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Patent Searching and Data


Title:
SPEED GOVERNOR FOR A PNEUMATIC ROTATION MOTOR
Document Type and Number:
WIPO Patent Application WO/2002/052127
Kind Code:
A1
Abstract:
A speed governor for a pneumatic rotation motor having a pressure air inlet passage (15, 15'), an inlet valve (16; 56) including a flow controlling valve element (18; 58) located in the inlet passage (15, 15'), and a speed responsive activating device (24; 54) operatively connected to the inlet valve (16; 56), wherein the activating device (24, 54) comprises a pilot circuit with an activating surface (20; 70) on the valve element (18; 58), a restricted air supply opening (21, 72) communicating with the activating surface (20; 70), a bleed-off valve (24; 54) which communicates with the activating surface (20; 70) and which comprises an electromagnet actuator (27; 76), and a generator (30) driven by the motor and delivering to the actuator (27; 76) a voltage of a magnitude responsive to the actual motor speed to thereby make the bleed-off valve (24; 54) operate in response to the output voltage of the generator (30) and the actual motor speed.

Inventors:
JACOBSSON ROLF ALEXIS (SE)
Application Number:
PCT/SE2001/002834
Publication Date:
July 04, 2002
Filing Date:
December 20, 2001
Export Citation:
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Assignee:
ATLAS COPCO TOOLS AB (SE)
JACOBSSON ROLF ALEXIS (SE)
International Classes:
B25F5/00; F01D15/06; F02C1/02; F01D15/10; H02P9/04; (IPC1-7): F01D17/06; F01D21/02; G05D13/00
Foreign References:
US4465443A1984-08-14
US3923429A1975-12-02
US3446483A1969-05-27
US3410030A1968-11-12
US3198954A1965-08-03
Attorney, Agent or Firm:
Pantzar, Tord (Atlas Copco Tools AB Stockholm, SE)
Download PDF:
Claims:
Claims.
1. Speed governor for a pneumatic rotation motor having a rotor (11) and a stator (10) with a pressure air inlet passage (15), comprising an inlet valve (16 ; 56) with a flow controlling valve element (18 ; 58) disposed in said inlet passage (15 je5), and a speed responsive activating device (24 ; 54) operatively connected to said inlet valve (16 ; 58), c h a r a c t e r i z e d in that said activating device (24 ; 54) comprises a pneumatic pilot circuit (21,20,25 ; 72, 70,77,78) for governing the operation of said inlet valve (16 ; 56), said pilot circuit (21,20,25 ; 72,70,77,78) comprises: an activating surface (20 ; 70) on said valve element (18 ; 58), a restricted pressure air supply opening (21 ; 72) communicating with said activating surface (20 ; 70), an air bleedoff valve (24 ; 54) communicating with said activating surface (20 ; 70) and comprising an electro magnetic actuator (27 ; 76), and a generator (30) driven by said motor and delivering a motor speed responsive output voltage, said generator (30) is connected to said electromagnetic actuator (27 ; 76) for accomplishing operation of said bleedoff valve (24; 54) and said inlet valve (16 ; 56) in response to said output voltage.
2. Speed governor according to claim 1, wherein said generator (30) comprises a permanent magnet (32) rigidly secured to said motor rotor (11), and a toroidshaped stator winding (34).
3. Speed governor according to claim 2, wherein said permanent magnet (32) is a bar magnet secured in a coaxial extension (33) of said motor rotor (11).
4. Speed governor according to claim 1, wherein said activating surface (70) is formed by a closed bellow (68) associated with said valve element (58), said bellow (68) is supplied with pressure air via said restricted pressure air supply opening (72) and is drained via said bleedoff valve (54) in response to the output voltage of said generator (30).
5. Speed governor according to claim 1 or 2, wherein said generator (30) is an alternator, and a rectifier (31) is provided between said generator (30) and said electro magnetic actuator (27 ; 76).
6. Speed governor according to anyone of claims 1 5, wherein said bleedoff valve (24 ; 54) comprises an outlet opening (25 ; 78), and a disc shaped valve element (26 ; 79) which is located across said opening (25 ; 78) for controlling the outflow therefrom, said disc shaped valve element (26 ; 79) consists of a ferromagnetic material for cooperation with said electromagnetic actuator (27 ; 76).
7. Speed governor according to anyone of claims 16, wherein said rotation motor is a turbine having a circumferential row of drive blades (12) on said rotor (11), and one or more air inducing drive nozzles (13) in said stator (10) communicating with said air inlet passage (15 je5') via said inlet valve (16 ; 56).