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JP-7855370-B2 - Pumping device

JP7855370B2JP 7855370 B2JP7855370 B2JP 7855370B2JP-7855370-B2

Inventors

  • 猪野 恭裕

Assignees

  • 株式会社ミクニ

Dates

Publication Date
20260508
Application Date
20220303

Claims (16)

  1. A housing having an intake passage defining an intake port at its upstream end, a discharge passage defining an outlet at its downstream end, and a return passage that returns a portion of the fluid flowing through the discharge passage back to the middle of the intake passage, A pump element housed in the aforementioned housing rotates around a predetermined axis to draw in, pressurize, and discharge fluid, The system includes an on/off valve for opening and closing the aforementioned return passage, The housing has a weir that protrudes from the bottom wall of the intake passage and defines a reservoir area in the intake passage upstream of the opening where the return passage opens to the intake passage, where fluid is accumulated in the area including the opening, and a directional wall that directs the flow of intake fluid drawn into the intake passage from the intake port away from the flow of return fluid returned from the return passage . The weir section includes an inclined surface that slopes upward toward the downstream side in order to define the directional wall. A pump device characterized by the following features.
  2. The opening of the return passage is formed along the bottom wall of the reservoir area. The pump device according to feature 1 .
  3. The return passage opens downstream from a position perpendicular to the intake passage. The pump device according to claim 1 or 2 .
  4. The housing has a flow straightening wall protruding from the bottom wall of the reservoir region in a predetermined region including an opening in which the return passage opens to the intake passage, in order to straighten the return fluid returned from the return passage so that it flows along the intake passage. A pump device according to any one of features 1 to 3 .
  5. The aforementioned intake port opens vertically downward when applied to the object being worked on. A pump device according to any one of features 1 to 4 .
  6. The discharge port opens upward in the vertical direction in the usage state. The pump device according to feature 5 .
  7. The housing includes, in the usage state, a housing body that opens upward in the vertical direction, and a housing cover connected to close the housing body from above. The pump device according to claim 5 or 6 , characterized by the features described herein.
  8. The housing body includes a pump housing recess opening vertically upward to accommodate the pump element, a groove-shaped passage opening vertically upward to define a portion of the suction passage, the discharge passage, and the return passage, and a weir formed in the groove-shaped passage. The pump device according to feature 7 .
  9. The housing cover includes a groove-shaped passage that opens downward in the vertical direction in order to define a portion of the intake passage and the discharge passage. The pump device according to feature 8 .
  10. The housing has pump chamber inlet ports on both end faces of the pump element in the axial direction for drawing fluid into the pump chamber of the pump element. The pump device according to feature 9 .
  11. The pump chamber inlet includes a one-end pump chamber inlet formed at the downstream end of the suction passage of the housing body so as to face one end face of the pump element, and a other-end pump chamber inlet formed at the downstream end of the suction passage of the housing cover so as to face the other end face of the pump element. The pump device according to feature 10 .
  12. The intake passage of the housing cover includes an inclined surface that is inclined in the same direction as the inclined surface of the weir formed in the housing body. The pump device according to feature 11 .
  13. The housing is formed such that the suction passage and the discharge passage are arranged in a V-shape with respect to the pump element. A pump device according to any one of features 1 to 12 .
  14. The housing includes a valve housing for housing the on/off valve and a return passage in the region between the intake passage and the discharge passage. The pump device according to feature 13 .
  15. The pump element includes an inner rotor that rotates integrally with a rotating shaft that is rotatably supported in relation to the housing around the axis, and an outer rotor that rotates in conjunction with the inner rotor. A pump device according to any one of features 1 to 14 .
  16. The inner rotor and the outer rotor are trochoidal rotors having a trochoidal tooth profile. The pump device according to feature 15 .

Description

This invention relates to a pumping device equipped with a return passage for returning fluid from a discharge passage to an intake passage, and more particularly to a pumping device applied to an internal combustion engine of an outboard motor for drawing in, pressurizing, and discharging oil (lubricating oil or hydraulic oil). Conventional pump devices include an oil pump comprising a pump housing having an intake passage, a discharge passage, and a drain passage connecting the discharge passage and the intake passage; a pump element housed within the pump housing that pressurizes and discharges the intake hydraulic fluid; a spool valve (relief valve) that opens and closes the drain passage to return excess hydraulic fluid in the discharge passage to the intake passage side; an intake pipe connected to the pump housing to introduce hydraulic fluid into the intake passage from the outside; and a flow straightening member fixed to the inner wall of the intake pipe to straighten the flow of hydraulic fluid returned from the drain passage and the flow of hydraulic fluid supplied from the intake pipe (for example, Patent Document 1). In this oil pump, the flow straightening member is positioned only in the region where the drain passage and the supply passage of the suction pipe intersect, and therefore cannot suppress or prevent collisions between the hydraulic fluid returned from the drain passage and the hydraulic fluid supplied from the supply passage of the suction pipe. Consequently, it cannot sufficiently reduce suction resistance due to flow turbulence. Furthermore, since the flow straightening member is formed as a dedicated component fixed to the suction pipe, it leads to an increase in the number of parts and higher costs. Other pump devices include a hydraulic circuit comprising a housing having an suction oil passage, a discharge oil passage, and a return oil passage connecting the discharge oil passage and the suction oil passage; a pump element (vane pump) housed within the housing that pressurizes and discharges the suctioned hydraulic fluid; and a flow straightening member that straightens the flow of oil returning from the return oil passage to the suction oil passage. The flow straightening member is formed as a seal plug having a curved inclined surface to change the direction of the oil flow by approximately 90 degrees and a fixed portion that fits into and secures the housing (for example, Patent Document 2). In this hydraulic circuit, the flow straightening member merely bends the oil flowing from the return oil passage and guides it into the intake oil passage; it cannot suppress or prevent collisions between the oil returning from the return oil passage and the oil flowing in the intake oil passage. Therefore, it cannot sufficiently reduce intake resistance due to flow turbulence. Furthermore, since the flow straightening member is a seal plug fitted into the housing, it is a separate component from the housing, leading to an increase in the number of parts and higher costs. Japanese Patent Publication No. 2007-255335Japanese Patent Publication No. 2018-53740 This is a schematic diagram showing the pump device of the present invention applied to an outboard motor, which is the target object.This is an external perspective view showing a pump device according to the first embodiment of the present invention.This is an exploded perspective view of the pump device according to the first embodiment, taken from above and at an oblique angle.This is an exploded perspective view of the pump device according to the first embodiment, taken from a downward oblique angle after disassembly.This is a perspective cross-sectional view of a part of the pump device according to the first embodiment.This is a perspective view of the pump device according to the first embodiment, with the housing cover that constitutes the housing removed, viewed from above and at an oblique angle.This is a cross-sectional view of the pump device according to the first embodiment, with the on/off valve closed, in a plane perpendicular to the axis of the rotating shaft (a horizontal plane when applied to an object).This is a cross-sectional view of the pump device shown in Figure 7, with the on/off valve in the open position.This is a cross-sectional view showing the suction passage area cut vertically when the pump device according to the first embodiment is applied to an object.This shows a pump device according to a second embodiment of the present invention, and is a perspective view taken from above and at an oblique angle with the housing cover that constitutes the housing removed.This is a cross-sectional view of the pump device according to the second embodiment, with the on/off valve in the open position, in a plane perpendicular to the axis of the rotating shaft (a horizontal plane when applied to an object).This shows a pump device according to a third embodiment of the present invention, and is a perspective v