In recent years, attention has been given to sealing joints in moving vehicles, and more particularly to an apparatus for sealing a track joint in a track chain. For example, crawler tractors, such as a bulldozer, typically have a sprocket, an idler, a track chain and a number of track shoes attached to the track chain for propelling the tractor over the ground. During use of the crawler tractor the sprocket rotates and engages the track chain, thereby causing the track chain, along with the attached track shoes, to rotate around a path defined by the sprocket and the idler. The rotation of the track chain causes the track shoes to engage the ground, thereby propelling the crawler tractor over the ground to perform various work functions.
Track chains generally include a pair of parallel chains, with each parallel chain being made up of a series of entrained master links and track links. Some track chains may further include a series of pins and bushings interposed between and connected to the parallel chains. The bushings and the entrained track links cooperate to form a number of track joints which allow the necessary movement of the bushings relative to the track links during use of the track chain, for example when the track chain rotates about the sprocket and the idler. Track joints are typically equipped with a track seal assembly to keep out various corrosive and abrasive mixtures of water, dirt, sand, rock or other mineral or chemical elements to which the track chain is exposed during its use. The track seal assembly also functions to keep a lubricant within the track joint to facilitate the aforementioned relative movement of the bushings and the track links.
A problem with track seal assemblies is to keep dirt out and keep lubrication within the track joint. Mud packing resistance should preferably be kept as high as possible. Another problem to consider is to maintain sealing capability. It is desired to maintain the different parts of a track seal assembly in place to avoid displacement of any parts and resulting loss of sealing capability. Wear life of a seal assembly may be a problem. The stability of a load ring and/or seal ring within a seal assembly may be a problem. A problem with seal assemblies may be to take up or compensate for misalignments within a seal assembly.
Other problems to consider alone or in combination with other mentioned problems relate to grooving of the different parts of a seal assembly. Grooving may arise by various abrasive particles found in the working environment of a track chain finding its way in to a seal assembly. If such grooving arises, then not only dirt may enter a track joint, but also lubrication within the track joint may escape.
It is further desirable to keep costs for manufacturing and/or assembling a seal assembly within a track joint down. It may also be desirable to avoid cumbersome arrangements. It may also be desirable to provide a simple assembling process of a track joint seal assembly.
The present invention is directed to overcoming one or more of the problems as set forth above.