| 摘要 |
1,044,192. Friction gearing. RITTER CO. Inc. May 7, 1964 [Feb. 27, 1964], No. 19075/64. Heading F2Q. [Also in Divisions A5 and F1] A friction drive between the output shaft 58, Fig. 1, of a rotary sliding vane motor 17 and a driven member 173, Fig. 2 (not shown), connected by a threaded rod to a collet and chuck assembly driving a dental tool, comprises outer and inner ball-races 81, 83 and a retainer 84 for the balls 82 formed with dogs 88 for engagement with complementary dogs 201 on the driven member 173. For the efficient running of the motor it is essential for the clearances between the end faces of its rotor 26 and the adjacent end faces of a plug 16 and a member 98 loaded by a stack of Belleville washers 104 to be equal. To achieve this, firstly, a spring-loaded cup-washer 64 is adjusted inwardly and through a ball-bearing assembly 62 urges the shaft 58 and through stops 93 thereon the inner race 83 to the left. Secondly, a ring-nut 95 is adjusted inwardly to move the outer race 81 rightwardly and through a spacing collar 97 load the Belleville washers to move the member 98 to the right. On completion of the adjustment to equalize the clearances, the races 81, 83 are thrown out of alignment with respect to each other to impose a diagonal pressure therebetween, indicated by the arrow A which is dependent upon the initial adjustment of a spring 69 loading the cup-washer 64 to introduce a friction load on the retainer 84. This friction load causes the retainer and hence the collet and chuck assembly to rotate at a reduced speed as compared to the rotational speed of the rotor 26 and its shaft 58. Speed and direction of rotation of the dental tool is controlled by a foot controller controlling the compressed-air supply to the motor.
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