JP2001146955A - Oil pump driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make smooth changing-over of the drive of oil pump between by an engine and by electric motor, by securing the function of the oil pump at all times whether the engine is in operation or stopped. SOLUTION: An oil pump driving device is equipped with a first power transmitting mechanism 50 tying the output shaft of an electric motor 80 to the driving shaft of the oil pump 70 and a second power transmitting mechanism 60 tying the out t shaft of the engine E to the driving shaft of the oil pump 70. The first power transmitting mechanism 50 is furnished internally with a first one-way clutch 52 to admit power transmitting only in the direction from the motor 80 to the oil pump 70, while the second power transmitting mechanism 60 is furnished internally with a second one-way clutch 62 to admit power transmitting only in the direction from the engine E to the oil pump 70, and thus the intended oil pump driving device is configured. According to this arrangement, the oil pump 70 is driven by either the engine E or motor 80 whichever has the greatest driving rotation in the condition that both are in operation simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for an oil pump.

[0002]

2. Description of the Related Art Conventionally, an oil pump is mechanically directly connected to a prime mover (engine). For example, Japanese Patent Application Laid-Open No. 55-60756 discloses a mechanism in which an oil pump is driven by an engine via a shaft which is provided through a turbine shaft of a torque converter and is directly connected to an engine output shaft. .

In Japanese Patent Publication No. 53-22214, an electric motor for driving an oil pump is provided separately from the main motor, and the oil pump is driven by this electric motor to supply hydraulic oil. A disclosed transmission is disclosed. Further, Japanese Patent Publication No. 51-18082 discloses a transmission configured to drive an oil pump by an engine (main motor) and to drive the oil pump by an electric motor when the engine is stopped.

[0004]

[Problems to be Solved by the Invention] Japanese Patent Publication No. 51-1808
In Japanese Patent Application Publication No. 2 (1993) -1992, the oil pump can be driven by an engine or an electric motor. However, this is to drive the motor by driving the motor after the engine is stopped, and to drive the oil pump by driving the motor. Need to detect by form. In addition, this is a temporary stop at an intersection etc.
When performing control to stop the engine, the oil pump is driven even when the engine is stopped. For this reason, in this device, it is necessary to set the capacity of the oil pump so that the amount of oil discharged from the oil pump is the amount of oil required for lubrication and shift control when the engine is idling. Indeed, the oil pump loss increases.

[0005] It is considered that the amount of lubricating oil and the amount of shift control oil required in the transmission are substantially constant irrespective of the rotational speed of the prime mover. Although the required amount of lubricating oil slightly increases in accordance with the rotation speed of the prime mover, the rate of increase is extremely small with respect to the increase in the rotation of the prime mover, and there is no problem even if it is considered to be substantially constant.

However, as disclosed in Japanese Patent Application Laid-Open Nos. 55-60756 and 51-18082, when an oil pump is driven by a prime mover, the discharge oil is almost in proportion to the rotational speed of the prime mover. Amount (oil supply amount)
Therefore, in a region where the rotation speed of the prime mover is high, only a part of the oil discharged from the oil pump is required, and there is a problem that the oil pump drive loss is large.

The hydraulic oil required for the transmission has little relation to the rotation speed of the prime mover, and when the prime mover is idling,
That is, a predetermined amount of hydraulic oil must be supplied even at the lowest rotation speed. For this reason, it is necessary to set the capacity of the oil pump so that a predetermined amount of hydraulic oil can be supplied when the prime mover is idling, and as the rotational speed of the prime mover increases, the extra discharge amount increases and the oil discharge increases. Pump drive loss increases.

On the other hand, as disclosed in Japanese Patent Publication No. 53-22214, an oil pump is driven by an electric motor for driving an oil pump provided separately from the main motor to supply hydraulic oil. Then, the above problem does not occur. However, since the electric motor must be constantly driven while the engine is operating, its durability tends to be a problem. In particular, it is desirable to reduce the power consumption by making the pump drive motor as small and compact as possible due to problems such as battery capacity.
As the size is reduced in this way, the durability tends to be a problem. In addition, if the size of the motor is increased, the problem of durability can be suppressed. However, there is a problem that the power consumption is increased and the size of the battery is increased.

The present invention has been made in view of the above problems, has a relatively small and compact structure, can reduce the oil pump drive loss, and always maintains the function of the oil pump regardless of whether the prime mover is driven or stopped. It is an object of the present invention to ensure that the driving of the oil pump by the prime mover and the driving by the electric motor can be performed smoothly.

[0010]

According to the present invention, a first power transmission path connecting an output shaft of an electric motor to a drive shaft of an oil pump, an output shaft of a prime mover, and the like. A second power transmission path connecting the drive shaft of the oil pump; and a first one-way clutch that allows only power transmission from the electric motor to the oil pump in the first power transmission path, A state in which a second one-way clutch that allows only power transmission from the prime mover to the oil pump is provided in the second power transmission path to constitute an oil pump driving device, and the prime mover and the electric motor are simultaneously driven. Thus, the oil pump is driven by a motor having a larger driving rotation by the motor and the electric motor.

When the oil pump is driven by using the oil pump driving device having such a configuration, the operation of the first and second one-way clutches causes the oil pump to be driven by one of the prime mover and the electric motor having a higher rotation speed. Is driven. In other words, even when both the prime mover and the electric motor are operating, even if one of them is low, the motor is driven by the higher rotation, so the oil pump can always be driven regardless of whether the engine is running or stopped. Therefore, the switching between the driving of the oil pump by the prime mover and the driving by the electric motor can be smoothly performed.

Further, in this case, the drive selecting means controls the drive of the electric motor for driving the pump in accordance with the required amount of hydraulic oil to be supplied to the transmission. It is preferable to drive the electric motor and to drive the pump driving electric motor at high speed when the amount of required oil supply is large. When the pump driving electric motor is driven at a low speed, the predetermined rotation speed is set to a low value, and when the pump driving electric motor is driven at a high speed, the predetermined rotation speed is set to a high value.

[0013]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a specific structure of a transmission provided with an oil pump driving device according to the present invention, and FIG. 3 schematically shows a power transmission structure of the transmission.
This transmission has left and right housings 10a and 10b,
The transmission mechanism 1, the differential mechanism 4, and the oil pump driving device 5 are provided in a space surrounded by the left and right housings 10a and 10b. The engine E is joined to the left end face of the left housing 10a, and the engine output shaft is connected to the transmission input shaft 1 via a joint C (mechanical direct coupling, friction clutch, fluid coupling, torque converter, etc.).
Connected to 1.

The transmission mechanism 1 includes left and right housings 10a, 1
0b, a transmission input shaft 11 rotatably supported by
A transmission counter shaft 12 rotatably supported by the left and right housings 10a and 10b and disposed in parallel with the transmission input shaft 11; and between the transmission input shaft 11 and the transmission counter shaft 12. Are provided with a plurality of power transmission gear sets and clutches.

The power transmission gear set includes a first speed gear set including a first speed drive gear 21a and a driven gear 21b meshing with each other, and a second speed gear set including a second speed drive gear 22a and a driven gear 22b meshing with each other. And a third speed gear set including a third speed drive gear 23a and a driven gear 23b meshing with each other, and a reverse drive gear 25a and a driven gear 2 meshing with each other via a reverse idler gear (not shown).
5b for a reverse gear set. In addition, the clutch for selecting the power transmission by the first-speed gear set is used as the clutch.
A second-speed hydraulic clutch 32 for selecting power transmission by a second-speed gear set, a third-speed hydraulic clutch 33 for selecting power transmission by a third-speed gear set, and power transmission by a reverse gear set And a reverse dog tooth clutch 35 for selecting

For this reason, the clutches 31, 32, 3
By selectively operating the gears 3 and 35, power transmission via any of the gear sets can be selected. As a result, the engine output transmitted to the transmission input shaft 11 via the joint C can be transmitted to the transmission counter shaft 12 by shifting the speed. The power transmitted to the transmission counter shaft 12 is transmitted to the differential mechanism 4 via transmission output gear sets 27 and 28 meshing with each other, and is transmitted to the left and right axle shafts 42 and 43 via the differential gear set 41. The power is divided and transmitted, and the left and right wheels (not shown) are driven.

The oil pump driving device 5 includes a gear oil pump 70 fixedly held on the left housing 10a, an electric motor 80 joined and disposed on the right housing 10b,
The first power transmission mechanism 50 transmits the driving force of the electric motor 80 to the oil pump 70, and the second power transmission mechanism 60 transmits the driving force from the engine E to the oil pump via the transmission input shaft 11. Is done. As shown in detail in FIG. 2, the oil pump 70 includes first and second pump gears 71, 75 rotatably supported in pump cases 70a, 70b, 70c fixedly held in the left housing 10a and meshing with each other. It is arranged and configured.
Both pump gears 71 and 75 are provided with bearings 72 and 7 respectively.
6, the right end of the shaft 71a of the first pump gear 71 protrudes into the first power transmission mechanism 50, and the left end of the shaft 75a of the second pump gear 75 is supported by the second power transmission mechanism 60. Protrude into.

The first power transmission mechanism 50 includes a pump case 7
An outer rotating member 51 rotatably supported by a supporting member 70d fixed to the outer rotating member 51 and spline-coupled to the drive shaft 81 of the electric motor 80;
The inner rotating member 53 is disposed on the inner diameter side of the first rotating member 53 so as to be rotatable relative thereto, and a first one-way clutch 52 is disposed between the rotating members 51 and 53. The inner rotating member 53 is the first pump gear 7 of the oil pump 70.
When the drive shaft 81 of the electric motor 80 is rotationally driven, the first pump gear 71 (that is, the first pump gear 71)
The oil pump 70) can be driven. However, since the first one-way clutch 52 is provided, the rotational driving force in the driving direction of the electric motor 80 is transmitted, but the rotational driving force in the opposite direction is not transmitted. In order to lubricate the first one-way clutch 52, the outer rotating member 51
And the inner rotating member 53 has lubricating oil passage holes 51a, 53
a is formed.

The second power transmission mechanism 60 includes a pump case 7
A pump drive gear 61 rotatably mounted on the transmission drive shaft 0a and meshing with the second speed drive gear 22a integrally connected to the transmission input shaft 11, and has an inner diameter side of the pump drive gear 61 rotatably relative thereto. An inner rotating member 63 disposed between the pump drive gear 61 and the inner rotating member 63;
And 2. The inner rotating member 63 is key-coupled to the shaft 75a of the second pump gear 75 of the oil pump 70, whereby the second pump gear 7 is driven by the engine E via the transmission input shaft 11 and the second power transmission mechanism 60.
5 (that is, the oil pump 70) can be driven. However, also in this case, the second one-way clutch 6
2, the rotation driving force is transmitted from the engine E side, but the rotation is not transmitted in the opposite direction. Although the electric motor 80 shown here is a motor for driving an oil pump, the electric motor may be a driving assist motor, that is, an electric motor having an output capable of driving the oil pump. It is not necessary to limit to driving.

The electric motor 80 has its connector terminals 8
5 through a connector 91 connected to the controller 90.
Is connected. The controller 90 controls the power supply from the battery 95 to the electric motor 80 to control the rotation of the electric motor 80. By performing this rotation control, the oil pump 70 can be driven by the electric motor 80 via the first power transmission path 50 or by the engine E via the second power transmission path 60. .

That is, the controller 90 plays a role as drive selection means. The control by the controller 90 will be described with reference to the graph of FIG. 4 and the flowcharts of FIGS. 5 and 6 show one flowchart in which A and B in a circle are connected to each other.

First, the discharge characteristics of the oil pump 70 will be described with reference to FIG. In this figure, the vertical axis shows the discharge amount Q of the oil pump 70, and the horizontal axis shows the drive rotation speed Nm of the oil pump 70 converted into rotation on the transmission input shaft (main shaft). In the figure, solid line L1
Represents the discharge characteristics of the oil pump 70 of the present invention,
A broken line L2 represents the discharge characteristics of a conventional oil pump (oil pump directly connected to the engine). The horizontal line L3 indicates the amount of hydraulic oil required during gear shifting, and the horizontal line L4 indicates the amount of hydraulic oil required for lubrication and the like during non-shifting.

As can be seen from this figure, in the case of the conventional oil pump, when the engine is idling (about 900
(rpm), a discharge amount at point A4 is obtained, and an oil amount equal to or more than the hydraulic oil amount required at the time of gear shifting is obtained over the entire practical rotation range of the engine, so that the hydraulic oil amount is insufficient under any conditions. Never. However, as the engine speed increases, the pump discharge oil amount also increases, as indicated by the line L2, so the useless oil amount increases, and the pump drive loss increases as the engine speed increases. .

On the other hand, the oil pump 70 of the present invention
In this case, when the oil pump 70 is driven by the engine E, it is necessary for lubrication or the like during non-shifting only when the rotation of the engine E reaches the first predetermined rotation (about 1800 rpm). Hydraulic oil can be secured (point A
2), a second predetermined rotation (about 400
0 rpm), it is possible to secure the required amount of hydraulic oil during shifting (point A1). Conversely, when the engine E alone is driven, when the engine E is at or below the first or second predetermined rotation, the amount of hydraulic oil is insufficient.

For this reason, in the apparatus of this embodiment, the rotation of the electric motor 80 is controlled by the controller 90 so that this shortage of oil does not occur. This controller 90
In FIG. 5, as shown in FIG. 5, when the ignition key is first turned on and the operation is started, zero is set as an integrated time t in step S1 (set to t = 0).
And set t1 as the determination time T (T = t
Set to 1). Then, according to the flow of steps S2 to S4, the electric motor 80 is driven at full rotation until t> T, that is, only during the determination set time t1.
Thereby, the hydraulic oil can be distributed to the oil passage in the transmission.

Then, the program proceeds to a step S5, wherein it is determined whether or not the shift position of the transmission (position of the shift lever) is in the P range or the N range. When the shift position is in the P range or the N range, almost no hydraulic oil for shifting and lubrication is needed, so the process proceeds to step S10, in which the power supply from the battery 95 to the electric motor 80 is cut off, and the driving of the electric motor 80 is stopped. Let it.

At this time, if the engine E is driven by idling, this rotation is transmitted to the oil pump 70 via the second power transmission mechanism 60, which is rotated. The amount of oil discharged from the oil pump 70 at this time is as indicated by point A3 in FIG. 4 and is extremely small. However, as described above, there is no problem since the amount of hydraulic oil is hardly required at this time. When an electric motor is used instead of the engine E as in an electric vehicle, the electric motor is stopped in the P or N range, so that the oil pump 70 is not driven and the supply of the hydraulic oil is stopped.

If the shift position is other than the P range or the N range, the process proceeds to step S6, where it is determined whether or not the shift position has just been changed. If it is immediately after the shift position is changed, the shift is often performed, so the process proceeds to step S12 to reset the integrated time t to zero (reset to t = 0).
And set t2 as the determination time T (T = t
2). Then, according to the flow of steps S2 to S4, the electric motor 80 is driven at full rotation during the determination time t2. As described above, the oil pump 70 is driven so that the discharge amount of the oil pump 70 when the electric motor 80 is driven at full rotation is the discharge amount indicated by the line L3 in FIG.
A capacity of 0 is set. Therefore, at this time,
The required amount of hydraulic oil at the time of shifting can be secured.

On the other hand, if it is not immediately after the shift position has been changed, the process proceeds to step S7, where the engine output rotational speed Ne converted into the transmission input shaft is changed to the first predetermined rotational speed N.
It is determined whether it is greater than one. The first predetermined rotation speed N1 is a rotation speed corresponding to the point A1 in FIG. 4, and is approximately 4000 rpm in this case. And N
When e> N1, the process proceeds to step S10, in which the driving of the electric motor 80 is stopped.

As can be seen from FIG. 4, when the electric motor 80 is driven at full rotation and the engine output rotation Ne is smaller than the first predetermined rotation speed N1, the electric motor 8
The converted oil pump drive rotation speed for the rotation speed of 0 is greater than the converted oil pump drive rotation speed for the engine E rotation speed. Here, since the first and second one-way clutches 52 and 62 are provided in the first and second power transmission mechanisms 50 and 60, respectively, the oil pump 70 is driven by the one whose conversion oil pump drive rotation speed is higher. Driven by drive means.

That is, when the electric motor 80 is driven at full rotation, the rotation speed Ne of the engine E is reduced to the first rotation speed Ne.
If the rotational speed is lower than the predetermined rotational speed N1, the oil pump 70 is driven by the electric motor 80, and the rotational speed N of the engine E is increased.
If e is greater than the first predetermined rotation speed N1, the oil pump 70 is driven by the engine E. Therefore, when it is determined in step S7 that Ne> N1, the oil pump 70 is driven by the engine E, and the process proceeds to step S10, in which the driving of the electric motor 80 is stopped, and the life of the battery 95 is extended. This is to save power. At this time, the amount of oil discharged from the oil pump 70 driven by the engine E is larger than the required amount of oil at the time of shifting, and a sufficient amount of oil is supplied.

When Ne ≦ N1, the routine proceeds to step S8, where it is determined whether or not there is a shift instruction. When there is a gearshift instruction, the amount of oil necessary for gearshifting, that is, the amount of oil indicated by line L3 in FIG. 4 is necessary, and therefore the electric motor 80 is driven at full rotation according to the flow from step S12 to steps S2 to S4.

If there is no shift instruction, the process proceeds to step S9, and it is determined whether or not the engine output rotational speed Ne in terms of the transmission input shaft is greater than a second predetermined rotational speed N2. It should be noted that the second predetermined rotation speed N2 is a point A2 in FIG.
, Which in this case is about 1800 rpm. If Ne> N2, step S10
Then, the driving of the electric motor 80 is stopped. On the other hand, when Ne ≦ N2, the process proceeds to step S11, and the electric motor 80 is driven to perform partial rotation. This partial rotation drive means that the oil pump 70
Is driven at a rotation speed at which the discharge amount when the is driven is the amount indicated by the line L4 (that is, the oil amount required during non-shifting).

For this reason, as can be seen from FIG. 4, when the electric motor 80 is driven in partial rotation, the oil pump 70 is driven by the electric motor 80 when the engine output rotation Ne is smaller than the second predetermined rotation speed N2. When the rotation speed Ne of the engine E is higher than the second predetermined rotation speed N2, the oil pump 70 is driven by the engine E. Therefore, in step S9, Ne>
When it is determined that N2, the oil pump 70 is in a state of being driven by the engine E.
The driving of the electric motor 80 is stopped to save power so as to extend the life of the battery 95. At this time, the amount of oil discharged from the oil pump 70 driven by the engine E is larger than the required amount of oil during non-shifting. In this case, a sufficient amount of oil is supplied.

When it is determined in step S9 that Ne ≦ N2, the electric motor 80 is driven to rotate partially. Thereby, the oil pump 70 is driven by the electric motor 80, and the oil amount indicated by the line L4 in FIG.
That is, it is possible to supply the required amount of oil during non-shifting.

[0036]

As described above, when the oil pump is driven by using the oil pump driving device according to the present invention, the rotation of the prime mover and the electric motor is performed by the action of the first and second one-way clutches. The oil pump is driven by the larger number. That is, even when both the prime mover and the electric motor are operating, even if either one of them is low in rotation, the motor is driven by the higher rotation, so the oil pump function is always maintained regardless of whether the engine is running or stopped. It is possible to smoothly switch between driving by the motor of the oil pump and driving by the electric motor.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a transmission including an oil pump driving device according to the present invention.

FIG. 2 is an enlarged sectional view showing an oil pump driving device in the transmission.

FIG. 3 is a schematic diagram showing a power transmission structure in the transmission.

FIG. 4 is a graph showing discharge characteristics of an oil pump used in the oil pump driving device of the present invention.

FIG. 5 is a flowchart showing operation control contents of the oil pump driving device.

FIG. 6 is a flowchart showing operation control contents of the oil pump driving device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmission mechanism 4 Differential mechanism 5 Oil pump drive device 11 Transmission input shaft 12 Transmission counter shaft 50 First power transmission mechanism 60 Second power transmission mechanism 70 Oil pump 80 Electric motor 90 Controller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shuichi Fujimoto 1-4-1, Chuo, Wako, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Inventor Makoto Kojima 1-4-1, Chuo, Wako, Saitama Prefecture Inside Honda R & D Co., Ltd.

Claims (3)

[Claims] 1. A drive device for an oil pump, comprising: a first power transmission path connecting an output shaft of an electric motor and a drive shaft of the oil pump; and connecting a drive shaft of the motor and a drive shaft of the oil pump. A first one-way clutch that allows only power transmission from the electric motor to the oil pump in the first power transmission path, the second power transmission path A second one-way clutch that allows only power transmission from the prime mover to the oil pump is disposed within the prime mover and the electric motor while the prime mover and the electric motor are simultaneously driven. An oil pump driving device characterized in that the oil pump is driven by the one whose driving rotation is larger. And a drive selection unit that selects one of the first power transmission path and the second power transmission path, wherein the drive selection unit is configured to output the power when the output rotation speed of the prime mover is equal to or less than a predetermined rotation. 2. The oil pump driving device according to claim 1, wherein a first power transmission path is selected, and the second power transmission path is selected when an output rotation speed of the prime mover exceeds a predetermined rotation. 3. The drive selecting means drives the electric motor at a low speed when the required amount of hydraulic oil supplied from the oil pump is small, and drives the electric motor at a high speed when the required oil amount is large. When the electric motor is driven at a low speed, the predetermined rotation speed is set to a low value when the electric motor is driven at a low speed, and when the electric motor is driven at a high speed, the predetermined rotation speed is set to a high value. The oil pump driving device according to claim 2, wherein the setting is set.