Hydraulic and pneumatic cylinder construction

• US 6,439,103 B1
• Filed: 09/07/2000
• Issued: 08/27/2002
• Est. Priority Date: 09/07/1999
• Status: Expired due to Fees

• Current Assignee: Vector Engineering Co.
• Original Assignee: Vector Engineering Co.
• Inventors: Miller, Gary L.
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): Lazo, Thomas E.
• Application Number:
  US09/656,767
• Time in Patent Office: 719 Days
• Field of Search: 921/28, 921/64, 921/691
• US Class Current: 92/128
• CPC Class Codes: F01B 29/00 Machines or engines with pertinent characteristics other than those provided for in preceding main groups
• CPC Class Codes: F15B 15/1438 Cylinder to end cap assemblies

Abstract

A fluid actuator includes a cylindrical housing with a flared open end and an opposite end having a diameter less than the flared end. A rod cap is insertable into the housing at the open end, and moveable through the housing to the opposite end where it is contained by an annular rim welded to the housing. A piston and piston rod assembly is inserted into the housing through the open end. A blind end cap, also insertable into the housing at the open end, is releasably secured near the open end to substantially close the housing. The piston is reciprocable in the housing between the rod cap and the blind end cap. The housing incorporates a conical ramp portion between the flared end and the smaller diameter end of the housing, to provide a gradual transition between the larger and smaller diameters. The ramp tends to center the components as they are inserted, and gradually and evenly compresses elastomeric seals of the components during their insertion, to better preserve the integrity of the seals. The rim is welded to the opposite end before insertion of the components, to avoid heat damage to the seals and permit painting or plating of the housing/rim combination before assembly. One (single acting) or two (double acting) passages, through the housing or through one or both of the end caps, are provided for supplying air or hydraulic fluid under pressure to the housing, to extend and/or retract the cylinder. In alternative embodiments, the positions of the rod cap and blind end cap are reversed, and the housing has a uniform diameter rather than a flared end.

Claims

1. An actuator enclosure for containing a reciprocating piston;

including;

a cylindrical housing defining a chamber including a first end region, a second end region opposite the first end region and including an open end of the housing, and a medial region between the first and second end regions;

a first end closure member insertable in a first axial direction into the chamber through the open end, and shaped for a conforming and contiguous surface engagement with the housing at a first predetermined location along the first end region;

a second end closure member insertable in the first axial direction into the chamber through the open end, and shaped for a conforming and contiguous surface engagement with the housing at a second predetermined location along the second end region; and

a closure member containing structure integral with the housing and positioned to engage the first closure member substantially upon a complete insertion thereof to the first predetermined location, thereby to prevent further travel of the first closure member in the first axial direction, the closure member containing structure including an annular rim extended radially inwardly from the housing and disposed at least proximate the first end region of the chamber;

wherein the housing is adapted to accommodate a piston for reciprocation along the medial region of the chamber, and a selected one of the first and second closure members includes an opening adapted to slideably support a piston rod coupled to the piston.

2. The enclosure of claim 1 wherein:

said annular rim is welded to an edge of the housing adjacent the first end region.

3. The enclosure of claim 1 further including:

a first closure member mounting device for securing the first end closure member with respect to the housing at the first predetermined location.

4. The enclosure of claim 3 wherein:

the first closure member mounting device includes a retaining structure for releasably securing the first end closure member against movement away from the first predetermined location in a second axial direction opposite to the first axial direction.

5. The enclosure of claim 4 wherein:

a portion of the first end closure member extends beyond the first end region of the housing when in the first predetermined location, and the retaining structure includes a groove formed circumferentially about the first closure member and a retaining ring removably mounted within the groove.

6. The enclosure of claim 3 further including:

a second closure member mounting device for releasably securing the second end closure member with respect to the housing at the second predetermined location.

7. The enclosure of claim 6 wherein:

the second closure member mounting device comprises a first opening formed in the second end closure member, at least one second opening formed through the housing along the second end region and positioned for an alignment with the first opening when the second end closure member is at the second predetermined location, and a pin insertable through the first and second openings to maintain said alignment.

8. The enclosure of claim 7 wherein:

the first opening extends through the second end closure member, the at least one second opening comprises two second openings on opposite sides of the housing, and the pin is insertable simultaneously through the first opening and both of the second openings to maintain said alignment.

9. The enclosure of claim 8 further including:

first and second bushings each inserted into the first opening through one of said second openings, and disposed in surrounding relation to the pin.

10. The enclosure of claim 6 wherein:

the second closure member mounting device comprises external threads formed about the second closure member, and corresponding internal threads formed in the housing along the second end region.

11. The enclosure of claim 6 wherein:

the second closure member mounting device comprises a groove formed in the second closure member, at least one slot formed through the housing and positioned for an alignment with the groove when the second closure member is at the second predetermined location, and a retaining ring releasably insertable through the slot and into the groove.

12. The enclosure of claim 1 wherein:

the first end region of the chamber has a first diameter, and the second end region at least along a portion thereof near the open end has a second diameter larger than the first diameter.

13. The enclosure of claim 12 wherein:

the medial region of the chamber has a third diameter substantially equal to the first diameter.

14. The enclosure of claim 13 wherein:

the housing incorporates a flared portion extending from the medial region to said portion of the second end region to provide a gradual transition from the first diameter to the second diameter.

15. The enclosure of claim 12 wherein:

the first end closure member is said selected one of the closure members and consists essentially of a rod end cap; and

the second end closure member consists essentially of a blind end cap.

16. The enclosure of claim 1 further including:

a closure member mounting device for releasably securing the second end closure member with respect to the housing at the second predetermined location.

17. The enclosure of claim 16 wherein:

the closure member mounting device comprises a first opening formed into the second end closure member, a second opening formed through the housing along the second end region and positioned for an alignment with the first opening when the second end closure member is at the second predetermined location, and a pin insertable through the first and second openings for maintaining said alignment.

18. The enclosure of claim 1 wherein:

said selected one of the end closure members is the first end closure member.

19. The enclosure of claim 1 wherein:

said selected one of the end closure members is the second end closure member.

20. The enclosure of claim 1 further including:

a piston mounted to reciprocate along the medial region of the chamber, and a fluid passage open to the medial region between the piston and one of the end closure members for supplying a fluid under pressure to the chamber.

21. The enclosure of claim 20 wherein:

said selected one of the closure members is the first end closure member, and the fluid passage is open to the chamber between the piston and the second end closure member.

22. The enclosure of claim 21 further including:

a second fluid passage open to the medial region of the chamber between the piston and the first end closure member for supplying a fluid under pressure to the chamber.

23. The enclosure of claim 22 wherein:

the first fluid passage is formed through the second end closure member, and the second fluid passage is formed through the first end closure member.

24. The enclosure of claim 20 wherein:

the fluid passage is formed through said one of the end closure members.

25. The enclosure of claim 1 wherein:

the first end closure member, the piston, and the second end closure member are insertable in succession through said open end, respectively to the first predetermined location, the medial region, and the second predetermined location.

26. The enclosure of claim 1 wherein:

said closure member containing structure further is adapted to prevent an insertion of the first end closure member into the chamber in a second axial direction opposite the first axial direction.

27. A fluid actuator including the actuator enclosure of claim 1, and further including:

a piston contained inside the housing for reciprocation along the medial region;

a first closure member mounting device for securing the first end closure member at the first predetermined location;

a second closure member mounting device for securing the second closure member at the second predetermined location; and

a piston rod secured to the piston and extending axially through the selected end closure member to a piston rod termination outside of the housing.

28. A fluid actuator system including the fluid actuator of claim 27 and further including:

a fluid source containing a fluid;

a first supply line fluid coupled to the source and to the medial region of the chamber at a first location;

a pump fluid coupled along the supply line for providing the fluid under pressure to the chamber; and

a directional valve fluid coupled along the supply line, for permitting, alternatively, the supplying of the fluid to the chamber and the evacuation of the fluid from the chamber.

29. The system of claim 28 further including:

a second supply line for supplying the fluid to the intermediate region of the chamber at a second location on an opposite side of the piston from the first location.

30. The system of claim 28 wherein:

the fluid comprises a hydraulic fluid.

31. A fluid actuator, including:

a cylindrical housing defining a chamber including a first region adjacent an open end of the housing, and a second region adjacent an opposite end of the housing;

wherein the first region, at least along a portion thereof near the open end, has a first diameter, and the second region of the chamber has a second diameter less than the first diameter;

wherein the housing incorporates a transition region extending from the second region to said portion of the first region to provide a gradual transition from the second diameter to the first diameter;

a first end closure member insertable in a first axial direction into the chamber through the open end, and shaped for a conforming and contiguous surface engagement with the housing along the first region and along the transition region to position the first end closure member at a first predetermined location with respect to the cylindrical housing; and

a closure structure for closing the housing at said opposite end thereof;

where and the closure structure includes an opening there through.

32. The actuator of claim 31 further including:

a closure member mounting device for releasably securing the first end closure member with respect to the housing at the first predetermined location.

33. The actuator of claim 32 wherein:

the closure member mounting device comprises a first opening formed into the first end closure member, at least one second opening formed through the housing along the first region and positioned for an alignment with the first opening when the first end closure member is at the first predetermined location, and a pin insertable through the first and second openings for maintaining said alignment.

34. The actuator of claim 33 wherein:

the first opening extends through the first end closure member, the at least one second opening comprises two second openings on opposite sides of the housing, and the pin is insertable simultaneously through the first opening and both of the second openings to maintain said alignment.

35. The actuator of claim 34 further including:

first and second bushings each inserted into the first opening through one of said second openings, and disposed in surrounding relation to the pin.

36. The actuator of claim 31 wherein:

said closure structure comprises a second end closure member shaped for a conforming and contiguous surface engagement with the housing at a second predetermined location along the second region near said opposite end.

37. The actuator of claim 36 wherein:

the second end closure member is insertable in said first axial direction into the chamber through the open end.

38. The actuator of claim 37 further including:

a closure member containing structure integral with the housing and positioned to engage the second end closure member substantially upon a complete insertion thereof to the second predetermined location, thereby to prevent further travel of the second end closure member in the first axial direction.

39. The actuator of claim 38 wherein:

the closure member containing structure includes an annular rim extended radially inwardly from the housing and disposed at least proximate said second end.

40. The actuator of claim 39 wherein:

the annular rim is welded to the housing at said second edge.

41. The actuator of claim 38 wherein:

said closure member containing structure further is adapted to prevent an insertion of the second end closure member into the chamber in a second axial direction opposite the first axial direction.

42. The actuator of claim 36 further including:

a closure member mounting device for securing the second end closure member with respect to the housing at the second predetermined location.

43. The actuator of claim 42 wherein:

the closure member mounting device includes a retaining structure for releasably securing the second end closure member against movement away from the second predetermined location in a second axial direction opposite to the first axial direction.

44. The actuator of claim 31 further including:

a piston mounted to reciprocate along the second region of the chamber piston rod mounted slideably in said opening and coupled to reciprocate with the piston, and a fluid passage open to the second region between the piston and the first end closure member for supplying a fluid under pressure to the chamber.

45. The actuator of claim 44 further including:

a second fluid passage open to the second region of the chamber between the piston and the closure structure for supplying a fluid under pressure to the chamber.

46. A process for assembling a fluid actuator, including:

providing a cylinder having first and second opposite open ends, a first diameter over a majority of its length including said first end, a second diameter larger than the first diameter along an end region of the cylinder including the second end, and a transition region providing a gradual transition between the First diameter and the second diameter;

securing an end cap containment feature proximate the first end of the cylinder;

inserting a first end cap into the cylinder through the second end, and moving the first end cap in a first axial direction along the cylinder until it contacts the containment feature and substantially closes the first end upon reaching a first predetermined location;

after so inserting the first end cap, inserting a piston into the cylinder through the second end, and moving the piston in said first axial direction to a location beyond said transition region;

after so inserting the piston, inserting a second end cap into the cylinder through the second end to a second predetermined location to substantially close said second end; and

extending the piston rod from the piston, through an opening provided through a selected one of the end caps, to a piston rod termination outside of the cylinder.

47. A fluid actuator, including:

a cylindrical housing defining a chamber including a first region adjacent an open end of the housing, a second region adjacent an opposite end of the housing, and a medial region between the first and second regions;

a closure structure for closing the housing at said opposite end thereof;

a first end closure member insertable in a first axial direction into the chamber through the open end, and shaped for a conforming and contiguous surface engagement with the housing; and

a closure member mounting device for releasably securing the first end closure member with respect to the housing at a first predetermined location along the first region, including a first opening formed into the first end closure member, at least one second opening formed through the housing along the first region and positioned for an alignment with the first opening when the first end closure member is at the first predetermined location, and a pin insertable through the first and second openings for maintaining said alignment.

48. The actuator of claim 47 wherein:

the first opening extends through the first end closure member, the at least one second opening comprises two diametrically opposed second openings through the housing, and the pin is insertable simultaneously through the first opening and both of the second openings to maintain said alignment.

49. The actuator of claim 48 further including:

first and second bushings, each inserted into the first opening through one of the second openings and disposed in surrounding relation to the pin.

50. The actuator of claim 47 wherein:

the closure structure comprises a second end closure member insertable in the first axial direction into the chamber through the open end, and shaped for a conforming and contiguous surface engagement with the housing at a second predetermined location along the second region near the opposite end.

51. The actuator of claim 50 further including:

a closure member containing structure integral with the housing and positioned to engage the second end closure member substantially upon a complete insertion thereof to the second predetermined location, and further adapted to prevent an insertion of the second end closure member into the chamber in a second axial direction opposite the first axial direction.

52. The actuator of claim 47 wherein:

the first region has a first diameter, and the second region and the medial region have a second diameter less than the first diameter; and

the housing incorporates a transition region extending from the medial region to the first region to provide a gradual transition from the second diameter to the first diameter.

53. An actuator enclosure for containing a reciprocating piston, including:

a cylindrical housing defining a chamber including a first end region, a second end region opposite the first end region and including an open end of the housing, and a medial region between the first and second end regions;

a first end closure member insertable in a first axial direction into the chamber through the open end, and shaped for a conforming and contiguous surface engagement with the housing at a first predetermined location along the first end region;

a second end closure member insertable in the first axial direction into the chamber through the open end, and shaped for a conforming and contiguous surface engagement with the housing at a second predetermined location along the second end region; and

a closure member containing structure non-removably fixed with respect to the housing and positioned to engage the first closure member substantially upon a complete insertion thereof to the first predetermined location, thereby to prevent further travel of the first closure member in the first axial direction;

wherein the housing is adapted to accommodate a piston for reciprocation along the medial region of the chamber, and a selected one of the first and second closure members includes an opening adapted to slideably support a piston rod coupled to the piston.

54. The enclosure of claim 53 wherein:

the closure member containing structure includes an annular rim extended radially inwardly from the housing and disposed at least proximate the first end region of the chamber.

55. The enclosure of claim 54 wherein:

the annular rim is welded to an edge of the housing adjacent the first end region.

56. The enclosure of claim 53 further including:

a retaining structure for releasably securing the first end closure member against movement away from the first predetermined location in a second axial direction opposite to the first axial direction.

57. The enclosure of claim 56 wherein:

a portion of the first end closure member extends beyond the first end region of the housing when the first end closure member is at the first predetermined location, and the retaining structure includes a groove formed circumferentially about the first end closure member and a retaining ring removably mounted within the groove.

58. The enclosure of claim 53 wherein:

the first end region and the medial region have a first diameter, the second end region has a second diameter larger than the first diameter, and the housing incorporates a flared portion extending from the medial region to the second end region to provide a gradual transition from the first diameter to the second diameter.

59. A fluid actuator including:

a cylindrical housing defining a chamber including a first end region, a second end region opposite the first end region and including an open end of the housing, and a medial region between the first and second end regions;

a first end closure member insertable in a first axial direction into the chamber through the open end, and shaped for a conforming and contiguous surface engagement with the housing at a first predetermined location along the first end region;

an annular flexible first seal surrounding the first end closure member and adapted to be compressed between the first end closure member and the housing when the first end closure member is at the first predetermined location;

a piston insertable in the first axial direction into the chamber through the open end for reciprocation along the medial region;

an annular flexible piston seal surrounding the piston and adapted to be compressed between the piston and the cylindrical housing when the piston is disposed in the medial region;

a second end closure member insertable in the first axial direction into the chamber through the open end, and shaped for a conforming and contiguous surface engagement with the housing at a second predetermined location along the second end region;

an annular flexible second seal surrounding the second end closure member and adapted to be compressed between the cylindrical housing and the second end closure member when the second end closure member is at the second predetermined location; and

a first fluid passage formed through a selected one of the end closure members and open to the medial region between the selected end closure member and the piston.

60. The actuator of claim 59 wherein:

the selected one of the end closure members is the second end closure member.

61. The actuator of claim 60 further including:

a closure member mounting device for releasably securing the second end closure member with respect to the housing at the second predetermined location.

62. The actuator of claim 61 wherein:

the closure member mounting device comprises a first opening formed in the second end closure member, at least one second opening formed through the housing along the second end region and positioned for an alignment with the first opening when the second end closure member is at the second predetermined location, and a pin insertable through the first and second openings to maintain said alignment.

63. The actuator of claim 59 further including:

a second fluid passage formed through the one of said end closure members other than the selected one, and open to the medial region between said other one and the piston.

64. The actuator of claim 59 wherein:

the first end closure member, the piston, and the second end closure member are insertable in succession through said open end, respectively to the first predetermined location, the medial region, and the second predetermined location.

65. The actuator of claim 59 further including:

a closure member containing structure integral with the housing and positioned to engage the first closure member substantially upon a complete insertion thereof to the first predetermined location to prevent further travel of the first closure member in the first axial direction, and further adapted to prevent an insertion of the first end closure member into the chamber in a second axial direction opposite the first axial direction.

66. The actuator of claim 59 wherein:

the first end region and the medial region have a first diameter, the second end region has a second diameter larger than the first diameter, and the housing incorporates a flared portion extending from the medial region to the second end region to provide a gradual transition from the first diameter to the second diameter.

67. The actuator of claim 66 wherein:

the second end closure member includes a medial portion shaped for a conforming and contiguous surface engagement with the flared portion of the housing, and an inner end portion confronting the medial region adjacent to flared portion when the second end closure member is at the second predetermined location; and

the second seal surrounds the inner end portion of the second end closure member.