JP5863038B2 - Friction damper - Google Patents

Description

  The present invention relates to a friction damper, and more particularly to a friction damper that reduces gear rattling noise in a gear transmission such as an automobile transmission.

As this type of friction damper, a structure shown in FIGS. 5 and 6 is known. (Patent Document 1)
That is, this type of friction damper is integrally formed with a mounting ring 400 made of a metal material having an L-shaped cross section, which is fitted and fixed to one of a gear shaft and a gear that rotate relative to each other via a bearing (not shown). The lip 500 is made of a rubber-like elastic material that opens in a conical shape and is in sliding contact with the other peripheral surface of the gear shaft.
Then, four oil grooves 510 are formed on the sliding surface of the lip 500 at equal intervals on the circumference.
Further, both end surfaces 5110 and 5120 parallel to the axis forming the oil groove 510 exist in a form orthogonal to the sliding surface of the lip 500.

  A friction damper lip 500 fitted and fixed to one of the gear shaft and the gear rotating relative to each other is slidably brought into contact with the other peripheral surface of the gear shaft and the gear to generate friction. Gear backlash is suppressed by the input of idling vibration, torsional vibration of the crankshaft, etc., and the rattling noise is reduced.

  This type of friction damper mainly requires high friction in order to suppress backlash and reduce rattling noise in a low speed region (which can be said to be a low gear, for example, a region where gear side rotation is fast such as 1st to 2nd gears). However, in a high speed region (a region that can be said to be a high gear, for example, a region in which the rotation on the shaft side is fast, such as 3rd speed or higher), low friction is required to improve fuel efficiency.

However, with this type of conventional friction damper, it has been difficult to achieve both high friction in the low speed range and low friction in the high speed range.
This is presumably because both end surfaces 5110 and 5120 parallel to the axis forming the oil groove 510 are symmetrical and exist in a shape perpendicular to the sliding surface of the lip 500.

JP 2006-46447 A

  In view of the above-described circumstances, an object of the present invention is to provide a friction damper capable of achieving both high friction in a low speed region and low friction in a high speed region.

  In order to achieve the above object, in the present invention, a gear shaft that relatively rotates via a bearing and a mounting ring that is fitted and fixed to one of the gears, and a gear ring that is integrally formed with the mounting ring, the gear shaft and the gear. An axis that forms the oil groove in a friction damper that is formed of a rubber-like elastic material lip that is in sliding contact with the other peripheral surface of the lip, and has a plurality of oil grooves formed on the sliding surface of the lip. One of the corners of both end faces parallel to the surface of the lip is a gentle inclined surface with respect to the peripheral surface of the lip as compared with the other.

The present invention has the following effects.
According to the friction damper of the first aspect of the present invention, one of the corners of both end faces parallel to the axis forming the oil groove is a gently inclined surface with respect to the lip circumferential surface as compared with the other. Therefore, both high friction in the low speed range and low friction in the high speed range can be achieved.
According to the friction damper of the second aspect of the present invention, since the inclined surface is formed as a gentle flat surface with respect to the peripheral surface of the lip, along the inclined surface formed as a flat surface at a high speed range. Since oil is smoothly supplied to the lip sliding surface, low friction can be achieved at high speeds.

Furthermore, according to the friction damper of the third aspect of the present invention, since the inclined surface is formed with a gentle curved surface with respect to the lip peripheral surface, the oil is formed along the inclined surface formed with the curved surface at a high speed range. Is smoothly supplied to the lip sliding surface, so that low friction in a high speed range can be achieved.
According to the friction damper of the fourth aspect of the invention, since the other end surface is a flat surface orthogonal to the lip peripheral surface, high friction in a low speed region can be achieved.

  Further, according to the friction damper of the invention described in claim 5, since the inclined surface is formed on the end surface located on the opposite side to the rotation direction of the both end surfaces, the oil is forcibly forced by the rotational force. Therefore, low friction in the high speed range can be reliably achieved.

The front view which showed the 1st aspect of the friction damper which concerns on this invention. The top view of FIG. FIG. 2 is a partial half sectional view showing a state in which the friction damper shown in FIG. 1 is mounted on a gear transmission device. The figure which showed the 2nd aspect of the friction damper which concerns on this invention similarly to FIG. The figure which showed the cross section which cut | disconnected the friction damper which concerns on a prior art in the plane which passes along an axial center in the upper half, and showed the side surface in the lower half. FIG. 6 is a front view showing the friction damper of FIG. 5 without cutting.

Hereinafter, the best mode for carrying out the present invention will be described.
A first embodiment for carrying out the invention will be described with reference to FIGS. 1 to 3.

  As shown in FIG. 3, the friction damper according to the present invention includes a mounting ring 4 made of a metal material having an L-shaped cross section, which is fitted and fixed to the gear shaft 2 side that rotates relative to each other via a bearing 1, and the mounting ring. 4 and a lip 5 made of a rubber-like elastic material that is formed in a conical shape and is in sliding contact with the inner peripheral surface of the gear 3.

The friction damper according to the present invention is interposed, for example, between the sleeve 21 of the gear shaft 2 and the gear 3 in a transmission of an automobile.
In this transmission, the gear 3 rotates in conjunction with a crankshaft of an automobile engine (not shown) and is supported on the outer periphery of the sleeve 21 of the gear shaft 2 through a bearing 1 that is a needle roller bearing so as to be relatively rotatable. Has been.
The friction damper is disposed outside the needle roller bearing in the axial direction.

Specifically, the cylindrical portion of the mounting ring 4 is press-fitted to the outer peripheral surface of the sleeve 21.
The elastic material lip 5 fixed to the gear shaft 2 side (sleeve 21) via the mounting ring 4 has the outer peripheral portion slightly compressed in the radial direction, and the inner peripheral surface of the gear 3. It is closely slidable.

Therefore, when the gear shaft 2 and the gear 3 are repeatedly relatively displaced in the circumferential direction by the engine idling vibration or the vibration input from the crankshaft, the lip 5 fixed to the gear shaft 2 side (sleeve 21) is Along with this, it repeatedly slides in the circumferential direction with the inner peripheral surface of the gear 2 to generate friction.
For this reason, backlash can be suppressed and the gear rattling sound of the gear 3 can be effectively reduced.

The lip 5 has four oil grooves 51 formed on the sliding surface thereof at equal intervals on the circumference.
In the oil groove 51, one of the corners of both end faces 511 and 512 parallel to the axis forming the oil groove 51 is a gently inclined surface X with respect to the circumferential surface of the lip 5 as compared with the other. ing.
In the present embodiment, the inclined surface X is formed as a flat surface, and as shown in FIG. 1, is a flat surface extending in a tangential direction from the bottom of the oil groove 51 to the left side in the drawing.

Since such a configuration is adopted, oil is smoothly supplied to the sliding surface of the lip 5 along the inclined surface X formed as a flat surface in a high speed region, so that low friction in the high speed region can be achieved. .
On the other hand, the other end surface 512 is a flat surface orthogonal to the peripheral surface of the lip 5. The corner portion of the end surface 512 is slightly chamfered.
For this reason, when backlash acts, the other end surface 512 prevents oil from being excessively supplied to the sliding surface of the lip 5, so that high friction can be obtained.

  In this way, one of the corners of both end faces 511 and 512 parallel to the axis forming the oil groove 51 has an asymmetric shape with a gentle inclined surface X with respect to the peripheral surface of the lip 5 as compared with the other. Therefore, it has been possible to achieve both high friction in the low speed range and low friction in the high speed range.

In the present embodiment, the number of the oil grooves 51 is four, but two or more oil grooves 51 may be used, and various configurations of the oil grooves 51 can be employed.
Further, the inclined surface X is formed on an end surface 511 located on the opposite side to the rotational direction of the both end surfaces 511 and 512.

That is, assuming that the friction damper is attached to the gear shaft in the state of FIG. 1, the gear rotates in the clockwise direction (right side in the figure).
By this, since the inclined surface X is formed on the end surface 511 located on the opposite side to the rotational direction of the both end surfaces 511, 512, oil is forcibly supplied to the lip sliding surface by the rotational force. Low friction at high speeds can be reliably achieved.

  As described above, in the above configuration, when the gear 3 rotates, the oil existing in the portion corresponding to the oil groove 51 of the lip 5 on the inner peripheral surface of the gear 3 is taken into the oil groove 51, and the oil groove 51. The oil fills the inside and leaches out on both sides of the oil groove 51 to form an oil film on the sliding contact surface.

  When the gear 3 rotates at a high speed, the amount of oil taken in along the inclined surface X of the oil groove 51 increases according to the rotation speed, so that the film thickness of the oil film formed on the slidable contact surface of the lip 5 is thick. Due to the thick oil film, the sliding contact surface is maintained in a fluid lubrication state, and the rotational resistance becomes extremely small.

  On the other hand, when the gear 3 rotates at a low speed during idle operation, the amount of oil taken into the oil groove 51 is reduced, so that the oil film formed on the sliding surface of the lip 5 is thin and the rotation resistance is increased. .

In particular, the other end surface 512 is a flat surface orthogonal to the peripheral surface of the lip 5. And since the corner | angular part of this end surface 512 is only given some chamfering, the oil film which can be made into the lip 5 sliding contact surface becomes thin, and high friction is obtained.
And by this rotation resistance, the backlash of the gear 3 is suppressed and generation | occurrence | production of a meshing hitting sound is suppressed.

Next, a second mode for carrying out the invention will be described with reference to FIG.
The difference from the first embodiment described above is that the inclined surface X is formed of a curved surface.
As a result, the inclined surface X is formed with a gently curved surface with respect to the peripheral surface of the lip, so that oil is smoothly supplied to the lip sliding surface along the inclined surface X formed with the curved surface at a high speed. Therefore, low friction at high speed can be achieved.

  Further, the present invention is not limited to the best mode for carrying out the invention described above, and various other configurations can be adopted without departing from the gist of the present invention.

  It is suitably used for gear transmissions such as automobile transmissions.

1 Bearing 2 Gear Shaft 3 Gear 4 Mounting Ring 5 Lip 51 Oil Groove 511 End Face 512 End Face

Claims (5)

A gear shaft (2) that rotates relative to the bearing (1) and a mounting ring (4) that is fitted and fixed to one of the gears (3), and the gear shaft (4) are integrally formed with the mounting ring (4). 2) and a lip (5) made of rubber-like elastic material that is in sliding contact with the other peripheral surface of the gear (3), and a plurality of oil grooves (51) are formed on the sliding surface of the lip (5). In the friction damper that formed
One of the corners of both end faces (511) and (512) parallel to the axis forming the oil groove (51) is a gentle inclined surface with respect to the peripheral surface of the lip (5) compared to the other ( X) is a friction damper.   The friction damper according to claim 1, wherein the inclined surface (X) is formed as a flat surface.   The friction damper according to claim 1, wherein the inclined surface (X) is a curved surface.   The friction damper according to any one of claims 1 to 3, wherein the other end surface (512) is a flat surface orthogonal to the peripheral surface of the lip (5).     The friction damper, wherein the inclined surface (X) is formed on the end surface (511) located on the opposite side to the rotational direction of the both end surfaces (511), (512).

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