| 摘要 |
1288145 Screw-and-nut mechanisms SKF INDUSTRIAL TRADING & DEVELOPMENT CO NV 5 May 1970 [6 May 1969] 21648/70 Heading F2Q A planetary ball screw mechanism comprises annular rows of balls 8 mounted in carriers 7 each of which carries two rows of balls, a shaft 1 having a number of helical grooves 2, and a nut 3 in which bearing rings 5, having endless ball races 6, are slidably mounted, the number of balls in each row corresponding to the number of helical grooves 2. The ball carriers may consist of a tubular body 9, Fig. 2, having pairs of ears 10 which are loop-formed to provide two annular seats for each ball. Alternatively, the ears 10 are each formed with a part-circular seat. In another modification, two similar washers 14, Fig. 4, are located back to back, each carrying pairs of loopformed ears 15. The carrier may comprise a ring of synthetic resin provided with ball pockets. The mechanism is subjected to a biasing force by an annular screw member 13. Fig. 9 shows an arrangement in which two interconnected ball nuts are located in similar housings 4a, 4b and are biased by spring washers 24. The bearing rings 5 have non-circular external shapes which are located in similarly shaped bores in the housings 4a, 4b. |
