Study of the working capacity of high-velocity radial bearings with hollow rollers

1. For practical purposes it is quite permissible to replace the spatial problems involved in determining the stressed state of a hollow roller by a planar problem of the elasticity theory for a ring loaded with mutually-equated concentrated forces. 2. The tangential stresses on the internal diameter of the roller in the plane of the loading forces are the most critical for destruction. 3. An empirical relationship was obtained for determining the elastic displacement of the cambered rollers in the bearing for the case in which contact deformations were commensurate with bending. 4. The load distributions between the oscillating bodies with identical radial gaps are the more uniform, the greater the size of the apertures in the rollers. This effect is reinforced with an increase in the radial gaps. 5. With increased loads, starting from values of c≥0.42, the use of hollow rollers allows an increase in the dimensions of the contact area, and consequently a reduction in the contact stresses. 6. The levels of maximum tangential stresses of 45–50 kg/mm2 can be recommended as the limiting permissible values for heavily loaded bearing units. This was confirmed by long-term testing of bearings with hollow rollers in the bearings of reducer satellites in aviation motors with cycles equivalent to 2000 h operation in service. 7. The durability of the bearings with hollow rollers operating on cycles not exceeding the maximum permitted level of tangential stresses can be substantially (3–5 times) greater than the durability of similar bearings with solid rollers. 8. On the basis of the research described above, engineering methods and practical recommendations were developed for the planning and use of bearings with hollow rollers for a number of specific working conditions.