JP2837576B2 - Hydraulic pump drive structure of transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive unit structure of a hydraulic pump for obtaining a hydraulic pressure used for a shift control or the like in a transmission, and more particularly to a pitot pressure corresponding to an input rotation for shift control. The present invention relates to a drive unit structure of a hydraulic pump unit in a transmission that has been used.

[0002]

2. Description of the Related Art In transmissions (particularly, automatic transmissions and continuously variable transmissions), gear shift control is often performed using hydraulic pressure. Such a transmission is provided with a hydraulic pump for obtaining control hydraulic pressure. Will be arranged. This control oil pressure is required as long as the engine is rotating, and is usually arranged so as to be directly driven to rotate by the engine.

In such a transmission, a pitot pressure according to the rotation of the engine may be used as the control oil pressure. In this case, a pitot cover is attached to a member that rotates together with the engine, a pitot tube is projected into a ring-shaped pitot groove of the pitot cover, and pitot pressure is obtained by dynamic pressure of oil in the pitot groove that rotates together with the pitot cover. It is configured as follows. Such a configuration is disclosed, for example, in Japanese Patent Application Laid-Open No. Sho 62-28864.

When a transmission is controlled using such a pitot pressure, a sufficiently large pitot pressure is often required even when the engine speed is low. For this reason, conventionally, a configuration has been adopted in which the diameter of the pitot cover is increased to increase the flow velocity of the oil in the pitot groove so that a sufficient pitot pressure can be obtained even at a low engine speed. For example, in the transmission disclosed in the above-mentioned publication, a pitot cover having a diameter larger than the pulley diameter is used beside the driving pulley.

[0005]

However, the pitot cover is provided in the transmission housing,
When a pitot cover with such a large diameter is used,
It is necessary to make the transmission housing large, and there is a problem that the transmission becomes large. Furthermore, when a large pitot cover is used, a large amount of oil is required in the pitot groove,
There is a problem that a large amount of oil needs to be supplied into the pitot cover when starting the engine.

On the other hand, since the hydraulic pump is driven by the engine, its drive shaft rotates in proportion to the engine, like the pitot cover. In this case, it is often required that a sufficient discharge oil amount be obtained even when the engine is running at a low speed, and therefore, a large capacity hydraulic pump is required, and the transmission is accordingly enlarged. There was a problem of doing.

The present invention has been made in view of such a problem.
It is an object of the present invention to provide a hydraulic pump drive unit structure that can obtain a necessary and sufficient pitot pressure even when the engine is running at a low speed without making the pitot cover diameter too large, and that can also reduce the size of the hydraulic pump.

[0008]

According to the present invention, a pump drive gear is mounted on a transmission input shaft connected to an engine output shaft and a hydraulic pump mounted on a transmission housing. A pump driven gear that meshes with the pump drive gear is mounted on the drive shaft, and a pitot cover is provided on the side of the pump driven gear. The hydraulic pump drive unit structure is configured to protrude into the pitot groove of the first embodiment, and the number of teeth of the pump drive gear is set to be greater than the number of teeth of the pump driven gear. In this case, it is preferable to dispose the hydraulic pump such that the drive shaft of the hydraulic pump is located vertically below the transmission input shaft.

[0009]

With the above structure, the engine rotation transmitted to the transmission input shaft is transmitted to the hydraulic pump drive shaft via the pump drive and the driven gear, and the hydraulic pump drive shaft rotates at a speed higher than the engine rotation. Driven by numbers. Therefore, the size of the hydraulic pump can be reduced as compared with the case where the hydraulic pump drive shaft is directly connected to the input shaft. Furthermore, since the pitot cover connected to the pump driven gear is also rotated at an increased speed, even if the pitot groove diameter is small, the oil flow rate in the groove increases, and even if the pitot cover is reduced, a sufficient pitot pressure can be obtained. And the size of the pitot cover can be reduced.

[0010]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 to 4 show a belt-type continuously variable transmission having a hydraulic pump drive unit structure according to the present invention. This continuously variable transmission is configured by disposing the following mechanism in a space surrounded by a housing 5 (configured by four housing members 5a, 5b, 5c, and 5d). The continuously variable transmission has a rotatable transmission input shaft 11. The transmission input shaft 11 is connected to a flywheel 2 attached to an end of an engine crankshaft 1 via a damper 3. ing. As shown, the transmission input shaft 11 is provided with the drive pulley device 20 and the forward / reverse switching device 40.

A transmission counter shaft 16 is provided in parallel with the transmission input shaft 11, and the driven pulley device 2 is mounted on the transmission counter shaft 16 as shown in FIG.
5 and a starting clutch device 50 are provided. A metal belt 30 is stretched between the drive pulley device 20 and the driven pulley device 25, thereby forming a belt-type power transmission mechanism.

A transmission output shaft 60 is provided in parallel with the transmission counter shaft 16, and the transmission output shaft 60 is formed with a counter driven gear 60a and a final drive gear 60b. The counter driven gear 60a meshes with the counter drive gear 17a, and the final drive gear 60b
5a. The counter drive gear 17a
Is a gear formed on a counter gear member 17 rotatably disposed on a transmission counter shaft 16. On the other hand, the final driven gear 65a is a gear formed on the final gear member 65 constituting the final reduction mechanism. Although not shown, the final speed reduction mechanism has a differential mechanism therein, and the final gear member 65 is connected to the left and right axle shafts via the differential mechanism.

As shown in detail in FIG.
A pump drive gear 12 is connected to the transmission input shaft 11 between the damper 3 and the drive pulley device 20 in FIG. A pump driven gear 13 meshing with the pump drive gear 12 is connected to and attached to a drive shaft 15a of the hydraulic pump 15. The hydraulic pump 15 is fixed at a predetermined position in the housing 5. Therefore, when the transmission input shaft 11 is rotationally driven by the engine, the pump drive and the driven gear 1 are driven.
The pump drive shaft 15a is driven via the gears 2 and 13, and the hydraulic pump 15 is driven to rotate.

Here, the number of teeth of the pump drive gear 12 is larger than the number of teeth of the pump driven gear 13, and the rotation of the input shaft (that is, the rotation of the engine) is reduced to the gears 1 and 2.
The speed is increased by 2 and 13 and transmitted to the pump drive shaft 15a. Therefore, the pump drive shaft 15a is driven at a higher speed than the engine rotation, and a sufficient discharge amount can be secured even if the capacity of the hydraulic pump 15 is reduced accordingly. That is, if the configuration that drives the hydraulic pump 15 at an increased speed as in this example is used, the hydraulic pump 15 can be downsized.

A pitot cover 14 having a ring-shaped pitot groove 14a is fixedly mounted on a side surface of the pump driven gear 13, and the pitot cover 14 is rotated together with the pump driven gear 13 whose speed is increased as described above. It has become. A tip portion 18a of a pitot tube 18 fixed to the housing 5 or the hydraulic pump 15 is provided to protrude into a pitot groove 14a of the pitot cover 14. A dynamic pressure intake hole is formed in the distal end portion 18a, and the pitot cover 14 is formed together with the pump driven gear 13.
The distal end portion 18a is provided so as to protrude into the pitot groove 14a so that the dynamic pressure intake hole is opened toward the flow of oil generated in the pitot groove 14a when is rotated.

For this reason, when the engine is driven, the pitot cover 14 is rotated together with the pump driven gear 13 at the speed increased as described above.
The oil in 4 a is rotated together with the pitot cover 14. On the other hand, since the pitot tube 18 is fixed to the housing 5 and held stationary, the tip portion 18a of the pitot tube 18
On the other hand, the oil in the pitot groove 14a flows at a relative speed corresponding to the rotation of the pitot cover 14. The dynamic pressure at this time is taken into the pitot tube 18 through the dynamic pressure intake hole of the tip portion 18a, and a pitot pressure can be obtained. This pitot pressure is a hydraulic pressure corresponding to the engine rotation. However, since the pitot cover 14 is rotated at a rotation speed higher than the engine rotation as described above, the outer diameter of the pitot cover 14 (that is, the pitot groove 14a A sufficient Pitot pressure can be obtained without increasing the diameter).

Next, the configuration of the continuously variable transmission will be briefly described. As shown in detail in FIG. 2, a drive pulley device 20 and a forward / reverse switching device 4 are provided on an input shaft 11 of the transmission.
0 are arranged in parallel. Drive pulley device 20
Has a fixed drive pulley 21 and a movable drive pulley 22 slidable in the axial direction with respect to the fixed drive pulley 21. The fixed drive pulley 21 is rotatably supported by the housing 5 via bearings 20a and 20b. The relative rotation in the rotation direction of the pulleys 21 and 22 is restrained by a ball 20c that performs a key action, and the pulleys 21 and 22 rotate integrally. A transmission input shaft 11 is provided to penetrate the fixed drive pulley 21 in the axial direction, and both are relatively rotatable by needle bearings 11a and 11b provided between the two. .

A rotary pickup gear 21a is formed at the outer peripheral end of the fixed drive pulley 21, and a rotation sensor 35 is disposed near the gear 21a. Therefore, the rotation of the fixed drive pulley 21 can be detected by the rotation sensor 35. A fixed cover 23a attached to the fixed drive pulley 21 and a movable cover 23b attached to the movable drive pulley 22 are provided on the back side of the movable drive pulley 22, and both the covers 23a and 23b are movable. A drive side hydraulic cylinder chamber 24 is formed surrounded by the drive pulley 22. By controlling the hydraulic pressure supplied to the drive-side hydraulic cylinder chamber 24, the slide position of the movable drive pulley 22 in the axial direction can be controlled.

The metal belt 30 spanned between the drive pulley device 20 and the driven pulley device 25 is composed of a number of metal V blocks 31 held by metal belt straps 32. The V-block 31 is disposed in a V-belt groove formed by the two pulleys 21 and 22, and a metal belt 30 is attached. Therefore, by sliding the movable drive pulley 22 in the axial direction as described above, the winding position (radius) of the metal belt 30 changes. For example, in FIG. 2, when the movable drive pulley 22 is closest to the fixed drive pulley 21 as shown on the upper half side, the winding radius of the metal belt 30 becomes maximum, and the movable drive pulley 22 is shown on the lower half side. Is farthest from the fixed drive pulley 21, the winding radius of the metal belt 30 becomes minimum.

The forward / reverse switching device 40 includes a sun gear 41,
A double pinion gear 42 rotatably supported by a pinion shaft 42a, and a pinion shaft 4
It has a double pinion type planetary gear set composed of a carrier 43 that supports 2a and a ring gear 44. The sun gear 41 is spline-coupled to the transmission input shaft 11, and the carrier 43 is spline-coupled to the fixed driven pulley 21 via a clutch casing. The device 40 further includes a forward clutch 45 capable of engaging and disengaging the sun gear 41 and the carrier 43, and a ring gear 4.
4 is provided with a reverse brake 46 capable of fixedly holding the brake 4.

Therefore, when the forward clutch 45 is engaged, the sun gear 41, the carrier 43 and the ring gear 44
Are rotated integrally, and the transmission input shaft 11
Is transmitted to the fixed drive gear 21 as it is.
Thereby, the fixed and movable drive pulleys 21 and 22
Rotates integrally with the transmission input shaft 11 and is driven to rotate forward. On the other hand, when the reverse clutch 45 is engaged, the ring gear 44 is fixedly held, and the carrier 43 is rotated in a direction opposite to the rotation of the sun gear 41 at a reduced rotation. Therefore, the fixed and movable drive pulleys 21 and 22 are driven at a reduced speed in a direction opposite to the rotation of the transmission input shaft 11. That is, the vehicle is decelerated and driven to the reverse.

As shown in detail in FIG. 3, a driven pulley device 25 and a starting clutch device 50 are arranged in parallel on a counter shaft 16 of the transmission. The driven pulley device 25 has a fixed driven pulley 26 and a movable driven pulley 27 slidable in the axial direction with respect to the fixed driven pulley 26. Fixed driven pulley 2
6 is formed integrally with the transmission counter shaft 16,
It is rotatably supported by the housing 5 via the bearings 25a and 25b. In addition, both pulleys 26 and 27
The relative rotation in the rotation direction is restricted by a ball 25c that performs a key action, and both pulleys 26 and 27 rotate integrally with the counter shaft 16.

On the back side of the movable driven pulley 27, a fixed cover 28 attached to the fixed driven pulley 26 is provided.
a and a movable cover 28b attached to the movable driven pulley 27.
A driven hydraulic cylinder chamber 29 is formed surrounded by the movable driven pulley 27 and the movable driven pulley 27. If the hydraulic pressure supplied to the driven hydraulic cylinder chamber 29 is controlled, the sliding position of the movable driven pulley 27 in the axial direction can be controlled. For example, in FIG. 3, when the movable driven pulley 27 is moved closest to the fixed driven pulley 26 as shown in the upper half, the winding radius of the metal belt 30 becomes maximum, and as shown in the lower half, the movable driven pulley 2 is moved.
7 is farthest from the fixed driven pulley 26, the winding radius of the metal belt 30 becomes minimum.

In this transmission, the hydraulic pressure supplied to the cylinder chamber 24 of the drive pulley device 20 and the hydraulic pressure supplied to the cylinder chamber 29 of the driven pulley device 25 are controlled, and the metal belt 30 of the two devices 20 and 25 is controlled. And the speed change ratio is variably controlled steplessly. When the gear ratio (= input rotational speed / output rotational speed) is at the maximum, the stepped inner diameter 27a of the movable driven pulley 27 is, as shown in the upper half of FIG. 3, the shoulder of the counter shaft 16 (fixed driven pulley). It contacts the part 16a. When the speed ratio is at a minimum, the step 22 a of the inner diameter of the movable drive pulley 22 comes into contact with the shoulder 21 b of the fixed drive pulley 21. Further, a preset spring 2 is provided in both hydraulic cylinder chambers 24 and 29.
4 and 29 are disposed, and both hydraulic cylinder chambers 24 and 2 are provided.
Even when hydraulic pressure is not supplied to the metal belt 9, the preset spring force prevents the metal belt 30 from becoming loose (slack). The pitot pressure obtained by the pitot tube 18 is used for controlling the control oil pressure supplied to the two cylinder chambers 24 and 29 at this time.

The starting clutch device 50 includes a clutch cylinder 51 spline-connected to the transmission counter shaft 16.
And a clutch hub 52 coupled to a counter gear member 17 rotatably disposed on the transmission counter shaft 16.
And a starting clutch 53 for engaging and disengaging the clutch cylinder 51 and the clutch hub 52. As described above, the counter gear member 17 includes the counter driven gear 6.
It has a counter drive gear 17a that meshes with 0a, and further has a parking gear 17b.

Therefore, by supplying the starting control oil pressure to the cylinder chamber 54 in the clutch cylinder 51, the clutch pressing force by the piston 55 can be controlled, and the engagement control of the starting clutch 53 can be performed. As described above, the counter shaft 16 includes the belt-type power transmission mechanisms 20 and 25.
The transmission of the engine output is transmitted to the transmission output shaft 60 by controlling the engagement of the starting clutch 53. Further, the transmission output shaft 60 is connected to the left and right axles via a final speed reduction mechanism. Therefore, the start control of the vehicle can be performed by controlling the engagement of the start clutch 53.

FIG. 4 shows the positional relationship between the shafts in the transmission having the above-described configuration. In this figure, an arrow U indicates an upward direction, and an arrow D indicates a downward direction, and the drive shaft axis of the hydraulic pump 15 is positioned obliquely below the transmission input shaft 11 in the vertical direction. . Control oil is contained in the transmission housing 5, and the transmission housing 5 also functions as an oil tank. Therefore, by positioning the drive shaft of the hydraulic pump 15 below the transmission input shaft 11 as described above, the hydraulic pump 15 can be brought closer to the oil level in the housing 5 and the suction head of the hydraulic pump 15 can be reduced. In addition, the suction efficiency can be improved. further,
Since the pitot cover 14 attached to the pump driven gear 13 is also located below, oil may enter the pitot groove 14a at the time of stop, and the supply amount of oil into the pitot groove 14a at the time of starting may be small.

[0028]

As described above, according to the present invention,
The pitot cover is connected to the side of the pump driven gear, and the pitot tube is attached to the transmission housing or the hydraulic pump, and the hydraulic pickup part is protruded into the pitot groove of the pitot cover to constitute a hydraulic pump drive unit structure. Further, since the number of teeth of the pump drive gear is set to be greater than the number of teeth of the pump driven gear, the rotation of the transmission input shaft (that is, engine rotation) is increased via the pump drive and the driven gear, and the hydraulic pump is driven. It is transmitted to the drive shaft. Therefore, the size of the hydraulic pump can be reduced as compared with a case where the hydraulic pump drive shaft is directly connected to the input shaft. Furthermore, since the pitot cover connected to the pump driven gear is also rotated at an increased speed, even if the pitot groove diameter is small, the flow velocity of the oil in the groove increases, and even if the pitot cover is small, a sufficient pitot pressure can be obtained. And the size of the pitot cover can be reduced. In this case, it is preferable to dispose the hydraulic pump such that the drive shaft of the hydraulic pump is positioned below the transmission input shaft in the up-down direction. In this case, the suction head of the hydraulic pump is small. As a result, the pump suction efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a belt-type continuously variable transmission having a hydraulic pump drive unit structure according to the present invention.

FIG. 2 is a sectional view showing the periphery of an input shaft of the belt type continuously variable transmission.

FIG. 3 is a cross-sectional view showing a periphery of a counter shaft of the belt-type continuously variable transmission.

FIG. 4 is a side sectional view of the belt type continuously variable transmission.

[Explanation of symbols]

 2 Flywheel 3 Damper 11 Transmission input shaft 12 Pump drive gear 13 Pump driven gear 15 Hydraulic pump 20 Drive pulley device 25 Driven pulley device 30 Metal belt 40 Forward / reverse switching device 50 Start clutch device

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 57/02 F04C 2/00 F16H 9/12

Claims (2)

(57) [Claims] A pump drive gear mounted on a transmission input shaft; a hydraulic pump mounted on a transmission housing at a predetermined distance in a direction perpendicular to the axis from the transmission input shaft; and a drive of the hydraulic pump. A pump driven gear attached to a shaft and meshing with the pump drive gear; a pitot cover having a ring-shaped pitot groove and arranged and coupled to a side portion of the pump driven gear; the transmission housing or the hydraulic pressure A transmission supported by a pump and comprising a pitot tube in which a hydraulic pickup portion is disposed so as to protrude into the pitot groove, wherein the number of teeth of the pump drive gear is larger than the number of teeth of the pump driven gear. Hydraulic pump drive structure. 2. The hydraulic pump drive unit structure for a transmission according to claim 1, wherein a drive shaft of the hydraulic pump is located vertically below the transmission input shaft.