

Series GC Small Frame Gear Pump/Motor

0.065 to 0.711 in³/rev
Bi-Rotational • Use as a Pump or Motor
Includes bi-rotational check valves to allow it to be used either as a pump or a hydraulic motor in either direction of rotation. The maximum back pressure is 400 PSI on the low pressure port. Inboard bearings will accept a maximum of 150 lbs. of overhung load, an outward thrust of 60 lbs.; and an inward thrust of 76 lbs. Oil viscosity of 100 to 1000 SSU

Motor body is cast iron with hardened steel gears running on needle bearings and with Viton seals. Listed below in the tables are some of the more popular pumps. The dimensions are: 3 1/2″ wide × 3 1/2″ high. Shaft dimension is: 1/2″ diameter x 1 1/2″ length with a 1/8″ key. These pumps come with a four bolt flange on a 2″ hole pattern. Pilot diameter is 1.780″. There are additional shaft, mounting, and valve options for the GC series motors, please consult your local Womack sales office.

Series F25 Pump/Motor
Bi-Rotational Gear Pump
1.400 to 5.300 in3/revLow Noise, High Efficiency, Cast Iron Construction10 Sizes; 1.4 in3 (23cc) to 5.3 in3 (87cc)Pressures to 3045 PSI (210 Bar) continuousBuna or Viton shaft sealsSingle Shaft Seal, Double Shaft Seal or Single Seal with Outboard BearingKeyed or Splined ShaftSide ports only, rear ports only or both side and rear portsFlanges and shafts meet SAE standards

Concentric F25 gear pumps are designed for low noise, high efficiency bi-rotational operation. The 14-tooth gear provides lower pressure ripple which results in lower noise. The cast iron construction also contributes to noise reduction. In addition, cast iron housings allow gear tips to generate their own run in paths, creating higher volumetric efficiency. The drive gear and drive shaft as well as the driven gear and shaft are one piece construction. This eliminates the potential problems of fretting and stress fatigue associated with two piece construction.

Series H Internal Gear Pump/Motor
Cast Iron Body
4.5 to 18.5 GPM
1800 to 5000 RPM and 1000 to 3000 PSI
Maximum PSI and RPM vary with displacement.

Inboard bearing will support a side or end load of 300 lbs. at 5000 RPM or 400 lbs. at 1200 RPM. Oil viscosity 100 to 500 SSU at the operating temperature.

Pump body is cast iron with hardened steel gears running on needle bearings, and with Viton seals. Dimensions are: Pump body 5” high x 4 1/4” wide x the body length shown in the chart below. The shaft is 3/4” in diameter x 1 3/4” long with a No. 606 Woodruff keyway. Inlet and outlet ports are 1” NPT, drain port is 3/8” NPT. Mounting flange is SAE 2-bolt “A” size (NFPA Code 82-2). Weight varies from 14 to 20 lbs., smallest to largest model.

NOTE: These pumps may be used as hydraulic motors, but only on those applications where back pressure on the outlet port can never exceed 400 PSI even during periods of deceleration. Before using as a motor please check your application with the Concentric factory or your nearest Womack sales office. A CW pump should only be used as a CCW motor, and a CCW pump only as a CW motor.

Series WM600 Gear Motor
Bushing Block Design
0.244 to 0.732 in3/revConcentric W600 pumps can be used as hydraulic motors. Concentric offers these motors in bi-rotational with case drain and bi-rotational with check valves, however the pumps listed on Womack 365 Product Catalog pages 48, 49, and 50 can be used as a single rotation hydraulic motor. Care must be used in the rotation. If the pump is clockwise rotation, it must be used counterclockwise as a motor. Below are performance curves for each series of hydraulic motors.

Series WM900 Gear Motor
Bushing Block Design
0.366 to 1.709 in3/revConcentric W900 pumps can be used as hydraulic motors. Concentric offers these motors in bi-rotational with case drain and bi-rotational with check valves, however the pumps listed on Womack 365 Product Catalog pages 48, 49, and 50 can be used as a single rotation hydraulic motor. Care must be used in the rotation. If the pump is clockwise rotation, it must be used counterclockwise as a motor. Below are performance curves for each series of hydraulic motors.

Series WM1500 Gear Motor
Bushing Block Design
1.159 to 3.050 in3/revConcentric W1500 pumps can be used as hydraulic motors. Concentric offers these motors in bi-rotational with case drain and bi-rotational with check valves, however the pumps listed on Womack 365 Product Catalog pages 48, 49, and 50 can be used as a single rotation hydraulic motor. Care must be used in the rotation. If the pump is clockwise rotation, it must be used counterclockwise as a motor. Below are performance curves for each series of hydraulic motors.