JP2522565Y2 - Universal joint sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] The present invention relates to a sealing device for a universal joint used in various industrial machines.

2. Description of the Related Art A universal joint is used for transmitting power between two axes forming an angle. Conventionally, rubber boots made of a rubber material such as chloroprene rubber have been used to prevent leakage of grease or the like sealed for lubrication inside the joint and entry of foreign matter from the outside. However, since rubber boots are not suitable for use in a poor environment such as in a steel plant, they have been replaced with rubber boots, and a sealing device as shown in FIG. 2 has been used. This sealing device has an opening (22
In (a), a spherical member (22) covering the outer diameter portion of the outer ring (23), one end is fixed to the outer ring (23), and the inner peripheral surface (22b) of the spherical member (22) is fixed by the sliding contact surface (25a) at the other end. ) Is formed of a metal sealing member (25) that comes into sliding contact with ()). The spherical member (22) is slidably mounted on the inner ring shaft (21) and includes a coil spring (26).
As a result, the pressure is urged toward the seal member (25). For this reason, the sliding contact surface (25
If a) is worn, the spherical member (2
2) slides toward the seal member (25), so that the sliding contact surface (25
Adhesion between a) and the inner peripheral surface (22b) is ensured.

[Problems to be solved by the invention]

The seal device shown in FIG. 2 presses and biases the spherical member (22) toward the seal member (25) with a coil spring (26) to thereby improve the adhesion between the seal member (25) and the spherical member (22). In addition, the wear dimension of the seal member (25) can be corrected. Therefore, the inner axle (2
There is a spherical member (2) between the mounting part of 1) and the spherical member (22).
A slight gap is required to allow the sliding of 2).
However, due to the clearance, especially under high-speed rotation, the spherical member (22) causes rotational blur, and uneven sliding occurs on the sliding contact surface (25a) of the seal member (25). Due to uneven wear of the sliding surface (25a), the sealing performance is significantly reduced.

In addition, in this sealing device, it is difficult to center the spherical member (22) and the sealing member (25). If the centering is not correct, uneven wear due to rotation blur occurs as described above.

Accordingly, an object of the present invention is to provide a sealing device which is less likely to cause uneven wear of a sliding contact surface and can exhibit a stable sealing function for a long period of time.

[Means for solving the problem]

The seal device according to the present invention has a spherical member whose one end is fixed to the inner ring shaft of the universal joint, and which covers the outer diameter portion of the outer ring of the universal joint at the opening at the other end, and slidably contacts the inner peripheral surface of the spherical member, and ,
An annular seal member movably arranged in the axial direction of the outer ring, and an elastic member for urging the seal member in the axial direction of the outer ring toward the inner peripheral surface of the spherical member.

The seal members having the above configuration may be arranged in two rows in the axial direction of the outer ring.

[Action]

The seal member is disposed so as to be movable in the axial direction. The seal member is urged in the axial direction by the elastic member to slide against the inner peripheral surface of the spherical member to seal the inside of the joint.
When the seal member is worn by a long use, the elastic member presses and moves the seal member toward the spherical member by the worn dimension, so that the adhesion between the seal member and the inner peripheral surface of the spherical member is always maintained. It is. Further, since one end of the spherical member is fixed to the inner ring shaft, there is no rotational shake, and uneven wear does not occur in the seal member. Further, since the seal member is pressed against the spherical member, the centering of the seal member and the spherical member is easy.

 As described above, a stable sealing property is always ensured.

When the seal members are arranged in two rows in the axial direction, the seal members on the opening side (outside) mainly play a role of preventing foreign matter from entering from outside, and the inner seal members are mainly formed from inside the joint. Since it plays the role of preventing grease leakage, the sealing performance is further improved. In particular, foreign matter such as dust easily adheres to the inner peripheral surface on the opening side of the spherical member, and the attached foreign matter may enter the joint through the sliding contact surface of the seal member with the bending operation of the joint. Or promote wear of the sliding contact surface. However, by arranging the seal members in two rows, the outer seal member acts as a kind of dust wiper, and the inner seal does not come into contact with foreign matter, thereby preventing foreign matter from entering and increasing abrasion of the sliding contact surface. Is done.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a sealing device according to the present invention. This sealing device has a spherical member (2) having one end fixed to an inner ring shaft (1) and an outer diameter portion of an outer ring (3) covered by an opening (2a) at the other end, and an inner peripheral surface of the spherical member (2). An annular seal member (5) for slidingly contacting the joint (2b) to seal the inside of the joint, and an elastic member for urging the seal member (5) toward the spherical member (2), for example, a coil spring (6) are main constituent elements. And

The seal member (5) is formed of a resin material, and its sliding contact surface (5a) has the same curvature as the inner peripheral surface (2b) of the spherical member (2). The seal member (5) is mounted on a seal base (7) fitted and fixed to the outer race (3).

The seal base (7) has two rows of steps (7a) in the axial direction, and the seal member (5) is mounted on each of the steps (7a) while being allowed to move in the axial direction. A mounting hole (6a) for mounting the coil spring (6) and a pin hole (8a) for press-fitting the pin (8) are formed in the side wall of the step portion (7a) in an appropriate number in the circumferential direction. ing. The seal member (5) mounted on the step (7a) was pressed toward the spherical member (2) by the coil spring (6) inserted into the mounting hole (6a), and was pressed into the pin hole (8a). The rotation is stopped by the pin (8).
In addition to using the pin (8) as a means for preventing the rotation of the seal member (5), for example, an uneven portion is formed on the seal member (5) and the step (7a), and the uneven portion is engaged. You may do so.

Since the seal device according to the present embodiment is arranged in two rows in the axial direction, the seal member (5) on the opening (2a) side mainly serves to prevent foreign matter from entering from outside, and the inner seal member. (5) mainly serves to seal the grease inside the joint. Further, since the seal member (5) is formed of a resin material, the friction coefficient on the sliding contact surface (5b) is smaller than that of a metal member. Therefore, in this sealing device, the sliding resistance at the time of bending the joint is small, and the amount of wear of the sliding contact surface (5b) is small.

[Effect of the invention]

 The present invention has the following effects.

Since the seal member is pressed toward the spherical member by the elastic member, the centering of the seal member and the spherical member is facilitated, and uneven wear of the seal member due to rotation blur is prevented.

Since the spherical member is fixed to the inner ring shaft, it does not rotate even under high-speed rotation. This prevents uneven wear of the seal member.

When the seal member is worn, the elastic member presses and moves the seal member toward the spherical member by an amount corresponding to the wear,
Adhesion between the seal member and the spherical member is always high, and stable sealability is maintained for a long time.

As shown in the embodiment, by making the seal member made of resin, the sliding resistance when the joint is bent can be reduced. In other words, the sliding contact area of the seal member can be increased, and the sealing performance can be improved. Also,
Since it is not necessary to manufacture the seal member with high precision, the processing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state in which the sealing device according to the present invention is mounted on a universal joint, and FIG. 2 is a sectional view showing a conventional sealing device. DESCRIPTION OF SYMBOLS 1 ... Inner ring shaft, 2 ... Spherical member 3 ... Outer ring, 2a: Opening, 2b: Inner peripheral surface 5 ... Seal member, 6 ... Coil spring

Claims (2)

(57) [Scope of request for utility model registration] A spherical member having one end fixed to an inner ring shaft of the universal joint and an opening at the other end covering an outer diameter portion of an outer ring of the universal joint;
An annular seal member slidably in contact with the inner peripheral surface of the spherical member and movably arranged in the axial direction of the outer ring; and an axial direction of the outer ring with the seal member facing the inner peripheral surface of the spherical member. And a resilient member for urging the joint. 2. The universal joint sealing device according to claim 1, wherein said seal members are arranged in two rows in the axial direction of said outer race.