Patent US5348448A successfully refreshed from Google Patents.
US5348448A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid rotating apparatus with plural drive motor synchronization system
Assignee: Panasonic Holdings Corp
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Filing: 1993-03-18
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Granted: 1994-09-20
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Expires: 2013-03-18
Abstract
Abstract A fluid rotating apparatus includes non-circular rotors accommodated in a housing, rotary shafts having the rotors, bearings for rotatably supporting the shafts, a fluid suction and a fluid discharge ports formed in the housing, a positive displacement pump section formed of combination of the housing and rotors, and gears connected with the shafts having backlash set smaller than backlash between the rotors. The apparatus includes motors for independently driving the shafts, a device for detecting a rotating angle or speed of rotation of the motors, a unit for controlling the motors to synchronously rotate, a unit for detecting a current running in the motors, a unit for detecting a relative position of the shafts, and a rotation commanding unit, to which outputs from the motor current detecting unit and relative position detecting unit are inputted, for deciding whether or not a shift amount of the synchronous rotation is larger than a specified value based on the outputs of the motor current detecting unit and/or the relative position detecting unit, and outputting to the motor controlling unit a signal to decelerate one shaft when the rotation command unit decides that the shift amount of the synchronous rotation is larger than the value.
Inventors
- 👤 Yoshihiro Ikemoto
- 👤 Teruo Maruyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:20
CPC Classifications
F; F04; F04C; F04C29/00; F04C29/0042; F04C29/0085; F04C18/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
265 words
A fluid rotating apparatus provided with a plurality of rotors accommodated in a housing, a plurality of rotary shafts connected to the rotors, bearings for rotatably supporting the plurality of rotary shafts, a fluid suction port and a fluid discharge port formed in the housing, a positive displacement pump section formed of combination of the housing and the plurality of rotors, and a plurality of gears connected with the rotary shafts having a backlash set smaller than a backlash between the plurality of rotors, the fluid rotating apparatus characterized by further comprising: motors for independently driving the plurality of rotary shafts; a rotation detecting means for detecting one of a rotating angle and speed of rotation of the motors; a motor controlling unit for controlling the motors to synchronously rotate; a motor current detecting unit for detecting a current running in the motors; a relative position detecting unit for detecting a relative position of the plurality of rotary shafts; and a rotation commanding unit, to which outputs from the motor current detecting unit and the relative position detecting unit are inputted, for deciding whether or not a shift amount of the synchronous rotation of the plurality of rotary shafts is larger than a specified value based on the outputs of the motor current detecting unit and/or the relative position detecting unit, and outputting to the motor controlling unit a signal to decelerate one of the plurality of rotary shafts when the rotation command unit decides that the shift amount of the synchronous rotation of the plurality of rotary shafts is larger than the specified value.
Claim 2
Dependent Claim
265 words
A fluid rotating apparatus provided with a plurality of rotors accommodated in a housing, a plurality of rotary shafts connected to the rotors, bearings for rotatably supporting the plurality of rotary shafts, a fluid suction port and a fluid discharge port formed in the housing, a positive displacement pump section formed of combination of the housing and the plurality of rotors, and a plurality of gears connected with the rotary shafts having a backlash set smaller than a backlash between the plurality of rotors, the fluid rotating apparatus characterized by further comprising: motors for independently driving the plurality of rotary shafts; a rotation detecting means for detecting one of a rotating angle and speed of rotation of the motors; a motor controlling unit for controlling the motors to synchronously rotate; a motor current detecting unit for detecting a current running in the motors; a relative position detecting unit for detecting a relative position of the plurality of rotary shafts; and a rotation commanding unit, to which outputs from the motor current detecting unit and the relative position detecting unit are inputted, for deciding whether or not a shift amount of the synchronous rotation of the plurality of rotary shafts is larger than a specified value based on the outputs of the motor current detecting unit and/or the relative position detecting unit, and outputting to the motor controlling unit a signal to decelerate one of the plurality of rotary shafts when the rotation command unit decides that the shift amount of the synchronous rotation of the plurality of rotary shafts is larger than the specified value.
Claim 3
Dependent Claim
49 words
The fluid rotating apparatus as claimed in claim 1, wherein the rotation command unit outputs such a signal to the motor controlling unit that a current to all of the motors is stopped to the plurality of rotary shafts while the contact of the plurality of gears is maintained.
Claim 4
Dependent Claim
21 words
The fluid rotating apparatus as claimed in claim 1, wherein the plurality of rotors are formed in the shape of screws.
Claim 5
Dependent Claim
40 words
The fluid rotating apparatus as claimed in claim 1, wherein the specified value for comparing with the shift amount of the synchronous rotation of the plurality of rotary shafts is set to be less than the backlash between the gears.
Claim 6
Dependent Claim
34 words
The fluid rotating apparatus as claimed in claim 1, wherein the rotation commanding unit outputs to the motor controlling unit a signal to decelerate and then stop one of the plurality of rotary shafts.
Claim 7
Dependent Claim
54 words
The fluid rotating apparatus as claimed in claim 1, wherein the rotation command unit outputs such a signal to the motor controlling unit that the plurality of rotary shafts are decelerated while a current is continuously supplied to one of the motors and a current is not supplied to the other of the motors.
Claim 8
Dependent Claim
63 words
The fluid rotating apparatus as claimed in claim 6, wherein after the plurality of rotary shafts are decelerated while a current is continuously supplied to one of the motors and a current is not supplied to the other of the motors, the rotation command unit outputs such a signal to the motor controlling unit that the plurality of rotary shafts rotate synchronously again.
Claim 9
Independent Claim
289 words
A method for controlling rotation of rotors in a fluid rotating apparatus provided with a plurality of rotors accommodated in a housing, a plurality of rotary shafts connected to the rotors, bearings for rotatably supporting the plurality of rotary shafts, a fluid suction port and a fluid discharge port formed in the housing, a positive displacement pump section formed of a combination of the housing and the plurality of rotors, and a plurality of gears connected with the rotary shafts having a backlash set smaller than a backlash between the plurality of rotors, the fluid rotating apparatus further including motors for independently driving the plurality of rotary shafts, a rotation detecting means for detecting one of a rotating angle and speed of rotation of the motors, a motor controlling unit for controlling the motors to synchronously rotate, a motor current detecting unit for detecting a current running in the motors, a relative position detecting unit for detecting a relative position of the plurality of rotary shafts and a rotation commanding unit to which outputs from the motor current detecting unit and the relative position detecting unit are inputted, the method characterized by comprising the steps of: detecting a shift amount of the synchronous rotation of the plurality of rotary shafts based on the outputs of the motor current detecting unit and/or the relative position detecting unit; deciding by the rotation command unit whether or not the shift amount of the synchronous rotation of the plurality of rotary shafts is larger than a specified value; and decelerating one of the plurality of rotary shafts when the rotation command unit decides that the shift amount of the synchronous rotation of the plurality of rotary shafts is larger than the specified value.
Claim 10
Independent Claim
289 words
A method for controlling rotation of rotors in a fluid rotating apparatus provided with a plurality of rotors accommodated in a housing, a plurality of rotary shafts connected to the rotors, bearings for rotatably supporting the plurality of rotary shafts, a fluid suction port and a fluid discharge port formed in the housing, a positive displacement pump section formed of a combination of the housing and the plurality of rotors, and a plurality of gears connected with the rotary shafts having a backlash set smaller than a backlash between the plurality of rotors, the fluid rotating apparatus further including motors for independently driving the plurality of rotary shafts, a rotation detecting means for detecting one of a rotating angle and speed of rotation of the motors, a motor controlling unit for controlling the motors to synchronously rotate, a motor current detecting unit for detecting a current running in the motors, a relative position detecting unit for detecting a relative position of the plurality of rotary shafts and a rotation commanding unit to which outputs from the motor current detecting unit and the relative position detecting unit are inputted, the method characterized by comprising the steps of: detecting a shift amount of the synchronous rotation of the plurality of rotary shafts based on the outputs of the motor current detecting unit and/or the relative position detecting unit; deciding by the rotation command unit whether or not the shift amount of the synchronous rotation of the plurality of rotary shafts is larger than a specified value; and decelerating one of the plurality of rotary shafts when the rotation command unit decides that the shift amount of the synchronous rotation of the plurality of rotary shafts is larger than the specified value.
Claim 11
Dependent Claim
39 words
The method as claimed in claim 8, wherein in the decelerating step, a current to all of the motors is stopped to thereby decelerate the plurality of rotary shafts while the contact of the plurality of gears is maintained.
Claim 12
Dependent Claim
42 words
The method as claimed in claim 8, wherein in the deciding step, the specified value for comparing with the shift amount of the synchronous rotation of the plurality of rotary shafts is set to be less than the backlash between the gears.
Claim 13
Dependent Claim
22 words
The method as claimed in claim 8, wherein in the decelerating step, the one of the plurality of rotary shafts stops finally.
Claim 14
Dependent Claim
42 words
The method as claimed in claim 8, wherein in the decelerating step, the plurality of rotary shafts are decelerated while a current is continuously supplied to one of the motors and a current is not supplied to the other of the motors.
Claim 15
Dependent Claim
24 words
The method as claimed in claim 12, further comprising, after the decelerating step, a step of synchronously rotating the plurality of rotary shafts again.
References Cited (Backward Citations)
JPS5882266A
Cited
JPS58103889A
Cited
SU1179516A1
Cited
US4617498A
Cited
EP0221003A2
Cited
JPS62195481A
Cited
US4808077A
Cited
JPS6455089A
Cited
JPH01200084A
Cited
JPH0343689A
Cited
US5197861A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-09-19 | 1998-03-21 | 1998-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-19 | 2002-03-21 | 2002-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-19 | 2006-03-21 | 2006-09-20 | $7700.00 | Window Closed / Lapsed |