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| Illustration 1 | g01190441 |
The propel system of the RM300 contains an electrical portion, a hydraulic portion, and a mechanical portion. The electrical controls consists of electronic control modules (ECM's) and associated input and output devices. The hydraulic portion consists of two closed circuit hydrostatic loops. One closed loop is for the front propel circuit and one closed loop is for the optional rear propel circuit. The mechanical portion consists of a planetary final drive unit for each front wheel.
The front propel hydraulic circuit contains a variable displacement pump, and a two-speed motor for each front wheel. The optional rear propel hydraulic circuit contains a variable displacement pump and a single speed hydraulic motor for each rear wheel. The propel circuits are equipped with flow divider valves which provide equal traction to the wheels when the traction control system is engaged.
The front propel motors transfer power to the front wheels through the planetary final drives. The rear propel motors transfer power to the corresponding rear wheels through the direct drive. There is no gear reduction. Each front planetary final drive unit contains a parking brake which is spring applied. The parking brakes are released by hydraulic pressure. The hydraulic drive circuits provide hydrostatic service braking.
The electronic control system monitors the machine operating conditions. The ECM's on the machine communicate through controller area network (CAN) data link lines. The control system determines if an output signal should be sent to the electronic displacement controls (EDC's) on the hydraulic pumps.
Under normal operating conditions, the system prevents the machine from moving under the following conditions:
- The propel lever is out of the NEUTRAL position when the machine is started.
- The parking brake switch is in the ON position.
- The rotor service switch is in the SERVICE position.
- An abnormal operating condition generates a fault state which requires a neutral reset. (A neutral reset involves the return of the propel lever to the NEUTRAL position.)
The electronic control system is also programmed with load control logic. When the load control system is activated, the electronic control system adjusts the propel speed in order to maintain an optimum engine speed. The optimized engine speed will match the cutting load of the rotor.