Supporting wheels seal leakage analysis
Views：3707  Time：2012/11/26 10:22:53  Source: Internet

Wheels is a crawler type engineering machinery is the important load bearing components (commonly known as the " wheel " ), which is composed of a supporting roller body, a shaft, the left and the right bearing seats and a seal assembly and other parts. A shaft through a supporting seat is fixed on a table or frame, wheel body has pressing sleeve and a shaft with rotation, rotation of the wheel body and a fixed supporting seat is arranged between the left and right seal assembly, in order to maintain the support shaft and the shaft sleeve and other parts of the lubricating oil sealing. The seal assembly comprises a pair of tapered metal material of the sealing ring and two small eyes rubber fixed compression ring. Rubber ring are respectively arranged on the wheel body and the supporting seat seal seat inside the mouth, since the metal seal ring bearing ring rubber extrusion support, ensure the annular edge belt during the rotation of the tight engagement, so the sealing of floating seal.

Supporting wheels seal leakage analysis

Supporting wheels is a crawler type engineering machinery is the important load bearing components (commonly known as the " wheel " ), which is composed of a supporting roller body, a shaft, the left and the right bearing seats and a seal assembly and other parts. A shaft through a supporting seat is fixed on a table or frame, wheel body has pressing sleeve and a shaft with rotation, rotation of the wheel body and a fixed supporting seat is arranged between the left and right seal assembly, in order to maintain the support shaft and the shaft sleeve and other parts of the lubricating oil sealing. The seal assembly comprises a pair of tapered metal material of the sealing ring and two small eyes rubber fixed compression ring. Rubber ring are respectively arranged on the wheel body and the supporting seat seal seat inside the mouth, since the metal seal ring bearing ring rubber extrusion support, ensure the annular edge belt during the rotation of the tight engagement, so the sealing of floating seal.

In 1995, I plant for a company excavator supporting the production of supporting wheels, provided by the company in foreign production drawings, floating seal assembly imported from abroad. Installation test was found in part of supporting wheels on the floating oil seal leakage, after many tests, analysis and testing finally found, the company floating seal assembly and the seat opening obviously smaller than the cone angle of my factory production of other types of oil seal angle; through graphic calculation, the rubber ring compression larger.

We think, of floating oil seal of the cone angle is small, to reduce the supporting wheels shocks caused by the floating sealing ring engagement ring beating, improve sealing the meshing surface of axial force and maintain its axial force axial clearance for system becomes large and dramatic changes are useful. But the sealing cone angle is smaller, the roller assembly are caused when the rubber ring on the conical surface deflection, together with sealing seat hole on the rubber ring compression volume increase, more difficult to ensure the sealing engagement with the blade assembly in the correct position. Analysis on international a few Progressive Corp information knowledge, floating oil seal cone angle is smaller, the design development trend.

According to the above analysis, we have adopted two measures:

( L ) the original design of the floating oil seal rubber ring seat orifice taper and taper angle and other parameters unchanged, the most simple design changes appropriately change the sealing rubber ring compression.

( 2) to improve assembly process, add special tools, ensure the floating oil seal rubber ring in the correct position on the sealing ring cone and its filling sealing seat in the correct position, to ensure that the two seal ring edge mesh correctly.

According to the above measures strictly after assembly, either test or installed and used, and found no leakage phenomenon.

We think, in order to improve the engineering machinery walking mechanism supporting wheel floating seal assembly life, foreign companies will seal ring cone angle and the rubber ring seat cone angle is small, from theory and practice are beneficial, but manufacturing if not guarantee accurate assembly in place, will get the opposite of what one wants.

If the floating seal assembly error, in the static original position, while the factory to be airtight inspecting, but due to the elasticity of the rubber ring, airtight inspecting pressure not quite value is undetectable, oiling do not occur after leakage after a certain period of time, due to the various components, the frictional heating cavity the pressure rises to a certain value, rotation of the meshing position due to the elastic rubber ring cutter with the appropriate minimum axial force, there will be intermittent instantaneous leakage; if this situation stops rotating, the meshing leakage at the moment but is not a serious oil spill, and continued into the cavity pressure dropped to a certain value, the elastic rubber ring to reach a new equilibrium, leakage stopped.

In the assembly error condition, operation will appear in local edge surface due to the pressure, friction and wear increased sharply at the same time, generates heat, resulting in lowered viscosity of lubricating oil, the rotating pair increased wear.

The above analysis, a high quality parts, in addition to the advanced design, high quality parts production, properly perfect assembly is very important.