JP2002168294A - Rotary vibration prevention unit for propeller shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary vibration prevention unit for a propeller shaft capable of surely controlling twisted vibration of the propeller shaft. SOLUTION: A step portion 21c is formed in a part of a flange 21 of a differential gear, and a dynamic damper 29 formed by a vibration ring 32 as a ring- shaped mass body, a rubber material 31 as an elastic connecting body, and a sleeve 30 is pressed and installed in the step portion 21c. Further, a notch portion 32a is formed in an inner periphery of one side of the vibration ring 32, and an outer periphery of the flange portion 21b so as to retain predetermined intervals with the notch portion 32a is arranged in the notch portion 32a. As the dynamic damper 29 can be arranged between the flange 21 and a carrier of the differential gear, the dynamic damper 29 can be miniaturized and enlargement of the differential gear can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing rotational vibration of a propeller shaft applied to a differential device of an automobile.

[0002]

2. Description of the Related Art A wheel drive mechanism of an automobile is provided with a differential device so that the vehicle can run smoothly when the vehicle turns. This differential device smoothly transmits power to the left and right wheels even when the vehicle turns, in which the rotational speeds of the left and right wheels change, due to meshing of the differential gears, but also receives resistance from the road surface side via the wheels. Therefore, torsional vibration may occur on the input shaft side of the differential device during traveling. Further, since the differential device receives a reaction force from the wheels and the suspension device, there is a movement other than the rotation direction of the rotating shaft called a windup, and a whirling at a high speed rotation.

[0003] Therefore, conventionally, a rotational vibration preventing device is interposed at a connecting portion between an input shaft of a differential device and a propeller shaft. This will be described with reference to the drawings. FIG. 4 shows a layout of a drive mechanism of a rear-wheel drive vehicle. The tip of a propeller shaft 5 is connected to the output shaft 3 of the transmission 2 connected to the engine 1 via a universal joint 4. An output shaft 7 is connected to a rear end of the propeller shaft 5 via a universal joint 6, and a differential flange 9 is connected to a flange 8 attached to the output shaft 7 by a bolt (not shown).

[0004] The differential flange 9 is connected to an input shaft of a differential device 10, and the differential device 10 incorporates a differential gear inside a differential carrier 11. Output shaft 1 projecting left and right from differential carrier 11 of differential device 10
A drive wheel axle 14 is connected to the drive wheel 2 via a universal joint 13, and left and right rear wheels 16 are connected to the drive wheel axle 14 via a universal joint 15.

In such a structure, when a device for preventing rotation of a propeller shaft composed of a dynamic damper is provided, it is provided at a portion of the differential flange 9 although not shown in FIG. An outline of a conventional dynamic damper will be described with reference to FIG. The differential flange 9 includes a pipe portion 9a into which the input shaft of the differential device is inserted and a flange portion 9b. A sleeve 18 as a component of the dynamic damper 17 and a rubber material 19 (elastic material) are provided on the outer peripheral surface of the flange portion 9b. And vibrating ring 20
(Functioning as an annular mass body) are sequentially fitted and attached to the respective outer peripheral sides. Reference numeral 9c denotes a bolt insertion hole for connecting the flange portion 9b to the flange 8.

The sleeve 18 has a crank-shaped cross section, and a rubber material 19 (functioning as an elastic coupling body) is fitted to a fitting portion with the flange portion 9b and is integrally adhered. The rubber material 19 partially abuts the side surface of the base end of the rising portion rising from the fitting portion of the sleeve 18, and the rubber material 19 is formed wide on the inner peripheral side and the outer periphery thereof. The side is narrow, so that the outer peripheral portion does not always contact the rising portion of the sleeve 18. The inner peripheral side of the vibration ring 20 (which functions as an annular mass body) is connected to the outer peripheral side of the rubber member 19.

In this structure, when the propeller shaft 5 is rotated by the rotational driving force from the engine side via the transmission 2, torsional vibration acts on the differential flange 9 for the above-described reason. 9 is suppressed by the mass of the vibration ring 20 that rotates together with the vibration ring 9. If the amount of movement of the vibrating ring 20 during operation of the vibrating ring 20 becomes excessively large, there is a possibility that the vibrating ring 20 may come into contact with another member. Therefore, the shape of the sleeve 18 is made to be a complicated shape such as a crank shape, and when the axial vibration becomes excessive, the side portion of the vibration ring 20 is brought into contact with the upright portion of the sleeve 18 to regulate the position. When the radial vibration becomes excessive, the inner peripheral side of the vibrating ring 20 is placed on the sleeve 18.
The position is regulated by being in contact with the outer peripheral portion of the upright portion.

[0008]

As described above, the conventional dynamic damper can also suppress excessive movement of the vibration ring due to excessive input, but the conventional dynamic damper has a complicated sleeve shape. In addition, since the entire dynamic damper is attached to the outer peripheral surface of the flange portion of the differential flange, the size of the dynamic damper increases.

Japanese Patent Laid-Open Publication No. 3-129141 discloses a conventional rotary vibration preventing device in which a dynamic damper is provided in the vicinity of a rear joint of a propeller shaft, and a differential connecting member and a joint are provided at a weight portion of the dynamic damper. It is disclosed to provide a relief for a bolt fixing the side connection member.

Further, as another conventional rotational vibration preventing device, Japanese Patent Laid-Open Publication No. Hei 8-200444 discloses that a dynamic damper set to a different frequency is provided in a cylindrical portion of a connecting member for connecting a companion flange.
It is disclosed that vibrations are reduced by limiting a frequency range previously aimed at.

[0011] These conventional rotational vibration preventing devices can achieve predetermined objects, respectively. However, as in the present invention, the outer diameter of the dynamic damper is reduced to reduce the size of the differential device. It is not possible to simplify the shape of the components constituting the rotational vibration preventing device.

The present invention has been made in view of the above, and an object of the present invention is to provide a device for preventing rotational vibration of a propeller shaft which can reliably suppress torsional vibration of the propeller shaft.

[0013]

According to the present invention, as a means for solving the above problems, the invention described in claim 1 is provided.
In a propeller shaft rotational vibration prevention device in which a dynamic damper is interposed in a differential flange that couples an input shaft of a differential device to a propeller shaft, a step portion having a smaller diameter than a maximum diameter portion of the differential flange is formed in a part of the differential flange. A dynamic damper sleeve composed of an annular mass, an elastic coupling body and a sleeve is attached to the step, and the inner diameter of the annular mass is formed to be smaller than the maximum diameter of the differential flange. With this configuration, the dynamic damper can be arranged between the differential carrier and the differential flange, so that the rotational vibration preventing device, that is, the outer diameter of the dynamic damper is reduced, and the differential device is increased in size. To prevent that. Further, torsional vibration when the propeller shaft rotates is suppressed by an annular mass body having a sufficient weight although the outer diameter dimension is reduced.

According to a second aspect of the present invention, in the apparatus for preventing rotational vibration of a propeller shaft according to the first aspect, when the dynamic damper receives an excessively large input in the axial direction to a part of the annular mass body. It is characterized in that an axial direction restricting portion that contacts the differential flange is formed. With this configuration, even if excessive vibration in the axial direction occurs during rotation of the propeller shaft, the excessive vibration is caused by the contact between the axial restriction portion of the annular mass body and the differential flange, whereby the differential flange functions as a stopper. As a result, the elastic coupling body is prevented from being damaged, and the position of the annular mass body is appropriately maintained.

Further, according to a third aspect of the present invention, in the apparatus for preventing rotational vibration of a propeller shaft according to the first or second aspect, a dynamic damper receives a radially excessive input to a part of the annular mass body. It is characterized in that a radial restriction portion that sometimes comes into contact with the differential flange is formed. With such a configuration, even if excessive radial vibration occurs during rotation of the propeller shaft, the excessive vibration is caused by the contact between the radial restricting portion of the annular mass body and the differential flange so that the differential flange functions as a stopper. As a result, the elastic coupling body is prevented from being damaged, and the position of the annular mass body is appropriately maintained.

Further, the invention described in claim 4 is:
The rotational vibration preventing device for a propeller shaft according to any one of claims 1 to 3, wherein an annular notch is formed on an inner peripheral side of at least one side surface of the annular mass, and the notch is
The outer peripheral side of the differential flange is arranged so as to maintain a predetermined interval between the notch and the notch. With this configuration, even if excessive axial and radial vibrations occur during rotation of the propeller shaft, the excessive vibrations come into contact with the notch of the annular mass body and the differential flange so that the differential flange serves as a stopper. It functions to prevent breakage of the elastic coupling body and properly maintain the position of the annular mass.

Further, the invention described in claim 5 is:
The rotational vibration preventing device for a propeller shaft according to any one of claims 1 to 4, wherein a cross-sectional shape of the elastic connector is
The inner peripheral side and the outer peripheral side are formed thicker, and the central portion is formed thinner than the inner peripheral side and the outer peripheral side. With this configuration, when the dynamic damper receives an excessive input in the axial direction and the radial direction, the dynamic damper is easily deformed, and absorbs the excessive input.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1 which shows a state in which a rotational vibration preventing device according to the present invention is mounted on a differential device, and FIG.
A description will be given with reference to FIG. 2 showing an A section and FIG. Parts and members equivalent to those in FIGS. 4 and 5 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. The differential device 10 shown in FIGS. 1 and 2 includes a differential flange 21 bolted to a flange (see FIG. 4) of an output shaft connected to a rear end of a propeller shaft (not shown) via a universal joint. The differential flange 21 is connected to a distal end of an input shaft 23 rotatably supported via two bearings 24 inside the differential carrier 11 by a nut 22. A drive pinion gear 23 a is integrally provided at the rear end of the input shaft 23, and the drive pinion gear 23 a meshes with the ring gear 25.
The ring gear 25 is bolted to a differential case 25a.
It rotates together with a. Differential case 25a
Inside, the pinion shaft 26 is parallel to the ring gear 25.
And a pinion gear 27 is attached to both ends of the pinion shaft 26. Side gears 28 meshing with the pinion gears 27 are provided on both inner sides of the differential case 25a. The side gears 28 are spline-coupled to the output shaft 12 projecting left and right of the differential carrier 11. The rotational driving force of a propeller shaft (not shown) is provided by a differential flange 21, a drive pinion gear 23 a of an input shaft 23 to which the differential flange 21 is connected,
The power is transmitted to the output shaft 12 connected to the drive wheels via a differential case 25a coupled so as to rotate integrally with the ring gear 25, a pinion shaft 26, a pinion gear 27, and a side gear 28 provided in the differential case 25a. You.

As shown in FIG. 3, an annular stepped portion 21 having a diameter smaller than the maximum diameter portion of the differential flange 21 is provided at the boundary between the pipe portion 21a and the flange portion 21b of the differential flange 21.
The sleeve 30 of the members constituting the dynamic damper 29 is press-fitted to the step 21c. The shape of the sleeve 30 is formed in a simple cylindrical shape, and is not formed in a complicated shape like the conventional sleeve 18 shown in FIG. An inner peripheral portion of an annular rubber material 31 as an elastic connecting body is adhesively fixed to an outer peripheral surface of the sleeve 30, and a vibration ring 32 as an annular mass body is adhesively fixed to an outer peripheral side of the rubber material 31. I have.

As is apparent from FIG. 3, the cross-sectional shape of the rubber material 31 as the elastic connecting body is thicker on the inner peripheral side, becomes gradually thinner toward the outer peripheral side, and becomes thicker at the portion where the vibration ring 32 is connected. Is formed. By making the rubber material 31 have such a shape, the dynamic damper 29
Are easily deformed when receiving an excessive input in the axial direction and the radial direction, and the excessive input can be effectively absorbed.

The vibration ring 32 as an annular mass body has an inner diameter formed to be smaller than the maximum diameter portion of the differential flange 21. The cross-sectional shape of the vibration ring 32 as the annular mass body has An annular cut-out portion 32a is formed, and the cut-out portion 32a is substantially L-shaped so as to overlap the outer peripheral side of the maximum diameter portion of the differential flange 21, that is, a part of the outer peripheral surface and side surface of the flange portion 21b. Is formed. A portion of the notch portion 32a formed in the vibration ring 32, which faces the outer peripheral surface of the flange portion 21b, functions as a radial direction regulating portion.
The portion facing the side surface of 1b functions as an axial direction restricting portion.

With the vibrating ring 32 having such a shape, even if the propeller shaft 5 is torsionally vibrated during the operation of the differential device 10, the torsional vibration is effectively suppressed by the mass and inertia of the dynamic damper 29. . When an excessive input in the axial direction occurs in the dynamic damper 29 for some reason,
The notch 32a of the vibrating ring 32 abuts against the side surface of the flange 21b to suppress it, and when an excessive radial input is generated in the dynamic damper 29, the notch 32a of the vibrating ring 32 is This will be in contact with the outer peripheral surface of 21b to suppress this. In FIG. 3, reference numeral 33 denotes a dust cover that forms an labyrinth that protects the oil seal at the end of the differential carrier 11 and prevents foreign substances from entering the inside of the differential. Further, in the present embodiment, the annular cutout portion 32a is formed on the inner peripheral side of one side surface of the vibration ring 32, but the cutout portion 32a is formed on the inner peripheral side of both side surfaces of the vibration ring 32, The cross-sectional shape of the vibration ring 32 may be an inverted convex shape. Further, in the present embodiment, the annular notch 32a is formed on the inner peripheral side of one side surface of the vibration ring 32, but an annular notch may be formed on the flange 21b. In this case, it is necessary to form a bolt hole for securing a predetermined coupling force between the differential flange 21 and the propeller shaft.
Alternatively, the axial length of the differential flange needs to be increased.

[0023]

According to the first aspect of the present invention, the dynamic damper is provided in a narrow space between the differential carrier and the differential flange. Therefore, it is possible to reduce the size of the rotational vibration preventing device, thereby preventing the differential device from increasing in size. Further, since the outer diameter can be smaller than that of the conventional dynamic damper, the shape of the sleeve can be simplified, and the length in the axial direction can be reduced. Further, since the annular mass body can be arranged on the outer peripheral side of the flange portion of the differential flange, the weight (size) of the annular mass body required for vibration damping can be easily secured without being affected by a narrow mounting portion. In addition, since the shape of the annular mass body can be increased in the axial direction, the outer shape of the annular mass body can be reduced while securing necessary weight.

According to the second aspect of the invention, even if excessive vibration in the axial direction occurs during rotation of the propeller shaft, the excessive vibration is generated by the axial restricting portion of the annular mass and the differential flange, that is, the annular mass. The side surface of the flange portion functions as a stopper by contacting the axial direction restricting portion of the differential flange with the side surface of the flange portion of the differential flange, thereby preventing damage to the elastic coupling body and appropriately holding the position of the annular mass body. Becomes possible.

According to the third aspect of the present invention, even if excessive radial vibration occurs during rotation of the propeller shaft, the excessive vibration is caused by the radial restriction portion of the annular mass and the differential flange, that is, the annular mass. The outer peripheral surface of the flange portion functions as a stopper by contacting the radial direction regulating portion of the differential flange with the outer peripheral surface of the flange portion of the differential flange, thereby preventing damage to the elastic coupling body and appropriately holding the position of the annular mass body. It is possible to do.

According to the fourth aspect of the present invention, even if excessive axial and radial vibrations occur during rotation of the propeller shaft, the excessive vibrations are caused by the notch of the annular mass and the differential flange, that is, the annular shape. The notch portion of the mass body and the side surface and the outer peripheral surface of the flange portion of the differential flange come into contact with each other, so that the differential flange functions as a stopper, thereby preventing damage to the elastic coupling body and appropriately holding the position of the annular mass body. It becomes possible.

According to the fifth aspect of the present invention, when the dynamic damper receives an excessive input in the axial and radial directions, the dynamic damper is easily deformed, and the excessive input can be effectively absorbed.

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view showing a state in which a rotational vibration preventing device according to an embodiment of the present invention is mounted on a differential device.

FIG. 2 is a cross-sectional view of a portion along the line AA in FIG.

FIG. 3 is an enlarged schematic cross-sectional view of the rotational vibration preventing device shown in FIGS. 1 and 2;

FIG. 4 is an explanatory diagram showing a layout of a drive mechanism of a rear-wheel drive vehicle.

FIG. 5 is a cross-sectional view schematically illustrating a conventional rotational vibration preventing device.

[Explanation of symbols]

 Reference Signs List 5 propeller shaft 10 differential device 11 differential carrier 12 output shaft 21 differential flange 21c step 29 dynamic damper 30 sleeve 31 elastic coupling body (rubber material) 32 annular mass body (vibration ring)

Claims (5)

[Claims] An apparatus for preventing rotation of a propeller shaft in which a dynamic damper is interposed in a differential flange connecting an input shaft of a differential device to a propeller shaft, wherein a part of the differential flange has a step having a diameter smaller than a maximum diameter part of the differential flange. A portion of the dynamic mass damper, comprising an annular mass, an elastic coupling body and a sleeve, is attached to the step, and the inner diameter of the annular mass is formed to be smaller than the maximum diameter portion of the differential flange. A device for preventing rotational vibration of a propeller shaft. 2. The propeller according to claim 1, wherein an axial direction restricting portion that comes into contact with a differential flange when the dynamic damper receives an excessive input in the axial direction is formed in a part of the annular mass body. Shaft rotational vibration prevention device. 3. A part of the annular mass body, wherein a radial direction restricting portion which comes into contact with a differential flange when the dynamic damper receives an excessive radial input is formed. Rotary vibration prevention device for propeller shaft. 4. An annular notch is formed on the inner peripheral side of at least one side surface of the annular mass body, and a notch of the differential flange is formed in the notch so as to maintain a predetermined interval between the notch and the notch. The device according to any one of claims 1 to 3, wherein the outer peripheral side is disposed. 5. The cross-sectional shape of the elastic connector according to claim 1, wherein the inner peripheral side and the outer peripheral side are thicker and the central part is thinner than the inner peripheral side and the outer peripheral side. The device for preventing rotation of a propeller shaft according to the above.