JPH0410084Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a wheel structure that can supply air into a rotating tire, and more specifically, a device that can improve the sealing performance around the air path. It is related to.

<Prior Art> In automobiles and the like, it is desirable to change the air pressure of tires according to road surface conditions. In order to satisfy such demands, for example,
As seen in Publication No. 67504, a system has been proposed in which air can be supplied to the tires even while the automobile is running while the tires are rotating.

The above-mentioned conventional examples disclose various configurations related to air supply means, but in particular, the seal structure of the air supply passage has a complicated structure, has a large number of parts, and is difficult to assemble. There were flaws.

That is, FIG. 3 shows the above conventional example, in which a hub 1 on which a tire 2 is mounted is connected to a rotational drive source (not shown) via a drive flange 3 and an axle 4, and is rotationally driven. Note that the hub 2 is rotatably attached to a shaft body 5 fixed to a chassis 6, for example, via bearings 7 and 8.

Further, while forming a cavity 9 in the hub 1,
An air passage 10 is formed in the shaft body 5, and the cavity 9
is opened in the inner circumferential surface of the hub 1, and an opening 11 opposite to the opening of the cavity 9 is formed in the shaft body 5, so that the air passage 10 is
is maintained in communication with the cavity 9. Then, a pipe joint 12 communicating with an air supply source (not shown) is connected to the air passage 10, and a shutoff valve 13, a tire inlet valve stem 14, and a pipe line 15 are connected between the outlet of the cavity 9 of the hub 1 and the inside of the tire 2. By communicating through the tire 2, air in the cavity 9 can be supplied into the tire 2.

On the other hand, a seal structure shown in FIG. 4 is provided between the inner periphery of the hub 1 and the shaft body 5 to prevent air leakage from the cavity 9.

That is, as shown in FIG.
A sealing member 19 is installed between both shoulder parts 16 and the snap ring 17 by fitting the snap springs 17 into the grooves 18 formed on the outside of the shoulder parts 16. There is.

The sealing member 19 has a lip 21 that is attached to the inner peripheral edge of a main body 24 that is an annular body having an L-shaped cross section, and has a tip 20 in sliding contact with the outer peripheral surface of the shaft body 5.
and seal rings 22, 2 made of an elastic body that cover the side surface of the main body 24 that contacts the snap spring 17 and the outer peripheral surface of the main body 24 that contacts the inner peripheral surface of the hub 1.
3, the lip 21 is provided with the shaft body 5.
At the same time, the seal rings 22 and 23 are used to seal between the hub 1 and the hub 1. Reference numeral 25 denotes a garter spring that presses and holds the tip 20 of the lip 21 against the outer peripheral surface of the shaft body 5.

In the wheel structure of the bearing configured in this way, shoulders 1 are provided on both sides of the opening of the cavity 9.
6, and then a sealing member 1 is inserted between this shoulder portion 16 and a snap spring 17 fitted on the outside thereof.
9, the configuration becomes complicated and the number of parts and assembly steps increase. Furthermore, as in the above conventional example, the seal member 19
When sealing between the sealing member 19 and the hub 1 is achieved by covering the side surfaces and outer peripheral surface of the main body 24 with seal rings 22 and 23, respectively, the seal ring 23 is press-fitted onto the inner periphery of the hub 1. Since it is necessary to compress and deform this seal ring 23 to ensure sealing performance, it is necessary to make the dimensional accuracy of the inner diameter of the hub 1 and the outer diameter of the seal member 19 (seal ring 23) sufficiently high. With,
This makes it difficult to attach and detach the seal member 19.

Furthermore, in the above conventional example, the seal member 1
In order to prevent deterioration of the sealing performance due to the inclination of the seal member 9, it is necessary to strictly control the fit between the seal member 19 and the hub 1 at the expense of the ease of attaching and detaching the seal member 19, or at the expense of space. There is a need to increase the width (axial length) of the seal member 19, or there is a need to strictly control the mounting position of the snap spring 17 to ensure that the seal member 19 is held between the shoulder portion 16 and the snap spring 17. Therefore, there was a problem in that the manufacturing cost increased in any case.

<Problems to be solved by the invention> The present invention was made in order to solve the above-mentioned problems of the conventional example, and provides a wheel structure with a simple structure that can be easily manufactured without impairing the sealing performance of the passage that supplies air to the tire. The challenge is to provide the following.

<Means for Solving the Problems> In order to solve the above problems, the present invention has a pair of snap springs fitted on the inner peripheral surface of the hub at positions sandwiching the cavity opening, and the hub sandwiched between the two snap springs. The reduced stepped portion is configured by making the inner diameter smaller than the other portions. Further, a frame body covering the opening of the cavity is inserted into the reduction stepped portion. The frame body is constituted by an annular body having a U-shaped cross section and opening inward.

On the other hand, a pair of lips that are pressed against the outer peripheral surface of the shaft body are attached to the inner peripheral edge of the frame body, and an opening is provided on the outer peripheral surface of the shaft body sandwiched between the two lips, so that the air passage is connected to the frame body. communicate with the inside. The cavity and the inside of the frame are communicated through a hole provided in the frame, and an O is pressed against the outer circumferential surface of the shaft.
A sealing member between the cavity formed in the hub and the air passage formed in the shaft body is constructed by attaching a ring to the reduced stepped part with the opening of the cavity in between.

<Function> In the above configuration, the lip attached to the inner peripheral edge of the frame seals between the frame and the shaft, and the O-ring attached to the reduced stepped portion of the hub seals between the hub and the frame. to seal.

Therefore, there is no need to increase the dimensional accuracy of the reduced stepped portion of the hub and the frame to fit the frame into the reduced stepped portion of the hub, and even if the frame is inserted loosely, the O
Since the ring has a sealing effect, the workability of attaching and detaching the frame is improved. In addition, the two-point support effect of the pair of O-rings prevents the frame from tilting.
There is no need to clamp the frame with a snap spring, etc. as in the past, and the desired purpose can be achieved by preventing the frame from coming off with a pair of snap springs, so the workability of attaching and detaching the snap spring has also been improved. be done.

<Example> An example of the present invention will be described below in detail based on FIGS. 1 and 2. Note that parts having the same functions as those of the conventional example shown in FIG. 3 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

In these figures, a cavity 9 formed in the hub 1 is open to the inner peripheral surface of the hub 1. hub 1
A pair of snap springs 27 are fitted onto the inner peripheral surface of the cavity 9 with the opening of the cavity 9 interposed therebetween. The inner circumferential surface of the hub 1 sandwiched between these snap springs 27 is made smaller in diameter than other portions to form a reduced stepped portion 26. The movement of the sealing member 28 inserted into the reduced stepped portion 26 in the axial direction is restricted by the pair of snap springs 27, and the gap between the opening of the cavity 9 and the opening 11 of the air passage 10 formed in the shaft body 5 is adjusted. This is to prevent air leakage from the

The sealing member 28 includes a frame 29 formed of a ring having a U-shaped cross section and opening inward;
A lip 30 attached to the inner peripheral edge of this frame 29
It is made up of. Further, the outer diameter of the frame 29 that is inserted into the reduced stepped part 26 and covers the opening of the cavity 9 is made slightly smaller than the inner diameter of the reduced stepped part 26, so that the sealing member 28 (frame body 29) is reduced in size. By providing a hole 33 in the outer peripheral portion of the frame 29, the hole 33 can be easily attached to and removed from the frame 26.
The cavity 9 is maintained in communication with the inside of the frame body 29 via. Note that the hole 33 may be a long hole.

On the other hand, the lip 3 attached to the inner peripheral edge of the frame 29
0 is held in pressure contact with the outer circumferential surface of the shaft body 5 by the pressing force of the garter spring 31 at a position across the opening 11 of the air passage 10 provided in the shaft body 5, and the shaft body 5 and the sealing member 28 (frame body 29 ).

Ring grooves are provided at positions across the opening of the cavity 9 in the reduced stepped portion 26, and an O-ring 32 is attached to the ring groove, so that the O-ring 32 is pressed against the outer peripheral surface of the frame 29. This seals the space between the reduced stepped portion 26 and the frame body 29.

In the above configuration, the air supplied to the air passage 10 of the shaft body 5 is transferred from the opening 11 to the sealing member 28.
(the frame body 29) and flows from the inside of the sealing member 28 through the hole 33 provided in the frame body 29 into the cavity 9.
from this cavity 9 to the tire side. Note that a lip 30 seals between the shaft body 5 and the frame 29 of the seal member 28, and an O-ring 32 seals between the reduced stepped portion 26 of the hub 1 and the frame 29 of the seal member 28. Because of this, no air leaks occur.

Furthermore, a pair of lips 3 on the sealing member 28
0 are integrated through a frame 29, and this frame 29 is supported at two points by a pair of O-rings 32 attached at positions sandwiching the opening of the cavity 9. Therefore, even if the frame 29 of the seal member 28 is loosely fitted into the reduced stepped portion 26, the seal member 28 will not tilt.
A good sealing effect is achieved.

Therefore, there is no need to strictly control the fit between the seal member and the hub as in the past, or
There is no need to increase the width (axial length) of the seal member at the expense of space, or there is no need to prevent the seal member from tilting with a snap spring, and the diameter is smaller than other parts. Since the frame 29 of the seal member 28 is inserted into the stepped portion 26, the seal member 28 and the snap ring 27 can be easily attached and detached.

Note that when assembling the seal member 28, after installing the O-ring 32 in the ring groove provided in the reduced stepped portion 26, attach one of the snap springs 27.
Install. Then, move the seal member 2 to the position where it abuts the previously installed snap spring 27.
8 into the reduced stepped portion 26 and the O-ring 32 is brought into contact with the outer peripheral surface of the frame 29 of the seal member 28, the other snap spring 27 may be attached to prevent the seal member 28 from being attached or detached.

<Effects of the invention> As is clear from the above explanation, according to the invention, a pair of lips are integrated through a frame body supported at two points by O-rings, so that no air is trapped in the tire. The number of seal parts can be reduced and the structure can be simplified to improve manufacturability without impairing the sealing performance of the passage that supplies the gas.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of essential parts showing an embodiment of the present invention, FIG. 2 is a cross-sectional view showing the overall configuration of an embodiment of the present invention, FIG. 3 is a cross-sectional view of a conventional example, and FIG. The figure is a sectional view of a conventional seal portion. 1...Hub, 2...Tire, 5...Shaft body, 7,
8...Bearing, 9...Cavity, 10...Air passage, 1
DESCRIPTION OF SYMBOLS 1...Opening, 26...Reduction stepped part, 27...Snat spring, 28...Sealing member, 29...Frame body, 30...Lip, 31...Garter spring, 32
...O-ring, 33...hole.

Claims (1)

[Scope of utility model registration request] A wheel structure in which a hub on which a tire is attached is pivotally attached to a stationary shaft body, and a cavity formed in the hub communicates with an air passage formed in the shaft body to supply air to the tire. A pair of snap springs fitted on the inner circumferential surface of a hub with a hollow opening sandwiched between the hollow opening, and a reduced stepped part configured by making the inner diameter of the hub sandwiched between both snap springs smaller than other parts. and a frame body constituted by a ring body having a U-shaped cross section that is inserted into the reduced stepped portion to cover the opening of the cavity and open inward;
A pair of lips are attached to the inner peripheral edge of the frame and pressed against the outer peripheral surface of the shaft, and a lip is provided on the outer peripheral surface of the shaft sandwiched between the lips to direct the air passage inside the frame. a hole provided in the frame body so as to communicate the cavity with the inside of the frame body, and a hole provided in the frame body so as to communicate the cavity with the inside of the frame body, which is attached to the reduced stepped part across the opening of the cavity and is pressed against the outer circumferential surface of the frame body. A wheel structure that supplies air to the tire during rotation, comprising a pair of O-rings.