JPS6327149Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to an improved structure of a cardan type universal joint used in steering shafts, propeller shafts, drive shafts, etc. of automobiles, industrial machinery vehicles, etc.

Prior Art This type of universal joint has a pair of yokes fixed to the input shaft and output shaft, respectively, and a cross-shaped spider end is connected to the connecting hole formed in each yoke. They are connected by fitting through shaped roller bearings. Figure 1 shows the bearing part of a general Cardan type universal joint, in which the end of a spider 3 is inserted into a connecting hole 2 formed in a yoke 1, with a bottom at one end and a radially inward end at the other end. They are fitted via a needle roller bearing 5 covered with a metal shell-shaped cup 4 having a flange bent inward. In addition, 7 is a seal made of an elastic material such as rubber or synthetic resin, which is attached between the flange of the shell-shaped cup 4 and a shoulder 6 provided on the spider 3 so as to face the flange. It's a ring. As shown in the figure, the yoke 1 has a substantially U-shape, and its inner wall surface is partially cut out to meet the requirements for assembly operations when assembling the spider 3.

Problems to be Solved by the Invention The Cardan type universal joint described above is painted for the purpose of rust prevention, but the painting is usually done with the spider 3 assembled to the yoke 1 via the needle roller bearing 5. The portion of the bearing portion exposed from the inner wall surface of the yoke 1 (the shaded portion in FIG. 2) is structurally a blind spot in the yoke 1 and is not sufficiently coated. As a result, when cars are shipped and exported, there may be condensation due to temperature differences, antifreeze may adhere to the road surface when the car is being driven, or corrosion may occur in the bearings due to salt damage, resulting in problems in terms of product value and functionality. It was hot.

The main purpose of this invention is to provide a structure for the above-mentioned type of universal joint in which the bearing portion, which is a blind spot for painting, is rust-proofed.

Means for Solving the Problems The universal joint of this invention includes a generally cylindrical cover 18 having an open end surface 19 at one end with a shape matching the inner wall surface of the yoke 11 and a sealing lip 21 at the other end. ing. This cover 18 has an open end surface 19 when the universal joint is in an assembled state.
It tightly adheres to the inner wall surface of the yoke 11,
A sealing lip 21 is elastically abutted against a sealing surface 20 formed on the outer periphery of the spider 13.

Function: The cover 18 extends from the inner wall surface of the yoke 13 to the sealing surface 20 of the spider 13, and the shell-shaped cup 14 exposed from the inner wall surface of the yoke 11.
The outer surface of the cup 14 and the sealing ring 17 are protected from the external environment by covering the outer surface of the cup 14 and the sealing ring 17.
It works to prevent rust, corrosion, etc. In addition, the seal lip 21 elastically abuts against the seal surface 20 to prevent dust and foreign matter from entering the interior, and the cover 18 is displaced in the axial direction to create a gap between the cover 18 and the inner wall surface of the yoke. It also has the role of preventing water from burning.

Embodiment FIG. 3 shows an embodiment of the universal joint of this invention, in which the end of a cross-shaped spider 13 is inserted into the connecting hole 12 formed in the yoke 11, and has a bottom at one end. A metallic shell-shaped cup 14 having a flange bent radially inward at the other end is fitted through a needle roller bearing 15 covered with the flange, and the flange of the shell-shaped cup 14 is opposed to the flange. A seal ring 17 made of an elastic material such as rubber or synthetic resin is attached between the shoulder portion 16 provided on the spider 13 and the opening of the shell-shaped cup 14 is sealed. Furthermore, a cover 18 is fitted to cover the portion of the shell-shaped cup 14 exposed from the inner wall surface of the yoke 11 and the seal ring 17.

The cover 18 is made of a material mainly made of an elastic body such as rubber or synthetic resin and is formed into a cylindrical shape, and as shown in FIG. A seal lip 21 is provided at the other end to elastically contact a seal surface 20 provided on the outer periphery of the spider 13. This cover 18
When assembling the universal joint, install spider 1 in advance.
After fitting the end of the spider 13 into the connecting hole 12 of the yoke 11 via the shell cup 14 and the needle roller bearing 15, The cup is moved over the shoulder 16 to the distal end side, and is fitted onto the outer circumferential surface of the shell-shaped cup 14, and the opening end surface 19 is moved to the yoke 11.
Make sure it fits snugly against the inside wall. The cover 18 thereby extends from the inner wall surface of the yoke 11 to the sealing surface 20 of the spider 13, covering the exposed outer surface of the shell cup 14 and sealing ring 17.
completely cover.

FIG. 5 shows another embodiment of this invention, in which the cover 18
A reinforcing ring 22 made of metal is embedded inside the reinforcing ring 22, and the reinforcing ring 22 allows the cover 18 to be fitted more reliably to prevent it from shifting or coming off.

Effects of the invention According to this invention, the exposed outer surface of the metal shell-shaped cup 14, which was conventionally considered to be a blind spot in the yoke 11 and difficult to be coated with a sufficient anti-rust coating, can be covered with the cover 18.
Since it is coated with a rubber coating to cut off contact with the outside air, it not only prevents corrosion and loss of product value, but also maintains the desired function over a long period of time, extending the life of the bearing and, ultimately, the universal joint as a whole. Contribute to improvement.

In addition, since a satisfactory rust prevention effect can be obtained regardless of the type of coating, it is not necessary to pay attention to the details during painting as in the past, which greatly contributes to improving the efficiency of painting work.

Furthermore, since the seal lip 21 of the cover 18 can prevent foreign matter and dust from entering the bearing, the sealing function of the seal ring 20 can be used more effectively, resulting in a universal joint with excellent durability as a whole. can be provided.

[Brief explanation of drawings]

Figure 1 is a sectional view showing the bearing part of a conventional universal joint, Figure 2 is a plan view to explain the parts that are not sufficiently painted, and Figure 3 is the bearing part of a universal joint that is an embodiment of this invention. FIG. 4 is a sectional view of the cover, and FIG. 5 is a sectional view similar to FIG. 3 showing another embodiment of this invention. 1... York, 13... Spider, 14...
Shell type cup, 15... Needle roller bearing, 17...
... Seal ring, 18 ... Cover, 19 ... Opening end surface, 20 ... Seal surface, 21 ... Seal lip.

Claims (1)

[Scope of utility model registration request] Each end of the cross-shaped spider is connected to each connecting hole formed in a roughly U-shaped yoke with the inner wall surface partially cut out through needle-like roller bearings covered with metal shell-shaped cups. in a universal joint in which the opening side of the shell-shaped cup is sealed with a seal ring, and extends to cover the outer periphery of the shell-shaped cup exposed from the inner wall surface of the yoke and the outer periphery of the seal ring, 1. A universal joint characterized by comprising a cover having an open end face having a shape matching the inner wall surface of the yoke at one end and a seal lip at the other end that makes sliding contact with a sealing surface of a spider.