US3733813A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speed control system for hydraulic motor
Assignee: Harnischfeger Corp
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Filing: 1971-11-03
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Granted: 1973-05-22
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Expires: 1991-11-03
Abstract
Abstract Several embodiments of a speed control system for a hydraulic hoist motor are disclosed. The speed control means comprise a main hydraulic pump for driving the hoist motor; regulating means to vary the direction of flow and volume of fluid supplied to the hoist motor to thereby regulate motor direction and speed, respectively; and selectively operable operating means to actuate the regulating means. The operating means comprise a speed sensing hydraulic motor responsive to hoist motor speed. The operating means further comprise a manually or remotely controlled over-center pump for supplying a predetermined volume of fluid to the speed sensing motor through a control circuit to obtain a predetermined operating speed for the hoist motor. The fluid pressure in the control circuit theoretically is constant for any predetermined hoist motor speed but actually varies in proportion to changes in hoist motor speed (caused by load changes) to effect constant motor speed. In one embodiment, the main pump is a constant volume pump and it s output (and therefore hoist motor speed) is regulated by a pilot operated multi-position directional valve responsive to fluid pressure in the control circuit. In another embodiment, the main pump is a variable volume pump having its output (therefore hoist motor speed) regulated by a servo-stem device movable by a hydraulic actuator which, in turn, is responsive to fluid pressure in the control circuit.
Inventors
- 👤 R Gordon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:30
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/46; F16H61/47; B; B62; B62D; B62D11/00; B62D11/02; B62D11/06; B62D11/10; B62D11/14; B62D11/18; B62D11/183; B66; B66D; B66D1/00; B66D1/02; B66D1/08; B66D2700/00; B66D2700/01; B66D2700/0125; B66D2700/0133
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
159 words
A control system for a hydraulic motor comprises: a. fluid supply means, including a main pump, for supplying pressurized hydraulic fluid to said motor to effect its direction and speed of rotation; b. regulating means for said fluid supply means to vary the volume of fluid supplied from said fluid supply means to said motor and thereby control motor direction and speed, said regulating means comprising first multi-position valve means including a first multi-position control member therefor; c. and operating means for said regulating means comprising: i. a speed sensing hydraulic motor responsive to the direction and speed of said motor; and ii. pump means for supplying a predetermined volume of fluid to said speed sensing motor; said regulating means being responsive to the pressure of said fluid being supplied to said speed sensing motor to vary the volume of fluid supplied from said fluid supply means to said motor to regulate the direction and speed of said motor.
Claim 2
Dependent Claim
159 words
A control system for a hydraulic motor comprises: a. fluid supply means, including a main pump, for supplying pressurized hydraulic fluid to said motor to effect its direction and speed of rotation; b. regulating means for said fluid supply means to vary the volume of fluid supplied from said fluid supply means to said motor and thereby control motor direction and speed, said regulating means comprising first multi-position valve means including a first multi-position control member therefor; c. and operating means for said regulating means comprising: i. a speed sensing hydraulic motor responsive to the direction and speed of said motor; and ii. pump means for supplying a predetermined volume of fluid to said speed sensing motor; said regulating means being responsive to the pressure of said fluid being supplied to said speed sensing motor to vary the volume of fluid supplied from said fluid supply means to said motor to regulate the direction and speed of said motor.
Claim 3
Dependent Claim
27 words
A control system according to claim 1 wherein said pump means comprises an over-center pump and second multi-position valve means including a second multi-position control member therefor.
Claim 4
Dependent Claim
57 words
A control system according to claim 2 wherein said main pump is a constant volume pump; wherein said first multi-position valve means is a directional valve wherein a movable valve spool serves as said first multi-position control member; and wherein said valve spool responds to the pressure of the fluid being supplied to said speed sensing motor.
Claim 5
Dependent Claim
64 words
A control system according to claim 2 wherein said main pump is a variable volume pump; wherein said first multi-position valve means is a multi-position speed control valve on said main pump wherein a servo-stem serves as said first multi-position control member; and including actuator means responsive to the pressure of the fluid being supplied to said speed sensing motor to move said servo-stem.
Claim 6
Dependent Claim
31 words
A control system according to claim 2 wherein said over-center pump operates at constant speed and said second multi-position valve means controls the volume of fluid delivered by said over-center pump.
Claim 7
Dependent Claim
16 words
A control system according to claim 5 wherein said second multi-position control member is manually operated.
Claim 8
Dependent Claim
19 words
A control system according to claim 5 wherein said second multi-position control member is remotely operated by actuator means.
Claim 9
Dependent Claim
53 words
A control system according to claim 3 wherein said directional valve is a three-position variable orifice type valve for regulating motor speed and direction of rotation; and wherein said second multi-position valve is a three-position variable orifice type valve for said over-center pump for effecting changes in motor speed and direction of rotation.
Claim 10
Dependent Claim
59 words
A control system according to claim 4 wherein said multi-position speed control valve on said main pump is a three-position variable orifice type valve for regulating motor speed and direction of rotation; and wherein said second multi-position valve is a three-position vairable orifice type valve for said over-center pump for effecting changes in motor speed and direction of rotation.
Claim 11
Dependent Claim
48 words
A control system according to claim 1 wherein said motor is a hoist motor and wherein said speed sensing motor is directly responsive to the speed and direction of rotation of said hoist motor to effect constant speed of said hoist motor despite variations in load imposed thereon.
Claim 12
Dependent Claim
57 words
A control system according to claim 1 wherein said motor is a hoist motor and wherein said speed sensing motor is directly responsive to the speed and direction of movement of a hoist line to effect speed regulation of said hoist motor to maintain hoist line speed constant despite variation in load imposed on said hoist motor.
Claim 13
Dependent Claim
208 words
A control system for a hydraulic motor comprising: a. a main pump for supplying pressurized hydraulic fluid to said motor to effect its direction and speed of rotation; b. regulating means for said main pump to vary the direction and volume of fluid supplied from said pump to said motor and thereby control motor direction and speed of rotation, said regulating means comprising first multi-position valve means and a first multi-position control member therefor; c. and operating means for said first multi-position valve means comprising: i. a speed sensing hydraulic motor responsive to the direction and speed of rotation of said motor, said speed sensing motor capable of accommodating a predetermined volume of fluid at a predetermined speed of rotation; ii. pump means for supplying a predetermined volume of fluid to said speed sensing motor, said pump means comprising an over-center pump and second multi-position valve means and a second multi-position control member therefor; and iii. a control circuit connected between said speed sensing motor and said over-center pump and to said regulating means; said regulating means being responsive to fluid pressure conditions in said control circuit to vary the direction and volume of fluid supplied to said motor to thereby control motor direction and speed of rotation.
Claim 14
Dependent Claim
208 words
A control system for a hydraulic motor comprising: a. a main pump for supplying pressurized hydraulic fluid to said motor to effect its direction and speed of rotation; b. regulating means for said main pump to vary the direction and volume of fluid supplied from said pump to said motor and thereby control motor direction and speed of rotation, said regulating means comprising first multi-position valve means and a first multi-position control member therefor; c. and operating means for said first multi-position valve means comprising: i. a speed sensing hydraulic motor responsive to the direction and speed of rotation of said motor, said speed sensing motor capable of accommodating a predetermined volume of fluid at a predetermined speed of rotation; ii. pump means for supplying a predetermined volume of fluid to said speed sensing motor, said pump means comprising an over-center pump and second multi-position valve means and a second multi-position control member therefor; and iii. a control circuit connected between said speed sensing motor and said over-center pump and to said regulating means; said regulating means being responsive to fluid pressure conditions in said control circuit to vary the direction and volume of fluid supplied to said motor to thereby control motor direction and speed of rotation.
Claim 15
Dependent Claim
71 words
A control system according to claim 12 wherein said speed sensing motor and said over-center pump each have two ports; wherein said control circuit comprises two fluid lines, each line being connected between one speed sensing motor port and one over-center pump port; and wherein said two fluid lines are connected to said first multi-position valve means of said regulating means to effect movement of said first multi-position control member therefor.
Claim 16
Dependent Claim
81 words
A control system according to claim 13 including a pair of fluid lines whereby fluid is supplied to said motor from said main pump and further including meanS for supplying additional fluid to said pair of fluid lines and to said two fluid lines in said control circuit to make up for fluid leakage in all of said lines when said motor and said speed sensing motor are being maintained in stationary condition and a load is imposed on said motor.
Claim 17
Dependent Claim
18 words
A control system according to claim 14 wherein said means for supplying additional fluid comprises said main pump.
Claim 18
Dependent Claim
18 words
A control system according to claim 14 wherein said means for supplying additional fluid comprises an auxiliary pump.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |