JPH0694046A - How to install a seal on a cylindrical housing - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a new method of attaching a seal to a cylindrical housing. [Structure] Place the seal on the housing and place it in the groove of the seal. It is then heated to melt the boot and attach it to the housing, conforming to the shape of the housing. A metal boot clasp can then be placed around the seal if additional retention is desired.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates generally to a method of attaching a seal to a cylindrical housing. More particularly, the invention relates to mounting seals on constant velocity joint housings and shafts.

[0002]

BACKGROUND OF THE INVENTION Front-wheel drive vehicles utilize a pair of half shaft assemblies to transfer power from a transaxle to the front wheels. Each half shaft assembly includes a pair of constant velocity joints connected by an interconnecting shaft. One constant velocity joint is connected to the front wheels and another constant velocity joint is connected to the transaxle. The constant velocity joint at the wheel is a center fixed constant velocity joint. This joint has a large angle (45 ~
It can move at 50 degrees. The large angular performance of this joint allows the front wheels to be moved by an angle that depends on the steering angle of the steering wheel. The constant velocity joint in the transaxle is a plunging constant velocity joint. The joint has a movable center of rotation and is capable of moving over an angle of 20-25 degrees. Due to the movable center of rotation and angular performance of this joint, manufacturing tolerances can be increased for vehicle and suspension movements and engine vibrations.

Since the constant velocity joint operates inside the lubricating oil, it is necessary to constantly supply the lubricating oil. The lubricating oil is usually contained within the chamber formed by the seal or boot. The seal is usually made from a flexible material such as rubber or plastic. One end of the boot is attached to the outer diameter of the constant velocity joint and the other end is connected to the interconnection shaft. Such a structure forms a generally conical chamber. A certain amount of grease is filled in the chamber during assembly of the half shaft. The grease is usually sufficient to lubricate the constant velocity joint during the life of the vehicle. Since the seal of the constant velocity joint must always supply lubricating oil,
It is an important part of the half shaft assembly. Even if the seal breaks for some reason, the breakage is barely noticeable to the vehicle operator. Should the lubricant leak out of the assembly due to seal failure, the constant velocity joint will soon fail.

The flexibility of the seal allows the shaft to move angularly with respect to the housing of the constant velocity joint.
During the angular movement of the joint, one side of the boot is compressed and the other side is stretched. The boot is periodically compressed and stretched while the joint is angularly moving. The cycle of this cyclic motion depends on the rotational speed of the joint. Early constant velocity joint seals were made of rubber or neoprene. This material is highly flexible and can be easily attached to the housing and shaft of the constant velocity joint using a metal band. Although their rubber seals work well, the rubber is very likely to be torn due to its softness. Torn rubber boots can be caused by contact between the boot and other vehicle components during handling of the half shaft, vehicle assembly, or vehicle assembly. Even properly assembled, rubber boots can be damaged by road hazards, repair pliers, tow hooks, or other objects that sandwich the boot with one of the other parts of the half shaft.

In order to reduce or eliminate the risk of tearing, plastic boots, usually Dupont
Hytrel ° (trade name) of t) has been developed.
A plastic material that is stronger than a rubber material can withstand a reasonable degree of mishandling and other rough handling that will tear the rubber boot. Unfortunately, as the material becomes stronger, it becomes more difficult to attach the plastic boot to the outer race and shaft of the half shaft assembly. In order to hold and seal the plastic boot to the half shaft assembly during operation, the plastic material requires a metal band with a large cross section. In addition to the increased cross-section, the metal band material has been replaced by inexpensive plated steel with relatively expensive stainless steel. With the increase in cross section and the change to more expensive materials, the cost of boot tightening devices has increased significantly.

[0006]

Therefore, it would be desirable to have an application specific method for attaching a plastic constant velocity joint boot to a half shaft assembly.

[0007]

The present invention provides a method of attaching a plastic boot to a half shaft assembly. The boot is put in place and then heated to shrink the boot to the shape of the half shaft assembly.

[0008]

DETAILED DESCRIPTION The following detailed description is about mounting a plastic seal on a fixed center ball joint of a half shaft assembly. It is assumed by those skilled in the art that the mounting method described herein can be applied to other types of universal joints. Reference is made to the drawings, in particular FIGS. 1 and 2, in which a fixed center constant velocity joint end 10 of a half shaft is shown. The mounting method begins by positioning the plastic seal 20 on the interconnecting shaft 22. The plastic seal is Hypon from Dupont
It is manufactured from rel ° (trade name) by a well-known blow molding technique. The small end 24 of the seal is placed in a groove 26 formed on the outer surface 28 of the interconnecting shaft 22. This positions one end of the seal 20 against the end of the interconnecting shaft 22. The interconnecting shaft 22 and seal 20 are then assembled into a constant velocity joint assembly 30. Typically, the interconnecting shaft 22 and the constant velocity joint inner race 32 are connected by spline means 34, as shown in FIG.

The large end 36 of the seal 20 is then placed over the outer race 38 of the constant velocity joint assembly 30. The seal 20 has a ribbed protrusion 40. The protrusion is placed in a groove 42 machined in the outer surface 44 of the outer race 38. The ribbed protrusions 40 are aligned with the grooves 42 to properly position the seal 20 with respect to the constant velocity joint assembly 30. Then, the seal 20 and the chamber 50 formed by the outer rail 36 and the interconnection shaft 22.
Fill the inside with the appropriate type and amount of lubricant.
The ends 24 and 38 of the seal 20 are then heated to a temperature just above their melting points. This heating of the seal can be accomplished by providing external heating sources around the ends 24 and 38 of the seal 20 by methods well known in the art. Another method of applying the required heat is to induction heat the outer race 36 and interconnecting shaft 22 also by methods well known in the art. The induction heating of the outer race 36 and the interconnecting shaft 22 can be heated only in the area of the seal 20 designed for installation by easily controlling the localized heating area.

When the melting point of the seal 20 is reached, the heat source is removed and the assembly is cooled. Cooling the assembly 10 allows the seal 20 to conformally adhere to the outer race 36 and the interconnecting shaft 22. Once the seal 20 is attached to the coupling assembly 30 and the interconnecting shaft 22 as described above, the seal 20 attachment is typically a secure and complete assembly. To make the seal 20 very reliable to install, the metal bands 52, 54 can be assembled over the seal 20 as shown in FIG. Metal band 52,
54 and the techniques for tightening them are similar to the low cost plated steel bands used to hold the rubber seals.

[Brief description of drawings]

1 is a partial cross-sectional side view of a seal attached to a half shaft prior to heating in accordance with the present invention.

2 is a partial cross-sectional side view of a seal attached to a half shaft after heating according to the present invention. FIG.

FIG. 3 is a partial cross-sectional side view similar to FIG. 2 showing the addition of a metal band.

[Explanation of symbols]

 20 plastic seal 22 interconnecting shaft 24, 36 end of seal 26, 42 groove 28 outer surface of interconnecting shaft 30 constant velocity joint 32 inner race of constant velocity joint 34 spline 38 outer race of constant velocity joint 40 ribbed protrusion

Claims (2)

[Claims] 1. A step of disposing a first end of a seal on the outside of a cylindrical housing; a step of heating the first end of the seal above a melting point of a material of the seal; Cooling one end of the seal and shrink-fitting the first end of the seal onto the housing. 2. A step of disposing a first end of a seal on a constant velocity joint housing, a step of disposing a second end of the seal on a shaft, and a first end of the seal. Heating the part above the melting point of the seal material, heating the second end of the seal above the melting point of the seal material, cooling the first end of the seal, and Shrinking the first end of the seal onto the constant velocity joint housing, cooling the second end of the seal, and connecting the second end of the seal to the constant velocity joint housing. A step of shrink fitting up, and a method of attaching a seal to a constant velocity joint housing and shaft.