JP2527117B2 - Gear hitting sound generation prevention device for gear transmission - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear transmission, such as a manual transmission of an automobile, for preventing the generation of gear rattle, and more specifically, to a member on the rotating side. The present invention relates to the structure of a sliding contact surface of an elastic friction member that contacts.

[0002]

2. Description of the Related Art A transmission of an automobile has a gear that constantly rotates in conjunction with the crankshaft of an engine and a gear shaft that rotatably supports the gear, and a gear transmission composed of the gear and the gear shaft. In the device, a meshing sound is generated when idle.

As a device for preventing the generation of this mesh hitting sound, conventionally, an elastic friction member is mounted between the gear and the gear shaft, and this elastic friction member causes a proper friction between the gear and the gear shaft. , There is a device that suppresses the generation of the above-mentioned mesh hitting sound.

FIG. 8 shows a conventional example of the device for preventing the generation of the engagement hammering sound.
Shown in In the drawings, reference numeral 31 is a gear that rotates in conjunction with the crankshaft of the engine, 32 is a gear shaft that rotatably supports the gear 31, 33 is a sleeve integrally provided with the gear shaft 32, and 34 is a needle roller. Bearing, 35
Is an elastic friction member provided on the side of the needle roller bearing 34. FIG. 9 is a front view of the elastic friction member 35.

As shown in FIGS. 8 and 9, the elastic friction member 35 has a shape similar to that of a general oil seal and is fitted to a sleeve 33 which is a non-rotating member. 36 and an elastic material 37 such as rubber attached to the outer periphery of the cored bar 36. The elastic member 37 has a skirt-shaped lip 37a that is in sliding contact with the inner peripheral surface of the shaft hole of the gear 31 over substantially the entire circumference. A semicircular notch 38 is formed as a lubricant passage at several locations (four locations in the illustrated example) on the outer periphery of the lip 37a.

[0006]

The above-mentioned elastic friction member 3
No. 5 gives rotation resistance to the gear 31, thereby eliminating backlash of the gear 31 and suppressing generation of a meshing hitting sound. The lip 37a is always in contact with the inner circumferential surface of the shaft hole of the gear 31. Since they are in contact with each other, there is rotational resistance even at high speed rotation in which no meshing sound is generated, and the loss of engine power is correspondingly large, leading to an increase in fuel consumption.

Further, in the conventional elastic friction member 35, since the contact between the lip 37a and the member on the rotating side is a relatively smooth surface contact, the lubricant is scraped off from the sliding contact surface. Therefore, the oil film of the lubricant is not easily formed on the sliding contact surface. Therefore, when used in the high-speed rotation range, poor lubrication is liable to occur and abnormal heat generation and abnormal wear are likely to occur, which causes a problem in durability.

In view of the above problems, it is an object of the present invention to reduce the rotational resistance of the elastic friction member during high speed rotation and to extend the life of the elastic friction member.

[0009]

In order to achieve the above-mentioned object, the present invention is provided with an elastic friction member on the side of the bearing between a gear shaft and a gear wheel that relatively rotate through the bearing. The mesh hammering sound generation preventing device of the gear transmission has the following configuration.

In the device for preventing the generation of a mesh hitting sound of a gear transmission according to the present invention, the elastic friction member includes a core metal fitted to a non-rotating side member of the gear shaft and the gear, and the core metal integrated with the core metal. An elastic material that is provided and is in sliding contact with the member on the rotation side,
A plurality of oil grooves are formed on the sliding contact surface of the elastic material, and the oil groove has a front end in the sliding contact direction that is open to the outside of the sliding contact surface and a rear end in the sliding contact direction that is closed or has a small cross section. It was configured.

[0011]

With the rotation of the member on the rotating side, the lubricant existing outside the sliding contact surface with the elastic material is taken into the oil groove from the opening at the front end in the sliding contact direction of the oil groove, and the sliding contact surface. An oil film is formed on. In particular, at high speed rotation, the amount of lubricant taken into the oil groove increases, so the oil film formed on the sliding contact surface becomes thicker,
Friction resistance decreases.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the embodiments shown in FIGS. First, FIGS. 1 and 2 relate to a first embodiment of the present invention. FIG. 1 is a cross-sectional view of a device for preventing the generation of an engaging hitting sound, and FIG. 2 is a front view of an elastic friction member which is a part thereof.

In FIG. 1, reference numeral 1 is a gear that rotates in conjunction with the crankshaft of the engine, 2 is a gear shaft that rotatably supports the gear 1, and 3 is a sleeve integrally provided with the gear shaft 2. Reference numeral 4 is a needle roller bearing, and 5 is an elastic friction member.

The elastic friction member 5 is provided on the side of the needle roller bearing 4 between the gear 1 which is a rotating member and the sleeve 3 which is a non-rotating member, and is fitted to the sleeve 3. Core metal 6 and an elastic material 7 such as rubber attached to the outer periphery of the core metal 6. And the elastic material 7
Has a skirt-shaped lip 7a, and the lip 7a is in sliding contact with the inner peripheral surface of the shaft hole of the gear 1 over substantially the entire circumference. In FIG. 2, reference symbol D indicates the sliding contact width of the lip 7a. Semicircular notches 8 are formed as passages for the lubricant at several locations (four locations in the illustrated example) on the outer periphery of the lip 7a.

Further, the sliding contact surface of the lip 7a is formed with a plurality of oil grooves 9 for taking in a lubricant from the outside of the sliding contact surface (in the illustrated example, one for each notch 8; a total of four). Has been done. In the present embodiment, the oil groove 9 has a linear shape parallel to the sliding contact direction (a), and the front end in the sliding contact direction is opened in the notch 8 outside the sliding contact surface, and the cross-sectional area is rearward in the sliding contact direction. Has become smaller and is closed before the next notch 8.

In the above-mentioned structure, when the gear 1 rotates, the lubricant existing in the inner peripheral surface of the gear 1 corresponding to the cutout 8 of the elastic member 7 is oiled from the opening opened in the cutout 8. The oil is taken into the groove 9, fills the inside of the oil groove 9, and leaches to both sides of the oil groove 9 to form an oil film on the sliding contact surface.

When the gear 1 rotates at a high speed, the amount of the lubricant taken into the oil groove 9 increases in accordance with the rotation speed, so that the thickness of the oil film formed on the sliding contact surface is large. As a result, the sliding contact surface is kept in a fluid lubricated state, and the rotational resistance becomes extremely small.

On the other hand, when the gear 1 rotates at a low speed during idle operation, the amount of the lubricant taken into the oil groove 9 decreases, so that the oil film formed on the sliding contact surface is thin and the rotation resistance is high. growing. Due to this rotation resistance, backlash of the gear 1 is suppressed, and the generation of mesh hitting sound is suppressed.

By the way, in the first embodiment, the shape of the oil groove is a line parallel to the sliding contact direction, but the oil groove may have a shape capable of taking in and storing the lubricant from the outside of the sliding contact surface. However, specifically, it can be formed into a shape as shown in the following second to fifth embodiments. The parts other than the oil groove in the second to fifth embodiments are designated by the same reference numerals as the corresponding parts in the first embodiment, and detailed description thereof will be omitted.

3A and 3B show an elastic friction member according to the second embodiment. FIG. 3A is a half sectional view thereof, and FIG. 3B is a front view thereof. The oil groove 92 in the second embodiment is formed in a tree-like shape extending from the notch 8, and the trunk portion parallel to the sliding contact direction is in front of the next notch 8 and the branch portion. Are closed within the range of the sliding contact width D. In the oil groove 92 of this embodiment, a sufficient amount of lubricant is retained inside, and this lubricant is dispersed and leached out almost evenly throughout the sliding contact surface to form an oil film over the entire sliding contact surface. It

FIG. 4 shows an elastic friction member according to the third embodiment, (A) is a half sectional view thereof, and (B) is a front view thereof. The oil groove 93 in the third embodiment has a shape cut obliquely from the side of the leading edge of the lip 7a (right side in the drawing) to the inside of the sliding contact surface, and the cross-sectional area decreases as the distance from the leading edge of the lip 7a increases. , Is closed within the width D of the sliding contact surface. The oil groove 93 is formed in a large number between two notches 8 that are adjacent to each other in the circumferential direction. In the oil groove 93 of this embodiment, the lip 7a
The lubricant existing on the side of the leading edge is taken inside the sliding contact surface.

FIG. 5 shows an elastic friction member according to the fourth embodiment, (A) is a half sectional view thereof, and (B) is a front view thereof. The oil groove 94 in the fourth embodiment has a shape cut obliquely from the lip 7a base side (left side in the drawing) to the inside of the sliding contact surface, and the cross-sectional area becomes smaller as the distance from the lip 7a base increases, and It is closed within the width D of the contact surface. The oil groove 94 is formed in a large number between the two notches 8 that are adjacent to each other in the circumferential direction, as in the previous embodiment. Oil groove 9 of this embodiment
At 4, the lubricant present on the base side of the lip 7a is taken inside the sliding contact surface.

6A and 6B show an elastic friction member according to the fifth embodiment, FIG. 6A being a half sectional view thereof, and FIG. 6B being a front view thereof. The oil groove 95 in the fifth embodiment is composed of two sets of oil grooves 95a and 95b provided alternately along the circumferential direction. The oil groove 95a of one set has a shape in which the oil groove 95a is obliquely cut inward from the leading edge side of the lip 7a to the inside of the sliding contact surface and is closed on the opposite side within the width D of the sliding contact surface. The oil groove 95b has a shape that is cut obliquely from the lip 7a base side toward the inside of the sliding contact surface and is closed on the opposite side within the width D of the sliding contact surface. In the oil groove 95 of this embodiment, both the lubricant existing on the leading edge side of the lip 7a and the lubricant existing on the base side of the lip 7a are taken into the inside of the sliding contact surface.

In each of the above embodiments, the elastic friction member 5 fixedly mounted on the gear shaft 2 side is shown, but as shown in FIG. 7, the elastic friction member is fixedly mounted on the gear side. It is also possible to have a structure that is set.

FIG. 7 shows an elastic friction member according to the sixth embodiment, (A) is a half sectional view thereof, and (B) is a front view thereof. The elastic friction member 10 in the sixth embodiment includes a core metal 11 fitted to the inner peripheral surface of a shaft hole of a gear (not shown), and the core metal 1.
1. A skirt-shaped lip 12a made of an elastic material 12 such as rubber attached to the inner periphery of the skirt 1 and formed on the elastic material 12.
Is in sliding contact with the outer peripheral surface of the gear shaft or a member integral therewith over substantially the entire circumference. A semicircular notch 1 is provided as a passage for the lubricant at several points on the inner circumference of the lip 12a.
3 is formed, and an oil groove 14 for taking in the lubricant from the notch 13 is formed on the sliding contact surface of the lip 12a. Similar to the oil groove 9 in the first embodiment, the oil groove 14 has a linear shape parallel to the sliding contact direction, has a smaller cross-sectional area toward the rear in the sliding contact direction, and closes before the next notch 13. There is. In the elastic friction member 10 of this embodiment, the lubricant existing in the outer peripheral surface of the gear shaft side member corresponding to the notch 13 of the elastic member 12 is taken into the oil groove 14 to form a sliding contact surface. An oil film is formed on.

Also in the inner peripheral sliding contact type elastic friction member as shown in the sixth embodiment, the oil groove provided on the sliding contact surface of the lip can take in and store the lubricant from the outside of the sliding contact surface. Needless to say, it may be formed in the same shape as that shown in the second to fifth embodiments.

In each of the illustrated embodiments, the oil groove has a shape in which the rear end in the sliding contact direction is closed in the sliding contact surface, but the rear end in the sliding contact direction is not necessarily closed, and the sliding contact surface is not necessarily closed. In the oil groove having a shape penetrating through, the cross-sectional area of the rear end in the sliding contact direction may be smaller than that of the opening at the front end so as to store the lubricant therein.

[0028]

As described in detail above, according to the present invention,
Depending on the rotation speed, the lubricant is taken into the sliding contact surface to form an oil film, so the effect of suppressing the engagement noise due to friction at low speed rotation is not impeded, and at high speed rotation, a thick oil film greatly increases the rotation resistance. Can be reduced to
As a result, loss of engine power can be reduced, wear of the elastic friction member can be reduced, and durability can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an engagement hitting sound generation preventing device according to a first embodiment of the present invention.

FIG. 2 is a front view of the elastic friction member according to the first embodiment.

FIG. 3 shows an elastic friction member according to a second embodiment of the present invention,
(A) is a half sectional view thereof, and (B) is a front view.

FIG. 4 shows an elastic friction member according to a third embodiment of the present invention,
(A) is a half sectional view thereof, and (B) is a front view.

FIG. 5 shows an elastic friction member according to a fourth embodiment of the present invention,
(A) is a half sectional view thereof, and (B) is a front view.

FIG. 6 shows an elastic friction member of a fifth embodiment of the present invention,
(A) is a half sectional view thereof, and (B) is a front view.

FIG. 7 shows an elastic friction member according to a sixth embodiment of the present invention,
(A) is a half sectional view thereof, and (B) is a front view.

FIG. 8 is a cross-sectional view of a conventional meshing hitting sound generation preventing device.

FIG. 9 is a front view of the elastic friction member of the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gear 2 Gear shaft 3 Sleeve 4 Needle roller bearing 5 Elastic friction member 6 Core bar 7 Elastic material 8 Notch 9 Oil groove

Claims (1)

(57) [Claims] 1. A mesh hammering sound generation preventing device for a gear transmission, comprising: an elastic friction member on the side of the bearing between a gear shaft and a gear wheel that rotate relative to each other via the bearing. , A gear shaft and a mandrel fitted to a non-rotating member of the gear, and an elastic member integrally provided with the mandrel and slidingly contacting the rotating member. Is formed with a plurality of oil grooves, and the oil groove has a front end in the sliding contact direction which is open to the outside of the sliding contact surface, and a rear end in the sliding contact direction is closed or has a small cross section. A device for preventing the generation of meshing hit sounds in gear transmissions.