Controlled By Torque Of Motor Or Motor Discharge Pressure Patents (Class 60/451)
  • Patent number: 4579039
    Abstract: A power drive unit for thrust reverser structure includes a reversible motor in a hydraulic circuit and has normal stow and deploy cycles of operation. In a deploy cycle, the load on the motor is aiding and, in the event the deploy cycle is inadvertent, the load on the motor can be substantially higher. In order to avoid this increased loading on the motor in an inadvertent deploy cycle, the hydraulic circuit has an auto-restow valve which senses the high aiding load in the event of an inadvertent deploy operation and changes the operation of the power drive unit to operate the motor in a stow cycle to prevent continued high loading on the motor and thrust reverser structure.
    Type: Grant
    Filed: December 12, 1983
    Date of Patent: April 1, 1986
    Assignee: Sundstrand Corporation
    Inventor: Steven J. Ebbing
  • Patent number: 4554992
    Abstract: A hydrostatically operated vehicle, such as a street sweeper, includes an engine driven reversible hydrostatic pump coupled to a single hydrostatic pump driving wheels of the vehicle. The pump is shiftable from neutral to reverse and forward, low and high speed positions, and the hydrostatic motor is controlled between low and high speed positions with a metering valve automatically adjusting the motor speed in response to variation in reaction torque between the drive wheels and the ground. The vehicle also includes a reversible hydrostatic component drive system for powering motors which drive an elevator, pick-up broom and two gutter brooms in a forward working direction and which may be reversed for clearing debris jams by reversing the pump. The component drive system includes valve means for selectively driving the gutter brooms and for holding the gutter brooms inactive when the pump is driven in reverse.
    Type: Grant
    Filed: September 9, 1983
    Date of Patent: November 26, 1985
    Assignee: FMC Corporation
    Inventor: Denes P. Kassai
  • Patent number: 4503674
    Abstract: A hydrostatic drive system is provided with an adjustable hydraulic motor operatively connected between a high pressure main line and a low pressure line and equipped with a control arrangement that influences the setting in an r.p.m.-dependent manner, the improvement comprising a safety means that limits the stream flowing through the hydraulic motor.
    Type: Grant
    Filed: August 2, 1982
    Date of Patent: March 12, 1985
    Assignee: Linde Aktiengesellschaft
    Inventors: Wolfgang Backe, Franz Weingarten, Hubertus Murrenhoff
  • Patent number: 4495769
    Abstract: A control valve for booster power steering has a back pressure check valve openable by pressure caused by wheel jolting, which check valve connects between a servopump pressure passage of the control valve through the inner bore of a valve sleeve operable within a housing bore to the inlet of a metering pump. Such valve ensures that the steering is "closed" under all circumstances including during steering to prevent pressure jolts being transmitted from the vehicle wheels due to road roughness. However, after completion of a steering operation high pressure can build up within the valve sleeve causing expansion of the valve sleeve and jamming within the housing bore, making operation difficult. Accordingly, a pressure limiting valve is provided connected to relieve the pressure within the valve sleeve bore.
    Type: Grant
    Filed: August 13, 1981
    Date of Patent: January 29, 1985
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventors: Werner Tischer, Karl-Heinz Liebert, Rolf Fassbender
  • Patent number: 4481769
    Abstract: A control system for a hydraulically driven vehicle having a variable displacement hydraulic motor connected with a variable displacement hydraulic pump in a closed loop and driven thereby.A spring-applied and fluid-released brake is mounted on an output shaft of the motor. A regulator is operatively connected to the motor for controlling the displacement thereof in response to a fluid pressure at both ports thereof. When fluid pressure at either one of the ports of the motor exceeds a predetermined level, the variable displacement motor is changed over to a high displacement position thereby generating a large braking force when the vehicle is to be stopped.
    Type: Grant
    Filed: December 21, 1981
    Date of Patent: November 13, 1984
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventor: Yoshikazu Nagahara
  • Patent number: 4474002
    Abstract: A hydraulic drive apparatus for a wellhead pump jack which utilizes oppositely driven single-acting hydraulic cylinders as actuated by a variable volume pump having flow direction and flow volume controlled by a servo linkage and control lever. The linkage transmits oscillatory sine function motion of the walking beam for movement of the control lever as intermediate biasing force prevents nulling of the system.
    Type: Grant
    Filed: June 9, 1981
    Date of Patent: October 2, 1984
    Inventor: L. F. Perry
  • Patent number: 4459806
    Abstract: A method of controlling an internal combustion engine (14) having a power control (15) and a variable hydrostatic transmission (16, 17) including a hydraulic pump (16) driven by the internal combustion engine, and a hydraulic engine (17) connected therewith.By automatic adjustment of the power control (15) and the ratio (E) of the hydrostatic transmission (16, 17) independently of each other according to a predetermined mathematical control function (FIG. 1) which describes a desired relationship between power and rotational speed of the internal combustion engine, a specific discrete power output is delivered between zero load and full load only at an associated discrete rotational speed of the internal combustion engine.
    Type: Grant
    Filed: September 4, 1980
    Date of Patent: July 17, 1984
    Assignee: Kockums Industri AB
    Inventor: Lars I. Falk
  • Patent number: 4444286
    Abstract: The present invention is directed to a torque control with overspeed regulation and a method of controlling a hydrostatic drive for use in an auxiliary wheel drive of a vehicle which has both primary driven wheels and auxiliary driven wheels. The torque control permits maximum torque drive of the auxiliary wheels when the primary driven wheels slip but yet prevents overspeed operation of the auxiliary wheels. Preferably the torque control with overspeed regulation has both an aggressive control and a sensitivity control so that the auxiliary wheel drive can be selectively modulated with respect to the primary wheel drive.
    Type: Grant
    Filed: May 13, 1982
    Date of Patent: April 24, 1984
    Assignee: Sundstrand Corporation
    Inventors: Royal R. Hawkins, Leland E. Kuntz
  • Patent number: 4434616
    Abstract: A system for varying the speed and displacement of a variable-displacement hydraulic motor and for providing a feedback signal which prevents the motor from stalling when an operator tries to reduce the motor displacement below the stall level. The system is especially useful for operating a hydraulic winch system on a wire rope crane. A variable displacement hydraulic pump provides pressurized fluid to operate a variable displacement hydraulic motor for lifting loads supported by the wire rope. The motor speed is controlled by varying the displacement of the pump and/or the motor, with the motor speed generally increasing as motor displacement decreases. The motor could stall if the crane operator decreases motor displacement below a critical value. A feedback signal coupled to the motor controls the motor displacement to prevent motor stalls.
    Type: Grant
    Filed: October 23, 1981
    Date of Patent: March 6, 1984
    Assignee: FMC Corporation
    Inventors: Terry M. Christopher, Randolph J. Nelson
  • Patent number: 4382360
    Abstract: A closed loop hydraulic swing circuit is provided with crossover auxiliary actuating connections between the pump control lines and the system relief valves to cause the relief valves to open at lower than maximum system pressure in an unloading action that limits braking when a coasting load is causing the motor to return more fluid than the pump can accept.
    Type: Grant
    Filed: September 15, 1980
    Date of Patent: May 10, 1983
    Assignee: Bucyrus-Erie Company
    Inventor: Robert E. Dummer
  • Patent number: 4284389
    Abstract: A variable displacement pump has a displacement control cam operably connected to a displacement control cylinder within a pump housing and a pressure and flow sensitive compensating valve is connected to the pump housing for regulating output of the pump. The compensating valve is secured to the pump housing through a spacer block. A lever is disposed partly in the spacer block and partly in a housing of the compensating valve responsive to positioning of the pump cam through a mechanical connection for actuating a sleeve in the compensating valve to incorporate torque-limiting feedback regulation of the pump. An adjustment is operable from an outer surface of the spacer block to limit torsional operation of the lever about a pivot point.
    Type: Grant
    Filed: August 24, 1979
    Date of Patent: August 18, 1981
    Assignee: General Signal Corporation
    Inventors: John E. G. Young, Donald R. Schneckenburger
  • Patent number: 4199944
    Abstract: A load responsive fluid power control system using servo type flow control valves and fluid motors supplied by a variable displacement pump. The pump displacement is either regulated by an electro-hydraulic control valve in response to an electrical signal proportional to motor load or the pump displacement is regulated to maintain a constant discharge pressure. The flow of pressurized fluid from the pump is automatically cut off from a servo type valve controlling a negative or aiding load once this load exceeds a certain minimum level and the inlet flow requirement of the actuator is supplied from a low pressure source bypassing the servo valve.
    Type: Grant
    Filed: January 11, 1979
    Date of Patent: April 29, 1980
    Inventor: Tadeusz Budzich
  • Patent number: 4195479
    Abstract: A vehicle drive system including a rotary output, variable displacement, hydraulic motor (22) adapted to drive a wheel or the like, a pump (10) for providing hydraulic fluid under pressure to the motor, a pressure control valve (30) connected to the motor for regulating the displacement thereof to achieve a desired system pressure and having a pressure responsive surface (34) receiving a signal representative of system pressure and a biasing spring (36) acting in opposition thereto. The invention contemplates the improvement wherein a variable, settable, pressure reducing device (60,106) is connected to the pump and to the pressure control valve to apply hydraulic fluid under reduced pressure to the pressure control valve in bucking relation to the system pressure signal.
    Type: Grant
    Filed: February 8, 1979
    Date of Patent: April 1, 1980
    Assignee: Caterpillar Tractor Co.
    Inventor: Joseph E. Dezelan
  • Patent number: 4174614
    Abstract: A vehicle drive system including a wheel adapted to at least partially propel a vehicle over underlying terrain and a hydraulic motor coupled to the wheel to drive the same. A flow and pressure compensated pump has an output for providing hydraulic fluid under pressure to the motor and includes a control system having an input for receiving a hydraulic signal and for controlling pressure and flow output characteristics of the pump. A manually settable, pressure reducing valve interconnects the pump output and the control system input to provide a substantially constant, but adjustable, pressure signal to the control system so that output pressure from the pump to the motor may be controlled independently of loading on the motor to set the maximum torque delivery of the motor at a desired value.
    Type: Grant
    Filed: February 1, 1978
    Date of Patent: November 20, 1979
    Assignee: Caterpillar Tractor Co.
    Inventor: Joseph E. Dezelan
  • Patent number: 4167855
    Abstract: A hydrostatic transmission control system is provided of the type utilizing a main control valve to vary the control pressure being ported to the strokers which control the swashplate position of a variable displacement pump. The control valve includes a control port connected to a source of control pressure fluid and a pair of stroker ports, each of which is connected to one of the strokers. The control valve includes a valve member having a valve land associated with each of the stroker ports, the lands preferably being either zero-lapped or under-lapped and disposed to provide a substantially zero neutral band to provide an improved control response when it is necessary for the valve member to cross the neutral band and port control pressure to the opposite stroker.
    Type: Grant
    Filed: May 18, 1978
    Date of Patent: September 18, 1979
    Assignee: Eaton Corporation
    Inventor: Kenneth K. Knapp
  • Patent number: 4139987
    Abstract: A load responsive fluid power control system using servo type flow control valves and fluid motors supplied by a variable displacement pump. The pump displacement is regulated by an electro-hydraulic control valve in response to an electrical signal proportional to motor load or motor load pressure to vary the pump displacement to maintain a controlled constant or variable pressure differential between the pump outlet pressure and motor load pressure or to vary the pressure differential between pump outlet pressure and motor load pressure in response to a signal from a computing device. The pump control also limits maximum and minimum system pressures.
    Type: Grant
    Filed: September 23, 1977
    Date of Patent: February 20, 1979
    Inventor: Tadeusz Budzich
  • Patent number: 4103489
    Abstract: A total fluid power system for an engine powered vehicle includes an engine driven, variable displacement pump, a pair of variable displacement wheel motors and auxiliary functions. Transducers sense engine speed, pump output pressure and motor speeds to supply signals to pump and motor controls which process the signals with operator input signals to maintain pump and motor displacements for optimum engine power usage and desired vehicle performance.
    Type: Grant
    Filed: April 15, 1977
    Date of Patent: August 1, 1978
    Assignee: Deere & Company
    Inventors: Edward Horton Fletcher, Gordon K. Wiegardt
  • Patent number: 4034564
    Abstract: A piston pump having a housing and an angularly adjustable swash plate for controlling piston displacement and the flow of fluid discharged from the pump has improved control means for controllably positioning the swash plate in response to a modified load pressure signal.
    Type: Grant
    Filed: January 23, 1976
    Date of Patent: July 12, 1977
    Assignee: Caterpillar Tractor Co.
    Inventors: Howard L. Johnson, Walter Z. Ruseff
  • Patent number: 4028890
    Abstract: A piston pump having a housing and an angularly adjustable swash plate for controlling piston displacement and the flow of fluid discharged from the pump has control means for controllably positioning the swash plate in response to a load pressure.
    Type: Grant
    Filed: January 23, 1976
    Date of Patent: June 14, 1977
    Assignee: Caterpillar Tractor Co.
    Inventors: Cyril W. Habiger, Donald L. Hopkins
  • Patent number: 4028889
    Abstract: A load responsive fluid power multiple load control system using load responsive direction and flow control valves in combination with pump control responding to highest system load. Each direction flow control valve is equipped with a load responsive positive load control which automatically regulates valve inlet pressure to maintain a relatively constant pressure differential between pump inlet pressure and load pressure at a first level and a load responsive negative load control which automatically regulates valve inlet pressure to maintain a relatively constant pressure differential between pump inlet pressure and load pressure at a second higher level. The load responsive control of each direction control valve blocks the pump flow to the motor while controlling negative load, providing the motor inlet with fluid from the motor exhaust.
    Type: Grant
    Filed: October 5, 1976
    Date of Patent: June 14, 1977
    Inventor: Tadeusz Budzich
  • Patent number: 4004418
    Abstract: A demand compensated hydraulic system includes a pump responsive to pressurized fluid in a demand feedback pilot line. The pilot line is connected to sense fluid demand between a hydraulic motor and its associated control valve which is closed by servo feedback from the motor. A flow sensitive device is interposed in an output line connecting the pump and the control valve to sense when the flow decreases until it is insufficient to operate the function. At a predetermined decreased flow rate, the flow sensitive device operates to momentarily connect the demand feedback pilot line to a reservoir to cause the pump to go into a stand-by condition.
    Type: Grant
    Filed: December 29, 1975
    Date of Patent: January 25, 1977
    Assignee: Deere & Company
    Inventor: Harlan Welbert VanGerpen
  • Patent number: 3999387
    Abstract: A hydrostatic transmission for accelerating, driving and braking a high inertia load, such as the swing mechanism of a power shovel or crane, includes an engine-driven swashplate-type variable displacement constant speed reversible main hydraulic pump coupled in a closed loop circuit to a swashplate-type fixed displacement variable speed reversible hydraulic motor. A pair of control lever operated pilot pressure modulated pump displacement control valves selectively direct control fluid from an engine-driven fixed displacement constant speed charge pump to the stroking pistons of the servo control cylinders on the main pump to thereby control motor direction and speed. The charge pump also supplies replenishing fluid to the main pump/motor circuit through replenishing check valves.
    Type: Grant
    Filed: September 25, 1975
    Date of Patent: December 28, 1976
    Inventor: Frank A. Knopf
  • Patent number: 3999892
    Abstract: A pump assembly having at least two variable displacement pumps each having a separate pump control assembly are interconnected for control in response one to the other. Each pump control assembly has first and second biasing means acting on a respective swash plate. The first and second biasing means have interconnecting fluid pathways formed through a pump control housing. Means are provided within the housings for modifying the discharge pressures of the separate pumps to provide a resultant pressure signal for controlling the second biasing means.
    Type: Grant
    Filed: February 9, 1976
    Date of Patent: December 28, 1976
    Assignee: Caterpillar Tractor Co.
    Inventor: Allyn J. Hein
  • Patent number: 3990237
    Abstract: A hydraulic system having fluid flow feedback from a fluid motor to a demand control valve which operates to change pump output to compensate for motor demand includes a pressure amplifier between the feedback system and the valve. The pressure amplifier includes a chamber with a piston therein which is slidable to connect or block pump output fluid flow to the valve in response to feedback pressure variations from the motor.
    Type: Grant
    Filed: December 29, 1975
    Date of Patent: November 9, 1976
    Assignee: Deere & Company
    Inventor: Harlan Welbert Van Gerpen
  • Patent number: 3973399
    Abstract: A demand compensated hydraulic system includes a pump responsive to a pressurized fluid in a demand feedback pilot line. The pilot line is connected to sense fluid demand between a hydraulic motor and an associated control valve which is closed by servo feedback from the motor. A dither is connected to the pilot line to continuously oscillate the pressurized fluid in the pilot line to prevent the occurrence of a situation wherein the flow across the control valve is sufficient to prevent the pump from going to a stand-by condition while being insufficient to operate the motor to close the valve to thereby cause the pump to go into the standby condition.
    Type: Grant
    Filed: December 29, 1975
    Date of Patent: August 10, 1976
    Assignee: Deere & Company
    Inventor: Harlan Welbert Van Gerpen
  • Patent number: 3969896
    Abstract: A transmission ratio control system including an engine having fuel supply means for controlling engine power, a hydrostatic transmission driven by the engine including means for varying transmission ratio, a ratio control valve for controlling the ratio varying means, means for applying a bias to the ratio control valve proportional to engine speed, and means responsive to system pressure in the hydrostatic transmission for applying an opposing bias to the ratio control valve proportional to engine torque. In operation, the fuel supply means calls for a predetermined amount of power to be delivered by the engine and the system pressure in the hydrostatic transmission is utilized and as modified by the transmission ratio to provide an indication of engine torque, with the ratio control valve being responsive to the engine speed and the engine torque to vary the transmission ratio to obtain a desired power/speed curve for operation of the engine.
    Type: Grant
    Filed: May 8, 1975
    Date of Patent: July 20, 1976
    Assignee: Sundstrand Corporation
    Inventor: Joseph E. Louis
  • Patent number: RE29671
    Abstract: A demand compensated hydraulic system includes a pump responsive to pressurized fluid in a demand feedback pilot line. The pilot line is connected to sense fluid demand between a hydraulic motor and its associated control valve which is closed by servo feedback from the motor. A flow sensitive device is interposed in an output line connecting the pump and the control valve to sense when the flow decreases until it is insufficient to operate the function. At a predetermined decreased flow rate, the flow sensitive device operates to momentarily connect the demand feedback pilot line to a reservoir to cause the pump to go into a stand-by condition.
    Type: Grant
    Filed: June 24, 1977
    Date of Patent: June 20, 1978
    Assignee: Deere & Company
    Inventor: Harlan Welbert Van Gerpen
  • Patent number: RE29672
    Abstract: A hydraulic system having fluid flow feedback from a fluid motor to a demand control valve which operates to change pump output to compensate for motor demand includes a pressure amplifier between the feedback system and the valve. The pressure amplifier includes a chamber with a piston therein which is slidable to connect or block pump output fluid flow to the valve in response to feedback pressure variations from the motor.
    Type: Grant
    Filed: June 24, 1977
    Date of Patent: June 20, 1978
    Assignee: Deere & Company
    Inventor: Harlan Welbert Van Gerpen
  • Patent number: RE29673
    Abstract: A demand compensated hydraulic system includes a pump responsive to a pressurized fluid in a demand feedback pilot line. The pilot line is connected to sense fluid demand between a hydraulic motor and an associated control valve which is closed by servo feedback from the motor. A dither is connected to the pilot line to continuously oscillate the pressurized fluid in the pilot line to prevent the occurrence of a situation wherein the flow across the control valve is sufficient to prevent the pump from going to a stand-by condition while being insufficient to operate the motor to close the valve to thereby cause the pump to go into the standby condition.
    Type: Grant
    Filed: June 24, 1977
    Date of Patent: June 20, 1978
    Assignee: Deere & Company
    Inventor: Harlan Welbert Van Gerpen