More and more fleet managers are turning to Eaton track drive motors to keep their excavators and other tracked machines running efficiently. However, this brand is still somewhat new to many in the United States. We've already talked about Eaton JMV motors and why they are popular, but this blog post serves as more of a technical summary for the JMV series of Eaton track drive motors.
JMV Series Basic Specs
Eaton's JMV series motors are track drive hydraulic motors that were designed to pack as much torque into as small a space as possible. They boast smooth starts and stops, excellent efficiency, lower power losses, and increased start-up torque.
The JMV series of track drive motors consist of a 2-speed axial piston hydraulic motor with an integrated gear box. They are rated for a pressure up to 365 bar (5.29 psi) and are available in displacements from 16cc to 274cc (0.98 cu. in. to 16.7 cu. in.). Models are available for machine ranging in size from from 1.5 tons to 50 tons.
Integrated Parking Brake
These track drive motors have an integrated fail-safe parking brake to provide controlled operation (braking) and reduce the wear and tear on the motor. The brake is applied via a spring force acting against multiple wet friction plates. The brake is released by the operating pressure of the motor, which means that when the machine is in operation the parking brake is off.
Integrated Relief Valve
Also included on these track drive motors is an integrated relief valve which prevents internal damage to the hydraulic motor. There is no flow to the motor when the control valves A and B are blocked. However, due to the inertia of the machine, the motor may continue to rotate. When this happens, it can cause an increase in pressure at the downstream port. The relief valve prevents this from happening by discharging this higher pressure to the low pressure port.
Integrated Counterbalance Valves
JMV motors have an integrated counterbalance valve. First, the parking brake will be off when the machine is in operation. When the machine is traveling down a slope, the travel velocity will be controlled. Finally, if the machine stops on a slope, the counterbalance valve will prevent slipping.
The JMV track drive motors have a two-speed switch that changes the angle of the swash plate to adjust the speed. To run at low speed, the swash plate is adjusted to its maximum angle; to run at high speed, the swash plate is adjusted to its minimum angle.
Remote pilot pressure is used to accomplish this. When the pilot pressure is disconnected, spring force shifts the two-speed valve to the low speed position; when pilot pressure is applied, the valve is moved to its high speed position. Note that these motors can also auto-shift from low speed (LSHT) to high speed (HSLT).
These track drive motors are used in excavators (both full size and mini), horizontal drilling machines, crawler cranes, asphalt milling, rotary drilling, crushers, winches, and special crawler vehicles. There are many applications for them.
Why Eaton JMV Series
Keep in mind that the Eaton JMV series track drive hydraulic motors were designed with equipment such as excavators and other tracked machines in mind. Aside from the technical details we've already talked about they offer high efficiency, compact size, high start-up torque, and excellent torque density. In addition, Eaton JMV motors are also compatible with the installation requirements of many machines, brands, and models. Don't forget that Eaton hydraulic motors are an excellent aftermarket option when it comes time to replace your final drive and track drives.
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