JP2003240107A - Oil cooler built-in type speed reducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil cooler built-in type speed reducer furnished with both high durability and a high cooling effect by having sufficient strength against flowing force of oil, etc., of an oil cooler set in a housing of a speed reducing mechanism in which lubricating oil is reserved. <P>SOLUTION: This oil cooler built-in type speed reducer constituted by arranging the oil cooler to cool the lubricating oil opposite ring gear of the speed reducing mechanism in the casing in which the speed reducing mechanism is stored. The oil cooler is furnished with a plurality of hollow plate type elements in the inside of which cooling water channels are formed and radiating fins held between the elements. An outer surface of one of the elements is arranged opposite the ring gear. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle such as an automobile, in which a deceleration mechanism of the vehicle is housed and an oil cooler for cooling the lubricating oil is stored in a casing in which the lubricating oil is stored. The present invention relates to a reduction gear with a built-in oil cooler that is arranged so as to face the above.

[0002]

2. Description of the Related Art In a vehicle such as an automobile, a reduction gear such as a differential gear or a transfer gear generates a large amount of heat from a hypoid gear (ring gear) when the transmission power becomes large, and is arranged relatively close to an exhaust pipe. In this case, since the radiant heat of the exhaust pipe is received, a technique has been proposed in which an oil cooler for circulating engine cooling water is installed inside the casing to cool the oil (lubricating oil).

One of such technologies is the utility model registration No. 25.
There is an invention of 16687. In this invention, an oil cooler for cooling the lubricating oil is disposed inside a casing of the differential device in which the lubricating oil is stored, facing the ring gear of the differential device, and the oil cooler includes a pair of plate-shaped metal plates. A single element in the form of a hollow plate formed by forming a cooling water flow path inside and facing each other and liquid-tightly brazing the periphery, and fixed to the outer surface of the element facing the ring gear along the longitudinal direction of the element. And heat dissipation fins.

[0004]

In the inside of the casing, oil is agitated by the rotation of a reduction gear mechanism including a ring gear, and this oil is cooled by an oil cooler installed in a lower portion inside the casing. . In particular, since the ring gear has a large outer diameter, the action of stirring the oil by the ring gear is great. Therefore, if an oil cooler is installed around the ring gear, the effect of cooling the oil in the casing by the oil cooler increases.

In the invention of Utility Model Registration No. 2516687, the oil cooler is disposed inside the casing so as to face the ring gear, and the outer surface of the single hollow plate-shaped element facing the ring gear has a longitudinal direction of the element. Since the radiating fins are fixed along the above, it is possible to effectively cool the oil agitated by the ring gear.

However, in such a prior art, since the heat dissipating fins formed by curving a thin plate in a wave shape are arranged so as to face the ring gear, the fluid force of the oil agitated by the ring gear directly reduces the thin wall strength. Since the radiation fins are supported in a cantilever shape by brazing the roots to a single element, the radiation strength of the oil is small. There is a possibility that the heat radiation fin may fall off or be damaged by the force. On the other hand, if the thickness of the radiation fins is increased in order to prevent the radiation fins from falling off or being damaged, the cooling efficiency of the oil cooler decreases, and the oil cooler becomes large in size, making it difficult to install in a casing with a limited installation space. Become.
There are problems such as.

The present invention has been made in view of the above problems of the prior art.
The oil cooler installed in the casing of the vehicle speed reduction mechanism in which lubricating oil is stored has sufficient strength against the fluidity of the oil, and has both high durability and high oil cooling effect. An object is to provide a built-in speed reducer.

[0008]

In order to solve the above problems, the present invention provides, as an invention according to claim 1, an oil for cooling a lubricating oil in a casing in which a speed reducing mechanism is housed and lubricating oil is stored. An oil cooler built-in reduction device in which a cooler is disposed so as to face a ring gear of the reduction mechanism, wherein the oil cooler includes a plurality of hollow plate-shaped elements in which cooling water flow paths are formed, and the elements of the elements. There is proposed a speed reducer with a built-in oil cooler, characterized in that a heat dissipation fin is sandwiched between the heat dissipation fins and the outer surface of one of the elements is arranged to face the ring gear. In claim 1, preferably, the element is provided in three or more rows, and the heat radiation fins are sandwiched between the elements.

A third aspect of the present invention relates to a specific configuration of the oil cooler and its periphery, wherein the oil cooler is formed in a substantially arc shape along the circumferential direction of the ring gear and is formed in the casing. And a cooling water inlet portion connecting the cooling water supply passage and one end side of the cooling water flow passage of the element, a cooling water delivery passage formed in the casing, and the other end side of the cooling water flow passage of the element. A cooling water outlet portion and brackets extending from both ends of the oil cooler toward the center of the ring gear and fixed to the casing are provided.

The invention according to claim 4 is based on claim 1
The element is constructed by forming a pair of plate-shaped metal plates inside to form the cooling water flow path and facing each other and brazing the periphery in a liquid-tight manner, and reinforcing ribs are fixed to at least the outer surface of the element facing the ring gear. It is characterized by

According to this invention, the engine cooling water supplied to the cooling water supply passage formed in the casing accommodating the speed reducing mechanism flows into the one end side of the hollow plate-shaped element from the cooling water inlet of the oil cooler. When the cooling water flow path in the element flows in the longitudinal direction, heat is exchanged with the oil (lubricating oil) flowing in the casing through the heat radiation fins sandwiched between the elements to cool the oil. To do. The cooling water after the oil cooling is delivered from the other end side of the cooling water flow path of the element to the cooling water delivery passage formed in the casing through the cooling water outlet portion.

When the oil cooler is used to cool the oil, the oil cooler is constructed so that the radiation fins are sandwiched between a plurality of elements so that both ends are fixed.
Compared with the conventional cantilever support heat dissipation fin, the support rigidity of the heat dissipation fin is much higher, and in addition, it is difficult for the heat dissipation fin to directly receive the fluid force of the oil that greatly flows in the casing, which makes the heat dissipation fin high. Even if the thin fin having cooling efficiency is configured, the oil flow force does not cause the radiation fin to fall off or be damaged from the element.

Further, the oil cooler has a structure in which one outer surface of the element is arranged to face the ring gear, and a thin and low-strength radiation fin is not installed in a portion facing the ring gear. The fluid force of the agitated oil is received by the outer surface of the hollow plate-shaped element, and it is avoided that the fluid force directly acts on the heat radiation fin, and the oil fluid force from the ring gear as in the prior art directly acts on the heat radiation fin. It is possible to prevent the radiation fin from falling off or being damaged due to the action.

As described above, according to this invention, it is possible to improve the durability against the fluid force of the oil while maintaining the high cooling efficiency without increasing the size of the oil cooler by forming the heat radiation fin to be thin. Thus, an oil cooler having sufficient strength against the fluidity of oil and having high durability and a high oil cooling effect can be obtained.

Further, when the element of the oil cooler is provided in three or more rows and the radiating fins are sandwiched between the elements, the element and the radiating fins can be laminated in the axial direction of the ring gear. It is possible to avoid increasing the size of the ring gear in the radial direction, increase the heat transfer area of the oil cooler, and improve the cooling efficiency.

According to the third aspect of the invention, the oil cooler is formed in a substantially arc shape along the circumferential direction of the ring gear, and the oil is cooled by the brackets extending from both ends of the oil cooler toward the center of the ring gear. Since the cooler is fixed to the casing, the required cooling performance can be maintained by the oil cooler mounting structure having a compact structure in which the circumferential length of the oil cooler is suppressed.

Further, according to the present invention, the reinforcing ribs are fixed to at least the outer surface of the brazed hollow plate-shaped element facing the ring gear, so that the bending rigidity of the element is improved by the reinforcement and the ring gear prevents The deformation of the element due to the flow force of the agitated oil is avoided, and a high-strength oil cooler can be obtained while maintaining the required cooling performance.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, and other relative arrangements of the components described in this embodiment are not intended to limit the scope of the present invention thereto, unless there is a specific description, and are merely illustrative examples. Not too much.

FIG. 1 is a front view of an oil cooler for an automobile transfer according to an embodiment of the present invention, and FIG. 2 is a view taken in the direction of arrow A in FIG. 3 is a front view of an oil cooler mounting portion in the transfer, and FIG. 4 is a sectional view taken along line BB of FIG.

3 to 4 showing a transfer for a four-wheel drive vehicle according to an embodiment of the present invention, reference numeral 1 is a transfer casing, and a reduction mechanism 06 is housed in a transfer chamber 2 inside. Although the structure of the speed reduction mechanism 06 itself is known, a detailed description thereof will be omitted, but one output of a center differential device (not shown) is input to the input member 7 and is rotationally driven. Reference numeral 6 denotes a ring gear of the reduction mechanism 06, which is fixed to the input member 7 and rotates together with the input member 7, and transmits a driving force to a pinion gear (not shown) to output the drive to the rear wheel side. Also,
Reference numeral 9 denotes a differential case of the front wheel differential device 09, which is rotationally driven by inputting the other output of the center differential device (not shown). 8 is a ring gear 6 and an input member 7
Is the axis of rotation. 10 is a transfer casing 1
An oil cooler that cools the oil (lubricating oil) that is stored or flowed therein, has the configuration described below, and is housed in the transfer casing 1 (transfer chamber 2).

1 to 2 showing the details of the oil cooler 10.
In 2, 11 is a cup plate (element),
It is configured as a hollow plate in which a pair of dish-shaped metal plates are internally formed with a cooling water flow path so as to face each other and are brazed in a liquid-tight manner. In this example, three rows are provided (four rows even if two rows). Or more). Reference numeral 12 denotes a radiating fin formed by corrugating a thin plate, which is disposed between the cup plates 11 along the longitudinal direction and is sandwiched between the cup plates 11 by brazing. 17 is the cup plate 1
1 is a supporting member that fixes both end portions of 1 to maintain rigidity.

The cup plate 1 of the oil cooler 10
As shown in FIG. 2, the heat radiating fins 1 and the heat radiating fins 12 are formed in a substantially arcuate shape having a radius of curvature R along the circumferential direction of the ring gear 6. Further, one outer surface of the cup plate 11, that is, the outer surface 20 on the ring gear side is arranged so as to face the ring gear 6, and the heat radiation fin 12 is not installed at a portion facing the ring gear 6.
Brackets 18 are provided on the lower portions of both ends of the cup plate 11.
And the bracket 18 is fixed to the cup plate 1
1 and the radiating fins 12 extend toward the center of the radius of curvature R, that is, toward the center of the ring gear 6, and the tips thereof are fixed to the transfer casing 1 by bolts 19 as will be described later. An inlet boss 13 and an outlet boss 14 are fixed to the lower surface of each bracket 18, and the inside of the inlet boss 13 and the outlet boss 14 are connected to one end side of the cooling water flow passage in the cup plate 11. Inlet hole 15 and outlet hole 1 communicating with the other end of the cooling water flow path
6 are perforated respectively.

Further, as shown in FIGS. 3 to 4, the oil cooler 10 is formed by fitting the inlet boss 13 and the outlet boss 14 from a mounting surface 1a perpendicular to the rotation axis 8 of the transfer casing 1. An O-ring 21 (see FIG. 1) for fluid sealing is fitted and inserted into the fitting hole 1b, and the brackets 18 are fastened to the transfer casing 1 with bolts 19 to be fixed to the transfer casing 1.

As shown in FIG. 3, reference numeral 5 denotes an inlet passage for cooling water which is bored in the transfer casing 1, and has an outlet end communicating with the inlet hole 15. Reference numeral 07 denotes a cooling water outlet passage that is bored in the transfer casing 1, and has an inlet end communicating with the outlet hole 16. Reference numeral 3 is a cooling water inlet joint connecting the cooling water inlet pipe 03 from the engine and the cooling water inlet passage 5, and 4 is cooling water connecting the cooling water outlet passage 07 and the cooling water outlet pipe 04. It is an outlet joint.

In the speed reducer with a built-in oil cooler having such a structure, as shown in FIG. 3, the engine cooling water introduced from the cooling water inlet joint 3 into the inlet passage 5 in the transfer casing 1 is at the inlet shown in FIG. From the one end side of each cup plate 11 through the inlet hole 15 in the boss 13, it flows into the cooling water flow passage in the cup plate 11, and is sandwiched between the cup plates 11 when flowing in the cooling water flow passage in the longitudinal direction. The heat is exchanged with the oil (lubricating oil) flowing in the transfer chamber 2 through the heat radiation fins 12 to cool the oil. The cooling water after the oil cooling is sent to the cooling water outlet pipe 04 from the other end side of the cup plate 11 through the outlet passage 07 and the outlet joint 4.

Oil cooler 10 constructed as described above
When the oil is cooled by the oil cooler 10, the oil cooler 10 is configured by sandwiching the heat radiation fins 12 between a plurality of cup plates (elements) 11, and the heat radiation fins 12 are supported by the cup plate 11 in a form of fixing both ends. Due to the structure, the support rigidity of the heat radiation fin is much higher than that of the conventional cantilever support heat radiation fin, and in addition to this, the cup plate 11 serves as a tray to greatly flow in the transfer chamber 2. It is difficult for the heat radiation fins 12 to directly receive the fluidity of the existing oil. As a result, even if the radiation fin 12 is formed as a thin fin with high cooling efficiency, it is possible to prevent the radiation fin 12 from falling off the cup plate 11 and the radiation fin 12 itself from being damaged by the oil flow force. It

Further, in the oil cooler 10, one outer surface of the cup plate 11, that is, the outer surface 20 on the ring gear side is arranged so as to face the ring gear 6, and the portion facing the ring gear 6 has a thin and low strength heat radiation. Since the fins 12 are not installed, the fluid force of the oil agitated by the ring gear 6 is received by the ring gear side outer surface 20 of the hollow plate-shaped cup plate 11. As a result, it is possible to prevent the fluid flow of the oil from directly acting on the heat radiation fin 12, and the oil radiation force from the ring gear 6 directly acts on the heat radiation fin as in the prior art, so that the heat radiation fin may be removed or damaged. It can be avoided.

Further, the cup plate 11 constituting the element of the oil cooler 10 is replaced by the cup plate 11 as in this embodiment.
By providing a row, or four or more rows, with the radiation fins 12 sandwiched between the cup plates 11,
The cup plate 11 and the radiating fins 12 can be stacked in the axial direction of the ring gear 6, so that the ring gear 6 can be prevented from becoming large in the radial direction and the heat transfer area of the oil cooler 10 can be increased.

Further, according to this embodiment, the oil cooler 10 is formed in a substantially arcuate shape along the circumferential direction of the ring gear 6, and from both ends of the oil cooler 10 toward the center of the ring gear 6 (the radius of curvature R). Since the oil cooler 10 is fixed to the transfer casing 1 by a bracket 18 extending in the center direction of the oil cooler 10, it is not necessary to dispose mounting bolts at both ends in the circumferential direction of the oil cooler 10, and the circumferential length of the oil cooler 10 is reduced. The required cooling performance can be maintained with a compact oil cooler mounting structure that suppresses this.

Further, in another embodiment of the present invention, at least the ring gear 6 of the outer surface of the hollow plate-shaped cup plate 11 formed by brazing facing the ring gear, that is, the ring gear side outer surface 20 and the bracket 18 side outer surface. As shown by a chain line in FIG. 1, a reinforcing rib 30 is fixed along the radius of curvature R of the central portion of the cup plate 11 to the outer surface of the ring gear opposite to. According to this structure, since the reinforcing rib 30 is fixed to at least the outer surface of the brazed hollow plate-shaped cup plate 11 facing the ring gear 6, the bending rigidity of the cup plate 11 is improved and the ring gear 6 stirs the mixture. The deformation of the cup plate 11 due to the flowing force of the oil thus obtained is avoided, and the strength of the oil cooler 10 is improved while maintaining the required cooling performance. In this case, the reinforcing rib 30 may be replaced with a reinforcing plate formed in an arc shape similar to that of the cup plate 11 to perform the reinforcement process. In the above embodiment, an example of application to a transfer is shown, but the present invention can be applied to a differential device and the like.

[0031]

As described above, according to the present invention, since the oil cooler is constructed by sandwiching the heat radiation fins between a plurality of elements, the oil cooler has a heat radiation fin in comparison with the conventional cantilever support heat radiation fins. In addition to the significantly higher support rigidity, it is difficult for the heat radiation fins to directly receive the fluid force of the oil that largely flows in the casing, and even if the heat radiation fins are configured with thin fins with high cooling efficiency, It is possible to prevent the radiation fin from falling off or being damaged by the element due to the oil flow force.

Furthermore, since the oil cooler has a structure in which one outer surface of the element is arranged so as to face the ring gear, and a thin and low-strength heat radiation fin is not installed at a portion facing the ring gear, The fluid force of the agitated oil is received by the outer surface of the hollow plate-shaped element, and it is avoided that the fluid force directly acts on the heat radiation fin, and the oil fluid force from the ring gear as in the prior art directly acts on the heat radiation fin. It is possible to prevent the radiation fin from falling off or being damaged due to the action.

As a result, it is possible to improve the durability against the fluid force of the oil while maintaining the high cooling efficiency without increasing the size of the oil cooler by making the radiation fins thin, and to the fluid force of the oil. It is possible to provide an oil cooler having sufficient strength, high durability, and a high oil cooling effect.

According to the second aspect of the present invention, the element and the radiation fin can be laminated in the axial direction of the ring gear, the radial size of the ring gear can be prevented from increasing, and the heat transfer area of the oil cooler can be increased. The cooling efficiency can be improved.

According to the third aspect of the present invention, the oil cooler is formed in a substantially arc shape along the circumferential direction of the ring gear, and the oil cooler is provided by the brackets extending from both ends of the oil cooler toward the center of the ring gear. Since the structure is fixed to the casing, the required cooling performance can be maintained by the oil cooler mounting structure having a compact structure in which the circumferential length of the oil cooler is suppressed.

Further, according to the fourth aspect, since the reinforcing rib is fixed to at least the outer surface of the brazed hollow plate-shaped element facing the ring gear, the bending rigidity of the element is improved by the reinforcement, and the ring gear can improve the rigidity. The deformation of the element due to the flow force of the agitated oil is avoided, and a high-strength oil cooler can be obtained while maintaining the required cooling performance.

[Brief description of drawings]

FIG. 1 is a front view of an oil cooler for a vehicle transfer according to an embodiment of the present invention.

FIG. 2 is a view on arrow A of FIG.

FIG. 3 is a front view of an oil cooler mounting portion in the transfer.

FIG. 4 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

1 Transfer casing 1a Mounting surface 1b Mating hole 2 transfer rooms 3 inlet fittings 4 outlet fittings 5 entrance passages 6 ring gear 06 Reduction mechanism 7 Input member 07 Exit passage 8 axis of rotation 10 oil cooler 11 cup plate 12 radiation fins 13 entrance boss 14 Exit boss 15 entrance holes 16 exit holes 17 Support member 18 bracket 20 Ring gear side outer surface 30 Reinforcing rib

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akito Kato             Mitsubishi Motors, 5-3-8 Shiba, Minato-ku, Tokyo             Industry Co., Ltd. (72) Inventor Fumiaki Harashino             16 580, Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa             Within Ryo Automotive Engineering Co., Ltd. F-term (reference) 3J063 AA02 AB04 AC01 BA15 CA01                       CA05 CD41 XD03 XD15 XD33                       XH02 XH12 XH22 XH43                 3L103 AA11 AA37 BB39 CC09 CC22                       DD13

Claims (4)

[Claims] 1. A speed reducer with a built-in oil cooler, wherein an oil cooler for cooling the lubricating oil is disposed inside a casing in which the speed reducing mechanism is housed and the lubricating oil is stored so as to face a ring gear of the speed reducing mechanism. In the oil cooler, the oil cooler includes a plurality of hollow plate-shaped elements in which cooling water flow paths are formed, and heat radiation fins sandwiched between the elements, and an outer surface of one of the elements serves as the ring gear. A speed reducer with a built-in oil cooler, which is arranged facing each other. 2. The oil cooler built-in speed reducer according to claim 1, wherein the elements are provided in three or more rows, and the heat radiation fins are sandwiched between the respective elements. 3. The oil cooler is formed in a substantially arc shape along the circumferential direction of the ring gear, and connects the cooling water supply passage formed in the casing and one end side of the cooling water passage of the element. A cooling water inlet portion, a cooling water outlet portion connecting the cooling water delivery passage formed in the casing and the other end side of the cooling water flow passage of the element, and both ends of the oil cooler in the center direction of the ring gear. The speed reducer with a built-in oil cooler according to claim 1, further comprising a bracket that extends and is fixed to the casing. 4. The element is constituted by forming a pair of dish-shaped metal plates on the inside to form the cooling water flow paths so as to face each other and brazing the periphery in a liquid-tight manner, and at least an outer surface of the element facing the ring gear. The speed reducer with a built-in oil cooler according to claim 1, wherein reinforcing ribs are fixed.