JP2950062B2 - Power transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device having a structure for transmitting power by inserting and connecting a mating member to an inner peripheral portion of a rotating member supported by a bearing. .

[0002]

2. Description of the Related Art For example, when an output shaft is connected to a driven sprocket supported by bearings in a casing,
If an insertion hole is formed along the center axis of the driven sprocket, and the output shaft is inserted and spline-fitted, the inside of the place supported by the bearing can be used effectively as a connection part. Can be shortened. The applicant has disclosed such a structure in Japanese Patent Application Laid-Open No. 63-8 / 1988.
No. 2830 has already proposed this.

[0003] In brief, a shaft portion is formed at each end of the chain sprocket in the axial direction, and a bearing is fitted to the shaft portion, so that the chain sprocket is rotatable in the casing via the bearing. It is supported by. A through hole is formed along the center axis of the chain sprocket, and the output shaft is inserted into the through hole and spline-fitted. In addition, a plug is fitted to the end of the through hole that is open in the casing while maintaining a liquid-tight state,
This plug prevents leakage of lubricating oil from inside the casing.

[0004]

The above-mentioned chain sprocket may be subjected to carburizing and quenching in order to improve the hardness of the surface layer. In this case, the through holes for spline-fitting the output shaft are provided at both ends in the axial direction. Since the opening is formed in the portion, the quenching oil is smoothly circulated, and as a result, uniform quenching quality can be ensured. However, in a state where the chain sprocket is assembled in the casing, the through hole communicates the inside and the outside of the casing as it is, and the lubricating oil in the casing may leak. For this reason, in the above-mentioned conventional apparatus, the end of the through-hole that opens into the casing among the open ends is sealed with a plug, which is one of the factors for increasing the number of parts and the number of assembling steps. There was room to be.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a power transmission device capable of reducing the number of parts without impairing the hardenability due to quenching oil. is there.

[0006]

SUMMARY OF THE INVENTION The present invention, in order to achieve the above object, interpolation in hole at least a portion for fitting the mating member in a relatively non-rotatable manner is hardened along the central axis In a power transmission device having a rotating member formed and having an outer peripheral portion at least on one end side closely fitted to a bearing member, the insertion hole has a shape of a blind hole closed at one end side which is closely fitted to the bearing member. At the same time, a small hole is formed at the closed end of the insertion hole, the small hole being opened on the inner peripheral surface and the outer peripheral surface on which the bearing member is closely fitted, and the outer peripheral surface opening of the small hole is formed. It is characterized by being sealed by the bearing member.

[0007]

[Action] and the rotating member and the mating member in this invention, are connected to each other than in particular to non-rotatably fitted by inserting the mating member into the insertion hole formed in the rotating member. Although the insertion hole itself has a blind hole shape, the insertion hole is communicated to the outside by a small hole formed on the closed end side, so the insertion hole is
In a non-assembled state of the rotating member, the opening is substantially opened at both ends in the axial direction. Therefore, when carburizing and quenching is performed using quenching oil, the quenching oil circulates smoothly through the insertion holes and the small holes, so that uniform quenching quality can be ensured.

On the other hand, in the assembled state in which the rotating member is supported by the bearing member, the bearing member closely fits the outer periphery of the portion where the small hole is formed to seal the opening end of the small hole. Therefore, the insertion hole is completely closed at the end opposite to the end where the mating member is inserted, so that special sealing means for preventing leakage of lubricating oil is unnecessary.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing one embodiment of the present invention, and shows a driven sprocket 1 in a four-wheel drive transfer. This driven sprocket 1
The power supply is transmitted from a drive sprocket (not shown) by winding a silent chain, is accommodated in the transfer case 2 and is rotatably supported by a pair of left and right bearings 3 and 4. Have been. In addition, one end of the driven sprocket 1 is used to connect a mating member 5 such as a front wheel output shaft.
It faces the opening of the transfer case 2, and an oil seal 6 is attached to the outer peripheral portion of this end to ensure liquid tightness with the transfer case 2.

A blind hole-shaped insertion hole 7 is formed along the central axis of the driven sprocket 1 over a predetermined length from the one end. The insertion hole 7 is for inserting the mating member 5 and connecting them so as to rotate together, and a spline 8 is formed at a predetermined position on the inner peripheral surface thereof. A small hole 9 communicating with the outer peripheral surface is formed at a closed end (right end in FIG. 1) of the insertion hole 7. The small hole 9 is a hole having an inner diameter such that a fluid such as quenching oil flows smoothly, and is opened on the outer peripheral surface where the bearing 3 is closely fitted. Therefore, in the assembled state shown in FIG. 1, the outer peripheral open end of the small hole 9 is sealed by the bearing 3, and as a result, the insertion hole 7
Are not in communication with the inside of the transfer case 2.

The above-mentioned driven sprocket 1 is subjected to carburizing and quenching in order to increase the hardness of the spline 8 and improve the durability, but when the driven sprocket 1 is not assembled, the small holes 9 Since it is open on the surface side, the insertion hole 7 is substantially open at both ends in the axial direction. Therefore, the quenching oil for carburizing and quenching circulates smoothly without staying in the insertion hole 7. Therefore, the inner peripheral surface of the insertion hole 7 can be hardened uniformly.

On the other hand, in the assembled state, the small hole 9 is sealed by the bearing 3, and the insertion hole 7 is not in communication with the inside of the transfer case 2. That is, the insertion hole 7 is provided in the transfer case 2 without using any special sealing means.
And the lubricating oil in the transfer case 2 does not leak from the insertion hole 7. In other words,
The plug used conventionally is not required.

In the above-described embodiment, a description has been given by taking a drivance plot in a four-wheel drive transfer as an example. However, the present invention is not limited to the above-described embodiment, and the present invention is not limited to the driven sprocket. It can be applied to members. Therefore, the bearing member is not limited to the above bearing.

[0014]

As described above, according to the present invention,
Insertion holes for connecting mating materials quenched at least a part
Even the so-called bag pores is, from its closed end is in communication with the outside by small holes, at the time of quenching smoothly circulate inside the quenching oil insertion hole, as a result, uniform quenching quality And the small hole is sealed by the bearing member in the assembled state, so that special sealing means for preventing leakage of the lubricating oil through the insertion hole is unnecessary, and as a result, the number of parts and The number of assembly steps can be reduced and productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 driven sprocket 3 bearing 5 mating material 7 insertion hole 9 small hole

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 55/30 F16H 55/17 F16H 57/04 B60K 17/34

Claims (1)

(57) [Claims] 1. A method for fitting a mating member so that it cannot rotate relatively.
Interpolation in hole is at least partially be hardened is formed along the central axis of, and in the power transmission device having a rotating member at least one end side outer peripheral portion is fitted in close contact with the bearing member, said insertion hole, said It is formed in a blind hole shape that is closed at one end side that is tightly fitted to the bearing member, and has an opening at the closed side end of the insertion hole at the inner peripheral surface and the outer peripheral surface at which the bearing member is closely fitted. A power transmission device, wherein a small hole is formed, and an opening on the outer peripheral surface side of the small hole is sealed by the bearing member.