WO1982000868A1 - Commande de couple pour des moteurs hydrauliques - Google Patents

Commande de couple pour des moteurs hydrauliques Download PDF

Info

Publication number
WO1982000868A1
WO1982000868A1 PCT/US1979/000070 US7900070W WO8200868A1 WO 1982000868 A1 WO1982000868 A1 WO 1982000868A1 US 7900070 W US7900070 W US 7900070W WO 8200868 A1 WO8200868 A1 WO 8200868A1
Authority
WO
WIPO (PCT)
Prior art keywords
pressure
pump
hydraulic
signal
control valve
Prior art date
Application number
PCT/US1979/000070
Other languages
English (en)
Inventor
J Dezelan
Original Assignee
J Dezelan
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by J Dezelan filed Critical J Dezelan
Priority to PCT/US1979/000070 priority Critical patent/WO1982000868A1/fr
Publication of WO1982000868A1 publication Critical patent/WO1982000868A1/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F16H61/46—Automatic regulation in accordance with output requirements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F16H61/42—Control of exclusively fluid gearing hydrostatic involving adjustment of a pump or motor with adjustable output or capacity
    • F16H61/423—Motor capacity control by fluid pressure control means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F16H61/46—Automatic regulation in accordance with output requirements
    • F16H61/472—Automatic regulation in accordance with output requirements for achieving a target output torque

Definitions

  • This invention relates to hydraulic systems including variable displacement, rotary output, hydraulic motors and the provision of a means for torque control therein.
  • a hydraulic motor control system including a rotary output, variable displacement hydraulic motor.
  • a pump is utilized for providing hydraulic fluid under pressure to the motor and a pressure control valve is connected to the motor for regulating the displacement thereof to achieve a desired system pressure.
  • the pressure control valve includes a pressure responsive surface receiving a signal representative of system pressure and a biasing means acting in opposition thereto.
  • the biasing means includes a variable, setable, pressure reducing means connected to the pump and to the pressure control valve to apply hydraulic fluid under reduced pressure to the pressure control valve in buck.ing relation to the system pressure signal.
  • FIG. 1 is a schematic of one emboddlment of a hydraulic motor control system made according to the invention
  • Fig. 2 is a partial schematic of a modified embodiment.
  • the system includes a pressure compensated hydraulic pump 10 for providing hydraulic fluid under pressure to a flow control valve, generally designated 12, and to a plurality of hydraulic implement circuits each including a hydraulic motor. Three such circuits are shown schematically and are desiganted 14, 16 and 18.
  • the flow control valve 12 for purposes of the present invention, may be regarded as conventional and when open as shown, conveys fluid from the pump 10 to a line 20 connected to each of two variable displacement, rotary output, bidirectional hydraulic motors 22.
  • the implement circuits 14, 16 and 18 and their associated hydraulic motors would be utilized in, for example, the swing circle for the mold board, the circuit for elevating or lowering the mold board, etc.
  • a pilot line 24 is connected to the high pressure line 20 to direct hydraulic fluid under pressure to ports 26 and 28 of a pressure control valve 30.
  • the pressure control valve 30 includes a spool 32 having a pressure responsive surface 34 on one end thereof and in fluid communication with the port 28.
  • a compression spring 36 abuts the opposite end of the spool 32 to urge, in bucking relation to the pressure responsive surface 34, the spool 32 to the right as viewed in the figure.
  • the pressure control valve 30 further includes a port 38 which is connected to a conventional direction control valve 40 which may be utilized to control the direction of rotation of the output shafts of the motors 22 in the usual fashion.
  • the spool 32 includes a land 42 for controlling fluid communication through the pressure control valve 30, that is, allowing fluid communication between the port 38 and the port 26, or between the port 38 and a port 44 connected to the hydraulic reservoir for the system.
  • the pilot line 24 also extends to the direction control valve 40 in the manner shown and the latter is in fluid communication with two lines 46 and 48, each extending to the swashplate control of each of the motors 22.
  • the swashplate controls for the motors 22 are conventional and form no part of the present invention.
  • the operation of the direction control valve 40 is conventional.
  • the swashplates of the motors 22 will respond to progressively minimize the displacement .and when the pressures are the same the swashplates will assume a neutral condition.
  • the flow of hydrauluc fluid per unit of time also increases and this of course tends to decrease the system pressure once the maximum flow output of the pump is reached.
  • the pressure control valve 30 operates to alter the displacement of the motors 22 to maintain a given desired pressure level thereat.
  • the land 42 on the spool 32 will generally be in the position illustrated in the drawing, modulating fluid flow between the port 38 and the ports 26 and 44.
  • the total force applied to the pressure responsive surface 34 will decrease so that the spring 36 will tend to shift the spool 32 to the right as viewed in the drawing.
  • pressure fluid from the line 24 will be directed via the port 26 to the port 38 and through the direction control valve 40 to increase the pressure in the line 48 relative to the pressure in the line 46 and thereby destroke the motors 22, that is, reduce their displacement, thereby increasing system pressure until a steady state condition is again achieved.
  • the de sired pressure level representative of steady state operation is determined by the spring constant of the biasing spring 36 and the distance the land 42 must travel from its rightmost position to that illustrated, in the drawing. In general, this pressure level would be the minimum torque level every desired to be present on the output of the motors 22.
  • a higher torque level output will be desired. And this, in turn, will require that system pressure be elevated to some value greater than that associated with the minimum desired torque level.
  • a bore 50 of the pressure control valve 30 receiving the spool 32 also receives the reduced end 52 of a piston 54.
  • the head end of the piston 54 is enlarged and is received in a chamber 56 coaxial with the bore 50.
  • Both sides of the head end of the piston 54 are subjected to the pressure of any hydraulic fluid within the chamber 56 but by reason of the fact that the reduced, end 52 extends out of the chamber 56 into the bore 50 which is connected to the system reservoir via the valve 12, the application of fluid under pressure to the interior of the chamber 56 will impart a shifting force to the piston 54 tending to move the same to the right within the bore 50.
  • the valve 60 includes a body 62 having a bore 64 which slidably receives a spool 66.
  • the body includes axially spaced ports 68, 70 and 72 opening to the bore 64 with the port 70 serving as a reduced pressure hydraulic signal emitting port connected to the port 58 for the chamber 56.
  • the port 68 is connected to the system reservoir while the port 72 is connected to the high pressure line 20.
  • One end of the spool 66 is abutted by a spring 74 which is received within an interior bore 76 of a plunger 78.
  • the plunger 78 is mounted for reciprocation within the body 62 and those skilled in the art will appreciate that by varying the position of the plunger 78, through any desirable control linkage, the degree of pressure on the spring 74 can be selectively altered to adjust the biasing force applied thereby to the spool 66.
  • conventional detent or restraining means would be associated with any linkage used for controlling the position of the plunger 78.
  • the spool 66 includes a first land 80 which may be shifted upon spool movement to block fluid communication between the ports 68 and 70.
  • An additional land 82 is operative to control fluid communication between the ports 70 and 72.
  • a spr.ing 84 which acts against the opposite end of the spool 66. More specifically, the spring 84 acts against the spool 66 within a chamber 86 formed in the body 62.
  • the chamber 86 is connected by a flow passage including a restricted orifice 88 to the port 70.
  • the orifice 88 serves to restrict fluid flow through the passage between the port 70 and the chamber 86 to dampen oscillating movement of the spool 66 in response to changes in pressurization within the chamber 86.
  • the valve 60 acts, in effect, as a pressure reducing valve, reducing the pressure at the port 70 from that at the port 72 to some lesser pressure, depending upon the position of the plunger 78, and applies the reduced pressure to the piston 54. Because of the provision of feedback through the restricted orifice 88 of pressure in the port 70, the pressure in the port 70 will be at a substantially constant value dependent upon the setting of the plunger 78 irrespective of the pressure in the high pressure line 20, unless, of course, the pressure in the line 20 drops below that commanded by the setting of the plunger 78.
  • the body housing the pressure control valve 30 includes a bore 90 to the left of the chamber 56 which slidably receives a piston 92 which in turn is in abutment with the head of the piston 54.
  • a piston 92 which in turn is in abutment with the head of the piston 54.
  • rightward movement ofthe piston 92 within its bore 90 also may serve to increase the compression on the spring 36 ultimately causing an elevation in system pressure.
  • Fluid under pressure may be directed against the piston 92 to cause such movement via a port 94 connected to check valves 96 connected to the high pressure sides of the implement circuits 14, 16 and 18 in a conventional fashion.
  • the port 94 will be supplied with a hydraulic pressure signal indicative of the highest loading pressure on any of the circuits 14, 16 and 18.
  • the check valves 96 are also connected to a resolver 98.
  • the resolver 98 receives a second input on a line 100 connected to the port 70 of the pressure reducing valve 60.
  • the output of the resolver 98 is connected via a l.ine 102 to the pressure control mechanism 104 of the pressure compensated pump 10.
  • the pump control 104 receives a pressure signal corresponding to the highest pressure of those fabricating at the port 70 and the loading in the circuits 14, 16 and 18. In the usual case, the highest of such pressures will be that at the port 70. Should a higher pressure come into existence as a result of heavy loading in any of the implement circuits 14, 16, 18, it will be applied to the pressure control 104 to cause the pressure compensated pump 10 to increase its output pressure in a conventional fashion.
  • Fig. 2 illustrates, schematically, an alternate embodiment of the invention and specifically a variable orifice 106 is designated 72' and is connected to the line 20 just as the port 72 of the pressure reducing valve 60.
  • the output of the orifice 106 is designated 70' and is connected to the port 58 of the pressure control valve 30 as well as to the resolver 98 just as the output or signal port 70 of the pressure reducing valve 60.
  • the output 70' is also connected to the system reservoir through an orifice 108.
  • the plunger 78 of the pressure reducing valve 60 maybe set initially at a position whereat little or no fluid under pressure is directed to the chamber 56 of the pressure control valve 30.
  • fluid flow to the motors 22 and the pressure thereof will be governed principally by the bias of the spring 36 applied to the spool 32 which, it will be recalled, will typically be such that the system pressure value will correspond to a minimum torque output of the motors 22.
  • the plunger 78 is advanced to the left as viewed in Fig.
  • the reduced pressure signal from the port 70 or the load signal from the implement circuits 14, 16 and 18 are applied to the pump control 104 of the pressure compensated pump 10.
  • the increased pressure signal would be applied on the line 102 to the pump control 104 to upstage the same and provide a higher output pressure.
  • the pump 10 is operating at a high output pressure and a lesser one will suffice to provide the desired torque at the motors 22, movement of the plunger 78 by the operator to the right as viewed in Fig. 1 will result in a reduced pressure at the pump control 104 so that it may lower its output pressure accordingly.
  • a pressure upstage pump could be used in lieu thereof.
  • Such pumps typically operate at either a low pressure stage or a high pressure stage.
  • the pressure reducing valve 60 may be set to select the pressure at which the motors 22 begin to shift toward minimum displacement irrespective of whether the pump is operating in the high presusre stage or the low pressure stage as will be apparent to those skilled in the art. In such a case, the pressure reducing valve 60 does not set the absolute pressure applied to the motors 22, this being determined by the pressure of the output of the pump which will be dependant upon whether the pump is operating in the high or low pressure stage.
  • the pressure reducing valve 60 sets a pressure that will cause the motors 22 to shift towards minimum displacement if the system pressure falls below the value set by the valve 60.
  • the pressure compensating spool 32 will not always assume a modulating position under steady state conditions as shown in Fig. 1. If the system pressure is higher than the combined presure of that provided by the spring 36 and that acting on the piston 54 in a rightward direction, the spool 32 will shift to the left to connect the control systems of the motors 22 to the system reservoir via the valve 12. Consequently, the motors 22 will be at full displacement as is desired in such a situation.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Control Of Fluid Gearings (AREA)

Abstract

Un systeme d'entrainement d'un vehicule comprenant une sortie rotative, un deplacement variable, un moteur hydraulique (22) concu pour entrainer une roue ou un organe similaire, une pompe (10) alimentant le moteur en fluide hydraulique sous pression, une vanne de controle de la pression 130) reliee au moteur pour reguler son deplacement afin d'obtenir la pression desiree dans le systeme, et possedant une surface (34) sensible a la pression qui recoit un signal representant la pression du systeme et un ressort de rappel (36) fonctionnant en opposition. L'invention prevoit une amelioration dans laquelle un dispositif (60, 106) de reduction de la pression, variable, reglable, et connecte a la pompe ainsi qu'a la vanne de controle de la pression afin d'appliquer le fluide hydraulique sous pression reduite a la vanne de controle de pression en opposition au signal de pression du systeme.
PCT/US1979/000070 1979-02-08 1979-02-08 Commande de couple pour des moteurs hydrauliques WO1982000868A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US1979/000070 WO1982000868A1 (fr) 1979-02-08 1979-02-08 Commande de couple pour des moteurs hydrauliques

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
WOUS79/00070 1979-02-08
US18954790208 1979-02-08
PCT/US1979/000070 WO1982000868A1 (fr) 1979-02-08 1979-02-08 Commande de couple pour des moteurs hydrauliques

Publications (1)

Publication Number Publication Date
WO1982000868A1 true WO1982000868A1 (fr) 1982-03-18

Family

ID=22147507

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1979/000070 WO1982000868A1 (fr) 1979-02-08 1979-02-08 Commande de couple pour des moteurs hydrauliques

Country Status (1)

Country Link
WO (1) WO1982000868A1 (fr)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3984978A (en) * 1974-11-22 1976-10-12 The Cessna Aircraft Company Auxiliary front wheel drive

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3984978A (en) * 1974-11-22 1976-10-12 The Cessna Aircraft Company Auxiliary front wheel drive

Similar Documents

Publication Publication Date Title
US4400935A (en) Engine speed control
KR930006598B1 (ko) 정수압식 차량 제어장치
US4023637A (en) Programmable electronic tracking control for vehicles with hydrostatic transmissions
JP2004526916A (ja) バリエータの油圧制御回路
US3964262A (en) Hydrostatic transmission control system
US3988893A (en) Hydrostatic transmission drive system
US5447029A (en) Hydrostatic transmission control system
US5561979A (en) Control arrangement for a hydrostatic system
US20010025488A1 (en) Hydrostatic vehicle drive with control device and control device for hydrostatic drives
US4756157A (en) Control device for a hydrostatic gear
GB1435932A (en) Hydrostatic transmission drive system
GB1435931A (en) Hydrostatic transmissions
US4543787A (en) Controls for continuously adjustable drive
US4483663A (en) Output speed droop compensating pump control
US4107924A (en) Pump upgrading system
US4195479A (en) Torque control of hydraulic motors
US4189920A (en) Load signal control of hydraulic motor displacement
US4017219A (en) Control system for variable displacement pumps
US3800535A (en) Hydrostatic transmission control system
US4689955A (en) Vibration roller having a power limiting device
CA1191073A (fr) Transmission de couple
US4518320A (en) Variable displacement pump system
US5056311A (en) Hydrostatic steering device
US5184691A (en) Auxiliary power steering system
US4815289A (en) Variable pressure control

Legal Events

Date Code Title Description
AK Designated states

Designated state(s): US