JP3159429B2 - Oil leakage prevention structure for power transmission equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a structure for preventing oil leakage in power transmission equipment.

[0002]

2. Description of the Related Art Various power transmission devices such as a transfer gear box and a differential device of a vehicle are provided with a half coupling via a spline on a power transmission shaft protruding from a case. The half coupling is composed of, for example, a boss portion and a flange portion. The same shall apply hereinafter.), But it is necessary to prevent oil in the case from leaking out through splines. There is. As an oil leakage prevention structure, for example, there is a technology of Japanese Utility Model Publication No. Hei 6-3201, "A structure for preventing oil leakage from a differential carrier".

According to FIG. 1 of the publication, a companion flange 14 is attached to a drive pinion shaft 12 protruding from a differential carrier 10 of a vehicle (the number is cited in the publication. The same applies hereinafter). Are spline-connected. In the oil leakage prevention structure, a tapered shoulder 20 is formed radially outward of the drive pinion shaft 12, and a tapered shoulder 24 is formed radially outward of a spline (female spline) 22 of the companion flange 14. Then, an O-ring-shaped seal member 28 is inserted into a space 26 having the shoulders 20 and 24 facing each other, and the seal member 28 is compressed in the axial direction of the drive pinion shaft 12 to seal oil. . Seal member 28
Is axially compressed, a nut 34 is screwed onto the drive pinion shaft 12.

[0004]

However, according to the above-mentioned prior art, if the nut 34 is insufficiently tightened, leakage is likely to occur. When the nut 34 is excessively tightened, the compression allowance of the seal member 28 becomes excessive. Excessive compression may damage the seal member 28. Accordingly, the tightening work of the nut 34 requires skill, and the workability of mounting the seal member 28 is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a technique capable of easily mounting an O-ring for preventing oil leakage with an appropriate compression allowance, and improving mounting workability.

[0006]

In order to achieve the above object, the invention according to claim 1 is provided when a half coupling is mounted via a spline to a power transmission shaft protruding from a case housing a gear set. in oil leakage preventing structure of a power transmission device to prevent the oil in the casing through the spline leaks out, the power transmission shaft, a male spline, a retaining of the inner peripheral surface and O-ring of the O-ring
A straight shaft portion having a uniform outer diameter for fitting the inner peripheral surface of the annular ring to be formed is formed so that the straight shaft portion is on the shaft end side, and a spline female to the half coupling,
O-ring outer peripheral surface and O-ring retaining ring
A straight hole with a uniform inside diameter for fitting the outer peripheral surface of the ring is formed so that the straight hole is on the shaft end side, and a half coupling is spline-coupled to the power transmission shaft
Between the straight shaft and the straight hole
Form a space with the shaft end open, and measure the depth of this space
Match the width of the O-ring with the width of the annular ring
O-ring and annular in the space
The ring is fitted.

Since the O-ring is simply fitted between the straight shaft portion of the power transmission shaft and the straight hole of the half coupling, the O-ring for preventing oil leakage can be easily attached with an appropriate compression allowance. And mounting workability can be improved. Also, the straight shaft and straight
Even if the hole is slightly displaced in the axial direction, the annular
The ring prevents the O-ring from coming off. others
Therefore, the sealing property of the O-ring can be reliably maintained.
At the same time, damage to the O-ring can be prevented.

[0008] According to a second aspect of an end portion of the end and the straight hole portion of the straight shaft section, characterized in that a tapered portion for facilitating the fitting of the O-ring digits set.

When the O-ring is fitted between the straight shaft portion and the straight hole portion, the O-ring can be fitted by using the tapered portion as a guide, so that the workability of mounting the O-ring can be further improved. . There is no danger of damaging the O-ring .

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 is a plan view of a vehicular power transmission system according to the present invention. The vehicular power transmission system 1 includes a transfer gearbox 2 receiving driving force from an engine (not shown) via a transmission, and the transfer gearbox 2. The first connected in series to the output side of box 2
A propeller shaft 3 and a second propeller shaft 4,
The rear differential 5 connected to the second propeller shaft 4
And rear drive shafts 6 and 7 connected to the left and right output sides of the rear differential 5, respectively. These rear drive shafts 6, 7 are transmission members for driving rear wheels (not shown). In the figure, reference numeral 8 denotes an intermediate support for supporting the first propeller shaft 3.

FIG. 2 is a sectional view of a transfer gear box according to the present invention. A transfer / gearbox 2 as a power transmission device has a substantially L-shaped case 11 in plan view.
A pair of power transmission shafts (an input shaft 12 and an output shaft 13) housed in the case 11 so as to cross each other and supported rotatably, and an input-side gear integrally formed at one end of the input shaft 12 14, a drive-side hypoid gear 15 attached to the other end of the input shaft 12, a driven-side hypoid gear 16 formed integrally with one end of the output shaft 13 and meshing with the drive-side hypoid gear 15, and And a half coupling (companion flange) 17 attached via a spline.

One end of the input shaft 12 projects from the case 11. The input side gear 14 is gear-coupled to an output side of a transmission (not shown). A combination of the drive-side hypoid gear 15 and the driven-side hypoid gear 16 and a combination of a pair of gears are called a "gear set". The other end of the output shaft 13 is case 1
It protrudes from 1. Half coupling 17
Is a coupling half with a neck for coupling with the half coupling 3b for the universal joint 3a of the first propeller shaft 3 indicated by an imaginary line. These two half couplings 3b and 17 become one shaft coupling by being bolted.

The other end of the output shaft 13 has a male screw portion 13a, a male spline 13b having a larger diameter, a first straight shaft portion 13c having a larger diameter, and a large-diameter step portion 13d.
Are formed in this order. Then, as shown, the spacer 21, the bearing 22,
The half coupling 17 and the disc spring washer 23 are fitted in this order, and the whole is screwed with a nut 24. The spacer 21 is a bellows-type elastic spacer member that can expand and contract in the axial direction. In the figure, 31 to 34 are bearings,
35 is a collar, 36 is a nut, 37 is an oil seal, 3
Numerals 8 and 39 are covers.

FIG. 3 is an enlarged view of a part 3 of FIG.
3, a second outside of a uniform outer diameter for fitting the inner peripheral surface of the O-ring 25 outwardly in the axial direction from the male spline 13 b (to the right in the figure), that is, between the male spline 13 b and the male screw portion 13 a. A straight shaft portion 13e was formed, and the diameter of the second straight shaft portion 13e was larger than that of the male screw portion 13a and smaller than that of the male spline 13b. Then, an O-ring 25 is attached to the end of the second straight shaft portion 13e.
A tapered portion 13f is provided for guiding the second member to facilitate fitting. In other words, the output shaft 13 is on the shaft end side (the right
Side), the male screw part 13a, the taper part 13f, the second thread
The trait shaft 13e and the male spline 13b are placed in this order.
It is formed in. As a result, the male spline 13
The second straight shaft portion 13e is closer to the shaft end than b.
become. In addition, 13g is a chamfer part.

The half coupling 17 has a female spline 17a connected to the male spline 13b, and a straight hole 17b axially outward (to the right in the figure) from the female spline 17a. The straight hole portion 17b has a uniform inner diameter for fitting the outer peripheral surface of the O-ring 25, and has a larger diameter than the female spline 17a. For this reason, the half coupling 17 has a large-diameter step 17c between the end of the female spline 17a and the end of the straight hole 17b. The straight hole 17b has an open end (a right end in this figure) provided with a tapered portion 17d for guiding the O-ring 25 to facilitate the fitting. In other words, the half coupling 17 is connected to the shaft end (this
From the right side of the drawing), the tapered portion 17d, the straight hole portion 1
7b, large diameter step 17c, female spline 17a
In this order. As a result, the female spline
There is a straight hole 17b on the shaft end side than 17a
become.

The O-ring 25 is a male / female spline 1.
This prevents the oil in the case 11 (see FIG. 2) from leaking outside through 3b and 17a. Further, an annular ring (backup ring) 26 is inserted into the space S between the second straight shaft portion 13e and the straight hole portion 17b. The annular ring 26 extends from the space S to the O-ring 25.
The ring and the O-ring 25 move in the axial direction (from left to right in FIG. 3) and come into contact with the disc spring washer 23. The thickness is determined so that the inner peripheral surface of the O-ring 25 does not come off from the second straight shaft portion 13e.

Next, the procedure for assembling the oil leakage prevention structure having the above-described structure will be described. The assembling procedure is described for facilitating the understanding of the above configuration, and is not limited to this procedure. 4 (a) and 4 (b) are explanatory views of an assembling procedure of the oil leakage prevention structure according to the present invention. In (a), a half coupling 17 is spline-coupled to the output shaft 13. As a result, a space S is generated between the second straight shaft portion 13e and the straight hole portion 17b.

Next, the O-ring 25 is inserted into the space S (arrow), and fitted between the second straight shaft portion 13e and the straight hole portion 17b while being compressed. Thereafter, the annular ring 26 is fitted into the space S (arrow). Since the O-ring 25 can be fitted by using the tapered portions 13f and 17d as guides, the fitting operation becomes easy and there is no fear of damaging the O-ring 25. In (b), the disc spring washer 23 is inserted into the male screw portion 13a (arrow), and then the nut 2
4 is screwed into the male screw portion 13a (arrow). And
As shown in FIG.
Then, the half coupling 17 is prevented from coming off in the axial direction, and the operation is completed.

Next, the operation of the oil leakage prevention structure having the above structure will be described. FIGS. 5A and 5B are operation diagrams of the oil leakage prevention structure according to the present invention. (A) shows a state in which the O-ring 25 has entered the interior of the space S. In this state, the O-ring 25 is connected to the second straight shaft portion 13e and the straight hole portion 1e.
7b with an appropriate compression allowance. As a result,
The oil in the case 11 does not leak out through the spline. As is clear from the drawing, the disc spring washer 23
Is in contact with the half coupling 17, so the nut 2
4, the disc spring washer 23 is directly
The ring 25 and the annular ring 26 are not pressed.
That is, the tightening of the nut 24 does not affect the life of the O-ring 25.

FIG. 2B shows a state in which the O-ring 25 is near the entrance of the space S. The annular ring 26 is the disc spring washer 23
O ring 25 and annular ring 26 do not come out of space S. Of the O-ring 25
The outer peripheral surface is the second straight shaft portion 13e or the straight hole portion 1.
7B, the O-ring 25 fits between the second straight shaft portion 13e and the straight hole portion 17b with an appropriate compression margin. As a result, case 1
There is no worry that the oil in 1 leaks out.

As described above, the outer diameter of the second straight shaft portion 13e and the inner diameter of the straight hole portion 17b do not change. Then, the O-ring 25 is fitted with an appropriate compression margin only in the radial direction. For this reason, the O-ring 25 is movable in the axial direction between the position (a) and the position (b), and the compression allowance does not become excessively large, and is always fitted with an appropriate compression allowance. For example, the diameter of the second straight shaft portion 13e is 23 m
m, when the diameter of the straight hole 17b is 27 mm, the gap of the space S is 2 mm. Here, when an O-ring 25 having a wire diameter of 2.6 mm is fitted, the compression allowance is set to 0.
6 mm. The depth of the space S is sufficiently larger than the sum of the width of the O-ring 25 and the width of the annular ring 26. Therefore, even when the half coupling 17 is slightly displaced in the axial direction with respect to the output shaft 13 due to an assembly error or the like, the O-ring 25 can move in the axial direction, and the compression allowance does not become excessive. Absent. Less than
To summarize the above description, as is apparent from FIG.
The oil leakage prevention structure of the power transmission equipment consists of (1) a power transmission shaft and
Male shaft spline 13b and O-ring
The inner peripheral surface of the ring 25 and the inner peripheral surface of the annular ring 26 are fitted.
And a straight shaft portion 13e having a uniform outer diameter for
Formed so that the trait shaft portion 13e is on the shaft end side,
(2) Female spline 17 in half coupling 17
a, the outer peripheral surface of the O-ring 25 and the outer
Straight hole 17b with a uniform inner diameter for fitting the peripheral surface
Are formed such that the straight hole portion 17b is on the shaft end side.
(3) Splice the half coupling 17 to the output shaft 13.
By connecting the lines, the second straight shaft portion 13e and the
A space S whose shaft end side is open between the hole S and the plate hole 17b.
(4) The depth dimension of this space S is
5 with the width of the annular ring 26
(5) O-ring 25
And an annular ring 26 fitted.

In the embodiment of the present invention,
The power transmission device may be any device in which a gear set (gear mechanism) is housed in a case, and may be, for example, the rear differential device 5. Further, the oil leakage prevention structure prevents oil in the case from leaking outside through the splines in a power transmission device in which a half coupling is attached via a spline to a power transmission shaft protruding from the case. For this reason, the power transmission shaft is not limited to the output shaft 13 of the transfer / gearbox 2;
The input shaft 12 may be used, or the input / output shaft of the rear differential device 5 may be used.

Further, a flat washer may be used in place of the disc spring washer 23. In this case, the above-mentioned annular ring 26 is attached to the flat washer.
May be integrally formed. In the case of this configuration, the member serving as the annular ring 26 formed in the flat washer may not press the O-ring 25 in the axial direction.

[0024]

According to the present invention, the following effects are exhibited by the above configuration. According to the first aspect of the present invention, when a half coupling is mounted via a spline to a power transmission shaft protruding from a case housing a gear set, power transmission for preventing oil in the case from leaking outside through the spline. in oil leakage preventing structure of the device, the power transmission shaft, a male spline, omission of the inner peripheral surface and O-ring of the O-ring stopper
A straight shaft portion having a uniform outer diameter for fitting the inner peripheral surface of the annular ring, so that the straight shaft portion is on the shaft end side, and a spline female female to the half coupling; To prevent the outer peripheral surface of the O-ring and the O-ring from coming off
A straight hole with a uniform inside diameter for fitting the outer peripheral surface of the annular ring is formed so that the straight hole is on the shaft end side, and a half coupling is splined to the power transmission shaft.
In this way, a space with an open shaft end is formed between the straight shaft and the straight hole, and the depth of this space is
Match the O-ring width with the annular ring width.
O-ring and ring in the space
The shape ring is fitted.

Since the O-ring is merely fitted between the straight shaft portion of the power transmission shaft and the straight hole of the half coupling, the O-ring for preventing oil leakage can be easily attached with an appropriate compression allowance. And mounting workability can be improved. Also, the straight shaft and straight
Even if the hole is slightly displaced in the axial direction, the annular
The ring prevents the O-ring from coming off. others
Therefore, the sealing property of the O-ring can be reliably maintained.
At the same time, damage to the O-ring can be prevented. Furthermore, the sky
The depth of the space between the O-ring and the annular ring
The size of the space should be larger than that of the
The ring and the annular ring are fitted together.
Half-coupling in the axial direction with respect to the power transmission shaft
O-ring moves in the axial direction even if it is slightly displaced
It is possible and the compression cost will not be excessive.

The invention according to claim 2, the edge portion of the end portion and the straight hole portion of the straight shaft section, characterized in that a tapered portion for facilitating the fitting of the O-ring digits set.

When the O-ring is fitted between the straight shaft portion and the straight hole portion, the O-ring can be fitted by using the tapered portion as a guide, so that the workability of mounting the O-ring can be further improved. . There is no danger of damaging the O-ring .

[Brief description of the drawings]

FIG. 1 is a plan view of a vehicle power transmission system according to the present invention.

FIG. 2 is a sectional view of a transfer gear box according to the present invention.

FIG. 3 is an enlarged view of a part of FIG. 2;

FIG. 4 is an explanatory view of an assembling procedure of the oil leakage prevention structure according to the present invention.

FIG. 5 is an operation diagram of the oil leakage prevention structure according to the present invention.

[Explanation of symbols]

2, 5 ... Transfer gear box and rear differential as power transmission equipment, 11 ... Case, 12, 13 ... Power transmission shaft (input / output shaft), 13a ... Male thread, 13b
.. Male spline, 13e Straight shaft part (second straight shaft part), 13f Tapered part, 15, 16 Gear set (drive side / driven side hypoid gear), 17 Half coupling, 17a Female spline, 17b Straight Hole part, 17d: tapered part, 23: disc spring washer, 2
4 nut, 25 O-ring, 26 annular ring, S
Space department.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-134269 (JP, A) JP-A-62-37563 (JP, A) JP-A-7-103333 (JP, A) 51961 (JP, U) Jiko 6-3201 (JP, Y2) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 57/00-57/04 F16J 15/10

Claims (2)

(57) [Claims] 1. A power transmission device for preventing oil in a case from leaking outside through a spline when a half coupling is mounted via a spline to a power transmission shaft protruding from a case housing a gear set. reduce the oil leakage prevention structure, the power transmission shaft, a male spline, a retaining of the inner peripheral surface and O-ring of the O-ring
A straight shaft portion having a uniform outer diameter for fitting the inner peripheral surface of the annular ring is formed so that the straight shaft portion is on the shaft end side, and a female spline and ,
To prevent the outer peripheral surface of the O-ring and the O-ring from coming off
A straight hole having a uniform inner diameter for fitting the outer peripheral surface of the annular ring is formed so that the straight hole is on the shaft end side, and the half coupling is spliced to the power transmission shaft.
By connecting the lines, a space is opened between the straight shaft and the straight hole, with the shaft end open.
The depth dimension of the part is defined by the width dimension of the O-ring and the annular ring.
Larger set than a combination of the width of the air
An oil leakage prevention structure for a power transmission device , wherein the O-ring and the annular ring are fitted to an intermediate portion . The end of 2. The end of the straight shaft portion and the straight hole portion, a power transmission according to claim 1, wherein the setting digit tapered portion to facilitate engagement of the O-ring Oil leakage prevention structure for equipment.