Abstract: The present invention includes a trencher assembly with a motor that directly drives a sprocket through the rotation of a shaft of the motor. The rotation of the sprocket drives both a digging chain and an auger assembly simultaneously. The ability to use a motor to directly drive the sprocket decreases the components necessary for a drive train of the trencher assembly to promote a compact design. This occurs because the sprocket is able to drive both the digging chain and auger assembly through the transfer of driving forces from the motor without any intermediate gearing, belts, rotating support structure, and the like.

Abstract: A mower including a housing having a cutting apparatus such as a flail mower rotatably mounted therein. The mower includes a detector which determines during mower raising when the housing is positioned at least a predetermined distance above the ground surface directly below the housing. After passage of a time period during which the detector continuously detects that the housing is positioned at least the predetermined distance from the ground, a signal is sent to an actuator mechanism which interrupts the delivery of power to the motor rotating the cutting apparatus such that the flail mower comes to a stop. In one embodiment, a locking mechanism can be provided which prevents power from being reintroduced to the mower motor after the mower is lowered until the operator purposefully disengages the locking mechanism.

Abstract: An axially rotatable groundworking implement mountable to a host vehicle. The groundworking implement is powered by two hydraulic motors between the side ends of the groundworking implement. The shaft of each motor includes a bore which functions as either the hydraulic fluid input port or output port for that motor. Each hydraulic motor shaft is nonrotatably affixed to a groundworking implement protective cover. The groundworking implement can be removed from its supporting mechanism without detaching the motor from the work implement.

Abstract: A fluid motor includes an inner gear member and an outer gear member. The gear members are rotatable and orbital relative to each other and define expandable and contractible fluid pockets. The gear members rotate and orbit relative to each other as the fluid pockets expand and contract. A commutator valve is movable with one of the gear members and defines a first region in communication with high pressure, a second region in communication with low pressure, and a third region which is defined by a modulation opening which selectively communicates with high pressure or low pressure. The modulation opening communicates with at least one fluid pocket. A spool valve includes a valve member having at least two positions for controlling the speed of relative movement between the gear members. When the valve member is in a first position, the modulation opening communicates with the low pressure in the second region.

Abstract: A fluid motor having a gerotor gear set includes a first member having internal teeth and a second member having external teeth. The second member is rotatably and orbitally mounted within the first member. The teeth of the first and second members cooperate to define a plurality of variable volume working chambers. Some of said working chambers expand and other of said working chambers contract upon relative rotatable and orbital movement between said first and second members. A plurality of electrically controlled valves are provided, each working chamber having an associated valve. Each valve selectively communicates, in one condition, its associated working chamber with an inlet passage, which is, in turn, connected to a source or pressurized fluid, or, in a second condition, its associated working chamber to an outlet passage, which is, in turn, connected to a reservoir. Each of the valves is responsive to a respective electrical control signal for placing the valve in the first or second condition.

Abstract: A mechanism for moving an element in opposite directions includes a piston connected with the element. The piston reciprocates in a cylinder as high pressure fluid is alternately directed against one side or the other of the piston by a rotatable directional valve. The directional valve is rotated by a gerotor motor. A single rotatable valve element has passages at one end which form a commutator valve for the gerotor motor and ports at the other end which form the directional valve. A passage through the valve element connects the output of the gerotor motor with the directional valve ports. Cushioning means are provided to damp the motion of the piston at each end of its stroke to prevent impact with the ends of the cylinder.

Abstract: A hydraulic motor drives the cooling fan of an internal combustion engine. Fluid flow from a fixed displacement pump is directed through a pilot-operated pressure-compensated control valve to the hydraulic motor. The valve has a continuous bias to a fan-on position for directing fluid to the fan motor. Flow to the fan motor is diverted by the valve as a function of the pressure of the fluid in the system. In addition, flow to the fan motor is diverted as a function of a pilot pressure signal which is controlled by the temperature of the engine coolant fluid. The valve failsafes to a condition directing maximum flow to the fan motor in the event of loss of pilot fluid pressure.

Abstract: A hydraulic motor drives the cooling fan of an internal combustion engine. Fluid flow from a fixed displacement pump is directed through a pilot-operated pressure-compensated control valve to the hydraulic motor. The valve has a continuous bias to a fan-on position for directing fluid to the fan motor. Flow to the fan motor is diverted by the valve as a function of the pressure of the fluid in the system. In addition, flow to the fan motor is diverted as a function of a pilot pressure signal which is controlled by the temperature of the engine coolant fluid. The valve failsafes to a condition directing maximum flow to the fan motor in the event of loss of pilot fluid pressure.

Abstract: A drive assembly includes a casing containing a planetary gear assembly. A speed control arrangement is provided in association with the planetary gear assembly to vary the speed of rotation of an output member relative to the speed of rotation of an input member. The speed control arrangement includes a first disc pack which is engaged under the influence of a spring to prevent relative rotation between a ring gear and a planet carrier. A second disc pack is also engageable under the influence of a spring to prevent rotation of the ring gear relative to the casing. Hydraulic motors are selectively operable to release the disc packs against the influence of the associated springs. In the event of a failure in the source of hydraulic fluid, both disc packs are engaged with a resulting braking of rotation of the driven wheel. A secondary or towing clutch is selectively disengageable to release the output member and wheel for rotation, even though both of the disc packs are engaged.

Abstract: A two-speed transmission unit which couples a rotatable input shaft to a rotatable output shaft. A gear unit includes a sun gear fixed to the input shaft and rotatable therewith. One or more planet gears are disposed for orbital motion around the sun gear, and the planet gears are carried by a planet carrier which orbits with the planet gears about the sun gear. First clutch means is provided for coupling the sun gear to the output shaft for rotating the output shaft at a first angular velocity equal to the angular velocity of the sun gear, and second clutch means is provided for coupling the planet carrier to the output shaft for rotating the output shaft at a second angular velocity equal to the angular velocity of the planet carrier about the sun gear.