JP3162917B2 - Drive shaft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a male shaft and a female shaft provided with a spline sliding portion fitted to each other, at least a part of the female shaft is formed as a hollow pipe, and the spline sliding portion is press-formed. It concerns the drive shaft.

[0002]

2. Description of the Related Art Conventionally, a spline sliding portion of a female shaft has been finished into a spline shape having a predetermined dimension by cutting such as a broach. On the other hand, for male shafts as well, it is common to cut the spline sliding part from a solid round bar with a hob, etc. It was common to do.

[0003]

Accordingly, since the outer diameter of the material of the female shaft is the same at the spline sliding portion,
In order to cut the outer surface of the round bar on the male shaft as well, to increase the torque transmission diameter to reduce the surface pressure, improve the transmission efficiency, and extend the life, the entire female shaft material and male shaft material are Larger outer diameters were required, which meant higher material costs.

An object of the present invention is to increase the torque transmission diameter and reduce the surface pressure without increasing the material cost, to improve the transmission efficiency, and to obtain a drive shaft having a long life.

[0005]

In order to achieve this object, a drive shaft according to the present invention comprises both a female shaft and a male shaft formed of hollow pipes, and the outer diameter of a large-diameter portion of a spline sliding portion is defined by a hollow pipe. The spline sliding part is press-formed so as to have a shape larger than the outer diameter of the material, and the spline of the female shaft and the male shaft has a small tooth height from the small diameter portion of the spline to the large diameter portion of the spline and a large tooth width in the same direction. The large-diameter matching portion where the large-diameter portion is always in contact with each other, the tooth height from the spline small-diameter portion to the spline large-diameter portion is high and the tooth width is narrowed, the radial dimension of the tooth side is increased, and the female shaft and The spline sliding portions of both the female shaft and the male shaft are press-formed so that the side surfaces on both sides of the spline teeth of the male shaft alternately have tooth-to-face mating portions that are always in contact with each other. .

[0006]

According to the present invention, the plastic deformation of a hollow pipe by press molding can be performed by increasing the outer diameter of the large-diameter portion of the spline sliding portion to be larger than the outer diameter of the hollow pipe material without increasing the material cost. In the large diameter matching part, the play in the radial direction of the male and female spline sliding parts is eliminated, and in the tooth face matching part, the play in the rotating direction is eliminated, and there is no play in both the radial direction and the rotating direction as a whole. It is a telescopic drive shaft that can slide in the axial direction.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a side view of a drive shaft 1 according to the present invention. The female shaft 2 of the drive shaft according to the present invention is formed by inserting, for example, a mandrel-shaped mold into a pipe from a hollow pipe to form an outer diameter φD of a large diameter portion of a spline sliding portion.
Is press-formed (plastically deformed) so as to have a shape larger than the outer diameter φd of the hollow pipe material.

In the embodiment shown in FIG. 1, only the female shaft has φD> φd.
However, the male shaft can also be press-formed from a hollow pipe so as to satisfy this relationship.

FIG. 2 shows cross sections of various embodiments of the spline sliding portion of the female shaft.

FIG. 2A shows the tooth height from the spline small diameter portion to the spline large diameter portion in order to make all the teeth of the spline sliding portion have the same diameter as the teeth of the spline sliding portion of the male shaft 3. In this embodiment, the height of the large diameter portion is made longer than the normal tooth width by making the height of the large diameter portion smaller than the normal tooth height. In this embodiment, the diameter of the teeth of the spline sliding portion of the male shaft is large, that is, the top surface of the teeth of the large diameter portion of the male shaft and the inner bottom surface of the large diameter portion of the female shaft are constantly in contact over a wide area. The spline fits in this state.

FIG. 2 (b) shows the tooth height from the spline small diameter portion to the spline large diameter portion in order to align all the teeth of the spline sliding portion with the teeth of the male spline sliding portion. In this embodiment, the height is uniform, but the height is higher than the normal tooth width and narrower than the normal tooth width to increase the radial dimension of the tooth side surface. In this embodiment, the teeth are aligned with the teeth of the spline sliding portion of the male shaft, that is, the spline fitting is performed in a state where the side surface of the peak of the teeth of the male shaft and the inner side surface of the valley of the female shaft are constantly in contact over a large area. It is a match.

In the spline fitting shape shown in FIG. 2A only for large-diameter alignment, the spline large-diameter portions are always in contact with each other, so that there is no play in the radial direction perpendicular to the axis.
Since there is a gap on the side surface of the tooth, there is a tendency that rattling occurs in the rotation direction. Also, in the spline fitting shape of FIG. 2 (b) with only the tooth surface alignment, the side surfaces on both sides of the tooth are always in contact with each other so that there is no backlash in the rotational direction, but on the other hand, the top surface of the male shaft tooth Since there is a gap between the female shaft and the inner bottom surface (the large-diameter portions do not contact each other), there is a tendency for play to occur in a direction (radial direction) perpendicular to the axis.

Therefore, according to the present invention, as shown in FIG. 2 (c), the teeth from the small spline diameter portion to the large spline diameter portion have a tooth height higher than normal and a tooth width narrower than normal.
The spline of the female shaft and the male shaft has a large-diameter portion that is in constant contact with a large area and the side surfaces on both sides of the tooth. , And a part that is always in contact is wide alternately. According to the present invention, since spline fitting is performed to perform both large-diameter alignment and tooth surface alignment, it is possible to avoid both play in the rotational direction and play in the radial direction.

[0015]

According to the present invention, since press forming is performed from a hollow pipe, material costs do not increase, and the processing is simple, so that manufacturing costs do not increase.
Making the outer diameter of the spline sliding part of the female shaft or the male shaft larger than the outer diameter of the material pipe means that making it smaller also increases the arm length of the rotational moment, that is, improving the torque transmission efficiency. I do. Furthermore, expanding in the radial direction means that the contact area of the spline teeth in contact with each other is larger than contracting in the radial direction, and the pressure per unit area applied to the teeth of the male and female splines, that is, the surface pressure. Can be reduced, thereby increasing the durability and extending the life.

Further, making the outer diameter of the spline sliding portion larger than the outer diameter of the material pipe increases the surface area of the spline teeth rather than shrinking, and the large-diameter tooth profile of the spline sliding portion slides. Also, the effect of improving the radiating fin action for radiating the heat generated in the step is obtained, so that the deterioration of the lubricating grease can be prevented, so that the durability is further improved and the life is prolonged.

Further, according to the present invention, since the spline engagement is performed for both the large diameter adjustment and the tooth surface alignment, the elastically slidable and slidable in the axial direction without play in both the radial direction and the rotational direction. A drive shaft can be obtained.

[Brief description of the drawings]

FIG. 1 is a side view of a drive shaft according to the present invention.

FIGS. 2A and 2B are cross-sectional views of a spline sliding portion of a female shaft taken along line 2-2 in FIG. 1, wherein FIGS. 2A and 2B are examples of different cross-sectional shapes, and FIG. It is sectional drawing of the spline sliding part of a female shaft.

[Explanation of symbols]

 1 Drive shaft 2 Female shaft 3 Male shaft

Claims (1)

(57) [Claims] 1. A drive shaft comprising a male shaft and a female shaft provided with a spline sliding portion fitted to each other, at least a part of the female shaft being a hollow pipe, and a spline sliding portion being press-formed. and both the male shaft constituted by a hollow pipe, the outer diameter of the large diameter portion of the spline sliding portion of the spline sliding portion so as to be larger shape than the outer diameter of the hollow pipe material to press molding, the spline small diameter portion Splice
The tooth height to the large diameter part is low and the tooth width in the same direction is large,
Large diameter spline of female shaft and male shaft always contact each other
Large spline from large diameter matching part and small spline diameter part
The tooth height to the diameter is high and the tooth width is narrow,
Increase the radial dimension and adjust the splines of the female shaft and male shaft.
Tooth surface matching part where both sides of the tooth are always in contact with each other
Of both the female shaft and the male shaft so that
A drive shaft characterized in that a spline sliding portion is press-formed .