Power delivery system having a pressure modulated hydrodynamic retarder for controlling a load

A power delivery system for hoisting apparatus for raising and lowering a load and comprising, a power source, a change speed gear transmission driven by said source, a rotatable power output shaft driven by said transmission, a rotatable hoist means drivingly connected to said shaft and including a pneumatically actuated hoist clutch,

• a pressure fluid circuit, a hydraulically actuated disconnect clutch disengageably connected to and between said transmission and said shaft, a pneumatically actuated disconnect clutch control valve in said circuit for causing actuation of said disconnect clutch, a fluid pressurized and modulatable hydrodynamic retarder having a rotor drivingly connected to said power output shaft, said retarder having a pressure fluid inlet and a pressure fluid outlet in said circuit, a retarder outlet pressure control valve in said circuit, speed sensing means for sensing the rotational speed of said output shaft and for producing a pilot signal acting upon the retarder control valve to increase the fluid relief pressure of said retarder valve when the rotor speed increases to thereby cause increased torque of said retarder,
• a one-way clutch mounted between said shaft and said retarder for mounting said rotor on said shaft, said one-way clutch constructed and arranged for disconnecting said rotor from said shaft for free-wheeling thereon when said shaft is rotated in a direction to cause said hoist means to raise said load, and for connecting said rotor to said shaft when the latter is rotated in the opposite direction in lowering said load.

A power delivery system for hoisting apparatus for raising and lowering a load and comprising, a power source,a hydraulic torque converter driven by said source, a rotatable power output shaft driven by said torque converter, a rotatable hoist means drivingly connected to said shaft, a pressure fluid circuit, a fluid pressurized and modulatable hydrodynamic retarder having a rotor drivingly connected to said power output shaft, said retarder having a pressure fluid inlet and a pressure fluid outlet in said circuit, a retarder outlet pressure control valve in said circuit, speed sensing means for sensing the rotational speed of said output shaft and for producing a corresponding pilot signal acting upon the retarder control valve to increase the fluid relief pressure of said retarder outlet pressure control valve when the rotor speed increases to thereby cause increased torque of said retarder,

• a one-way clutch mounted between said shaft and said retarder for mounting said rotor on said shaft, said one-way clutch constructed and arranged for disconnecting said rotor from said shaft for free-wheeling thereon when said shaft is rotated in a direction to cause said hoist means to raise said load, and for connecting said rotor to said shaft when the latter is rotated in the opposite direction in lowering said load;
• a circuitry switch valve in said circuit and in fluid communication selectively with said torque converter and with said retarder for selectively directing pressure fluid (1) to said torque converter for raising said load or (2) to said retarder for lowering said load.

A power delivery system for hoisting apparatus for raising and lowering a load and comprising, a power source, a hydraulic torque converter driven by said source, a change speed gear transmission driven by said torque converter, a rotatable power output shaft driven by said transmission, a rotatable hoist means drivingly connected to said shaft and including a pneumatically actuated hoist clutch,

• a pressure fluid circuit, a hydraulically actuated disconnect clutch disengageably connected to and between said transmission and said shaft, a pneumatically actuated disconnect clutch control valve in said circuit for causing actuation of said disconnect clutch, a fluid pressurized and modulatable hydrodynamic retarder having a rotor drivingly connected to said power output shaft, said retarder having a pressure fluid inlet and a pressure fluid outlet in said circuit, a retarder outlet pressure control valve in said circuit, speed sensing means for sensing the rotational speed of said output shaft and for producing a corresponding pilot signal acting upon the retarder control valve to increase the fluid relief pressure of said retarder outlet pressure control valve when the rotor speed increases to thereby cause increased torque of said retarder,
• a one-way clutch mounted between said shaft and said retarder for mounting said rotor on said shaft, said one-way clutch constructed and arranged for disconnecting said rotor from said shaft for free-wheeling therein when said shaft is rotated in a direction to cause said hoist means to raise said load, and for connecting said rotor to said shaft when the latter is rotated in the opposite direction in lowering said load,
• a pneumatic circuit having pneumatic control valve means connected between said pneumatically actuated hoist clutch and said disconnect clutch control valve and providing an interlock therebetween which prevents engagement of said disconnect clutch and consequently prevents operation of said transmission while said hoist clutch is engaged for lowering the load through said retarder,
• and a circuitry switch valve in said circuit and in fluid communication selectively with said torque converter and with said retarder for selectively directing pressure fluid (1) to said torque converter for raising said load or (2) to said retarder for lowering said load.

A self-propelled, drill service rig comprising,

• a wheeled vehicle having,
• a power source for propelling the vehicle over the ground,
• a hoist means including a rotatable hoist drum and a clutch for said drum,
• a torque converter driven by said power source,
• a change speed hoist transmission driven by said torque converter,
• a power output shaft driven by said transmission and drivingly connected with said hoist means,
• a hydraulically actuated disconnect clutch disengageably connected to and between said transmission and said shaft,
• a pressure fluid circuit,
• a pneumatically actuated disconnect clutch control valve in said circuit for causing actuation of said disconnect clutch, a fluid pressurized and modulatable hydrodynamic retarder having a rotor drivingly connected to said power output shaft, said retarder having a pressure fluid inlet and a pressure fluid outlet in said circuit, a retarder outlet pressure control valve in said circuit, speed sensing means for sensing the rotational speed of said output shaft and for producing a corresponding pilot signal acting upon the retarder control valve to increase the fluid relief pressure of said retarder outlet pressure control valve when the rotor speed increases to thereby cause increased torque of said retarder,
• a one-way clutch mounted between said shaft and said retarder for mounting said rotor on said shaft, said one-way clutch constructed and arranged for disconnecting said rotor from said shaft for free-wheeling thereon when said shaft is rotated in a direction to cause said hoist means to raise said load, and for connecting said rotor to said shaft when the latter is rotated in the opposite direction in lowering said load,
• a pneumatic circuit having pneumatic control valve means connected between said pneumatically actuated hoist clutch and said disconnect clutch control valve and providing an interlock therebetween which prevents engagement of said disconnect clutch and consequently prevents operation of said transmission while said hoist clutch is engaged for lowering the load through said retarder,
• and a circuitry switch valve in said circuit and in fluid communication selectively with said torque converter and with said retarder for selectively directing pressure fluid (1) to said torque converter for raising said load or (2) to said retarder for lowering said load.