FIELD OF THE INVENTION The present invention relates to the field of pumps, and more specifically, to a pump system for an automotive engine.
BACKGROUND OF THE INVENTION Many mechanical engines, and particularly gasoline engines, require a constant circulation of oil for lubrication and cooling. One or more pumps, driven by the engine itself, are employed to move and control the oil flow. Such pumps are subjected to harsh operating conditions, especially in high performance vehicles such as race cars. It is desired to provide an improved pumping system for automotive engines.
SUMMARY OF THE INVENTION Generally speaking, there is provided a pump system, including a pressure pump having a primary drive shaft with a primary fluid moving element and a secondary drive shaft with a secondary fluid moving element that enmeshes with the primary fluid moving element; a first scavenge pump bank driven by the primary drive shaft and including at least one scavenge pump; and, a second scavenge pump bank driven by the secondary drive shaft and including at least one scavenge pump. Each scavenge pump bank has at least one or numerous scavenge pumps, each scavenge pump in a pump bank being driven by a common one of the primary drive shaft or the secondary drive shaft.
It is an object of the present invention to provide an improved pump system.
It is an object of the present invention to provide an improved pump system for an automotive engine.
Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a prior art pump system 10.
FIG. 2 is a perspective, cross-sectional view of the pump system 10 of FIG. 1, taken along the line 2-2 and viewed in the direction of the arrows.
FIG. 3 is a cross-sectional view of the pump system 10 of FIG. 1, taken along the line 3-3 and viewed in the direction of the arrows.
FIG. 4 is a perspective view of the rotor pair 48/51 of the pump system 10 of FIG. 1.
FIG. 5 is a rear, perspective view of a pump system 60 in accordance with one embodiment of the present invention.
FIG. 6 is a rear perspective view of the pump system 60 of FIG. 5, shown without filter 65 and filter manifold 66.
FIG. 7 is a front perspective view of the pump system 60 of FIG. 6.
FIG. 8 is a top view of the pump system 60 of FIG. 6.
FIG. 9 is a perspective, cross-sectional view of the pump system 60 of FIG. 8 taken along the lines 9-9 and viewed in the direction of the arrows.
FIG. 10 is a perspective, cross-sectional view of the pump system 60 of FIG. 8 taken along the lines 10-10 and viewed in the direction of the arrows.
FIG. 11 is a perspective, cross-sectional view of the pump system 60 of FIG. 8 taken along the lines 11-11 and viewed in the direction of the arrows.
FIG. 12 is a perspective, cross-sectional view of the pump system 60 of FIG. 8 taken along the lines 12-12 and viewed in the direction of the arrows.
FIG. 13 is a perspective, cross-sectional view of the pump system 60 of FIG. 8 taken along the lines 13-13 and viewed in the direction of the arrows.
FIG. 14 is a perspective, cross-sectional view of the pump system 60 of FIG. 12, and showing all of secondary drive shaft 75, secondary driven shaft 137 and rotors 154 and 155 of second scavenge pump section 63.
DESCRIPTION OF THE PREFERRED EMBODIMENT For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, and any alterations or modifications in the illustrated device, and any further applications of the principles of the invention as illustrated therein are contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring now to FIGS. 1-4, there is shown one embodiment of a prior art pump 10 for moving and controlling the flow of oil in a high performance engine. Pump 10 includes a pressure pump 11, five scavenge pumps 12-16, a pressure manifold 17 and a drive pulley 18. For clarity, pumps 11-16 are shown in FIG. 2 without drive rotors or gears, which elements are identical to those discussed herein in relation to the pump system 60 of FIGS. 3-12. Pumps 11-16 are connected together in a stacked relationship, with mutually parallel common drive shaft 22 and common idler shaft 23 extending therethrough, as shown. Drive shaft 22 extends rearwardly of pumps 11-16 and of pressure manifold 17 where it is fixed to and driven by drive pulley 18. Pressure pump 11 is an external gear pump and defines a pressure chamber 24, within which are mounted a pair of enmeshing gears 25 and 26. Gear 25 is a drive gear and is fixed to rotate with drive shaft 22 via a pair of keyways 27 defined in drive shaft 22 and matching keyways and keys (indicated at 30). Gear 26 is an idler gear and is mounted for free rotation on idler shaft 23 for meshing engagement with drive gear 25. Driven by drive shaft 22, drive gear 25 and thus idler gear 26 are forced to rotate within pressure chamber 24 and to pull fluid through suction port 28 and out the pressure port 29 at a desired pressure.
In like fashion, scavenge pumps 12-16 define scavenge chambers 31-35, respectively, each of which has a suction port (38-42) at its bottom portion (that is, below the drive and idler shafts 22 and 23). At their top portions (that is, above the drive shaft 22 and idler shaft 23), scavenge chambers 31-35 are in mutual communication via passageways, such as at 44, and the top portions of the scavenge chambers 31-35 are thus in mutual communication with outlets 45 and 46. From pressure pump 11, drive shaft 22 and idler shaft 23 extend forwardly, in parallel, through the scavenge chambers 31-35 of scavenge pumps 12-16, respectively. Seals, bearings and/or wipers are provided at desired points along drive shaft 22 and idler shaft 23 (for example at 47), to support these shafts 22 and 23 for rotation and to prevent fluid flow between chambers, as is known in the art. In each scavenge chamber 31-35, a helical drive rotor such as 48 (FIG. 4) is fixed to rotate with the drive shaft 22 via keyways 27 defined in drive shaft 22, keyway 49 defined in rotor 48 and a key (not shown). Also in each scavenge chamber 31-35, a helical idler rotor 51 is mounted and keyed to idler shaft 23 and for meshing engagement with the companion drive rotor 48.
In operation, drive pulley 18 is rotated by an appropriate mechanism such as a belt or gear. Rotation of drive pulley 18 rotates drive shaft 22, which rotates drive gear 25 in pressure chamber 24, which rotates its companion idler gear 26, the drive gear 25 and idler gear 26 together pumping fluid out of pressure port 29 and through the engine's systems. Rotation of drive shaft 22 also rotates each drive rotor 48 that is keyed thereto, each of which thus rotating its companion idler rotor 51. Each set of rotating, enmeshing drive rotor 48 and idler rotor 51 exerts a negative pressure to suck fluid in from its corresponding inlet (38-42) and out of outlets 45 and 46. Inlets 38-42 are connected via appropriate fluid lines to target fluid recovery points in the engine, such as the bottom of the oil sump, the valley, the cylinder heads and/or gear cluster chambers. Outlets 45 and 46 are connected via appropriate fluid lines (not shown) back to the engine's oil supply. The pressure manifold 17 contains a pressure relief valve 52 (not shown) operationally connected with pressure pump 11 to redirect fluid flow from the outlet side 54 to the inlet side 55 of pressure pump 11 should the outlet pressure exceed a predetermined value.
Referring to FIGS. 5-14, there is shown a pump system 60 in accordance with one embodiment of the present invention. Pump system 60 generally includes a pressure pump 61, first and second scavenge pump sections 62 and 63, a pressure manifold 64, a filter 65, a filter manifold 66 and an end plate 67, all held together by appropriate means such as bolts 68. Pressure manifold 64 and filter manifold 66 exist here as separate units, but either or both may be formed integrally or in other configurations with pressure pump 61. Pressure pump 61 has a body 69, which defines a pressure chamber 70 (FIG. 9), and further includes enmeshing first spur gear 71 and second spur gear 72, a primary drive shaft 74 and a secondary drive shaft 75. From within pressure chamber 70, primary drive shaft 74 extends forwardly into first and second scavenge pump sections 62 and 63 and extends rearwardly, through and out of pressure manifold 64 where it connects with a drive transfer element, such as a pulley (not shown), to be driven by an appropriate mechanism, such as a drive belt or gear (not shown). Within pressure chamber 70, first spur gear 71 is fixed to rotate with primary drive shaft 74 via one or more keyway assemblies (at 76). Also within pressure chamber 70, second spur gear 72 is fixed to rotate with secondary drive shaft 75 via one or more keyway assemblies (at 77). Secondary drive shaft 75 is mounted for otherwise free rotation by appropriate means such as thrust bearings and for extension from within pressure chamber 70 and into the scavenge chambers of first scavenge pump section 62 and second scavenge pump section 63, as described herein. Pump body 69 has a filter manifold interface surface 77 (FIG. 6) against which is connected filter manifold 66. Pump body 69 defines a pressure chamber inlet passageway 78 that extends from a pressure chamber inlet opening 80 defined in surface 77 to and in communication with pump chamber 70. Pump body 69 also defines signal orifice 83 and pressure relief inlet and outlet ports 84 and 85, respectively, that lead to pressure manifold 64. Pump body 69 also defines a pressure chamber outlet passageway 79 that extends from a pressure chamber outlet opening 81 defined in surface 77 and in communication with pump chamber 70.
Referring to FIG. 10, pressure manifold 64 is connected adjacent the rear side of pump body 69 and which defines outlet passageway 87, relief valve chamber 88 and relief passageway 89. Outlet passageway 87 exits pressure manifold 64 (and pump system 60) at pump outlet port 90. As viewed in FIG. 10, relief valve chamber 88 extends from stop surface 92 to the right where it opens outwardly of manifold 64 at opening 94. Relief valve chamber 88 slidably receives a relief valve piston 93. Piston 93 includes a nose 95, a reduced diameter section 97, a piston face 98 and a spring cavity 99, as shown. Cap 101 defines a spring cavity 102, and is threadedly received in opening 94 to close off relief valve chamber 88. In assembly, relief valve piston 93 is received in chamber 88 with nose 95 up against stop surface 92, and a coil spring (not shown) is seated to extend in cavities 99 and 102, between piston 93 and cap 101. Cap 101 is fixed in opening 94, but alternative embodiments contemplate cap 101 being threadedly received in opening 94 and being able to be turned in or out to vary the compressive spring force against piston 93 and thus the relief pressure threshold of the relief valve 52. Outlet side 54 of pressure chamber 70 (FIG. 9) is in communication with relief valve chamber 88 at piston face 98 through pressure chamber outlet passageway 79 and signal orifice 83. Relief passageway 89 of manifold 64 is in communication at its top end 103 with relief valve chamber 88 and at its bottom end 104 with pressure relief outlet port 85 of pump body 69, which opens into the inlet side 55 of pressure chamber 70, below spur gears 71 and 72. Piston 93 of pressure relief valve 52 is sized and shaped so that, when seated in the closed position (FIG. 10), piston face 96 and reduced diameter section 97 is to the left (as seen in FIG. 10) of relief passageway 89, thus closing off relief passageway 89 to chamber 88. In the event of a blockage downstream of orifice 83, increasing pressure at piston face 98 will act through orifice 83 and against piston face 98 until the spring force is overcome, whereupon piston 93 is moved to the right (as seen in FIG. 10) until piston face 96 moves to the right enough to permit fluid flow from chamber 88, through relief passageway 89, and back into the inlet side 55 of pressure chamber 70.
Referring to FIGS. 6 and 9, pump body 69 further defines an outlet passageway 110 that extends from a filter inlet port 111 defined in interface surface 77, through pump body 69 to a similar outlet passageway 116 defined in pressure manifold 64 (not shown), which extends rearwardly and exits at pump outlet port 90. Pump body 69 further defines a pressure relief passageway 112 that extends from outlet passageway 110 (within pump body 69) to a pressure relief port 113 defined in interface surface 77.
Referring to FIGS. 5, 6 and 9, filter manifold 66 connects to the mutually planar end faces 114, 77 and 115 of pressure manifold 64, pressure pump 61 and first scavenge pump section 62, respectively, by appropriate means, such as screws 118. Filter manifold 66 defines filter inlet passageway 120, filter outlet passageway 121, filter relief valve passageway 122 and pump inlet passageway 123. When filter manifold 66 is connected adjacent interface surface 77 and filter 65 is connected to filter manifold 66, as shown in FIG. 5, the various passageways and ports align to permit: fluid to flow from an inlet fitting 124 connected at inlet passageway 123, into pressure chamber inlet passageway 78; fluid to flow from pressure chamber outlet passageway 79, through filter inlet passageway 120 and into the inlet (not shown) of filter 65; and, fluid to flow from the outlet (not shown) of filter 65, through filter outlet passageway 121 and into pump outlet passageway 110, where it passes through outlet passageway 116 in pressure manifold 64 and out pump outlet port 90 to the engine's systems, as desired.
Similar to the pressure relief valve 52 of pressure manifold 64, filter manifold 66 is provided with a pressure relief valve, the relief valve chamber for which is shown at 125. In the event of a blockage in the filter, increasing fluid pressure acting on the filter inlet side forces a piston (not shown) to slide within relief valve chamber 125 and permit fluid to flow from the inlet side 126 to the outlet side 127 of the relief valve, and thence through pressure relief port 113, into pressure relief passageway 112 and out through outlet passageway 110.
In the present embodiment, pump system 60 is designed to pump oil, and filter 65 is a standard oil filter, such as a Fram oil filter, model HP4.
Referring to FIGS. 9 and 11, a cross-section of first scavenge pump section 62 reveals that pump section 62 includes a pump body 131, primary and first, secondary drive rotors 132 and 133, primary and secondary driven rotors 134 and 135, and primary and secondary driven shafts 136 and 137. Scavenge pump body 131 defines first and second scavenge chambers 141 and 142, each of which has a scavenge inlet 143 and 144, respectively, that are connected via appropriate fluid lines to target fluid recovery points in the engine, such as the bottom of the oil sump, the valley, the cylinder heads and/or gear cluster chambers. Like rotors 48 and 51 of pump 10 of FIGS. 1-4, rotors 132-135 are 90° helical rotors. Drive rotors 132 and 133 are fixedly secured to rotate with primary and secondary drive shafts 74 and 75, respectively, which extend from pressure pump 61 into first scavenge pump section 62. Driven rotors 134 and 135 are fixedly mounted to rotate with driven shafts 136 and 137, respectively, which are held for rotation by pump body 131, as shown. Scavenge chambers 141 and 142 outlet through passageways 147 and 148 to a common outlet chamber 149, which leads to scavenge pump outlet fitting 150 (FIG. 13).
Referring to FIG. 13, stacked next to first scavenge pump section 62 is second scavenge pump section 63, which includes a pump body 153, a second, secondary drive rotor 154, a second, secondary driven rotor 155, and second driven shaft 137, which extends through from first scavenge pump section 62. Pump body 153 defines a third scavenge chamber 159 which, like scavenge chambers 141 and 142, has a scavenge inlet 160. Pump body 153 further defines an outlet passageway 161 that leads from third scavenge chamber 159 to the common outlet chamber 149, which leads to outlet port 163, to which is connected outlet fitting 150. Like second chamber 142, the drive rotor 154 of third pressure chamber 159 is fixedly mounted to secondary drive shaft 75 by appropriate means such as a keyway assembly 164. The companion driven rotor 155 is likewise fixedly mounted to driven shaft 137 by appropriate means such as a keyway assembly 165. In assembly, primary drive shaft 74 extends rearwardly of pump system 60 to connect with and be driven by a pulley or other appropriate mechanism connected with the engine, and extends therefrom through pressure manifold 64, pressure pump 61 and first scavenge pump section 62, and primary driveshaft 74 is fixedly connected to rotate with first spur gear 71 and primary drive rotor 132. Likewise, secondary drive shaft 75 extends through pressure pump 61, first scavenge pump section 62 and second scavenge pump section 63, and secondary drive shaft 75 is fixedly connected to rotate with second spur gear 72, first, secondary drive rotor 133, and second, secondary drive rotor 154. Primary driven shaft 136 extends only within first scavenge pump section 62 and is fixedly connected to rotate with primary driven rotor 134. (As described below, shaft 136 does not in this embodiment extend into another pump section but, along with primary shaft 74, they do extend out of scavenge chamber 141 to connect with timing gears 171 and 172). Secondary driven shaft 137 extends through first scavenge pump section 62 and second scavenge pump section 63, and first, secondary driven rotor 135 and second, secondary driven rotor 155 are fixedly connected to rotate therewith.
Referring to FIG. 12, a recess 168 is defined in the forward surface 169 of first scavenge pump section 62 to receive a shaped drive gear spacer 170. Spacer 170 receives timing gears 171 and 172, which are fixedly connected to and at the rear ends of primary drive shaft 74 and primary driven shaft 136 by appropriate means such as keyway assemblies 164. Timing gears 171 and 172 thus rotate with shafts 74 and 136 and with rotors 132 and 134 and operate to eliminate momentary drive lag experienced by the independent drive function of the 90° helical rotors 132 and 134. Similar timing gears are not necessary with the rotors 133 and 135 of second scavenge chamber 142 because of the second pair of rotors 154 and 155 connected to rotate therewith in third scavenge chamber 159. That is, rotors 133, 135, 154 and 155 are 90° helical rotors, and the periodic momentary lag experienced by a single pair of such rotors is substantially, if not entirely eliminated by mounting rotors 154 and 155 offset (by about 45°) relative to rotors 133 and 135.
As described herein, pump system 60 comprises a pressure pump 61 and two scavenge pump banks: a primary scavenge pump bank 174 that is driven by primary drive shaft 74 and a secondary scavenge pump bank 175 that is driven by secondary drive shaft 75. In the present embodiment, primary scavenge pump bank 174 comprises only one scavenge pump 178 that is contained substantially within first scavenge pump section 62, is driven by primary drive shaft 74 and comprises a single pair of rotors 132 and 134. Secondary scavenge pump bank 175 comprises two scavenge pumps 179 and 180, both of which are driven by secondary drive shaft 75. Scavenge pump 179 is contained in first scavenge pump section 62 and comprises first, secondary drive rotor 133 and first, secondary driven rotor 135. Scavenge pump 180 is contained in second scavenge pump section 63 and comprises second, secondary drive rotor 154 and second, secondary driven rotor 155. Alternative embodiments are contemplated where either or both of the primary and secondary scavenge pump banks 174 and 175 each contain as few as one scavenge pump (such as scavenge pump 178) or two or more scavenge pumps (such as scavenge pumps 179 and 180), such two or more scavenge pumps being driven by one of primary drive shaft 74 and secondary drive shaft 75. Alternative embodiments are also contemplated wherein one scavenge pump bank (such as scavenge pump bank 175) is driven by one of primary drive shaft 74 and secondary drive shaft 75, and includes a secondary driven shaft (such as shaft 137) that then becomes a drive shaft for yet another, separate scavenge pump bank. In this scavenge pump “branching”, timing gears (such as timing gears 171 and 172) may be employed at appropriate places to maintain the timing and drive function of the pump banks. Branching is intended to mean the use of a driven shaft of one scavenge pump to act as a drive shaft for another scavenge pump, and alternative embodiments are contemplated where multiple branches are employed to permit considerable latitude in spatial configuration of the pump system.
In operation, primary drive shaft 74 rotates first spur gear 71 which enmeshes with and rotates second spur gear 72 to pump fluid through inlet 24, out through filter 65 and out pump outlet port 90. Primary drive shaft 74 thus also drives scavenge pump 178 by driving primary drive rotor 132, which enmeshes with its primary driven rotor 134. The secondary drive shaft 75 drives both pumps 179 and 180 in secondary scavenge pump bank 175 by driving first, secondary drive rotor 133 and second, secondary drive rotor 154, which enmesh with their companion secondary driven rotors 135 and 155, respectively, in scavenge pumps 179 and 180, respectively. The resulting suction created in scavenge pumps 178, 179 and 180 sucks fluid via inlets 143, 144 and 160 from the target recovery points in the engine. By using both shafts 74 and 75 of the primary pressure pump 61 to drive rotors in the scavenge pumps, the configuration of pump system 60 is dramatically shortened.
Pump system 60 has been described as having a pressure manifold, filter manifold, filter and pressure relief valves. However, the pump system of the present invention is contemplated to comprise, at a minimum, the pressure pump 61 and at least two scavenge pump banks contained in one or more scavenge pump sections. The pressure manifold, filter manifold, filter, pressure relief valves, and any other desired elements, fittings, or connections can be provided separately or in combination to operatively connect with such pump system.
Pressure pump 61 contains fluid moving elements in the form of spur gears 71 and 72 and the fluid moving elements in the various scavenge pumps 178-180 are in the form of 90° helical rotors. Alternative embodiments are contemplated where such fluid moving elements can be any appropriate elements such as, and without limitation, spur gears, helical rotors, gerotors or impellers.
The present embodiment is directed to a pumping system for a high performance racing engine. Alternative embodiments are contemplated wherein pumping system 60 is used with other engines or engine applications, such as and without limitation, diesel engines, boat engines, lawnmowers, motorcycles, aircraft engines, undersea vehicles or spacecraft. Alternative embodiments are contemplated wherein pumping system 60 is used with other mechanical devices, such as and without limitation, gearboxes or fuel systems.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrated and not restrictive in character, it being understood that only the preferred embodiment and a few alternative embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
