US5320499A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Open-loop hydraulic supply system
Assignee: Danfoss Power Solutions II Ltd
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Filing: 1992-09-10
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Granted: 1994-06-14
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Expires: 2012-09-10
Abstract
Abstract A system comprising a secondary mover such as an hydraulic pump driven by a prime mover such as a motor powered, in use, by an alternating current (AC) electrical supply, whereby the operation of the secondary mover is affected by any frequency variation in a substantially constant voltage AC supply. The system further comprises adjustment means in use powered by the same AC supply as the prime mover, having inherently substantially the same operating characteristics as the prime mover, being coupled to the secondary mover and operable to adjust the operating range thereof in accordance with variations in the frequency of the AC supply.
Inventors
- 👤 Peter M. Hamey
- 👤 John Ineson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:43
CPC Classifications
F; F04; F04B; F04B49/00; F04B49/10; F04B49/103; F04B49/06; F04B49/08
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
197 words
An open-loop hydraulic supply system comprising a variable displacement swash pump driven by an electric motor in use powered by an alternating current (AC) electrical supply, whereby the operation of the pump is affected by any frequency variation in the AC supply, characterised in that the system further comprises adjustment means in use powered by the same AC supply as the motor, having an inherently substantially similar operating characteristic as the motor, and being coupled to the pump and operable to adjust the operating range thereof in accordance with variations in the frequency of the AC supply, the adjustment means comprising first cylinder means in which the piston of the yoke actuator of the swash pump is mounted for limited sliding movement, the extent of which movement determines the operating range of the pump, the first cylinder means being slidably mounted, in the manner of a piston, in a second and fixed cylinder of the adjustment means, and electromagnetic drive means coupled to the first cylinder means is positioned within the second cylinder means in accordance with any variation in the frequency of the AC supply so as to vary the range of operation of the pump.
Claim 2
Dependent Claim
197 words
An open-loop hydraulic supply system comprising a variable displacement swash pump driven by an electric motor in use powered by an alternating current (AC) electrical supply, whereby the operation of the pump is affected by any frequency variation in the AC supply, characterised in that the system further comprises adjustment means in use powered by the same AC supply as the motor, having an inherently substantially similar operating characteristic as the motor, and being coupled to the pump and operable to adjust the operating range thereof in accordance with variations in the frequency of the AC supply, the adjustment means comprising first cylinder means in which the piston of the yoke actuator of the swash pump is mounted for limited sliding movement, the extent of which movement determines the operating range of the pump, the first cylinder means being slidably mounted, in the manner of a piston, in a second and fixed cylinder of the adjustment means, and electromagnetic drive means coupled to the first cylinder means is positioned within the second cylinder means in accordance with any variation in the frequency of the AC supply so as to vary the range of operation of the pump.
Claim 3
Dependent Claim
37 words
A system according to claim 1, wherein the inherently substantially similar operating characteristic is that of the torque or force output of the adjustment means and the motor is similarly entirely proportional to the AC supply frequency.
Claim 4
Dependent Claim
20 words
A system according to claim 1, wherein the adjustment means comprises electromagnetic means energized, in use, by said AC supply.
Claim 5
Dependent Claim
13 words
A system according to claim 3, wherein the electromagnetic means comprises a solenoid.
Claim 6
Dependent Claim
14 words
A system according to claim 3, wherein the electromagnetic means comprises a force motor.
Claim 7
Dependent Claim
14 words
A system according to claim 3, wherein the electromagnetic means comprises an electric motor.
Claim 8
Dependent Claim
31 words
A system according to claim 1, wherein the piston is provided with a collar which is engageable with the open end of the first cylinder means to limit said sliding movement.
Claim 9
Dependent Claim
30 words
A system according to claim 1, wherein the flow of hydraulic fluid is to be maintained substantially constant, the apparatus further comprising hydraulically-operated modulation means controlled by the adjustment means.
Claim 10
Dependent Claim
28 words
A system according to claim 8, wherein the modulation means comprises a sleeve in which is slidably mounted a spool, the sleeve and spool acting against spring means.
Claim 11
Dependent Claim
25 words
A system according to claim 8, wherein the modulation means comprises a piston generally coaxially mounted with a spool valve with spring means acting therebetween.
Claim 12
Dependent Claim
21 words
A system according to claim 1, wherein the adjustment means (90) is operable to adjust the torque of the secondary mover.
Claim 13
Dependent Claim
22 words
A system according to claim 1, wherein the adjustment means is operable to adjust the stroke or pressure of the swash pump.
Claim 14
Dependent Claim
143 words
An open-loop hydraulic system system for controlling the range of operation of a secondary hydraulic mover driven by an electric prime mover powered, in use, by substantially constant voltage alternating current variable frequency (AC) electrical supply, whereby the operation of the secondary mover is affected by any frequency variation in the AC supply, characterised in that the system further comprises AC electric adjustment means (90) on the secondary mover, the movement of which determines the operation range of the secondary mover in use powered by the same AC supply as the prime mover, having an inherently substantially similar operating characteristic as the prime mover, and being coupled to the secondary mover and operable to adjust the operating range of the secondary mover in accordance with variations in the frequency of the AC supply so as to vary the operation of the secondary mover.
Claim 15
Dependent Claim
143 words
An open-loop hydraulic system system for controlling the range of operation of a secondary hydraulic mover driven by an electric prime mover powered, in use, by substantially constant voltage alternating current variable frequency (AC) electrical supply, whereby the operation of the secondary mover is affected by any frequency variation in the AC supply, characterised in that the system further comprises AC electric adjustment means (90) on the secondary mover, the movement of which determines the operation range of the secondary mover in use powered by the same AC supply as the prime mover, having an inherently substantially similar operating characteristic as the prime mover, and being coupled to the secondary mover and operable to adjust the operating range of the secondary mover in accordance with variations in the frequency of the AC supply so as to vary the operation of the secondary mover.
Claim 16
Dependent Claim
14 words
Apparatus according to claim 13, wherein the prime mover is a ram air turbine.
Claim 17
Dependent Claim
123 words
An open-loop hydraulic supply system comprising a variable displacement pump driven by an electric motor in use powered by an alternating current (AC) electrical supply, whereby the operation of the pump is affected by any frequency variation in the AC supply, characterised in that the system further comprises adjustment means on the pump, the movement of which determines the operating range of the pump in use powered by the same AC supply as the motor, having an inherently substantially similar operating characteristic as the motor, and being coupled to the pump and operable to adjust the operating range of the pump in accordance with variations in the frequency of the AC supply so as to vary the range of operation of the pump.
Claim 18
Dependent Claim
123 words
An open-loop hydraulic supply system comprising a variable displacement pump driven by an electric motor in use powered by an alternating current (AC) electrical supply, whereby the operation of the pump is affected by any frequency variation in the AC supply, characterised in that the system further comprises adjustment means on the pump, the movement of which determines the operating range of the pump in use powered by the same AC supply as the motor, having an inherently substantially similar operating characteristic as the motor, and being coupled to the pump and operable to adjust the operating range of the pump in accordance with variations in the frequency of the AC supply so as to vary the range of operation of the pump.
Claim 19
Dependent Claim
24 words
A system according to any one of claim 13 and 15 wherein the adjustment means comprises electromagnetic means in the form of a solenoid.
Claim 20
Dependent Claim
25 words
A system according to any one of claim 7 and 8 wherein the adjustment means comprises electromagnetic means in the form of a force motor.
Claim 21
Independent Claim
25 words
A system according to any one of claims 13 and 15 wherein the adjustment means comprises electromagnetic means in the form of an electric motor.
Claim 22
Dependent Claim
20 words
Apparatus according to any one of claim 13 or 15, wherein the adjustment means is powered by a permanent magnet.
Claim 23
Independent Claim
47 words
A system according to any one of claims 7 or 8, characterised in that the inherently substantially similar operating characteristic is that of the torque or force output of the adjustment means and the prime mover or motor being similarly entirely proportional to the AC supply frequency.
Claim 24
Independent Claim
27 words
A system according to any one of claims 13 or 15, characterised in that the adjustment means comprises electromagnetic means energised, in use, by said AC supply.
Claim 25
Independent Claim
24 words
A system according to any one of claims 13 or 15, wherein the adjustment means comprises electromagnetic means in the form of a solenoid.
Claim 26
Independent Claim
25 words
A system according to any one of claims 13 or 8, wherein the adjustment means comprises magnetic means in the form of a force motor.
Claim 27
Independent Claim
25 words
A system according to any one of claims 13 or 24, wherein the adjustment means comprises electromagnetic means in the form of an electric motor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-06-13 | 1997-12-13 | 1998-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-13 | 2001-12-13 | 2002-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-13 | 2005-12-13 | 2006-06-14 | $7700.00 | Window Closed / Lapsed |