GB2142389A

GB2142389A - Mechanism for pumping fluid

Info

Publication number: GB2142389A
Application number: GB08414050A
Authority: GB
Inventors: Gerald Haft
Original assignee: Outboard Marine Corp
Current assignee: Outboard Marine Corp
Priority date: 1983-06-29
Filing date: 1984-06-01
Publication date: 1985-01-16
Also published as: GB8414050D0; GB2142389B; JPS6035187A

Abstract

The mechanism comprises a link 16, a mechanism 14 for causing reciprocative movement of the link 16, a shaft 18, a one-way clutch 22 connected between the link 16 and the shaft 18 for causing one-way rotation of the shaft 18 in response to movement of the link 16, and a pumping mechanism 26 for pumping fluid in response to rotation of the shaft 18. The mechanism 14 for causing reciprocative movement of the link 16 comprises a housing 30 with a recess 32. A movable wall 34 in the recess 32 defines a chamber 38 adapted to be in communication with a source of pulsating pressure, such as the crankcase of a two- cycle engine, and a second chamber 42. The link 16 is connected to the movable wall 34 and a spring 94 in the second chamber 42 between the shaft 18 and the movable wall 34 is provided for basing the movable wall 34 away from the shaft 18. <IMAGE>

Description

SPECIFICATION Mechanism for pumping fluid BACKGROUND OF THE INVENTION This invention relates to mechanisms for pumping a fluid such as oil and, more particularly, to mechanisms for pumping fluid which are driven by a variable pressure source.

Various mechanisms require the introduction of a flow of oil for purposes of lubrication. For example, two cycle engines such as those used on lawn mowers, outboard motors and motorcycles use oil to provide for lubrication of the engine. Other devices such as chain saws and engine attachments also use oil for lubrication. Prior means for pumping a fluid such as oil have included oil pumps driven by the crankshaft of an engine by having the driving mechanism for the oil pump either geared or belted to the crankshaft. Worm gearing was used to achieve the low pump speeds needed to introduce oil to the engine at a reasonable rate. Such gearing usually required the integration of the pump into the overall engine design.To allow for .the mounting of the oil pump at a more remote and probably more convenient location, some oil pumps have been driven by the variable pressure which occurs in the crankcase of a two-cycle engine.

SUMMARY OF THE INVENTION This invention provides a mechanism for pumping a fluid which comprises a link, means for causing reciprocative movement of the link, a shaft, one-way clutch means connected between the link and the shaft for causing oneway rotation of the shaft in response to movement of the link, and means for pumping fluid in response to rotation of the shaft.

In one embodiment, the pumping means comprises a pumping plunger, means for causing reciprocative movement of the pumping plunger in response to shaft rotation, and means for pumping fluid in response to the reciprocative movement of the pumping plunger.

In another embodiment, the pumping means comprises means for causing reciprocative movement of the shaft in response to rotation of the shaft, and means for pumping fluid in response to the reciprocative movement of the shaft.

In one embodiment, the means for causing reciprocative movement of the link comprises a housing with a recess. A moveable wall in the recess defines a chamber adapted to be in communication with a source of pulsating pressure, such as the crankcase of a two-cycle engine. The link is connected to the moveable wall and biasing means between the shaft and the moveable wall is provided for biasing the moveable wall away from the shaft.

One of the principal features of the invention is to provide means for pumping fluid from a cyclical actuating or driving means at a rate significantly less than the rate at which the driving means operates.

Another of the principal features of the invention is to provide a fluid pumping mechanism which can be driven by pressure pulsations.

Other features and advantages of embodiments of the invention will become apparent upon reviewing the following drawings, the detailed description and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view of a mechanism for pumping oil which embodies various of the features of the invention.

Figure 2 is a cross sectional view of a portion of the mechanism taken along line 2-2 in Figure 1.

Figure 3 is a cross-sectional view of a portion of an alternate embodiment of the mechanism shown in Figure 2.

Figure 4 is a cross-sectional view of the mechanism taken along line 4-4 in Figure 3.

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purposes of description and should not be regarded as limiting.

DESCRIPTION OF THE PREFERRED EMBODI MENT As illustrated in Figures 1 and 2, this invention provides a mechanism 10 for pumping a fluid such as oil. The mechanism 10 comprises means for causing reciprocative movement of a link 16, a shaft 18, one-way clutch means 22 connected between the link 1 6 and the shaft 18 for causing one-way rotation of the shaft 1 8 in response to movement of the link 1 6 and pumping means 26 for pumping oil in response to rotation of the shaft 1 8. The one-way clutch means 22 provides for rotation of the shaft 1 8 at a rate significantly less than the rate of reciprocation of the link 16, as hereinafter described.

The link 1 6 is received for sliding reciprocative movement in a bore 27 in a housing 30 and a second bore 28 in the housing 30 and at a right angle to the link 1 6 receives the shaft 18.

In the embodiment shown in Figure 1, the means for causing reciprocative movement of the link is in the form of a pneumatic motor 14. Other means for causing reciprocative movement of the link 16 can also be used.

As illustrated in Figure 1, the pneumatic motor 14 comprises the housing 30 including a recess 32 and a moveable wall 34 in the recess 32 which defines a first chamber 38 and a second chamber 42. The moveable wall 34 comprises a membrane 46 made of rubber or other flexible material attached to the sides of the housing 30 and a central metal piston 50 comprising two plates 54 and 56 each of which is attached to a side of the central portion of the flexible membrane 46. The first chamber 38 is in communication with a source of pulsating pressure by means of a bore 58 threaded with an adaptor 62 for connection to a conduit 66 from the source of pulsating pressure, such as the crankcase 70 of a two-cycle engine 74 in an outboard motor 78. In other embodiments (not shown), the housing 30 can be attached directly to the crankcase 70.The bore 27 extends from the second chamber 42 and receives the link 16 for reciprocal movement therein. One end of the link 1 6 is connected to the moveable wall 34 by a fastener 90 which extends through the piston 50 and the membrane 46.

The pneumatic motor 14 also includes biasing means in the form of a spring 94 in the second chamber 42 concentric with the link 1 6 and between the housing 30 and the moveable wall 34 for biasing the moveable wall 34 away from the bore 27. The spring 94 is calibrated so that when the pressure in the first chamber 38 increases and becomes greater than the spring force on the second chamber side of the piston 50, the moveable wall 34 moves towards the bore 27 compressing the spring 94 and causing movement of the link 1 6. The amount of displacement of the wall 34 and the link 1 6 depends on the amount of pressure in the first chamber 38 and force of the spring 94 and can be varied by varying the maximum pulsation pressure and spring constant of the spring 94.

In operation, as the pressure in the first chamber 38 increases the increased pressure moves the moveable wall 34 towards the bore 27 compressing the spring 94 and displacing the link 16. Then when the pressure in the first chamber 38 lessens, the biasing spring 94 causes movement of the moveable wall 34 away from the bore 27 and reverse movement of the link 1 6. As the pressure in the first chamber 38 then continues to rise and fall, the link 16 continues to move in a reciprocative fashion. The second chamber 42 is either evacuated or in communication with the atmosphere so that movement of the moveable wall 34 towards the bore 27 is not inhibited by air in the second chamber 42.

The one-way clutch means 22 is enclosed in a chamber 98 in the housing 30 and includes a pivot arm 102 having an end 106 with a pin 107 received in a slot 108 in the second end 110 of the link 16. The slot 108 permits movement of the pin 107 outward along the pivot arm 102 as the arm 102 rotates about the shaft 18, as hereinafter described.

The other end of the pivot arm 102 is connected to a one-way clutch 11 2 which encircles the shaft 1 8. Movement of the link 1 6 causes reciprocative movement of the pivot arm 102 which, in turn, results in oneway rotation of the shaft 1 8. Any conventional one-way clutch 11 2 and pivot arm 102 may be used, and the clutch 11 2 can be selected so as to rotate the shaft 18 either on the power stroke or return stroke of the piston 50. In one embodiment of the pumping means 26, the clutch 11 2 selected accommodates axial reciprocal sliding of the shaft 18, as hereinafter described.

In operation, the link 1 6 reciprocates causing pivoting of the pivot arm 102 and oneway rotation of the shaft 1 8. The length of the piston arm 102 and the amount of link travel can be varied to determine the amount of shaft rotation and resultant oil output, as hereinafter described.

An adjustment means or screw 114 is provided for adjusting the amount of travel of the reciprocating link 1 6 and the resulting amount of rotation of the shaft 18. The adjustment screw 11 4 is adjacent to the point of attachment of the link 1 6 to the pivot arm 102 and can be adjusted so as to abut the pivot arm 102 and vary the amount of travel of the pivot arm 102.

In addition to screw 114, an adjustment screw 11 6 is adjacent the fastener 90 and can be adjusted so as to abut the fastener 90 and vary the amount of travel of the pivot arm 102. The setting of the adjustment screw 11 6 affects the amount of travel of the pivot arm 102 when weak pressure pulsations result in only a slight deflection of the spring 94, while the setting of the adjustment screw 114 affects the amount of travel of the pivot arm 102 when stronger pressure pulsations result in greater deflections of the spring 94.

One embodiment of the means 26 for pumping oil in response to rotation of the shaft 18 is illustrated in Figure 2. In this embodiment, the pumping means 26 comprises means 11 8 for causing reciprocative movement of the shaft 18 in response to rotation of the shaft 18 and means 122 for pumping oil in response to the reciprocative movement of the shaft 18.

The reciprocative moving means 118 comprises a cam surface 1 26 on a first end 1 30 of the shaft 18, a point 1 33 on a mating cam surface 134 provided in the housing 30 adjacent the first end 1 30 of the shaft 18, and means in the form of a spring 142 adjacent the second end 144 of the shaft 18 for biasing the shaft -18 towards the housing cam surface 1 34. The spring 142 extends between the second end 144 of the shaft 1 8 and the end of the bore 28 in the housing 30.

The cam surface 126, the point 1 33 on the cam surface 134, and spring 142 cooperate to provide a camming action which causes longitudinal reciprocation of the shaft 1 8 relative to the clutch 11 2 and housing 30. More particularly, as the shaft 18 is rotated by the one-way clutch 112, the first end 1 30 of the shaft becomes unseated from the mating cam surface 1 34 provided in the housing 30.The housing cam surface point 1 33 acts upon the shaft cam surface 126 to cause the shaft 18 to move away from the housing cam surface 1 34. As the shaft 18 continues to rotate the shaft cam surface 1 26 returns to its mating relationship with the housing cam surface 1 34 under the influence of the spring 142. In other embodiments, a pin (not shown) can serve as the housing cam surface point 133, or the point can be on the shaft 1 8 and thecam surface on the housing 30.

The reciprocative pumping means 1 22 comprises the housing 30, inflow valve means 1 54 and outflow valve means 158. The housing 30 has the bore 28 which receives the shaft 1 8 for reciprocative sliding movement.

The second end 144 of the shaft 18 cooperates with the bore 28 to form a variable volume oil pumping chamber 1 50. Inflow or one-way valve means 1 54 allows for the inflow of oil into the variable volume oil pumping chamber 1 50 when the shaft 18 moves towards the housing cam surface 1 34.

Outflow or one-way valve means 1 58 allows for the outflow of oil from the variable volume oil pumping chamber 1 50 when the shaft 1 8 moves away from the housing cam surface 1 34 reducing the volume of the variable volume oil pumping chamber 1 50. The inflow valve means 1 54 is adapted to communicate through a conduit 1 62 with a suitable source of oil and the outflow valve means 1 58 is adapted to communicate through a conduit 1 66 with the mechanism to be lubricated, such as the engine 74.

Shown in Figures 3 and 4, is an alternate embodiment 1 80 of pumping means 26 for pumping oil in response to rotation of the shaft 1 8. The pumping means 180 comprises a pumping plunger 184, means 1 88 for causing reciprocative movement of the pumping plunger 1 84 and means 1 92 for pumping oil in response to the reciprocative movement of the pumping plunger 1 84.

The plunger moving means 1 88 comprises a cam surface 196 on a cam 216 on the shaft 1 8 adjacent the first end 204 of the pumping plunger 1 84 and biasing means in the form of a spring 208 adjacent the second end 21 2 of the pumping plunger 1 84 for biasing the pumping plunger 184 towards the cam surface 196. The spring 208 extends between the end of a bore 244 in the housing 30 for receiving the pumping plunger 1 84 and the second end 21 2 of the pumping plunger 184, as hereinafter described.

The cam 21 6 encircles the shaft 1 8 and rotates with the shaft 18. The cam 216 and shaft 1 8 are enclosed in a chamber 220 which is in the housing 30 and which is large enough to permit the cam 21 6 to rotate freely.

As illustrated in Figure 4, the plunger pumping means 1 92 comprises the housing 30, inflow valve means 228 and outflow valve means 232. The housing 30 has the bore 244 which receives the pumping plunger 184 for reciprocative sliding movement. The second end 212 of the pumping plunger 224 cooperates with the bore 244 to form a variable volume oil pumping chamber 224.

Inflow or one-way valve means 228 allows for the inflow of oil into the variable volume oil pumping chamber 224 as the pumping plunger 224 moves towards the shaft 1 8. The outflow or one-way valve means 232 allows for the outflow of oil from the variable volume oil pumping chamber 224 when the pumping plunger 224 moves away from the shaft 18 reducing the volume of the variable volume oil pumping chamber 224. The inflow valve means 228 is adapted to communicate through a conduit 236 with a suitable source of oil and the outflow valve means 232 is adapted to communicate through a conduit 240 with the mechanism to be lubricated, such as engine 74.

Various of the features of the invention are set forth in the following claims.

Claims

1. A mechanism for pumping fluid, said mechanism comprising a link, means for causing reciprocative movement of said link, a shaft, one-way clutch means connected between said link and said shaft for causing oneway rotation of said shaft in response to movement of said link, and means for pumping fluid in response to rotation of said shaft.

2. A mechanism in accordance with Claim 1 wherein said pumping means comprises a pumping plunger, means for causing reciprocative movement of said pumping plunger in response to rotation of said shaft, and means for pumping fluid in response to the reciprocative movement of said pumping plunger.

3. A mechanism in accordance with Claim 2 wherein said pumping plunger includes a first end and a second end, and wherein said plunger moving means comprises a cam surface on said shaft adjacent said first end of said pumping plunger and biasing means for biasing said pumping plunger towards said cam surface.

4. A mechanism in accordance with Claim 3 wherein said plunger pumping means comprises a housing with a bore which partially defines a variable volume pumping chamber, one-way valve means for introducing fluid into said variable volume pumping chamber, and one-way valve means for removing fluid from said variable volume pumping chamber, and wherein said pumping plunger is received for reciprocative movement in said bore and said second end of said pumping plunger cooperates with said housing to form said variable volume pumping chamber.

5. A mechanism in accordance with Claim 1 and further including a housing with a first bore which receives paid link for reciprocative movement therein and a second bore at a right angle to said link which receives said shaft.

6. A mechanism in accordance with Claim 5 wherein said pumping means comprises means for causing reciprocative movement of said shaft in response to rotation of said shaft, and means for pumping fluid in response to said reciprocative movement of said shaft.

7. A mechanism in accordance with Claim 6 wherein said shaft includes a first end and a second end, and wherein said reciprocative moving means comprises a cam surface on said first end of said shaft, a cam point which is on said housing adjacent said first end of said shaft and which cooperates with said shaft cam surface to provide a camming action which causes longitudinal reciprocation of said shaft, and means for biasing said shaft towards said housing cam point.

8. A mechanism in accordance with Claim 6 wherein said housing has a second bore which partially defines a variable volume pumping chamber, and wherein said reciprocative pumping means comprises one-way valve means for introducing fluid into said variable volume pumping chamber, one-way valve means for removing fluid from said variable volume pumping chamber, and wherein said shaft is received for reciprocative movement in said second bore and said second end of said shaft cooperates with said housing to form said variable volume pumping chamber.

9. A mechanism for pumping fluid, said mechansim comprising a housing with a recess, a moveable wall in said recess and defining a chamber adapted to be in communication with a source of pulsating pressure, a link connected to said moveable wall, a shaft, biasing means between said shaft and said moveable wall for biasing said moveable wall away from said shaft, one-way clutch means connected between said link and said shaft for causing one-way rotation of said shaft in response to movement of said link, and pumping means for pumping fluid in response to rotation of said shaft.

10. A mechanism in accordance with Claim 9 wherein said pumping means comprises a pumping plunger, means for causing reciprocative movement of said pumping plunger in response to shaft rotation, and means for pumping fluid in response to the reciprocative movement of said pumping plunger.

11. A mechanism in accordance with Claim 10 wherein said pumping plunger includes a first end and a second end, and wherein said plunger moving means comprises a cam surface on said shaft adjacent said first end of said pumping plunger and biasing means adjacent said second end of said pumping plunger for biasing said pumping plunger towards said cam surface.

12. A mechanism in accordance with Claim 11 wherein said housing has a second bore which partially defines a variable volume pumping chamber, and wherein said plunger pumping means comprises one-way valve means for introducing fluid into said variable volume pumping chamber, and one-way valve means for removing fluid from said variable volume pumping chamber, and wherein said pumping plunger is received for reciprocative movement in said housing and said second end of said pumping plunger cooperates with said housing to form said variable volume pumping chamber.

1 3. A mechanism in accordance with Claim 9 wherein said pumping means comprises means for causing reciprocative movement of said shaft in response to rotation of said shaft, and means for pumping fluid in response to said reciprocative movement of said shaft.

14. A mechanism in accordance with Claim 1 3 wherein said shaft includes a first end and a second end, and wherein said reciprocative moving means comprises a cam surface on said first end of said shaft, a cam point which is on said housing adjacent said first end of said shaft and which cooperates with said shaft cam surface to provide a camming action which causes longitudinal reciprocation of said shaft, and means for biasing said second end of said shaft towards said housing cam point.

1 5. A mechanism in accordance with Claim 14 wherein said housing has a second bore which partially defines a variable volume pumping chamber, and wherein said reciprocative pumping means comprises one-way valve means for introducing fluid into said variable volume pumping chamber, one-way valve means for removing fluid from said variable volume pumping chamber, and wherein said shaft is received for reciprocative movement in said second bore and said second end of said shaft cooperates with said housing to form said variable volume pumping chamber.

16. A mechanism for pumping fluid, said mechanism comprising a link, means for causing reciprocative movement of said link, a housing having a bore and a pumping chamber with an inlet and an outlet, a shaft having a first end in said pumping chamber and having a second end in said bore, one-way clutch means connected between said link and said shaft for effecting one-way rotation of said shaft in response to movement of said link, and means for causing reciprocative movement of said shaft in response to rotation of said shaft, whereby to displace said first end of said shaft in said pumping chamber to effect fluid pumping.

1 7. A mechanism for pumping fluid, said mechanism comprising a housing having a first portion with a recess, and a second portion with a bore, and a third portion with a pumping chamber having an inlet and an outlet, a moveable wall in said recess and defining a chamber adapted to be in communication with a source of pulsating pressure, a link connected to said moveable wall, a shaft received in said bore and having a first end received in said pumping chamber and a second end, means for biasing said moveable wall in a direction opposite to the action of the pulsing pressure, one-way clutch means connected between said link and said shaft for effecting one-way rotation of said shaft in response to movement of said link, a cam surface on said second end of said shaft, a camming surface located on said housing adjacent said second end of said shaft and cooperating with said shaft cam surface to effect longitudinal reciprocation of said shaft in response to rotation thereof, and means for biasing said shaft towards said housing camming surface.

1 8. A mechanism for pumping fluid, said mechanism comprising a housing having a first portion with a recess, and a second portion with a pumping chamber having an inlet and an outlet, a moveable wall in said recess and defining a chamber adapted to be in communication with a source of pulsating pressure, a link connected to said moveable wall, a shaft having a first end in said pumping chamber and a second end, means for biasing said moveable wall in a direction opposite to the action of the pulsing pressure, one-way clutch means connected between said link and said shaft for causing one-way rotation of said shaft in response to movement of said link, and means for causing reciprocative movement of said shaft in response to rotation of said shaft, whereby to displace said first shaft end in said pumping chamber to effect fluid pumping.

19. A mechanism for pumping fluid, said mechanism comprising a housing having a first portion with a recess, a second portion with a bore, and a third portion defining a pumping chamber with an inlet and an outlet, a moveable wall in said recess and defining a chamber adapted to be in communication with a source of pulsating pressure, a link connected to said moveable wall, a shaft received in said bore and having a first end in said pumping chamber and a second end, means for biasing said moveable wall in the direction opposite to the action of the pulsing pressure, one-way clutch means connected between said link and said shaft for effecting one-way rotation of said shaft in response to movement of said link, a cam surface on said second end of said shaft, a camming surface located on said housing adjacent said second end of said shaft and cooperating with said shaft cam surface to effect, in response to shaft rotation, longitudinal pumping reciprocation of said first end of said shaft in said pumping chamber and means for biasing said shaft towards said camming surface.

20. A mechanism for pumping fluid substantially as hereinbefore described with reference to the accompanying drawings.