JPH09229048A - Power transmitting shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the good bending strength and reduce the weight. SOLUTION: Four lines of recessed parts 17 extending in the lengthwise direction is formed at intervals of 90 deg. in the circumferential direction, on the outer circumferential side of the center territory 15 of a shaft main body 2. A balance weight is mounted on the reference recessed part 17a. The bending rigidity is improved, compared with a propeller shaft of customary technique having a cylindrical section. Hereby, good bending rigidity can be obtained even if the size is made small and the wall thickness is reduced, and hence the weight is reduced. It is easily held because of unevenness of the surface, and hence build-in property is improved. Further, the surface strength is improved and hence good bearing force is provided against a flying stone and the like.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a two-wheeled vehicle, a four-wheeled vehicle,
It also relates to a power transmission shaft such as a propeller shaft or a drive shaft used in a vehicle such as a special purpose vehicle.

[0002]

2. Description of the Related Art Generally, solid propeller shafts (circular cross-sections) and hollow shafts (ring cross-sections) are widely used as power transmission shafts such as propeller shafts and drive shafts. Among these, the propeller shaft 1 shown in FIG. 9 is an example of a hollow shaft-shaped (ring-shaped cross section) power transmission shaft. In the figure, a propeller shaft 1 has a cylindrical shaft body 2. The shaft main body 2 is provided with a power generation mechanism (not shown) such as a transmission, a reduction gear device, etc. via universal joints (hereinafter, for convenience, referred to as power generation side and power transmission side universal joints) 3 and 4, respectively. Is connected to a power transmission mechanism (not shown), and transmits power to the power transmission mechanism.

Universal joint 3 on the power generation side
Is a propeller shaft yoke connected to the shaft body 2 (hereinafter, referred to as a power generating side propeller shaft yoke) 5
And a sliding yoke 6 connected to the power generation mechanism
And the cross shaft 7 in general.

Propeller shaft yoke 5 on the power generation side
Is a base portion 8 provided at an end portion of the shaft body 2 and a support portion (hereinafter, referred to as a first and a second portion) protruding from the base portion 8 so as to face each other.
The support section of. ) 9a, 9b, and is substantially U-shaped in a plan view. Sliding yoke 6
The base 10 is connected to the power generation mechanism, and the supporting portions 11a and 11b are projected from the base 10 so as to face each other, and have a substantially U-shape. The cross shaft 7
It is composed of first and second axes 12 and 13 which are orthogonal to each other in a cross shape,
The first and second shafts 12 and 13 are rotatably supported by the propeller shaft yoke 5 and the sliding yoke 6 on the power generation side, respectively.

Universal joint 4 on the power transmission side
Is, compared to the universal joint 3 on the power generation side,
The difference is that instead of the sliding yoke 6, a flange yoke 14 connected to the power transmission mechanism is provided, and the other parts are the same. In order to distinguish the propeller shaft yoke of the universal joint 4 on the power transmitted side from the propeller shaft yoke 5 on the power generated side, the propeller shaft yoke 5 on the power transmitted side will be described below.
A. The propeller shaft yokes 5 and 5A on the power generation side and the power transmission side are manufactured by using a mold, and uneven thickness is likely to occur. The propeller shaft yokes 5 and 5A on the power generation side and the power transmission side are provided with the first and second support portions 9a and 9b facing each other.

The power transmission shaft described above has a constant diameter along the longitudinal direction of the shaft body 2, but instead of this, FIG.
As shown in 0, there is also a propeller shaft 1 in which the central region 15 of the shaft body 2 has a larger diameter than the end portion 16 side and has the same diameter dimension over a predetermined length.

[0007]

By the way, in order to reduce the weight of the vehicle, it is desired to reduce the diameter of the power transmission shaft such as a propeller shaft and the diameter of the pipe, and to reduce the thickness of the pipe. However, in the above-mentioned conventional power transmission shaft having a circular cross section and a ring cross section, if the diameter is reduced and the pipe wall thickness is reduced, the bending strength is lowered, and the above-mentioned demand cannot be properly met. Was the reality.

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 shaft capable of maintaining good bending strength and reducing weight.

[0009]

According to the first aspect of the present invention,
In the power transmission shaft whose end portions are respectively connected to the power generation mechanism and the power transmission mechanism, a plurality of protrusions or recesses extending in the longitudinal direction on the outer peripheral side are formed at predetermined intervals in the circumferential direction. In this case, the balance weight may be attached to the recessed portion between the convex portions or the concave portion.

According to a third aspect of the invention, the cross section has a ring shape,
Alternatively, in the power transmission shaft that has a circular shape and the ends are connected to the power generation mechanism and the power transmission mechanism, respectively, the central portion is set to a large diameter so that the diameter becomes smaller toward the ends. Characterize. In this case, a plurality of convex portions or concave portions extending in the longitudinal direction may be formed on the outer peripheral side at predetermined intervals in the circumferential direction.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A propeller shaft (power transmission shaft) 1 according to a first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. It should be noted that illustrations and descriptions of members and parts equivalent to those shown in FIGS. 9 and 10 are omitted as appropriate.

On the outer peripheral side of the central region 15 of the shaft body 2, four recesses 17 extending in the longitudinal direction are formed at intervals of 90 ° in the circumferential direction. With the formation of the four recessed portions 17 in this manner, a portion between the adjacent four recessed portions 17 that is relatively convex with respect to the recessed portions 17 (maximum diameter portion, hereinafter referred to as relative convex portion). 18 are left. The four-row recess 1
One of the seven recesses (hereinafter referred to as the reference recess) 17a
Are formed on the line connecting the first support portions 9a and 11a of the propeller shaft yokes 5 and 5A on the power generation side and the power transmission side, respectively.

Relative convex portion 1 adjacent to the reference concave portion 17a
No. 8 is shifted from the reference concave portion 17a by 45 ° in the circumferential direction (that is, the relative convex portion 18 has a phase difference of 45 ° with the propeller shaft yoke). Shaft body 2
The end portion side is formed in a tubular shape for welding connection with the propeller shaft yokes 5 and 5A on the power generation side and the power transmission side. A balance weight 19 is attached to the reference recess 17a.

In the propeller shaft 1 shown in FIGS. 1 and 2 described above, the outer peripheral side of the shaft body 2 is uneven along the circumferential direction. , The bending rigidity is improved. Therefore, even if the diameter is reduced and the wall thickness is reduced, good bending rigidity can be obtained, and the weight can be reduced accordingly. The cylindrical propeller shaft 1 as shown in FIG. 9 and FIG. 10 is slippery when held, but in contrast to this, the product of the present invention is easier to hold due to the unevenness, and as a result, the assembling property is improved. Also,
The surface strength is improved and it has good proof stress against flying stones.

Although the uneven thickness of the propeller shaft yokes 5, 5A on the power generation side and the power transmission side and the flange yoke 14 largely depends on the rotational balance, the propeller shaft yokes 5, 5A on the power generation side and the power transmission side. Since the balance weight 19 is attached to the reference recessed portion 17a formed on the line connecting the respective first support portions 9a and 11a,
It is easy to correct uneven thickness, balance can be adjusted properly, and good rotation can be maintained. Also, balance weight 1
Since 9 is attached to the recessed portion (reference recess 17a), the balance weight 19 is less likely to fall off.

Next, a second embodiment of the present invention will be described with reference to FIGS. It should be noted that the illustration and description of the members and parts equivalent to the members and parts shown in FIGS. 1, 2, 9 and 10 are omitted as appropriate. Central region 1 of shaft body 2
On the outer peripheral side of 5, there are formed four protrusions 20 extending in the longitudinal direction at intervals of 90 ° in the circumferential direction. By forming the four protrusions 20 in this manner, the adjacent four protrusions 2
A portion 21 (hereinafter referred to as a relative concave portion) that is relatively recessed with respect to the convex portion 20 is left between zero.

One of the four relative recesses 21 (hereinafter referred to as a reference relative recess) 21a is a first support portion of each of the propeller shaft yokes 5 and 5A on the power generation side and the power transmission side. It is formed on the line connecting 9a and 11a. A relative concave portion (hereinafter referred to as a facing relative concave portion) 21b facing the reference relative concave portion 21a is on a line connecting the second support portions 9b and 11b of the propeller shaft yokes 5 and 5A on the power generation side and the power transmission side, respectively. Is left in. The balance weight 19 is provided in the facing relative recess 21b.
Is installed.

The convex portion 2 adjacent to the reference relative concave portion 21a
0 is 45 ° in the circumferential direction with respect to the reference relative concave portion 21a.
It is shifted (that is, the convex portion 20 has a phase difference of 45 ° with the propeller shaft yoke).

In the propeller shaft 1 shown in FIGS. 3 and 4 described above, since the outer peripheral side of the shaft main body 2 is uneven along the circumferential direction, compared to the propeller shaft 1 of the prior art having a cylindrical cross section. , The bending rigidity is improved. Therefore, even if the diameter is reduced and the wall thickness is reduced, good bending rigidity can be obtained, and the weight can be reduced accordingly. The cylindrical propeller shaft 1 as shown in FIG. 9 and FIG. 10 is slippery when held, but in contrast to this, the product of the present invention is easier to hold due to the unevenness, and as a result, the assembling property is improved. Also,
The surface strength is improved and it has good proof stress against flying stones.

Further, the second supporting portions 9 of the propeller shaft yokes 5 and 5A on the power generating side and the power transmitted side, respectively.
Opposing relative concave portion 21b formed on a line connecting b and 11b
Since the balance weight 19 is attached to the, the uneven thickness can be easily corrected, the balance can be properly adjusted, and good rotation can be maintained. Further, since the balance weight 19 is attached to the recessed portion (opposing relative concave portion 21), the balance weight 19 is less likely to fall off.

In the above first and second embodiments, the case where four recesses or protrusions are formed has been taken as an example, but the present invention has four.
It is not limited to articles.

Next, a third embodiment of the present invention will be described with reference to FIGS. 1 to 4,
Illustration and description of members and portions equivalent to those shown in FIGS. 9 and 10 are omitted as appropriate. 5 and 6, the shaft body 2 is set such that the central portion 2T has a large diameter, and the diameter dimension becomes smaller as shown in FIGS. 5, 7 and 8 toward the end portion 16 side. ing.

Generally, in a propeller shaft, a large bending stress is applied to the central portion, but in the propeller shaft 1 in which the central portion 2T of the shaft body 2 has a large diameter as described above, the central portion 2T of the shaft body 2 is bent. Since the strength is improved, it is possible to reliably withstand a large bending stress even when it is applied. Further, since the diameter is reduced toward the end portion 16 side, the weight can be reduced accordingly.

In the above first to third embodiments, the case where the shaft body 2 is cylindrical has been taken as an example, but instead of this, a solid shaft-shaped (circular cross-section) shaft body may be used. Good. Also,
In the above-described first to third embodiments, the case where the power transmission shaft is the propeller shaft 1 has been described as an example, but the present invention is not limited to this and may be, for example, a drive shaft.

[0025]

According to the invention described in claim 1, since a plurality of convex portions or concave portions extending in the longitudinal direction are formed on the outer peripheral side at predetermined intervals in the circumferential direction, the power transmission shaft having a cylindrical cross section or the circular cross section is formed. Bending rigidity is improved as compared with a solid shaft-shaped power transmission shaft. Good bending rigidity can be obtained by reducing the diameter and thickness, and the weight can be reduced accordingly. With the round power transmission shaft of the prior art, it is slippery when holding, but in comparison with this, the power transmission shaft of the present invention is easier to hold due to the unevenness,
As a result, the assemblability is improved. Further, the surface strength is improved, and it has a good proof stress against flying stones and the like. Further, by providing the balance weight in the recessed portion, it is possible to adjust the rotational imbalance due to uneven thickness and maintain good rotation.

According to the third aspect of the present invention, since the central portion has a large diameter and the end portion has a smaller diameter, the bending strength of the central portion increases, and a large bending stress is reliably resisted. Bending can be prevented, and the diameter can be reduced toward the ends, so that the weight can be reduced accordingly. In this case, the bending rigidity is further improved by forming a plurality of convex portions or concave portions extending in the longitudinal direction on the outer peripheral side at predetermined intervals in the circumferential direction.

[Brief description of drawings]

FIG. 1 is a front view showing a propeller shaft according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically showing along line AA of FIG.

FIG. 3 is a front view showing a propeller shaft according to a second embodiment of the present invention.

4 is a cross-sectional view schematically showing along line BB in FIG.

FIG. 5 is a front view showing a propeller shaft according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view schematically showing along the line CC of FIG.

7 is a cross-sectional view taken along the line DD of FIG.

8 is a cross-sectional view taken along the line EE of FIG.

FIG. 9 is a partially cut front view showing a propeller shaft as an example of a conventional power transmission shaft.

FIG. 10 is a sectional view showing another example of a conventional power transmission shaft.

[Explanation of symbols]

 1 Propeller shaft 2 Shaft main body 2T Central part of shaft main body 15 Central area of shaft main body 16 End part of shaft main body 17 Recessed portion 20 Convex portion

Claims (4)

[Claims] 1. A power transmission shaft having ends connected to a power generation mechanism and a power transmission mechanism, respectively, wherein a plurality of projections or recesses extending in the longitudinal direction are formed on the outer peripheral side at predetermined intervals in the circumferential direction. Power transmission shaft characterized by. 2. The power transmission shaft according to claim 1, wherein a balance weight is attached to a concave portion or a concave portion between the convex portions. 3. The cross section has a ring shape or a circular shape,
In the power transmission shaft whose ends are connected to the power generation mechanism and the power transmission mechanism, respectively, the power transmission shaft is characterized in that the central portion is set to a large diameter so that the diameter dimension becomes smaller toward the end side. . 4. The power transmission shaft according to claim 3, wherein a plurality of convex portions or concave portions extending in the longitudinal direction are formed on the outer peripheral side at predetermined intervals in the circumferential direction.