JP2005030517A - Drive mechanism for oil pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive mechanism having a reduced size for driving an oil pump arranged on another shaft than an input shaft with an electric motor while achieving a higher degree of freedom in their layout. <P>SOLUTION: The drive mechanism for the circumscribed gear type oil pump P comprises a first gear G1 and a second gear G2 circumscribed to the first gear G1. One of the first and second gears G1, G2 can be driven by an engine E and the other can be driven by the electric motor M. The first gear G1 and the second gear G2 are different in the number of teeth. It is desirable that the gear having more teeth is driven by the engine and the gear having less teeth is driven by the electric motor. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an oil pump drive device, and more particularly to an oil pump drive device used as a pressure source for an automatic transmission for an automobile or the like.

  2. Description of the Related Art In general, an automatic transmission for an automobile including an automatic transmission for a vehicle and a continuously variable transmission has torque transmission mechanisms such as various rotating shafts and various gears as components constituting the transmission mechanism and other components. The speed ratio is changed in a path through which torque is transmitted between these torque transmission mechanisms. An oil pump is provided for generating pressure for driving the mechanism for changing the speed ratio and for lubrication.

  Also, due to recent demands for lower fuel consumption of engines and prevention of air pollution, for example, a vehicle of a type that stops the engine in a signal waiting state at an intersection is also known. In such a type of vehicle, an oil pump disposed on the input shaft of the transmission is usually installed on the input shaft because an early rise in hydraulic pressure in an automatic transmission or the like is required to shorten the start time. It may be necessary to place it on a different axis different from the above.

  An example of such an automatic transmission in which an oil pump is disposed on a different shaft from the input shaft is described in Patent Document 1. In Patent Document 1, a shaft directly connected to an output shaft of an engine, a main shaft of an electric motor, and a drive shaft of an oil pump are spanned over a sprocket mounted on each shaft via a one-way clutch. Thus, there is disclosed an oil pump drive device in which the oil pump is driven by an electric motor while the engine-side one-way clutch is idling when the engine speed is less than or equal to a predetermined value.

JP 2002-227978 A

However, in the oil pump drive device described in Patent Document 1 above, the shaft directly connected to the output shaft of the engine, the main shaft of the electric motor, and the drive shaft of the oil pump are one-way on each shaft. A structure in which one chain is connected to three sprockets mounted via a clutch, and an electric motor and an oil pump are arranged in parallel in a direction perpendicular to the axis of each axis. Therefore, there has been a problem that their layout is limited and the entire automatic transmission including the oil pump drive device is enlarged.
The object of the present invention has been made against the background of the above circumstances, and even when an oil pump disposed on a shaft different from the input shaft is driven by an electric motor, the degree of freedom in the layout thereof is increased. An object of the present invention is to provide an oil pump drive device which is large and can be miniaturized.

  An oil pump drive device according to an aspect of the present invention that achieves the above object is a gear-type oil pump drive device including a first gear and a second gear meshing with the first gear, One of the gear and the second gear can be driven by a first prime mover, and the other of the first gear and the second gear can be driven by a second prime mover.

  According to such a configuration, the oil pump can be driven by connecting separate prime movers to the first gear and the second gear without connecting separate prime movers to the same drive shaft of the oil pump. The degree of freedom of layout including the system is increased, and the overall size can be reduced.

  The first prime mover is an engine, and the second prime mover is an electric motor. The first gear and the second gear have different numbers of teeth, and among them, a gear having a large number of teeth is driven by the engine. It is preferable that a gear with a small amount is configured to be driven by the electric motor.

  In this way, there is no need to install a special speed reduction mechanism from the engine to the gear with the large number of teeth of the gear type oil pump, and from the electric motor to the gear with the small number of teeth of the gear type oil pump. Driving in a region is possible.

  As is apparent from the above description, according to the present invention, the oil is obtained by connecting separate prime movers to the first gear and the second gear without connecting separate prime movers to the same drive shaft of the oil pump. Since the pump can be driven, the degree of freedom in layout including those drive systems is increased, and the overall size can be reduced.

  Further, the first gear and the second gear have different number of teeth, and among them, a gear having a large number of teeth is driven by the engine, and a gear having a small number of teeth is driven by the electric motor. There is no need to install a special speed reduction mechanism from the engine to the gear with the large number of teeth of the gear type oil pump and from the electric motor to the gear with the small number of teeth of the gear type oil pump. It becomes possible.

  Embodiments of the present invention will be specifically described below with reference to the drawings.

  FIGS. 1 to 4 are skeleton diagrams in which the casing and the like are omitted when the present invention is applied to a transaxle TA for an FF vehicle (front engine front drive; front-wheel drive vehicle for engine front).

  First, as a common configuration in the first to fourth embodiments shown in FIGS. 1 to 4, E is an engine as a first prime mover, TC is a torque converter connected to the engine E, and the torque converter TC The output shaft constitutes the input shaft of the transaxle TA. The transaxle TA includes a forward / reverse switching mechanism F / R · M, a belt-type continuously variable transmission mechanism BCVT, and a final reduction mechanism FR in order. The PDS is a pump drive shaft connected to the pump impeller of the torque converter TC and directly driven by the engine E, and is arranged coaxially with the output shaft of the torque converter TC, that is, the input shaft of the transaxle TA. In addition, S1 has shown the 1st sprocket connected with the pump drive shaft PDS. P denotes an oil pump, and M denotes an electric motor as a second prime mover.

  As shown in FIG. 5, the oil pump P includes a first gear G1 disposed in the pump casing PC, and a circumscribed gear including a second gear G2 that is disposed so as to circumscribe the first gear G1 and rotate. The first gear G1 is connected to the first gear drive shaft GDS1, and the second gear G2 is connected to the second gear drive shaft GDS2, respectively. Note that PCI is an intake port and PCO is a discharge port. Here, when the number of teeth of the first gear G1 is Z1, and the number of teeth of the second gear G2 is Z2, the number of teeth Z1 is larger than the number of teeth Z2.

  Therefore, in the first embodiment of the present invention shown in FIG. 1, an endless chain ELC is spanned between the first sprocket S1 and the second sprocket S2 connected to the first gear drive shaft GDS1. The electric motor M is disposed on the opposite side of the second sprocket S2 across the oil pump P, and is provided so as to directly drive the second gear drive shaft GDS2.

  Thus, if necessary, the oil pump P is driven by the engine E through the pump drive shaft PDS, the first sprocket S1, the first endless chain ELC1, the second sprocket S2, and the first gear drive shaft GDS1. Operation is enabled by driving the gear G1 or driving the second gear G2 via the second gear drive shaft GDS2 by the electric motor M, respectively. When the first gear G1 is driven by the engine E to operate the oil pump P, the electric motor M is appropriately controlled in order to reduce the resistance of the electric motor M driven via the second gear G2. It is preferable. For example, the current may be shut down in order to set the electric resistance to 0, or a minute current may be passed so as not to generate back electromotive force.

  Next, a second embodiment of the present invention is shown in FIG. In the second embodiment, in addition to the configuration of the first embodiment described above, the first one-way clutch OWC1 is provided between the first gear drive shaft GDS1 connected to the first gear G1 and the second sprocket S2. This point is different from the first embodiment. Since other configurations are the same as those of the first embodiment including their arrangement relation, the same portions are denoted by the same reference numerals to avoid redundant description. Thus, when the first one-way clutch OWC1 is provided, for example, when the oil pump P is operated by driving the second gear G2 by the electric motor M while the engine E is stopped, the engine E is dragged and rotated. This is particularly preferable in a vehicle or the like that stops the engine while waiting for a signal at an intersection.

  In the first and second embodiments described above, when the oil pump P is driven by the engine E, the electric motor M is also always driven from the oil pump P side. You may make it generate regenerative power as a machine. Then, the generated electric power is stored in a predetermined storage battery, the electric motor M is operated with the electric power while the engine E is stopped, and the oil pump P is driven to obtain a predetermined hydraulic pressure. May be.

  A third embodiment of the present invention is shown in FIG. In the third embodiment, in addition to the configuration of the second embodiment described above, a second one-way clutch OWC2 is interposed in the middle of the second gear drive shaft GDS2 connected to the second gear G2. This point is different from the second embodiment. Since other configurations are the same as those of the second embodiment including their arrangement relationship, the same portions are denoted by the same reference numerals and redundant description is avoided.

  In the third embodiment, when the oil pump P is driven by either the engine E or the electric motor M, the oil pump P can be driven without affecting the other direction such as drag rotation. it can.

  Furthermore, the 4th Embodiment of this invention is shown in FIG. In the fourth embodiment, the electric motor M is disposed on the same side as the above-described second sprocket S2 with respect to the pump P as compared with the configuration of the above-described first to third embodiments. The third sprocket S3 is connected to the second gear drive shaft GDS2, and the fourth sprocket S4 is connected to the output shaft of the electric motor M. The second endless chain is connected to the third sprocket S3 and the fourth sprocket S4. ELC2 is spanned. Since other configurations are the same as those of the first embodiment including their arrangement relation, the same portions are denoted by the same reference numerals to avoid redundant description. In the fourth embodiment, the degree of freedom in the layout of the electric motor M is increased.

  In selecting the number of teeth Z1 of the first gear G1 and the number of teeth Z2 of the second gear G2, the electric motor shown in the graph (A) of FIG. 7 and the engine torque characteristics shown in (B) It is preferable to consider the relationship with the high efficiency region. That is, in the case of the electric motor M, high efficiency is generally obtained in the rotation region of about 4000 to 6000 rpm, whereas in the case of the engine (gasoline) E, high efficiency is obtained in the rotation region of about 2000 to 4000 rpm. Therefore, “the number of teeth Z2 of the second gear G2 driven by the electric motor M”: “the number of teeth Z1 of the first gear G1 driven by the engine E” = 1: 2 to 1.5 is preferable. . If it does in this way, it will become possible to drive oil pump P in each high efficiency field, without arranging a special reduction mechanism in the drive system of the 2nd gear G2 and the 1st gear G1.

  Here, an example in which the first embodiment is embodied in an actual machine among the embodiments of the present invention shown in the skeleton diagrams in FIGS. 1 to 4 will be described with reference to FIG.

  The transaxle TA is attached to the end of the engine, and is connected to the converter housing TCH that houses the torque converter TC, and the converter housing TCH. The forward / reverse switching mechanism, the belt-type continuously variable transmission mechanism, and the final reduction mechanism And a transaxle case TAC that accommodates an oil pan (not shown) is attached to the lower part of the transaxle case TAC. In addition, a valve body unit in which a hydraulic circuit and a circuit switching valve (not shown) are arranged is provided between the transaxle case TAC and the oil pan. Note that hydraulic oil and lubricating oil (not shown) supplied to the inside of the transaxle TA are stored inside the oil pan, and are sucked into the oil pump P through the strainer. ing.

  The oil pump P is disposed below the transaxle case TAC and at a position close to the converter housing TCH and the valve body unit. As described above, the oil pump P is constituted by an external gear pump, and is disposed on a shaft different from the rotation shaft of the torque converter TC, that is, the input shaft 150 of the transaxle TA. And driven by an electric motor M.

  As described in FIG. 5, the oil pump P includes a suction port PCI and a discharge port PCO (both not shown in FIG. 6), which are not shown formed in the transaxle case TAC, respectively. To the suction oil passage and the discharge oil passage. When the oil pump P is driven, the oil in the oil pan is pumped up through the strainer and the suction oil passage, and the discharge hydraulic pressure of the oil pump P is supplied to the hydraulic circuit of the valve body unit through the discharge oil passage. After that, it is controlled and distributed to each part of the transaxle TA.

  Here, as is well known, the torque converter TC includes a pump impeller 111, a turbine runner 112, and a stator 113 that are rotationally symmetrical around the input shaft 150 of the transaxle TA. The pump impeller 111 includes a converter cover 114. To the output shaft of the engine. One end of converter cover 114 is further connected to rotating member 115 corresponding to pump drive shaft PDS described above by welding or the like. In the present embodiment, the rotating member 115 mainly includes a disk-shaped portion 115D having an outer peripheral end connected to one end of the converter cover 114, and an axial direction from the inner peripheral end of the disk-shaped portion 115D. And a cylindrical portion 115 </ b> B extending in the direction. The turbine runner 112 is connected to the turbine hub 116 that is splined to the input shaft 150 described above, and the stator 113 is a stator support sleeve 118 fixed to a transaxle case TAC as a stationary member via a one-way clutch 117. It is supported by. The input shaft 150 is rotatably supported by the stator support sleeve 118 with a bush 119 interposed therebetween.

  In the present embodiment, torque converter TC includes a lockup mechanism 160. The lock-up mechanism 160 is disposed between the piston 162 movably in the axial direction on the turbine hub 116, the transmission member 166 disposed between the piston 162 and the converter cover 114, and provided with friction materials 164 on both sides. And a damper device in which the input side member is coupled to the transmission member 166, the output side member is coupled to the turbine hub 116, and a spring is disposed in a twisting direction between the input side member and the output side member. 168.

  Further, the cylindrical portion 115B of the rotating member 115 described above is formed to be substantially flat on the inner peripheral side, whereas the outer peripheral side is formed in a three-stage step shape from the tip portion toward the root portion. Yes. A bush 170 that seals a pressure oil passage, which will be described later, is disposed between the outer peripheral side of the minimum diameter on the distal end side of the cylindrical portion 115B of the rotating member 115 and the protruding portion 142 of the transaxle case TAC as a stationary member. The rotating member 115 is rotatably supported. And the spline which is one side of the connection part with above-mentioned 1st sprocket S1 is formed in the outer peripheral side of the intermediate part in the cylindrical part 115B of the rotating member 115. As shown in FIG. A spline that is the other of the connecting portions is formed on the inner peripheral side of the first sprocket S1.

  On the other hand, in the transaxle case TAC serving as a stationary member, a ball bearing 184 serving as a bearing is disposed on the outer peripheral side of the protruding portion 142 provided with the bush 170 on the inner peripheral side, and the first sprocket described above. S1 is rotatably held.

  In the present embodiment, the first sprocket S1 includes a disk-shaped portion S1A in which the above-described spline is formed on the inner peripheral side, and a cylinder extending in the axial direction from the outer end portion of the disk-shaped portion S1A. And a tooth portion S1C projecting radially from the cylindrical portion S1B. A step S1D and a groove S1E are formed on the inner peripheral side of the cylindrical portion S1B, and the outer race of the ball bearing 184 is positioned and held by the step S1D and a snap ring engaged with the groove S1E. Is configured to do. In addition to the step 142A, a groove 142B is formed on the outer peripheral side of the projecting portion 142 of the transaxle case TAC, and the inner race of the ball bearing 184 is positioned by the step 142A and a snap ring engaged with the groove 142B. The first sprocket S1 is prevented from moving in the axial direction. A mechanical oil seal 130 is interposed between the inner peripheral end of the converter housing TCH and the rotating member 115 to prevent oil leakage from the inside of the transaxle case TAC.

Further, as shown in FIG. 5, the oil pump P includes a first gear G1 disposed in the pump casing PC, and a second gear G2 that is rotatably disposed around the first gear G1. A first gear G1 is rotatably supported by the pump casing PC, and a second gear G2 is also rotatably supported by the pump casing PC. The two gear drive shafts GDS2 are connected to each other. And pump casing PC is being fixed to the predetermined position inside the step part wall TACW provided in transaxle case TAC.
Here, the second gear drive shaft GDS2 connected to the second gear G2 is provided through the step wall TACW provided in the transaxle case TAC in the axial direction, and the bracket is also attached to the side wall of the transaxle case TAC. It is connected to the output shaft MS of the electric motor M attached via MB by appropriate joint means. That is, the electric motor M is disposed on the opposite side of the second sprocket S2 across the oil pump P and outside the transaxle case TAC, and is provided so as to directly drive the second gear drive shaft GDS2.

  An endless chain ELC is stretched over the first sprocket S1 described above and the second sprocket S2 connected to the first gear drive shaft GDS1 of the oil pump P disposed on a shaft different from the input shaft 150. Two sprockets S2 are driven.

  Thus, the rotation of the converter cover 114 by the engine E is performed by the rotating member 115 as the pump drive shaft PDS via the first sprocket S1, the endless chain ELC, the second sprocket S2, and the first gear drive shaft GDS1. 1 gear G1 is transmitted. As a result, the second gear G2 circumscribing the first gear G1 also rotates and the oil pump P operates. On the other hand, the rotation by the electric motor M is directly transmitted to the second gear G2 via the second gear drive shaft GDS2. Similarly, the first gear G1 circumscribing the second gear G2 also rotates together and the oil pump P operates.

  Although the above is an embodiment in which the present invention is applied to a belt type continuously variable transmission, the present invention is a stepped automatic transmission provided with a planetary gear mechanism and a friction engagement device such as a clutch or a brake. Needless to say, this can also be applied to. Further, the above is an embodiment in which the present invention is applied to an external gear pump, but the present invention is equally applicable to an internal gear pump.

FIG. 3 is a skeleton diagram of the first embodiment in which the casing and the like are omitted when the present invention is applied to a transaxle TA. When the present invention is applied to a transaxle TA, the skeleton diagram of the second embodiment is shown with its casing and the like omitted. When the present invention is applied to a transaxle TA, the skeleton diagram of the third embodiment is shown with its casing omitted. When the present invention is applied to a transaxle TA, it is a skeleton diagram of a fourth embodiment shown with its casing omitted. It is sectional drawing which shows an example of the external gear pump with which this invention is applied. It is sectional drawing which shows an example which actualized the 1st Embodiment of this invention in the actual machine. It is a graph which shows the torque characteristic and high efficiency area | region of an electric motor (A) and an engine (B).

Explanation of symbols

P oil pump G1 first gear G2 second gear GDS1 first gear drive shaft GDS2 second gear drive shaft PDS pump drive shaft M electric motor ELC1 first endless chain ELC2 second endless chain OWC1 first one-way clutch OWC2 second one-way clutch TAC transaxle case 110 torque converter 114 converter cover 115 rotating member 118 stator support sleeve 150 input shaft 160 lockup mechanism

Claims (2)

A gear type oil pump drive device comprising a first gear and a second gear meshing with the first gear,
Driving an oil pump, wherein one of the first gear and the second gear can be driven by a first prime mover, and the other of the first gear and the second gear can be driven by a second prime mover. apparatus. The first prime mover is an engine, and the second prime mover is an electric motor. The first gear and the second gear have different numbers of teeth, and among them, a gear having a large number of teeth is driven by the engine and has a small number of teeth. The oil pump drive device according to claim 1, wherein a gear is configured to be driven by the electric motor.

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