JPH055317Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an oil cooling device for a final reduction gear of a vehicle that forcibly cools oil in a differential carrier of the final reduction gear of a vehicle.

(Prior Art) As shown in FIG. 4, a final reduction gear for a wheel is integrated into a housing formed by a reduction gear box (hereinafter referred to as a differential gear box) 2 and a cover 3, which constitute the final reduction gear 1. A differential case 5 in which a reduction gear device 4 configured as shown in FIG. It is circulated in the path shown by the arrow by the agitation of the large reduction gear (hereinafter referred to as ring gear) 7, and the meshing portion between these drive pinions 6 and ring gear 7, as well as the rotation axis of each of these gears 6 and 7, are rotated. Each supporting bearing 9,
9' (only the bearing of the shaft 8 of the drive pinion 6 is shown).

On the other hand, in the differential carrier 2, the ring gear 7 splashes up more oil, and the splashed oil sufficiently lubricates the meshing parts and bearings of each of the gears. The heat generated in the differential carrier 2 is removed and the heat is well radiated from the surface of the differential carrier 2 to the outside air.

By the way, as vehicles become more sophisticated, they are often driven at high speeds, and when such high-speed driving continues for a long time, the oil agitation resistance caused by the ring gear 7 becomes a cause of an increase in the temperature of the oil, causing the temperature of the oil to drop. The rise becomes severe, and as described above, heat radiation from the surface of the differential carrier 2 alone becomes insufficient.

Therefore, conventionally, as shown in FIG. 4, an oil cooling device 20 composed of an oil pump 18 and a cooler 19 is connected to the differential carrier 2 via pipes 15 to 17, and the oil pump 18 is connected to the oil cooler 19 via the cooler 19. The oil in the differential carrier 2 is forcedly cooled by circulation to prevent the oil from rising in temperature.

(Problems to be solved by the invention) However, the above conventional oil cooling device 20
Since a separate drive type oil pump such as an electric oil pump is used as the oil pump 18, a separate installation location is required for the oil pump 18, and the piping route of the pipes 15 to 17 of the oil circulation system is It is long and complicated, and together with the arrangement of the cooler 19, it is extremely difficult in terms of layout. Furthermore, the use of the expensive oil pump 18 increases the cost of the cooling device 20.

The present invention was developed to solve the above-mentioned problems, and aims to reduce the cost of the cooling system by incorporating an oil pump into the differential carrier and driving the oil pump using the rotation of the differential case. The purpose of the present invention is to provide an oil cooling device for a final reduction gear.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a cam that is provided in a differential case housed in a differential carrier of a vehicle and rotates together with the differential case, and a cam mounted on the inner bottom surface of the differential carrier. an oil pump that is disposed facing the cam surface and is driven by the rotation of the cam to suck oil in the differential carrier and discharge it to the outside; and an oil pump that is disposed outside the differential carrier and has one end connected to a discharge port of the oil pump. , a pipe having the other end connected to a hole drilled at a predetermined location of the differential carrier to circulate the oil, and a cooling means provided to the pipe to cool the oil circulating within the pipe. It is structured as follows.

(Function) The oil pump is driven by a cam that rotates together with the differential case when the vehicle is running, and circulates oil in the differential carrier through a pipe placed outside the differential carrier. The oil circulating within this pipe is forcibly cooled by the cooling means and returned to the differential carrier. This suppresses the temperature rise of the oil in the differential carrier.

(Example) An example of the present invention will be described below in detail based on the accompanying drawings.

Incidentally, the same members as the final reduction gear device 1 shown in FIG. 4 are given the same reference numerals.

In FIGS. 1 and 2, the final reduction gear 1 houses a reduction gear 4 integrated in a differential carrier 2 and a differential case 5 containing a differential gear, and the reduction gear 4 includes a drive pinion 6 and the drive It is composed of a pinion 6 and a ring gear 7 that meshes with it, and the differential case 5 is fixed to one end surface of the ring gear 7. The rotating shaft 8 of the drive pinion 6 is supported by the support portion 2a of the differential carrier 2 at both ends via bearings 9, 9', respectively, and each shaft 10, 10 formed in the ring gear 7 and the differential case 5 is supported by a bearing 1, respectively.
1 and 11, and are supported by support portions 2c and 2c formed on the inner surface of the differential carrier 2.

The cam 21 is fixed to one end surface 5a of the differential case 5 concentrically with the rotating shaft 10, and is rotatable together with the differential case 5. This cam 21 is for driving an oil pump which will be described later.

The oil pump 22 is disposed below the cam 21, and a boss 23 forming a pump chamber of the oil pump 22 is connected to the differential carrier 2 as shown in FIG.
It is protruded from the bottom surface 2b of the cam 21 at a position below the cam 21. This boss 23 is set so that the upper surface 23a is always lower than the oil level H of the oil in the differential carrier 2, and a hole 24 is vertically bored approximately in the center of the upper surface 23a of the boss 23. The upper opening end 24a of 24 is opened facing the cam surface 21a of the cam 21, and the lower opening end 24b is opened facing the cam surface 21a of the cam 21.
The opening is expanded downward facing the bottom surface 2b, and is a screw hole.

Further, this hole 24 has a groove 24c formed along the axial direction on the inner surface thereof and having a substantially U-shaped cross section. occluded in position. The upper open end of the groove 24c is used as an oil inlet, the lower open end 24b of the hole 24 is used as an oil outlet, and the hole 24 is used as a pump chamber.

One end of the piston 25 is slidably inserted into the hole 24 from the open end 24a, and the upper end surface is formed into a substantially hemispherical shape and abuts against the cam surface 21a of the cam 2.
A nipple 27 is screwed into the lower open end 24b of the hole 24, and a return spring 26 is compressed between the lower end surface of the piston 25 and the opposing end surface of the nipple 27. The spring 26 applies an upward biasing force to the piston 25 and presses its upper end surface against the cam surface 21a of the cam 21, causing the piston 25 to follow the cam 21.

When the piston 25 is pushed down by the cam 21 to the maximum downward position shown by the solid line in FIG. When pushed up to the upper position, its lower end surface is located above the lower end of the groove 24c, allowing oil to be sucked into the hole 24, that is, into the pump chamber.

A cover 3 that is attached to the open end of the differential carrier 2 and seals the differential carrier 2 is provided with a screw hole 3a at a position slightly below the center position,
A nipple 28 is screwed into the screw hole 3a. A discharge port 28a of the nipple 28 slightly protrudes into the differential carrier 2 and opens downward.

A nipple 27 attached to the open end 24b of the hole 24, that is, the discharge port of the pump chamber, is connected to the suction port of the cooler 19 via a pipe 29, and the discharge port of the cooler 19 is connected to the cover 3 via a pipe 30. The nipple 28 is connected to the nipple 28 attached to the nipple 28 .

The action will be explained below.

When the rotation of the engine is transmitted to the drive pinion 6 of the final reduction gear 1 shown in FIG. drive the vehicle. As the ring gear 7 rotates, it stirs the oil in the differential carrier 2 and splashes it up, and the splashed oil circulates inside the differential carrier 2 as shown by the arrow in FIG. 1 and meshes with the drive pinion 6 and ring gear 7. and the respective bearings 9, 9', 11, 11 of these gears 6, 7, etc., to lubricate them.

On the other hand, as the differential case 5 rotates, the cam 21 rotates in the direction of arrow C in FIG. 3, causing the piston 25 of the oil pump 22 to reciprocate upward and downward as shown by arrows A and B. The oil pump 22 has a piston 25 that moves upward in the direction of arrow A, and its lower end surface has a groove 24c.
The groove 24c is moved upward from a position beyond the lower end surface of the groove 24c to the maximum upper position shown by the two-dot chain line in the figure, and then moved downward.
While reaching the lower end surface, oil is sucked into the hole 24, that is, the pump chamber, from the groove 24c, and while the lower end surface moves downward from the position beyond the lower end surface of the groove 24c to the maximum downward position shown by the solid line, the pump The oil in the room is pumped to the cooler 19 via the discharge pipe 29.

The cooler 19 cools the oil taken in, and discharges the cooled oil into the differential carrier 2 via the pipe 30 and nipple 28. The oil is cooled while the differential case 5 is rotating, that is,
This is done while the vehicle is running to cool the oil. Of course,
The oil in the differential carrier 2 is
It is also cooled by heat radiation from the surface. As a result, the oil is cooled well and temperature rise is prevented.

In this embodiment, a case is described in which a cooler is used as an oil cooling means, but the invention is not limited to this. The oil flowing therein may be cooled. According to such a configuration, an expensive cooler is not required, the oil cooling device can be made more compact, and the configuration of the cooling system can be simplified and the layout can be made easier.

(Effects of the invention) As explained above, according to the invention, a cam is provided in a differential case housed in a differential carrier of a vehicle and rotates together with the differential case, and a cam is disposed on an inner bottom surface of the differential carrier opposite to a cam surface of the cam. an oil pump that is installed and driven by the rotation of the cam to suck in oil in the differential carrier and discharge it to the outside; and an oil pump that is arranged outside the differential carrier and has one end connected to the discharge port of the oil pump and the other end of the differential The structure includes pipes connected to holes drilled at predetermined locations to circulate the oil, and a cooling means provided in the pipes to cool the oil circulating in the pipes.
The oil pump can be driven using the rotation of the differential case, and the oil pump can be made to have a low power consumption.Moreover, by incorporating the oil pump inside the differential case, it can be driven separately from the differential case. It becomes unnecessary to arrange an oil pump, and as a result, there are excellent effects such as the ability to simplify the layout of the oil cooling system.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of a differential carrier to which the oil cooling device of the final reduction gear according to the present invention is applied, Fig. 2 is an end view taken along the arrow line in Fig. 1, and Fig.
The figure is a sectional view taken along the arrow line in FIG. 2, and FIG. 4 is a sectional view of a differential carrier of a final reduction gear equipped with a conventional oil cooling device. 1...Final reduction gear, 2...Differential carrier, 3...
…cover, 4…reduction gear, 5…differential case,
6...Drive pinion, 7...Ring gear,
9, 9', 11...Bearing, 19...Cooler, 21
...Cam, 22...Oil pump, 23...Boss, 25...Piston, 29,30...Pipe.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A cam that is provided in a differential case housed in a differential carrier of a vehicle and rotates together with the differential case; an oil pump that is driven by rotation to suck in oil in the differential carrier and discharge it to the outside; and an oil pump that is arranged outside the differential carrier, with one end being bored at a discharge port of the oil pump and the other end being bored at a predetermined location of the differential carrier. An oil cooling device for a final reduction gear, characterized in that the oil cooling device comprises: pipes that are connected to respective holes in which the oil is circulated; and a cooling means that is provided on the pipes and cools the oil that circulates within the pipes. . (2) The oil pump is provided with an opening in the upper surface of a boss provided on the inner bottom surface of the differential carrier facing the cam surface, and has an inlet port on the upper surface of the boss, and a discharge port formed on the upper surface of the boss. pump chambers each having an outlet opened at the bottom surface of the differential carrier;
A piston that is slidably inserted into the pump chamber, has one end surface in contact with the cam surface, and is reciprocated by the rotation of the cam, and is interposed between the other end surface of the piston and the bottom surface of the pump chamber. The oil cooling device for a final reduction gear according to claim 1, further comprising a spring that applies a biasing force to the piston in the direction of the cam. (3) The oil cooling device for a final reduction gear according to claim 1, wherein the cooling means is a cooler connected to the pipe. (4) The oil cooling device for a final reduction gear according to claim 1, wherein the cooling means is a plurality of heat radiation fins provided on the surface of the pipe.