JPH0738736Y2 - Centering bush - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an improvement in a centering bush used in a portion connecting a propeller shaft and an output shaft of a transmission in a drive system of an automobile or the like.

[Conventional technology]

BACKGROUND ART Conventionally, in a drive system of an automobile, a flexible coupling or a Tilger (dynamic) is provided at a connection portion between a propeller shaft and an output shaft of a transmission so as not to transmit a runout vibration generated on the propeller shaft side to the output shaft side. In addition to mounting a vibration absorber), a centering bush as shown in FIG. 3 is mounted for the purpose of suppressing mutual shaft runout between the propeller shaft and the output shaft.

In FIG. 3, reference numeral (21) is an outer sleeve concentrically fixed to the propeller shaft side, and (22) is an inner sleeve slidably inserted through an output shaft (26) of the transmission. An elastic body (23) made of rubber is vulcanized and bonded between the sleeves (21) and (22) with the (21) and (22) being positioned concentrically. Grease (not shown) is filled in the bush to make the sliding of the output shaft (26) and the inner sleeve (22) smooth, and the end of the output shaft (26) is sealed to seal the grease. Cap on (2
4) has a seal lip (25) on the base side.

If the inner peripheral surface of the inner sleeve (22) has chamfered portions at both axial ends, the entire inner surface of the inner sleeve (22) is molded into a cylindrical surface parallel to the axis, excluding the chamfered portions. The outer peripheral surface of the inner sleeve (22) is formed in a substantially mountain-shaped cross-section with taper on both sides in the axial direction, and the interval between the maximum outer diameter portion at the axial center and the inner peripheral surface of the outer sleeve (21) is sandwiched. The spring constant in the radial direction is set higher.

[Problems to be solved by the device]

The centering bush is the inner sleeve (22).
Is slidably fitted over the output shaft (26) to allow axial displacement of the propeller shaft and the output shaft (26) to some extent, and the elasticity of the elastic body (23) is used to make the shaft and the output shaft (26) )
The shaft runout of the shaft is prevented, but the relative relationship between this shaft and the output shaft (26) may cause the output shaft (26) to twist as shown by the arrow in FIG. The following problems have been pointed out regarding the effect on the.

That is, the centering bush responds to the twisting movement of the output shaft (26) by the deformation of the elastic body (23), but the elastic body (23) is the inner sleeve (22).
It operates (deforms) only in the degree of freedom area of only the minimum thickness part (23a) between the maximum outer diameter part and the outer sleeve (21). Since this area is narrow, it is possible to start early even when the prying angle is shallow. The deformation limit is reached, and the elastic body (2
8) may be damaged.

[Means for Solving the Problems]

In view of the above points, the present invention has been devised to solve the problems found in the above-mentioned prior art. In order to achieve this object, first, as shown in the first claim, two shafts are provided. In a centering bush that secures the concentricity of the outer sleeve, an outer sleeve that is concentrically fixed to one of the shafts, and two intermediate sleeves that are fitted to the inner peripheral side of the outer sleeve and are axially separated from each other. A sleeve and a spacer ring fitted on the inner peripheral side of the outer sleeve and arranged between the two intermediate sleeves, and slidably inserted through the other shaft on the inner periphery of the spacer ring. An inner sleeve, and an annular rubber-like elastic body connecting each of the intermediate sleeves and the inner sleeve,
A convex spherical surface that slidably contacts the inner peripheral surface of the spacer ring is formed on the outer peripheral surface of the inner sleeve, and the spacer ring, the inner sleeve, and either one of the rubber are formed on the inner peripheral side of the spacer ring. We decided to set two annular spaces surrounded by the elastic body.

The centering bush according to the second aspect is characterized in that, in addition to the structure of the first aspect, a concave spherical surface corresponding to the convex spherical surface of the inner sleeve is formed on the inner peripheral surface of the spacer ring. .

A centering bush according to a third aspect is characterized in that, in addition to the configuration of the first aspect, grease is sealed in the annular space.

A centering bush according to a fourth aspect of the present invention is characterized in that, in the third aspect, a communication hole is formed in the inner sleeve for guiding the grease to the inner peripheral side of the inner sleeve.

[Action]

In the centering bush according to the first aspect, the inner sleeve driven by the output shaft (the other shaft) is brought into sliding contact with the spacer ring fitted to the outer sleeve, thereby ensuring the concentricity during the prying movement of the output shaft. The outer peripheral surface of the inner sleeve, which is in sliding contact with the spacer ring, is formed in a spherical shape so as to be easily in sliding contact. The spacer ring is only interposed between the outer sleeve that is attached to (one shaft) of the propeller shaft and the inner sleeve that inserts the output shaft, and since there is no rubber as in the past, concentric accuracy is more reliable. Secure. Since the intermediate sleeves are arranged on both sides in the axial direction of the spacer ring, and each of the intermediate sleeves and the inner sleeve are connected by the annular rubber-like elastic body, the spacer ring and the inner sleeve are attached to the inner circumference of the spacer ring. An annular space surrounded by the sleeve and one of the rubber-like elastic bodies is set, and the existence of this space makes the movement of the inner sleeve extremely smooth.

In the centering bush according to the second aspect of the present invention, a concave spherical surface corresponding to the convex spherical surface of the inner sleeve is formed on the inner peripheral surface of the spacer ring to make the sliding contact of both parts smoother.

In the centering bush according to the third aspect of the present invention, lubricating grease is enclosed in the annular space to make the sliding contact between the spacer ring and the inner sleeve smoother.

In the centering bush according to the fourth aspect of the present invention, the inner sleeve is formed with a communication hole for guiding the grease to the inner peripheral side of the inner sleeve, so that the inner sleeve and the output shaft slide smoothly.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.
The centering bush shown in FIG. 1 is fitted to the outer sleeve (1) which is concentrically fixed to the propeller shaft side, and is fitted to the inner peripheral side of the outer sleeve (1) and is arranged so as to be axially separated from each other. Two intermediate sleeves (2)
(3), a spacer ring (4) fitted on the inner peripheral side of the outer sleeve (1) and arranged between the two intermediate sleeves (2) and (3), and the spacer ring (4). ), An inner sleeve (5) slidably inserted through the output shaft of the transmission, and an annular rubber shape in which each of the intermediate sleeves (2) and (3) and the inner sleeve (5) are connected. An elastic body (6) (7) is provided, and an annular sliding contact protrusion (5a) is provided on the outer peripheral side of the inner sleeve (5), and the outer peripheral surface thereof slides on the inner peripheral surface of the spacer ring (4). A convex spherical surface (5
b) is formed and is surrounded by the spacer ring (4), the inner sleeve (5) and one of the rubber-like elastic bodies (6) and (7) on the inner peripheral side of the spacer ring (4).
Two annular spaces (8) and (9) are set, and an inner sleeve (5) is further provided on the inner peripheral surface of the spacer ring (4).
A concave spherical surface (4a) corresponding to the convex spherical surface (5b) is formed, and lubricating grease (not shown) is enclosed in each of the annular spaces (8) and (9). Spacer ring (4)
The inner sleeve (5) and the inner sleeve (5) are made of the same or different metal or resin, and the centers of the spherical surfaces (4a), (5b) are aligned with the center (0) of the twisting motion of the output shaft. (10) is a cap, (11) is a seal lip integrated with one elastic body (6), and a step portion (1a) for positioning is formed on the inner peripheral surface of the outer sleeve (1). The spacer ring (4) is split in two or with slits.

The centering bush slides the outer peripheral surface of the inner sleeve (5) formed in a spherical surface (4a) (5b) shape against the inner peripheral surface of the spacer ring (4) in response to the input of the twisting motion, Since the rubber material (elastic body) is not elastically deformed with respect to the radial load unlike the prior art, it is possible to provide an excellent product which is not damaged and has high reliability and which can easily secure the concentricity. The inner sleeve (5) can be moved smoothly by setting the annular spaces (8) and (9) and enclosing grease in the spaces (8) and (9). Further, as shown in FIG. 2, in the inner sleeve (5), a communication hole (12) for guiding a part of the grease enclosed in the annular spaces (8) and (9) to the inner peripheral surface side of the inner sleeve (5). ) Is formed, the inner sleeve (5) is formed.
The sliding contact between the output shaft and the output shaft can be smoothed. It is desirable that a plurality of communication holes (12) be evenly arranged.

[Effect of device]

As described above, according to the centering bush of the present invention, there is no fear that the elastic body will be damaged, the follow-up performance with respect to the prying motion is improved, the concentricity is easily ensured, and the sliding portion is smoothly operated. be able to.

[Brief description of drawings]

1 is a half cutaway view of a centering bush according to an embodiment of the present invention, FIG. 2 is a half cutaway view of a centering bush according to another embodiment of the present invention, and FIG. 3 is a cross section of a centering bush according to a conventional example. It is a figure. (1) …… Outer sleeve, (1a) …… Step (2) (3) …… Intermediate sleeve, (4) …… Spacer ring (4a) …… Concave spherical surface, (5) …… Inner sleeve (5a ) …… Sliding contact protrusion, (5b) …… Convex spherical surface (6) (7) …… Rubber-like elastic body, (8) (9) …… annular space (10) …… Cap, (11) …… Seal lip (12) …… Communication hole

Claims (4)

[Scope of utility model registration request] 1. A centering bush for ensuring the concentricity of two shafts, an outer sleeve (1) fixed concentrically to one shaft, and the outer sleeve (1).
Two intermediate sleeves (2) and (3) fitted to the inner peripheral side of the outer sleeve (1) and axially separated from each other, and fitted to the inner peripheral side of the outer sleeve (1), And a spacer ring (4) arranged between the intermediate sleeves (2) and (3), and an inner sleeve (5) that is slidably inserted through the other shaft on the inner circumference of the spacer ring (4).
And an annular rubber-like elastic body (6) (7) connecting the inner sleeve (5) with each of the intermediate sleeves (2) and (3), and the inner sleeve (5)
A convex spherical surface (5b) slidably contacting the inner peripheral surface of the spacer ring (4) is formed on the outer peripheral surface of the spacer ring (4), and the spacer ring (4) is formed on the inner peripheral side of the spacer ring (4). ,
Two annular spaces (8) (9) surrounded by the inner sleeve (5) and one of the rubber-like elastic bodies (6) (7)
Centering bush characterized by being set. 2. A concave spherical surface (4a) corresponding to the convex spherical surface (5b) of the inner sleeve (5) is formed on the inner peripheral surface of the spacer ring (4). Centering bush described in paragraph. 3. The centering bush according to claim 1, wherein grease is filled in the annular spaces (8) (9). 4. The centering bush according to claim 3, wherein the inner sleeve (5) is formed with a communication hole (12) for guiding the grease to the inner peripheral side of the inner sleeve (5).