Hydraulic drive system for steerable wheel of dump truck

A hydraulic drive system of a steerable wheel of a vehicle, said drive system comprising:

• a yoke pivotally supported by a body of the vehicle and oriented substantially horizontally between the body of the vehicle and the steerable wheel of the vehicle,
• a receptacle seat mounted on said yoke so as to be pivotable relative to said yoke, said receptacle seat having a support shaft portion on which the steerable wheel is rotatably supported,
• a suspension cylinder and a knuckle arm connected to said receptacle seat,
• a drive axle rotatably supported within said support shaft portion of said receptacle seat,
• a speed-reducer connecting one end of said drive axle to the steerable wheel, and
• a hydraulic motor having an outer casing detachably mounted to said receptacle seat at side thereof remote from the steerable wheel such that said motor can be detached from and attached to said seat, said hydraulic motor also having a rotary shaft that extends into said receptacle seat and is connected to the other end of said drive axle,
• a hydraulic actuator connected to said knuckle arm,
• a main hydraulic pump driven by an engine of the vehicle,
• a steering circuit connecting said main hydraulic pump to said hydraulic actuator,
• an auxiliary hydraulic pump provided downstream of an output end of a power transmission of the vehicle with respect to the direction in which power is transmitted from the engine through the transmission,
• a drive circuit connected to said hydraulic motor, and
• a valve positionable to selectively connect said auxiliary hydraulic pump to said drive circuit and to said steering circuit.

A hydraulic drive system of a steerable wheel of a vehicle, said drive system comprising:

• a yoke pivotally supported by a body of the vehicle and oriented substantially horizontally between the body of the vehicle and the steerable wheel of the vehicle,
• a receptacle seat mounted on said yoke so as to be pivotable relative to said yoke, said receptacle seat having a support shaft portion on which the steerable wheel is rotatably supported,
• a suspension cylinder and a knuckle arm connected to said receptacle seat,
• a drive axle rotatably supported within said support shaft portion of said receptacle seat,
• a speed-reducer connecting one end of said drive axle to the steerable wheel,
• a hydraulic motor having an outer casing detachably mounted to said receptacle seat at a side thereof remote from the steerable wheel such that said motor can be detached from and attached to said seat, said hydraulic motor also having a rotary shaft that extends into said receptacle seat, and
• a clutch connecting said rotary shaft to the other end of said drive axle.

A hydraulic drive system of a steerable wheel of a vehicle, said drive system comprising:

• a yoke pivotally supported by a body of the vehicle and oriented substantially horizontally between the body of the vehicle and the steerable wheel of the vehicle,
• a receptacle seat mounted on said yoke so as to be pivotable relative to said yoke, said receptacle seat having a support shaft portion on which the steerable wheel is rotatably supported,
• a suspension cylinder and a knuckle arm connected to said receptacle seat,
• a drive axle rotatably supported within said support shaft portion of said receptacle seat,
• a speed-reducer connecting one end of said drive axle to the steerable wheel,
• a hydraulic motor having an outer casing detachably mounted to said receptacle seat at a side thereof remote from the steerable wheel such that said motor can be detached from and attached to said seat, said hydraulic motor also having a rotary shaft that extends into said receptacle seat, and
• a clutch connecting said rotary shaft to the other end of said drive axle,
• a hydraulic actuator connected to said knuckle arm,
• a main hydraulic pump driven by an engine of the vehicle,
• a steering circuit connecting said main hydraulic pump to said hydraulic actuator,
• an auxiliary hydraulic pump provided downstream of an output end of a power transmission of the vehicle with respect to the direction in which power is transmitted from the engine through the transmission,
• a drive circuit,
• a first valve positionable to selectively connect said auxiliary hydraulic pump to said drive circuit and to said steering circuit, and
• a second valve positionable to concurrently connect said drive circuit to both said hydraulic motor and said clutch and to connect said drive circuit to said hydraulic motor without said drive circuit being connected to said clutch.

A hydraulic drive system of a steerable wheel of a vehicle, said drive system comprising:

• a yoke pivotally supported by a body of the vehicle and oriented substantially horizontally between the body of the vehicle and the steerable wheel of the vehicle,
• a receptacle seat mounted on said yoke so as to be pivotable relative to said yoke, said receptacle seat having a support shaft portion on which the steerable wheel is rotatably supported,
• a suspension cylinder and a knuckle arm connected to said receptacle seat,
• a drive axle rotatably supported within said support shaft portion of said receptacle seat,
• a speed-reducer connecting one end of said drive axle to the steerable wheel,
• a clutch connecting an output end of said speed-reducer to the steerable wheel, and
• a hydraulic motor having an outer casing detachably mounted to said receptacle seat at a side thereof remote from the steerable wheel such that said motor can be detached from and attached to said seat, said hydraulic motor also having a rotary shaft that extends into said receptacle seat and is connected to the other end of said drive axle.

A hydraulic drive system of a steerable wheel of a vehicle, said system comprising:

• a steering assembly interposed between the wheel and a body of the vehicle, the steering assembly mounting the wheel on the body of the vehicle so as to be steerable, said steering assembly including a pivotal member pivotable about a substantially vertical axis, said pivotal member having an external end on which the steerable wheel is mounted and an internal end remote from the steerable wheel;
• a drive axle drivingly connected to the steerable wheel;
• a hydraulic motor having an outer casing detachably mounted to the internal end of said pivotal member such that said hydraulic motor is externally accessible at the side of the body of the vehicle and the hydraulic motor can be detached from and attached to the pivotal member, said hydraulic motor being drivingly coupled with said drive axle so as to output a drive torque transmitted to the steerable wheel by said drive axle;
• and
• a hydraulic fluid supply system including a hydraulic line connected to said hydraulic motor.

A hydraulic drive system for a steerable wheel for a vehicle also having a primary drive wheel driven by a vehicular prime mover, said system comprising:

• a steering assembly interposed between the steerable wheel and a body of the vehicle, the steering assembly mounting the steerable wheel on the body of the vehicle so as to be steerable, said steering assembly including a pivotal member pivotable about a substantially vertical axis, said pivotal member having an external end on which the steerable wheel is mounted;
• a hydraulic drive assembly including a hydraulic motor;
• a drive axle drivingly coupling the hydraulic motor to the steerable wheel so as to rotate the steerable wheel when said motor is driven;
• a hydraulic steering system connected to said pivotal member;
• a first pump driven at a speed corresponding to an output of the engine of the vehicle, and a hydraulic steering line placing said first pump in constant fluid communication with said hydraulic steering system such that a pressurized fluid is supplied to said hydraulic steering system to effect steering;
• a second pump driven at a speed corresponding to a rotational speed of the primary drive wheel of the vehicle, and connected to said hydraulic motor so as to drive said hydraulic motor at a speed proportional to the rotational speed of said drive wheel.