JP2001182808A - Differential gear oil cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a differential gear oil cooling device, which can mount a differential gear oil circulating means without enlarging a transaxle, and positively circulating differential gear oil for cooling. SOLUTION: The transaxle 1 has a clutch case 2 and a transmission case 3 arranged in series with respect to an engine, and is a tandem arrangement type in which a differential device 20 is disposed to be close to the rear and lower portion of a torque converter 5 in the clutch case. In the transaxle, an oil pump 27 guiding differential oil to an oil cooler 26 is disposed at a gap in the clutch case 2 and at the rear of the torque converter 5 and above the differential device 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertically arranged transaxle differential oil cooling system in which a transmission portion and a differential device for transmitting the speed change output to wheels are integrally formed.

[0002]

2. Description of the Related Art In general, in a differential device, a method is often employed in which a differential oil stored in a bottom portion of a differential housing is agitated and scattered by rotation of the differential device to lubricate each rotating portion and a gear meshing portion. ing.

When a vehicle equipped with such a differential device is running, the oil temperature of the differential oil increases due to agitation by the crown gear of the differential device, mesh between the crown gear and the drive pinion, and the like. In particular, during long-distance running or high-speed running, the oil temperature rise becomes remarkable, and in this case, the lubricating ability of the differential oil may be reduced.

As means for suppressing such temperature rise of the differential oil, a differential oil circulating means such as an electric oil pump is separately provided outside the transaxle, and the differential oil is guided to the oil cooler by the differential oil circulating means. It is common to cool the differential oil. However, separately providing an electric oil pump or the like in this way causes a large transaxle or the like.

To cope with this, for example, Japanese Patent Laid-Open No.
Japanese Patent Application Laid-Open No. 8-108803 discloses a differential device in which a hydraulic fluid (ATF) of an automatic transmission accommodated in a transmission case is configured to flow to an oil cooler via a torque converter with lock-up by a lock-up control valve. However, in a vehicle accommodated with a differential oil for lubrication inside a sealed differential housing, the differential oil is supplied by supplying working oil cooled by an oil cooler to a heat exchanger provided at the bottom of the differential housing. A cooling technique is disclosed. According to such a technique, it is possible to cool the differential oil without increasing the size of the transaxle.

[0006]

However, the use of the hydraulic oil of the automatic transmission for cooling the differential oil as in the technique described in Japanese Patent Application Laid-Open No. H8-14368 causes an increase in the oil temperature of the hydraulic oil. Not preferred for automatic transmissions. Therefore, in order to cool the differential oil without raising the oil temperature of the hydraulic oil or the like, it is desirable to provide a differential oil circulating means such as an oil pump for circulating the differential oil to the oil cooler in the differential oil cooling device, as described above. In addition, it has been difficult to install such a differential oil circulating means without increasing the size of the transaxle.

The present invention has been made in view of the above circumstances, and provides a differential oil cooling device in which a differential oil circulating means is provided without increasing the size of a transaxle, and in which differential oil is actively circulated for cooling. The purpose is to:

[0008]

According to a first aspect of the present invention, there is provided a differential oil cooling system comprising: a case member disposed between an engine and a transmission; A vertically arranged transaxle in which a starting clutch means for inputting to the transmission and a differential device for transmitting the shifting power from the transmission to the axle are provided in a differential housing portion which is a storage portion of the differential device. In a differential oil cooling device configured to cool stored differential oil, the differential oil cooling device includes: a differential oil cooling unit that cools the differential oil; and a differential oil circulation unit that guides the differential oil to the differential oil cooling unit. Inside the differential clutch device on the transmission side of the starting clutch means. Characterized in that disposed in the upper gap.

According to a second aspect of the present invention, in the differential oil cooling device according to the first aspect, the differential oil circulating means is an oil pump, and the oil pump is connected to the differential device. It is characterized by being driven in conjunction with it.

According to a third aspect of the present invention, there is provided the differential oil cooling device according to the first or second aspect, wherein the differential oil return passage from the differential oil cooling means is provided with the differential oil. It is characterized in that it faces each lubrication part of the device.

According to a fourth aspect of the present invention, there is provided a differential oil cooling device according to any one of the first to third aspects, wherein the differential oil cooling device is provided between the differential oil circulating means and the differential oil cooling means. A flow path opening / closing means for shutting off a flow path for supplying the differential oil from the differential oil circulation means to the differential oil cooling means when the differential oil temperature is low.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view showing a main part of a transaxle, FIG. 2 is a rear view showing a main part of a clutch housing and a differential housing, and FIG. 3 is an oil pump. FIG. 3 is a cross-sectional view showing a main part of FIG.

In FIG. 1, reference numeral 1 denotes a transaxle for FF. The transaxle 1 includes a clutch case 2 and a transmission case 3. Here, the transaxle 1 is disposed vertically with respect to the vehicle body, and a clutch case 2 and a transmission case 3 are connected in series to an engine (not shown).
It is a so-called vertical transaxle.

A front portion (engine side) of the clutch case 2 is formed as a clutch housing 4, and a torque converter 5 as a starting clutch means is housed in the clutch housing 4. A drive plate (both not shown) connected to a crankshaft of the engine is integrally connected to a converter cover 6 of the torque converter 5, and a pump impeller 8 is mounted on the converter cover 6.

A turbine runner 9 is opposed to the pump impeller 8, and the turbine runner 9 is connected to the connecting member 1.
0 is connected to the turbine shaft 11. The turbine shaft 11 extends into the transmission case 3 through the clutch case 2 and is connected to a transmission (not shown) in the transmission case 3.

A stator 12 supported by a one-way clutch 13 is disposed between the pump impeller 8 and the turbine runner 9. The rotation of the pump impeller 8 causes the hydraulic oil in the torque converter 5 to flow to the pump impeller 8 and the turbine runner 9 stator 12, thereby converting torque from the crankshaft and transmitting it to the turbine shaft 11. Has become.

A lock-up clutch 14 is connected to the connecting member 10.
4 is opposed to the converter cover 6 on the engine side. One of the lock-up clutches 14 is provided with a release chamber 14a, and the other is provided with an apply chamber 14b. When hydraulic oil is supplied to the release chamber 14a or the apply chamber 14b, the lock-up clutch 14
Is turned ON / OFF.

Here, between the clutch case 2 and the transmission case 3, an oil pump housing 1 on the transmission side is provided.
The inside of the clutch case 2 and the inside of the transmission case 3 are liquid-tightly partitioned by the oil pump housing 16. This oil pump housing 1
A transmission side oil pump 15 driven in conjunction with the converter cover 6 is built in the oil pump 6, and the oil pump 15 supplies hydraulic oil to the transmission and the torque converter 5.

On the other hand, in the clutch case 2, the rear lower portion of the clutch housing 4 is a differential housing 17.
In the differential housing 17, a front differential device (hereinafter, simply referred to as "differential device") 20 is provided horizontally below the turbine shaft 11 in a direction substantially orthogonal to the turbine shaft 11.

The differential gear 20 has a final reduction gear 20a fixedly mounted thereon. The final reduction gear 20a has a drive gear of a drive shaft 21 connected to a transmission via an output shaft and a reduction gear (not shown). 22 are engaged.

The lower end of the final reduction gear 20a is immersed in a differential oil stored at the bottom of the differential housing 17.

The transaxle 1 having such a vertical arrangement
, The clutch case 2 is located at the rear (transmission side) of the torque converter 5 and
0 has a gap at the top.

This gap is formed as an oil pump storage chamber 25 in which the differential oil stored in the differential housing 17 is provided with an oil cooler 2 as cooling means provided outside the transaxle 1.
Oil pump 2 as differential oil circulation means leading to 6
7 are provided.

More specifically, a pump support 28 is provided inside the clutch case 2. The pump support base 28 is formed integrally with the clutch case 2, and a lower portion thereof also serves as a bearing for inserting and supporting the turbine shaft 11 and the like.

An oil pump housing 29 is fixedly mounted on the upper surface of the pump support base 28. Inside the oil pump housing 29, for example, a trochoid type oil pump 2 having an inner gear 27a and an outer gear 27b is provided.
7 are provided.

A pump drive shaft 31 is fixed to the inner gear 27a, and an end of the pump drive shaft 31 penetrates through the pump support 28 and faces one side of the differential device 20.

A pump driven gear 32 is fixed to an end of the pump drive shaft 31. The pump driven gear 32 is fixed to a differential case 20b of the differential device 20 near one side of the differential device 20. It is meshed with the gear 33.

The suction port 29a of the oil pump housing 29 communicates with a differential oil suction pipe 34. The end of the differential oil suction pipe 34 is
It is immersed in the differential oil stored in.

On the other hand, the discharge port 29b of the oil pump housing 29 is connected to a differential oil discharge pipe 35 which communicates between the inside and the outside of the clutch case 2, and the differential oil discharge pipe 35 is connected to the oil cooler 26.

The oil cooler 26 has a differential oil return passage 3 communicating the inside and outside of the clutch case 2 with each other.
6 are connected. Although not shown, it is preferable that the downstream end of the differential oil return passage 36 faces a lubricating portion such as a rotating portion and a meshing portion of the differential device 20.

In the differential oil cooling device configured as described above, when the differential device 20 is driven, the oil pump 27 is driven by the differential case 2.
0b is driven via a pump drive gear 33 fixedly provided.

When the oil pump 27 is driven, the differential oil stored in the differential housing 17 is sucked up by the oil pump 27 via a differential oil suction pipe 34 and guided to the oil cooler 26 via a differential oil discharge pipe 35.

The differential oil cooled by the oil cooler 26 is returned into the differential housing 17 through a differential oil return passage 36.

According to such an embodiment, the oil pump 27 is disposed in the dead space in the clutch case 2 (at the rear part of the torque converter 5 and at the upper gap of the differential device 20), so that the transaxle 1 The oil pump 27 can be installed without increasing the size and the volume thereof. Then, the differential oil can be actively circulated to the oil cooler 26 by the oil pump 27, so that the differential oil can always be cooled to an appropriate temperature.

Further, since the oil pump 27 is of a mechanical type driven in conjunction with the differential device 20, no electric wiring or the like for driving the oil pump is required. It can be.

When the oil pump 27 is linked to the differential device 20 as shown in the present embodiment, the oil pump 27 is connected to the clutch case 2.
By providing the inside, members such as the pump drive shaft 31 can be shortened.

By providing the oil pump 27 inside the clutch case 2, it is possible to shorten an oil passage for guiding the differential oil to the oil pump 27.

Further, by providing the oil pump 27 inside the clutch case 2, it is possible to prevent the oil pump 27 from interfering with exterior parts (underbody parts and the like).

By providing the oil pump 27 inside the clutch case 2, it is not necessary to take measures against the leakage of the differential oil from the oil pump 27, and the structure of the oil pump 27 can be simplified.

Further, by actively circulating and cooling the differential oil by the oil pump 27, the amount of the differential oil stored in the differential housing 17 can be reduced. That is, by actively circulating and cooling the differential oil, the heat capacity of the differential oil can be reduced. Therefore, the immersion depth of the differential device 20 in the differential oil can be reduced, so that the stirring resistance due to the differential oil can be reduced and the rise in the oil temperature can be suppressed.

Further, by forcing the downstream end of the differential oil return passage 36 to face a lubricating portion such as a rotating portion or a meshing portion of the differential device 20, the forced circulation can be performed.

Here, as shown in FIG. 3, the differential oil cooling device includes a thermostat valve 40 as a flow path opening / closing means for shutting off the supply of the differential oil to the oil cooler 26 when the differential oil is at a low temperature, on the upstream side of the discharge port 29b. The configuration may be such that the differential oil discharged from the oil pump 27 is guided to the drain passage 41 when the differential oil temperature is low. With such a configuration, the supercooling of the differential oil can be prevented, and the differential oil can be controlled to a more appropriate oil temperature.

[0043]

As described above, according to the present invention, according to the differential oil cooling device of the first aspect, the differential oil circulating means is provided on the transmission side of the starting clutch means and the differential oil cooling means is provided on the differential device. By disposing in the upper gap, the differential oil can be actively circulated to the differential oil cooling means and cooled without increasing the size of the transaxle.

According to the differential oil cooling device of the second aspect, the differential oil circulating means is an oil pump driven in conjunction with the differential device. The structure can be inexpensive.

Further, according to the differential oil cooling device of the third aspect, the return passage of the differential oil from the differential oil cooling means faces each lubricating portion of the differential device, so that the differential oil is cooled. In addition to the effect described above, each lubricating part can be forcibly lubricated.

According to the fourth aspect of the present invention, the differential oil is supplied between the differential oil circulating means and the differential oil cooling means from the differential oil circulating means to the differential oil cooling means when the differential oil is at a low temperature. With the provision of the channel opening / closing means for blocking the channel, in addition to the effect of any one of the first to third aspects, the supercooling of the differential oil can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a transaxle.

FIG. 2 is a rear view showing a main part of the clutch housing and the differential housing in a cutaway manner;

FIG. 3 is a sectional view showing a main part of the oil pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transaxle 2 ... Clutch case 3 ... Transmission case 5 ... Torque converter (starting clutch means) 20 ... Differential device 25 ... Oil pump storage chamber (gap) 26 ... Oil cooler (Diff oil cooling means) 27 ... Oil pump (Diff oil circulation) Means) 31 Pump drive shaft 32 Pump driven gear 33 Pump drive gear 40 Thermostat valve (channel opening / closing means)

Claims (4)

[Claims] 1. A case member disposed between an engine and a transmission, a starting clutch means for inputting the engine power to the transmission, and a differential device for transmitting the shifting power from the transmission to the axle. A differential oil cooling device, which is a transaxle disposed vertically and configured to cool a differential oil stored in a differential housing portion that is a storage portion of the differential device, wherein: a differential oil cooling unit that cools the differential oil; A differential oil circulating means for guiding the differential oil to the differential oil cooling means, wherein the differential oil circulating means is disposed inside the case member, on the transmission side of the starting clutch means, and in an upper gap of the differential device. A differential oil cooling device, characterized in that: 2. The differential oil cooling device according to claim 1, wherein the differential oil circulating means is an oil pump, and the oil pump is driven in conjunction with the differential device. 3. The differential oil cooling device according to claim 1, wherein a return passage of the differential oil from the differential oil cooling means faces each lubricating portion of the differential device. 4. A flow path opening / closing means between the differential oil circulating means and the differential oil cooling means, the flow path opening / closing means for shutting off a supply flow path of the differential oil from the differential oil circulating means to the differential oil cooling means when the differential oil is at a low temperature. The differential oil cooling device according to any one of claims 1 to 3, characterized in that: