JP2011126317A - Power transmission mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission mechanism by which torque can be certainly transmitted by performing cross serration processing on a yoke flange of a propeller shaft and a companion flange of a final drive, and which eliminates the need for cross serration processing of an oscillation reducing device. <P>SOLUTION: The yoke flange (11) of the propeller shaft (1) and the companion flange (21) of the final drive (2) have areas (13, 23) on which the cross serration (15, 25) is processed. The companion flange (21) of the final drive (2) is fitted to a stepped part (35) formed at the side of the final drive (2) of a torsional damper (3). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power transmission mechanism in a truck such as a truck. More specifically, the present invention relates to a connection structure between a propeller shaft and a final drive.

In a power transmission mechanism in a truck such as a truck, a vibration reducing member (for example, a damper rubber) that attenuates the resonance frequency at a connection point between the propeller shaft and the final drive in order to attenuate vibration corresponding to the torsional resonance frequency of the drive system. There is a case where a torsional damper provided with is provided.
As such a torsional damper, for example, a power transmission device has been proposed in which a torsional damper provided with a damper rubber tuned to the torsional resonance frequency of the drive system is provided on the drive shaft (see Patent Document 1).

Here, FIG. 3 shows, in an exploded manner, a state in which the torsional damper 3J is attached to the connection portion of the propeller shaft 1J and the final drive 2J in the power transmission mechanism.
As shown in FIG. 3, when connecting the propeller shaft 1J and the final drive 2J using the torsional damper 3J as described above, for example, the bolt B, nut N, and washer W are used to connect the yoke flange 11J of the propeller shaft 1J to the yoke flange 11J. The three members of the torsional damper 3J and the companion flange 21J of the final drive 2J are overlapped and fastened (so-called “three-piece fastening”).
Reference numeral 33J in FIG. 3 indicates a damper rubber which is a vibration reducing member.

2. Description of the Related Art In recent years, it has become common for trucks and the like with a large input torque to transmit torque by applying cross serration processing to joint surfaces of propeller shafts and flanges of final drives.
In the prior art as shown in FIG. 3, in the case of performing cross serration on the yoke flange 11J of the propeller shaft 1J and the companion flange 21J of the final drive 2J for torque transmission, in the torsional damper 3J, It is necessary to process cross serration for the area in surface contact with the serrated surface. For simplification of illustration, FIG. 3 does not show a state in which the torsional damper 3J is processed with cross serration.
However, in order to process the cross serration in the torsional damper 3J, there is a problem that the processing cost increases.
For simplification of illustration, FIG. 3 does not show a state in which the torsional damper 3J is processed with cross serration.

  Even in the prior art (Patent Document 1) in which a torsional damper having a damper rubber tuned to the torsional resonance frequency of the drive system is provided, there is no disclosure of a technique for solving the problems associated with processing cross-serration.

Japanese Utility Model Publication No. 6-36934

  The present invention has been proposed in view of the above-mentioned problems of the prior art, and it is possible to reliably transmit torque by performing cross serration processing on the yoke flange of the propeller shaft and the companion flange of the final drive. An object of the vibration reduction device is to provide a power transmission mechanism that does not require processing of cross serration.

  The power transmission mechanism of the present invention has a region where the yoke flange (11) of the propeller shaft (1) and the companion flange (21) of the final drive (2) have processed cross serrations (15, 25). The processed cross serrations (15, 25) are engaged with each other, and the yoke flange (11) of the propeller shaft (1) and the companion flange (21) of the final drive (2) are connected to the first fastening member (bolt 4), the companion flange (21) of the final drive (2) and the torsional damper (3) having the vibration reducing member (for example, the damper rubber 33) are fastened by the second fastening member (bolt 6). Final drive (2) companion flange (21) of torsional damper (3) Is characterized in that fitted in § Lee null drive (2) stepped portion formed on the side (35).

  In the present invention, the yoke flange (11) of the propeller shaft (1) is formed with a through hole (14) for allowing the first fastening member (bolt 4) to pass therethrough, and the companion flange of the final drive (2). (21) includes a first through hole (24) for inserting the first fastening member (bolt 4) and a second through hole (26) for passing the second fastening member (bolt 6). The torsional damper (3) has a through hole (37) for inserting the second fastening member (bolt 6) formed in the region (312) where the vibration reducing member (33) is not provided. It is preferable.

  In the present invention, it is preferable that the pitches of the first through hole (24) and the second through hole (26) in the companion flange (21) of the final drive (2) are set to be the same.

According to the present invention having the above-described configuration, the cross serration (15) processed into the yoke flange (11) of the propeller shaft (1) and the cross processed into the companion flange (21) of the final drive (2). By engaging and engaging with the serration (25), even a large torque such as an input torque of a truck or the like is reliably transmitted from the propeller shaft (1) to the final drive (2).
At this time, since the centering of the propeller shaft (1) and the final drive (2) is performed by the meshing of the cross serrations (15, 25), the central axis (L1) of the propeller shaft (1) and the final shaft The center axis (L2) of the drive can be easily matched.

Since the yoke flange (11) of the propeller shaft (1) and the companion flange (21) of the final drive (2) are directly coupled by the first fastening member (bolt 4), the prior art of FIG. Thus, it is not necessary to process cross serration on the propeller shaft (1) side of the torsional damper (3).
Further, the torque is reliably transmitted between the yoke flange (11) of the propeller shaft (1) and the companion flange (21) of the final drive (2) by the engagement of the cross serrations (15, 25). The companion flange (21) and the torsional damper (3) of the drive (2) need only be prevented from relative movement in the direction of the central axis (L1) of the propeller shaft by the second fastening member (bolt 26). Therefore, there is no need to process torque transmission cross serrations on the final drive (2) side of the torsional damper (3).

  That is, according to the present invention, it is not necessary to process the cross serration on the propeller shaft (1) side or the final drive (2) side of the torsional damper (3).

However, rotational fluctuations caused by the torsional vibration of the drive system are transmitted to the torsional damper (3) via the companion flange (21) and the second fastening member (bolt 6) of the final drive (2). The
Therefore, the rotational fluctuation or the like is attenuated or absorbed by the vibration reducing member (33) provided in the torsional damper (3).

  Furthermore, according to the present invention, the companion flange (21) of the final drive (2) is fitted to the step (35) formed on the final drive (2) side of the torsional damper (3), so-called "inlay" It is like "joint". That is, by fitting the companion flange (21) of the final drive (2) to the step (35) formed on the final drive (2) side of the torsional damper (3), the torsional damper (3) Can be centered.

  In addition, if the pitches of the first through hole (24) and the second through hole (26) in the companion flange (21) of the final drive (2) are the same, the yoke of the propeller shaft (1) An increase in the type of companion flange (21) of the final drive (2) relative to the flange (11) can be suppressed.

It is a sectional side view which shows the assembly before the power transmission mechanism which concerns on embodiment of this invention. It is a sectional side view which shows the assembly of the power transmission mechanism which concerns on embodiment of this invention. It is a sectional side view which decomposes | disassembles and shows the power transmission mechanism in a prior art.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
In FIG. 1, a power transmission mechanism denoted as a whole by reference numeral 100 includes a propeller shaft 1, a final drive 2, and a torsional damper 3.
Here, FIG. 1 shows the state before the power transmission mechanism 100 is assembled, and FIG. 2 shows the assembled state.

In FIG. 1, the propeller shaft 1 includes a shaft body 10 a, a shaft body yoke 10 b, a cross joint 19, and a yoke flange 11.
The yoke 10b of the shaft body 10a and the yoke flange 11 are connected by a cross joint 19 so that the axis of the yoke 10b and the axis of the yoke flange 11 can be bent within a predetermined angle range.
The yoke flange 11 has a flange portion 12 and a yoke portion 13.
In the flange portion 12, fastening bolt through holes 14 are formed at four locations, although not clearly illustrated. The flange end surface 12f of the flange portion 12 is a joint surface that comes into contact with the final drive 2, and a cross serration 15 (for example, female (concave) cross serration) is formed on the flange end surface 12f.

The final drive 2 includes a carrier (not shown), a carrier end cover 2C, and a companion flange 21.
The companion flange 21 has a flange portion 22 and a cylindrical portion 23.
A cross serration 25 (for example, male (convex) cross serration) is formed on the flange end surface 22 f of the flange portion 22.
The cross serration 25 engages and meshes with the cross serration 15 formed on the yoke flange 11 of the propeller shaft 1, so that even a strong torque can be transmitted.

The flange portion 22 of the companion flange 21 is provided with four first bolt through holes 24 through which the first fastening bolts 4 pass. The flange portion 22 is formed with four second bolt through holes 26 through which the second fastening bolts 6 penetrate, separately from the first bolt through holes 24.
The first bolt through hole 24 corresponds to the connection bolt through hole 14 formed in the yoke flange 11 of the propeller shaft 1. The second bolt through holes 26 correspond to the four bolt through holes 37 formed in the torsional damper 3.
It is preferable to set the pitches of the first bolt through holes 24 and the second bolt through holes 26 in the companion flange 21 of the final drive 2 to be the same. This is because such a configuration can suppress an increase in the type of the companion flange 21 of the final drive 2 that is joined to the yoke flange 11 of the propeller shaft 1.

The torsional damper 3 includes an annular member 31, a damper holder 32, and a damper rubber 33.
The annular member 31 has an outer edge portion 311 and a flange portion 312, and the outer edge portion 311 and the flange portion 312 are integrated.
The thickness dimension of the flange portion 312 (dimension in the direction parallel to the axis: the dimension in the left-right direction in FIG. 1) is the thickness dimension of the outer edge portion 311 (dimension in the direction parallel to the axis: dimension in the left-right direction in FIG. 1). Smaller than. The left and right end surfaces in FIG. 1 of the flange portion 312 are inside (inside the torsional damper 3) in the thickness direction (axial direction: left and right direction in FIG. 1) than both end surfaces (left and right end surfaces in FIG. 1) of the outer edge portion 311. ).

The inner peripheral diameter (inner diameter) of the outer edge 311 on the final drive 2 side is set to a value that is smaller than the outer diameter of the flange 22 of the companion flange 21 and very close to the outer diameter of the flange 22 of the companion flange 21. Has been. The flange portion 22 of the companion flange 21 is fitted into a step portion 35 formed by the inner periphery of the outer edge portion 311 on the final drive 2 side and the end surface of the flange portion 312 on the final drive 2 side.
In other words, the inner periphery of the outer edge portion 311 and the outer diameter of the flange portion 22 of the companion flange 21 constitute a so-called “in splice joint”.

Further, the flange portion 12 of the yoke flange 11 is inserted into the inner periphery 34 of the flange portion 312 of the annular member 31. The inner periphery 34 of the flange portion 312 of the annular member 31 is in contact with the outer periphery 120 of the flange portion 12.
A total of four through holes 37 of the second fastening bolt 6 are formed in the flange portion 312 of the annular member 31.

The damper holder 32 has an annular groove part 322, and the annular groove part 322 is connected to the outer edge of the central flat part 321 and the central flat part 321 and has a U-shaped cross section.
The outer peripheral portion 311 i on the left side of FIG. 1 in the outer edge portion 311 of the annular member 31 is fitted to the inner wall side 322 i of the annular groove portion 322.
A damper rubber 33 is fixed to the annular groove portion 322 by vulcanization, and the damper rubber 33 is provided to suppress torsional vibration of a propeller shaft system including a power transmission mechanism.
Reference numeral 5 in FIG. 1 indicates a nut, reference numeral 7 indicates a spring washer, and reference numeral 8 indicates a detent nut.
Moreover, the code | symbol L1 in FIG. 1 shows the center axis | shaft in case the cross joint 19 in the propeller shaft 1 is not bent. Reference numeral L2 indicates the central axis of the final drive 2.

In FIG. 2, an example in which the propeller shaft 1, the torsional damper 3, and the final drive 2 are assembled will be described with reference to FIG. 1.
For example, first, the step portion 35 in the torsional damper 3 is fitted to the outer periphery of the flange portion 22 of the companion flange 21 in the final drive 2.
In this manner, the torsional damper 3 is rotated so that the bolt through hole 37 of the torsional damper 3 and the second bolt through hole 26 of the companion flange 21 are aligned.
If the bolt holes 26 and 37 coincide with each other, the second fastening bolt 6 is inserted into the bolt through holes 26 and 37, and the female screw of the locking nut 8, for example, is connected to the male screw of the connection bolt 6 through the spring washer 7. And tighten to the proper torque.

Next, the yoke flange 11 in the propeller shaft 1 is inserted into the inner periphery 34 of the flange portion 312 of the annular member 31 in the torsional damper 3.
Then, the flange end surface 12 f of the yoke flange 11 is brought into contact with the end surface 22 f of the flange portion 22 of the companion flange 21 in the final drive 2.

If both flanges are in contact with each other, the propeller shaft 1 is rotated while the female cross serration 15 (see FIG. 1) formed on the flange portion 12 of the yoke flange 11 and the flange portion 22 of the companion flange 21 are formed. The male cross serration 25 (see FIG. 1) is engaged, and strong torque transmission between the flange portions 12 and 22 is enabled by the engagement of the cross serration.
Then, for example, the first fastening bolt 4 is inserted from the yoke flange 11 side, the female screw of the locking nut 5 is screwed with the male screw of the first fastening bolt 4, and tightened with an appropriate torque.
Thereby, the assembly work of the propeller shaft 1, the torsional damper 3, and the final drive 2 in the power transmission mechanism is completed.
Of course, the propeller shaft 1, the torsional damper 3, and the final drive 2 can be assembled in an order different from that described above.

According to the illustrated embodiment, the female cross serration 15 formed on the flange end surface 12 f of the yoke flange 11 of the propeller shaft 1 and the male cross serration 25 formed on the companion flange 21 of the final drive 2 are engaged. As a result of meshing, even a large torque such as an input torque of a truck or the like is reliably transmitted from the propeller shaft 1 to the final drive 2.
At this time, since the centering of the propeller shaft 1 and the final drive 2 is performed by the cross serrations (15, 25) meshing with each other, the central axis L1 of the propeller shaft 1 and the central axis L2 of the final drive can be easily performed. Can be matched.

Since the yoke flange 11 of the propeller shaft 1 and the companion flange 21 of the final drive 2 are directly coupled by the first connection bolt 4, the propeller shaft 1 of the torsional damper 3 is used as in the prior art of FIG. There is no need to machine cross serrations on the side.
As described above, the torque is reliably transmitted to the yoke flange 11 of the propeller shaft 1 and the companion flange 21 of the final drive 2 by the meshing of the cross serrations (15, 25). Therefore, it is sufficient for the second connection bolt 6 to prevent relative movement of the propeller shaft in the direction of the central axis L1 in the companion flange 21 and the torsional damper 3 of the final drive 2. Due to the shear strength of the second connection bolt 6, a large torque such as an input torque of a truck or the like is not transmitted.

In other words, according to the illustrated embodiment, it is not necessary to process a torque transmission cross serration on the final drive 2 side of the torsional damper 3.
Similarly, according to the illustrated embodiment, there is no need to process cross serrations on either the propeller shaft 1 side or the final drive 2 side of the torsional damper 3.

Here, also in the illustrated embodiment, the rotational fluctuation or the like due to the torsional vibration of the drive system is transmitted to the torsional damper 3 via the companion flange 21 and the second fastening bolt 6 of the final drive 2. .
Therefore, the rotational fluctuation or the like is attenuated or absorbed by the damper rubber 33 that is a vibration reducing member provided in the torsional damper 3.

  Further, according to the illustrated embodiment, the companion flange 21 of the final drive 2 is fitted to a step portion 35 formed on the final drive 2 side of the torsional damper 3 so as to form a so-called “in splice”. . That is, the torsional damper 3 can be centered by fitting the companion flange 21 of the final drive 2 to the step 35 formed on the final drive 2 side of the torsional damper 3.

  In addition, if the pitches of the first bolt through hole 24 and the second bolt through hole 26 in the companion flange 21 of the final drive 2 are the same, the companion flange of the final drive 2 with respect to the yoke flange 11 of the propeller shaft 1 is used. 21 can suppress an increase in types.

  The illustrated embodiment is merely an example, and is not intended to limit the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Propeller shaft 2 ... Final drive 3 ... Torsional damper 4 ... 1st fastening bolt 5 ... Non-rotating nut 6 ... 2nd fastening bolt 7 ... Spring washer 8 ... Detent nut 10a ... Propeller shaft body 11 ... Yoke flange 12 ... Flange part 13 ... Yoke part 14 ... Bolt through hole 15 ... Cross serration / female cross serration 21 ... companion flange 22 ... flange portion 23 ... cylindrical portion 24 ... first bolt through hole 25 ... cross serration / male cross serration 26 ... second bolt through hole 31 ... Ring member 32 ... Damper holder 33 ... Vibration reducing member / damper rubber 35 ... Step 37 ... Bolt through hole

Claims (3)

  The propeller shaft yoke flange and the final drive companion flange have a cross serration processed area, and the processed cross serrations are engaged with each other. The propeller shaft yoke flange and the final drive companion flange Is fastened by the first fastening member, the final drive companion flange and the torsional damper having the vibration reducing member are fastened by the second fastening member, and the final drive companion flange is the final of the torsional damper. A power transmission mechanism characterized by being fitted to a step portion formed on the drive side.   A through hole for passing the first fastening member is formed in the yoke flange of the propeller shaft, and a first through hole and a second hole for inserting the first fastening member are formed in the companion flange of the final drive. A second through hole for inserting the fastening member is formed, and a through hole for inserting the second fastening member is formed in a region where the vibration reducing member is not provided in the torsional damper. The power transmission mechanism according to claim 1.   The power transmission mechanism according to claim 2, wherein pitches of the first through hole and the second through hole in the companion flange of the final drive are set to be the same.

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