High efficiency pneumatically driven electric power generator

• US 6,628,019 B2
• Filed: 07/21/1999
• Issued: 09/30/2003
• Est. Priority Date: 07/21/1999
• Status: Expired due to Term

• Current Assignee: Westinghouse Air Brake Co (Westinghouse Air Brake Technologies Corporation)
• Original Assignee: Westinghouse Air Brake Technologies Corporation
• Inventors: Carroll, John B.
• Primary Examiner(s): Ramirez, Nestor
• Assistant Examiner(s): Perez, Guillermo
• Application Number:
  US09/358,206
• Publication Number:
  US 20020047324A1
• Time in Patent Office: 1,532 Days
• Field of Search: 310/28, 310/30, 310/67.R, 310/12, 310/14, 310/15, 310/16, 310/17, 310/20, 310/21, 310/23, 310/36, 310/37
• US Class Current: 310/30
• CPC Class Codes: H02K 35/02 with moving magnets and stationary coil systems
• CPC Class Codes: H02K 7/1892 Generators with parts oscillating or vibrating about an axis

Abstract

A pneumatically driven electric power generator includes a cylinder having one end connected to an air supply passage for receiving pressurized air and a piston having an associated magnetic moment. A portion of the piston is free to move into and out of the open end of the cylinder. An O-ring prevents airflow between the piston and the cylinder when a portion of the piston is located within the cylinder. A spring forces the piston from a position outside of the cylinder to a position inside the cylinder, so that the piston oscillates, moving into and out of the cylinder, driven by air supplied through the air supply passage. One or more electric coils are placed to enclose changing magnetic flux caused by the magnetic moment associated with the oscillating piston whereby an emf is generated in the coil(s) so that an external circuit connected to the coil(s) to complete a circuit through the coil(s) may receive electric power from the coil(s).

Claims

1. A pneumatically driven electric power generator comprising:

a single cylinder having a first end connectable through a single inlet flowpath to an air supply passage containing air at a positive pressure, a second end of said cylinder being open;

a cylinder extension at least one of formed integrally with and attached to said single cylinder, said cylinder extension having an inner surface having a transverse dimension greater than a transverse dimension of said single cylinder, said cylinder extension including a threaded portion adjacent one end thereof;

an end closure threadably connected to an end of said cylinder extension;

a single piston having a magnetic moment associated therewith, said piston being positionable in a first location wherein at least a first portion of said piston is disposed within said cylinder and in a second location wherein said first portion of said single piston is outside of said single cylinder so that clearance is provided between said single cylinder so that air may exhaust from said single cylinder;

sealing means disposed on at least one of an outer surface of said first portion of said single piston and an inner surface of said mingle cylinder to prevent loss of air between said single piston and said single cylinder and permit air pressure in said single cylinder to increase when said first portion of said single piston is disposed within said single cylinder;

a single biasing means caged between a ledge portion adjacent one end of said single piston and an inner surf ace of said end closure for moving said single piston from said second position toward said first position so that after said single cylinder has substantially exhausted, said single piston moves to said first position, whereby said single piston oscillates, moving back and forth between said first position and said second position, driven alternately by air supplied through such air supply passage to said single cylinder and by said biasing means; and

at least one electric coil placed to enclose changing magnetic flux caused by said magnetic moment associated with said piston whereby an emf is generated in said electric coil, so that an external circuit connected to said electric coil receives electric power from said electric coil.

2. A pneumatically driven electric power generator, according to claim 1, wherein said sealing means is an O-ring in a groove formed on said outer surface of said first portion of said piston.

3. A pneumatically driven electric power generato,r according to claim 1, wherein said inlet flowpath includes an air filter for excluding foreign material from said cylinder.

4. A pneumatically driven electric power generator, according to claim 1, wherein said inlet flowpath includes a choke to control an impedance of said inlet flowpath.

5. A pneumatically driven electric power generator, according to claim 1, wherein said generator further includes an exhaust passage connected to at least one of said cylinder extension and said end closure.

6. A pneumatically driven electric power generator, according to claim 5, wherein said piston further includes a piston extension at least one of formed integrally with and attached to said piston, at least a portion of said piston extension contacting at least a portion of said cylinder extension to provide positional constraint to said piston.

7. A pneumatically driven electric power generator, according to claim 6, wherein said portion of said piston extension contacting at least a portion of said cylinder extension is an outer surface of said piston extension and said portion of said cylinder extension is an inner surface of said cylinder extension.

8. A pneumatically driven electric power generator, according to claim 7, wherein at least one of said outer surface of said piston extension and said inner surface of said cylinder extension is at least one of made from and coated with a low friction material.

9. A pneumatically driven electric power generator, according to claim 6, wherein said piston extension has at least one longitudinal air passage to carry air to an end of said piston adjacent said end closure, said exhaust being connected to said end closure.

10. A pneumatically driven electric power generator, according to claim 9, wherein said at least one longitudinal air passage is a longitudinal slot formed in said outer surface of said piston extension.

11. A pneumatically driven electric power generator, according to claim 6, wherein said magnetic moment associated with said piston is provided by a magnet attached to at least one of said piston and said piston extension.

12. A pneumatically driven electric power generator, according to claim 6, wherein said magnetic moment associated with said piston is provided by forming at least one of said piston and said piston extension of a material having a magnetic moment.

13. A pneumatically driven electric power generator, according to claim 5, wherein said exhaust passage includes a muffler to reduce noise released from said generator.

14. A pneumatically driven electric power generator, according to claim 5, wherein said exhaust passage includes an electrically actuated shutoff valve to prevent air flow through said generator, thereby turning off said generator.

15. A pneumatically driven electric power generator, according to claim 1, wherein said biasing means is a spring.

16. A pneumatically driven electric power generator, according to claim 15, wherein said spring is a compression spring disposed between said piston extension and said end closure.

17. A pneumatically driven electric power generator, according to claim 1, wherein said inlet flowpath includes an electrically actuated shutoff valve to prevent air flow through said generator, thereby turning off said generator.

18. A pneumatically driven electric power generator, according to claim 1, wherein said at least one electric coil is connected to a rectifier to supply DC electric power.

19. A pneumatically driven electric power generator, according to claim 18, wherein said rectifier is a full bridge rectifier to supply DC electric power whenever a net flux through said at least one electric coil is changing.

20. A pneumatically driven electric power generator comprising:

a first cylinder having a first end connectable through a first inlet flowpath to an air supply passage, a second end of said first cylinder being open;

a first cylinder extension at least one of formed integrally with and attached to said first cylinder, said first cylinder extension having an inner surface having a transverse dimension greater than a transverse dimension of said first cylinder;

a second cylinder having a first end connectable through a second inlet flowpath to said air supply passage, a second end of said second cylinder being open;

a second cylinder extension at least one of formed integrally with and attached to said second cylinder, said second cylinder extension having an inner surface having a transverse dimension greater than a transverse dimension of said second cylinder;

a means for connecting said first cylinder extension and said second cylinder extension;

a common exhaust for said first cylinder and said second cylinder;

a single piston having a magnetic moment associated therewith, said single piston having a first end portion and a second end portion, said single piston being positionable in a first location wherein said first end portion of said single piston is disposed within said first cylinder and said second end portion of said single piston is disposed outside of said ascend cylinder, said single piston further being positionable in a second location wherein said second end portion of said single piston is disposed within said second cylinder and said first portion of said single piston is outside of said first cylinder;

so that when said single piston is disposed in said first position, air pressure received in said first cylinder through said first inlet flowpath drives said single piston toward said second position, whereupon said first cylinder exhausts, and when said single piston is disposed in said second position, air pressure received in said second cylinder through said second inlet flowpath drives said single piston toward said first position, whereupon said second cylinder exhausts, so that said single piston oscillates; and

at least one electric coil placed to enclose changing magnetic flux caused by said magnetic moment associated with said piston whereby an emf is generated in said electric coil, so that an external circuit connected to said electric coil receives electric power from said electric coil.

21. A pneumatically driven electric power generator, according to claim 20, wherein said generator further includes a spring engaging said piston to bias said piston toward one of said first position and said second position to facilitate starting said generator when air is supplied through said first air supply passage and said second air supply passage.