Claims
- 1. A pump comprising, a body; a crank chamber in the body; a crankshaft rotatably mounted on the body and including a drive end located outwardly of the body and a cylindrical eccentric in the crank chamber; a piston bore in the body, the bore extending from one side of the body to the crank chamber adjacent the eccentric; a closure sealing the bore at the side of the body; an outlet check valve located in the piston bore inwardly from said closure; a high pressure outlet passage in the body opening into the bore between the check valve and the closure; a hollow, cylindrical piston moveably mounted in the piston bore between the crank chamber and the check valve, the piston having a convex inner end adjacent the crank chamber and an inlet opening extending through said end, said piston and bore defining a variable volume pumping chamber; a spring in the pumping chamber, said spring including a spring end engaging said piston end; a slipper located between the piston end and the eccentric, the slipper including a partial cylindrical surface engaging the eccentric and a concave surface engaging the convex surface of the end of the piston to permit rotation of the slipper about the piston end, the spring biasing the end of the piston against the slipper and the slipper against the eccentric; the slipper including a slipper opening communicating with the piston opening during return strokes of the piston, a recess in the said recess communicating with the slipper opening during return strokes of the piston; a source of fluid to be pumped, and an inlet passage extending from the source of fluid, through the body, the crank chamber, the recess, the slipper opening and the piston opening to the pumping chamber, said inlet passage unobstructed during return strokes of the piston.
- 2. The pump as in claim 1 including a sleeve in the end of the bore adjacent said body wall, said sleeve having a tapered inner surface; a cylindrical seat having a tapered outer surface, said seat driven into said sleeve with said tapered surfaces engaging each other to deform the sleeve against the bore; a poppet disk on the side of the seat away from the pumping chamber; said closure comprising a plug in the bore; and a poppet valve spring biasing the disk against the seat.
- 3. The pump as in claim 2 including a first sleeve opening extending through the sleeve between the plug and the seat, said high pressure passage extending through said first opening.
- 4. The pump as in claim 3 including a second sleeve opening extending through the sleeve between the plug and the seat, a second eccentric on said crankshaft, pumping means driven by said second eccentric, said high pressure outlet passage extending to said pumping means through said first and second sleeve openings.
- 5. The pump as in claim 1 wherein said source of fluid to be pumped comprises an inlet throttle valve.
- 6. The pump as in claim 5 wherein said inlet throttle valve comprises a throttle bore, a spool in the throttle bore moveable between opened and closed positions; and an inlet throttle valve spring biasing the spool toward the open position.
- 7. The pump as in claim 6 wherein said spool comprises a wall and a closed end; and including a plurality of flow openings extending through said wall and spaced along said wall.
- 8. The pump as in claim 7 wherein the inlet passage surrounds the spool.
- 9. The pump as in claim 8 wherein said wall is cylindrical and said flow openings overlap each other.
- 10. The pump as in claim 8 wherein said flow openings include an opposed pair of openings.
- 11. The pump as in claim 1 wherein said piston and slipper define a generally spherical interface, the interface including a spherical surface on the end of the piston, a nearly spherical surface in the slipper, such surfaces engaging each other only at a circumferential band formed in the slipper surface, such surfaces gradually separating from each other to either side of the band, the band extending around the piston opening and the slipper opening.
- 12. The pump as in claim 11 wherein the slipper is formed from a material softer than the material forming the piston.
- 13. The pump as in claim 12 wherein the slipper is formed from bronze and the piston is formed from steel.
- 14. The pump as in claim 11 wherein said nearly spherical surface is a revolved positive offset surface.
- 15. The pump as in claim 11 wherein said spherical surface is convex and said nearly spherical surface is concave.
- 16. A pump comprising, a body; a crank chamber in the body; a crankshaft rotatably mounted on the body and including a rotary drive member in the crank chamber; a piston bore in the body, the bore extending from one side of the body to the crank chamber adjacent the drive member; a closure in the bore at the side of the body; an outlet check valve located in the piston bore inwardly from said closure; a high pressure outlet passage opening into the bore; a hollow, cylindrical piston moveably mounted in the piston bore between the crank chamber and the check valve, the piston having an inner end adjacent the crank chamber and an inlet opening at said end, said piston and bore defining a variable volume pumping chamber; a drive connection between the drive member and the piston to move the piston through pumping and return strokes; a source of fluid to be pumped, and an inlet passage extending from the source of fluid, through the body, the crank chamber and the piston opening to the pumping chamber, said inlet passage unobstructed during return strokes of the piston.
- 17. The pump as in claim 16 wherein the source of fluid to be pumped comprises an inlet throttle valve.
- 18. The pump as in claim 17 wherein the inlet throttle valve includes a bore, and a valving member moveable along the bore between opened and closed positions.
- 19. The pump as in claim 18 wherein the inlet throttle valve includes a spring biasing the valving member toward the open position.
- 20. The pump as in claim 18 wherein the valving member comprises a spool having a wall, a closed end and at least one flow opening extending through the wall.
- 21. The pump as in claim 20 wherein the inlet passage at the inlet throttle valve surrounds the inlet throttle valve bore.
- 22. The pump as in claim 20 wherein said spool includes a plurality of flow openings, such openings overlapping each other along the wall.
- 23. The pump as in claim 20 wherein said wall is cylindrical; said flow openings are arranged in opposed pairs of openings; and said inlet passage surrounds the spool.
- 24. The pump as in claim 16 wherein said drive connection includes a slipper located between the piston and the rotary drive member and including a slipper opening engageable with said inlet opening and said inlet passage extending through the slipper opening during return strokes of the piston.
- 25. The pump as in claim 24 including a generally spherical interface between the piston and slipper, the interface including a spherical surface on the end of the piston, a nearly spherical surface in the slipper, such surfaces engaging each other only at a circumferential band deformed in the slipper surface, such surfaces gradually separating from each other away from the band, the band extending around the inlet opening and the slipper opening.
- 26. The pump as in claim 25 wherein said slipper is formed from a material softer than the material forming said piston.
- 27. The pump as in claim 25 wherein said nearly spherical surface is a revolved positive offset surface.
- 28. The combination of a pump slipper and a pump piston moveable by the slipper through repetitive pumping strokes, one of said slipper and piston formed from a material harder than the material forming the other of said piston and slipper; a generally spherical interface between the slipper and piston, the interface including a spherical surface on one of said slipper and piston, and a nearly spherical surface on the other said slipper and piston, one of said surfaces being convex and the other of said surfaces being concave, the convex surface extending into the concave surface, said surfaces engaging each other only at a circumferential band in the nearly spherical surface and extending around the interface, the surfaces gradually separating from each other away from the band, said interface permitting movement of the slipper relative to the piston during pumping strokes of the piston while maintaining surface-to-surface engagement between the slipper and piston at the circumferential band.
- 29. The combination of claim 28 wherein the radius of curvature of the spherical surface is less than the radius of curvature of the nearly spherical surface.
- 30. The combination of claim 29 wherein the spherical surface is on the piston and the nearly spherical surface is on the slipper.
- 31. The combination of claim 30 wherein the piston is formed from material harder than the material forming the slipper.
- 32. The combination of claim 31 wherein the slipper is formed from bronze.
- 33. The combination of claim 32 wherein the piston is formed from steel.
- 34. The combination of claim 28 including an opening in the piston at the interface.
- 35. The combination of claim 34 including an opening in the slipper at the interface, said openings cooperating to form part of an inlet passage, each surface surrounding one of said openings.
- 36. The combination of claim 28 wherein said nearly spherical surface is a revolved offset surface.
- 37. The combination of claim 36 wherein said nearly spherical surface has a positive offset.
- 38. The combination of claim 28 wherein the band is deformed in the nearly spherical surface.
- 39. The combination of claim 38 wherein the spherical surface is on the piston.
- 40. The combination of claim 39 wherein the piston is formed from steel and the slipper is formed from bronze.
- 41. The combination of a pump piston and a slipper for moving the piston through repetitive pumping strokes, said piston formed from a material harder than the material forming said slipper, and including a convex spherical end, a piston passage extending through the spherical end of the piston, said slipper including a concave nearly spherical recess, said piston spherical end seated in said slipper recess to form a generally spherical interface between the piston and slipper, said piston end engaging the slipper only at a circular band in the interface and being gradually spaced apart to either side of the band, said band surrounding said passage.
- 42. The combination of claim 41 wherein the nearly spherical surface is a revolved offset surface.
- 43. The combination of claim 42 wherein said nearly spherical surface has a positive offset.
- 44. The combination of claim 41 wherein the band has a width less than 16 degrees.
- 45. The combination of claim 41 wherein the slipper is formed from bronze.
- 46. The combination of claim 45 wherein the piston is formed from steel.
- 47. The combination of claim 41 including a slipper passage in the slipper, said piston passage and said slipper passage cooperating to form an unobstructed passage during return strokes.
- 48. The method of forming a surface-to-surface interface between a pump slipper having a concave surface and a pump piston having a convex surface seated in the concave surface, and one of the slipper and piston is formed from material softer than the material forming the other of the slipper and piston, comprising the steps of:
A) forming an initial contact between the piston and slipper at a circular line extending around the interface; and B) relatively rotating the slipper about the piston to increase the width of the contact and form a band in said one of said slipper and piston, said band having an area supporting said piston on the slipper.
- 49. The method of claim 48 including the step of:
C) forming the band in the slipper.
- 50. The method of claim 48 including the step of:
C) forming a band by deforming the softer material.
- 51. The method of claim 48 including the step of:
C) forming said nearly spherical surface to the shape of a revolved offset surface.
Parent Case Info
[0001] This application is a continuation-in-part of my co-pending application for Pump Assembly and Method, Ser. No. 09/580,877, filed May 30, 2000.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09580877 |
May 2000 |
US |
Child |
10097369 |
Mar 2002 |
US |