This invention relates in general to drive train assemblies for transferring rotational power from an engine to an axle assembly in a vehicle. In particular, this invention relates to an improved structure for providing a seal between two telescoping members in a slip yoke assembly adapted for use in such a vehicle drive train assembly.
In most land vehicles in use today, a drive train assembly is provided for transmitting rotational power from an output shaft of an engine/transmission assembly to an input shaft of an axle assembly so as to rotatably drive one or more wheels of the vehicle. To accomplish this, a typical vehicular drive train assembly includes a hollow cylindrical driveshaft tube. A first universal joint is connected between the output shaft of the engine/transmission assembly and a first end of the driveshaft tube, while a second universal joint is connected between a second end of the driveshaft tube and the input shaft of the axle assembly. The universal joints provide a rotational driving connection from the output shaft of the engine/transmission assembly through the driveshaft tube to the input shaft of the axle assembly, while accommodating a limited amount of angular misalignment between the rotational axes of these three shafts.
Not only must the drive train assembly accommodate a limited amount of angular misalignment between the engine/transmission assembly and the axle assembly, but it must also typically accommodate a limited amount of axial movement therebetween. A small amount of such relative axial movement frequently occurs when the vehicle is operated. To address this, it is known to provide one or more slip yoke assemblies in the drive train assembly. A typical slip yoke assembly includes first and second splined members which are connected to respective components of the drive train assembly. The splined members provide a rotational driving connection between the components of the drive train assembly, while permitting a limited amount of axial misalignment therebetween. In some instances, the first splined member may be provided on the end of a yoke member connected to a universal joint assembly, while the second splined member may be connected to a portion of the driveshaft of the drive train assembly.
As is well known in the art, most slip yoke assemblies are provided with one or more seals to prevent the entry of dirt, water, and other contaminants into the region where the splined members engage one another. Such contaminants can adversely affect the operation of the slip yoke assembly and cause premature failure thereof Exterior seals are typically disposed on the outer surface of the slip yoke assembly to prevent contaminants from entering into the region where the splined members engage one another from the exterior environment. A number of external seals are known in the art for use with conventional slip yoke assemblies. For example, a typical exterior seal includes a rigid annular housing which is mounted on the outer surface of the female splined member. A resilient annular seal is supported on the housing and extends radially inwardly into sliding and sealing engagement with the outer surface of the male splined member to provide the seal. Another example of an external seal is a convoluted boot which is positioned over the splined members of a slip yoke assembly. One end of the convoluted boot is fastened to the female splined member and the other end is fastened to the male splined member. The length of the convoluted boot can expand or contract to accommodate the axial movement between the splined members of the slip yoke assembly.
Several structures are known in the art for mounting the rigid annular housing of a seal or the ends of a convoluted boot. In one known structure, the ends of either the seal housing or an end of the convoluted boot and the female splined member are formed having mating threads which allow the seal housing or the end of the convoluted boot to be threaded onto the end of the female splined member. In another known structure, a portion of the seal housing or the end of the convoluted boot is crimped or otherwise deformed about the end of the female splined member. In yet another known structure, a band clamp or other mechanical fastener is used to retain the seal housing or the end of the convoluted boot on the end of the female splined member. Although these known structures have been effective, it has been found that they are relatively expensive or time consuming in structure and installation. Thus, it would be desirable to provide an improved structure for providing a seal between two telescoping members in a slip yoke assembly adapted for use in such a vehicle drive train assembly which is relatively simple and inexpensive in structure and installation.