Loading capacity under radial load

The radial load of a rotary stroke bearing is determined by the position of the application point of the radial force P_R in relation to the center of the ball contact length e.

The radial force P_R can also be  the resultant of several forces. Depending on the position of the force application point, the forms of the radial load illustrated in the overview are determined.

The diagram provided in the overview takes into account the deflection of the rotary stroke bearing when a load is applied, which is determined by the elastic deformation of the balls and the surfaces of the guide bush and guide shaft. The axes of the guide bush and guide shaft are assumed to be rigid; the deflection of the shaft must therefore be taken into account, where applicable.

1. The radial load is evenly distributed over the contact length corresponding to a centered radial force P_R.
2. The radial load is unevenly distributed over the length. In special cases it results in a moment only. 

With the different forms of the radial load, the balls in certain sections are charged more than in other sections. The calculation of the loading capacity is based on determining the highest rated radial force P₁₀ of a 10 mm long ball zone. In the following, the correlation between the external load P_R or M and the rated radial force P₁₀ are specified for the various forms of the static radial load.

The elastic deformation of the ball zones causes a deflection of the rotary stroke bearing axis. Depending on the load, the elastic deformation of certain ball zones also differs. For a rated radial force P₁₀, the radial deflection of the axis of the most heavily loaded 10 mm ball zone is defined as the specific deflection A₁₀. This can be used to calculate the expected deflection of the shaft at force contact point A.