Patent Application
20130126024
The present disclosure relates to a bi-directional pump. More specifically, the present disclosure relates to a bi-directional pump having a uni-directional output flow.
In vehicles having transmissions composed of complex mechanical systems, it is necessary to lubricate moving parts of the vehicle for dissipating heat and facilitating smooth operation. It is convenient to utilize the power generated by the already moving parts of the transmission to drive pumps that provide lubrication to the transmission or, for example, a power takeoff system. The pumps must provide continuous lubrication to the moving parts for all operative modes of the transmission. If the transmission operates in both forward and reverse directions, known pumps running off of the transmission will direct lubrication toward the moving parts in the forward direction, but the pump will draw lubrication away from the moving parts in the reverse direction.
As such, a second pump system may be implemented with reverse gearing for providing lubrication to the moving parts in the reverse direction. Alternatively, complex valve systems that are distinct from the pump may be added thereto to reroute the lubrication flow toward the moving parts in the reverse direction. Or, alternatively, a gear and a clutch cluster may convert a bi-directional input to a uni-directional output for driving the pump. Adding additional pumps, valve systems, or gear and clutch clusters adds complexity and costs to the mechanics of the lubrication system. What is needed is a simple, affordable bi-directional pump having a uni-directional output flow.
According to the present disclosure, a bi-directional pump is provided. The bi-directional pump comprises a pump housing, and the pump housing comprises a pump outlet. A fluid pressurizer is positioned in the pump housing and configured to provide fluid flow selectively in a first direction and a second direction. A first passage and a second passage are positioned in the pump housing. A junction is fluidly positioned, in the pump housing, connecting the first and second passages to the pump outlet. A flow controller is positioned in the pump housing to move relative thereto, between a first position, placing the first passage, in fluid communication, with the pump outlet via the junction when the fluid pressurizer provides fluid flow in the first direction, and a second position placing the second passage, in fluid communication with the pump outlet, via the junction when the fluid pressurizer provides fluid flow in the second direction. The disclosed bi-directional pump provides a uni-directional output flow, and it is simple and cost effective.
The detailed description of the drawings refers to the accompanying figures in which:
Referring to
The bi-directional pump 10 comprises a pump housing 17, and the pump housing 17 comprises a pump inlet 18 (see
Referring to
The flow controller 40 may be positioned, on a first side 47 of the junction 35, when the flow controller 40 is in the first position 42, and the flow controller 40 may be positioned, on a second side 50 of the junction 35, when the flow controller 40 is in the second position 45. The flow controller 40 may shuttle between the first and second positions 42, 45. An outer diameter 52 of the flow controller 40 may greater than an inner diameter 55 of the pump outlet 20.
The first passage 30 may comprise a first passage bend 57, and a first passage aperture 60 opening into the first passage bend 57, and a first travel limiter 62. The first travel limiter 62 may be configured to limit the travel of the flow controller 40 so as to space the flow controller 40 from the first passage aperture 60. The first travel limiter 62 may be a first limiter shoulder 65. The outer diameter 52 of the flow controller 40 may be greater than an inner diameter 70 of the first limiter shoulder 65.
The bi-directional pump 10 may further comprise a second travel limiter 72 that is distinct from the pump housing 17. The second passage 32 may comprise a second passage bend 77 and a second passage aperture 80 opening into the second passage bend 77. The second passage bend 77 may be included in the second travel limiter 72, and the second travel limiter 72 may be configured to limit the travel of the flow controller 40 so as to space the flow controller 40 from the second passage aperture 80. Illustratively, the second travel limiter 72 is in alignment with the junction 35, but in other embodiments, the second travel limiter 72 may be perpendicular to the junction 35 or any angle in between.
The second travel limiter 72 may comprises a second limiter shoulder 66 having an inner diameter 82 smaller than the outer diameter 52 of the flow controller 40. The second travel limiter 72 may comprise a first limiter aperture 87 and a second limiter aperture 90. The second passage bend 77 may be positioned between the first and second limiter apertures 87, 90. The pump housing 17 may comprise a bore 92, and the bore 92 may comprise a portion of the first passage 30 and of the second passage 32 and of the junction 35. The bore 92 may comprise the first travel limiter 62.
The bi-directional pump 10 may further comprise a key 95. The second travel limiter 72 may comprise a limiter keyway 97, and the pump housing 17 may comprise a pump housing keyway 100. The key 95 may be positioned in the limiter keyway 97 and in the pump housing keyway 100. The bore 92 has a bore axis 102, and the key 95 may angularly align the first limiter aperture 87 with the second passage aperture 80 relative to the bore axis 102.
The bore 92 may comprise a stop 105. The stop 105 may contact the second travel limiter 72 thereby axially aligning the first limiter aperture 87 with the second passage aperture 80 relative to the bore axis 102. A plug 170 may retain the second travel limiter 72 against the stop.
The second travel limiter 72 may be positioned in the bore 92. The bore 92 may comprise a second travel limiter portion 107 and a junction portion 110 in alignment with the second travel limiter portion 107. The second travel limiter 72 may be positioned in the bore 92 or, more specifically, in the second travel limiter portion 107. The junction portion 110 may be included in the junction 35. A diameter 112 of the second travel limiter portion 107 may be greater than a diameter 115 of the junction portion 110.
The bore 92 may further comprise a first passage portion 117 that is in alignment with the junction portion 110. The junction portion 110 may be positioned between the second travel limiter portion 107 and the first passage portion 117. The first passage portion 117 may be included in the first passage 30. The diameter 115 of the junction portion 110 may be greater than a diameter 120 of the first passage portion 117. The flow controller 40 may be positioned in the junction portion 110. Illustratively, the junction portion 110 and the pump outlet 20 cooperate to for a âTâ shape, but the junction portion 110 and the pump outlet 20 may join together at various other angles as well.
As shown, in
The pump housing 17 may comprise a first radially inner recess 140 positioned contiguously with the first passage 30, and a second radially inner recess 142 positioned contiguously with the second passage 32. The first radially inner recess 140 may be symmetric to the second radially inner recess 142 about a plane 145 that encompasses the rotation axis 130. Further, the pump housing 17 may comprise a first radially outer recess 147 positioned contiguously with the first passage 30, and a second radially outer recess 150 positioned contiguously with the second passage 32. The second radially outer recess 150 is symmetric to the first radially outer recess 147 about the plane 145.
The pump housing 17 may comprise a cavity 152 that is adjacent to a set of gear teeth 155 of the gear 125. A fluid, such as hydraulic oil, may be used to cool and lubricate the clutch pack 14 (see
The set of gear teeth 155 has an addendum radius 157 and a dedendum radius 160, and the cavity 152 may have a width 162 approximately equal to a difference between the addendum radius 157 and the dedendum radius 160. As shown, in
In operation, fluid (e.g., hydraulic oil) flows out of the transmission and into front power takeoff 12. In the front power takeoff 12, the fluid cools and lubricates the clutch pack 14. Then, the fluid flows out of the front power takeoff 12 and into the cavity 152. If the gear 125 rotates, in the first direction 172, then it pumps fluid from the cavity 152 and into the first passage 30. The first radially inner and outer recesses 140, 147 may reduce noise that the gears 125, 135 make as the result of pumping the fluid.
In the embodiment shown, as the fluid flows in the first direction 25, the flow controller 40 is positioned, in the pump housing 17, in the first position 42 (see
If the gear 125 rotates in the second direction 177, then it pumps fluid from the cavity 152 and into the second passage 32. The second radially inner recess and outer recesses 142, 150 may reduce noise that the gears 125, 135 make as the result of pumping the fluid.
In the embodiment shown, if the fluid flows in the second direction 27, then the flow controller 40 is positioned, in the pump housing 17, in the second position 45 (see
While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description is to be considered as exemplary and not restrictive in character, it being understood that illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected. It will be noted that alternative embodiments of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations that incorporate one or more of the features of the present disclosure and fall within the spirit and scope of the present invention as defined by the appended claims.
