Silk hat type bending gear type gear unit (SILK HAT TYPE FLEXIBLE MESH ENGAGEMENT GEAR DEVICE)

摘要

The bending external gear 13 of the bending gear type gear unit 11 is composed of the body part 22, the diaphragm part 23 and the boss part 25. A thin portion 221 having a thickness of about 80% of the thickness of the main body portion is formed between the main body portion of the trunk portion 22 and the curved portion 222. The thickness of the diaphragm portion 23 is set such that the inner peripheral edge portion (point A) is the maximum thickness, the central portion (point B) is the minimum thickness, and the peripheral edge portion (point C) is slightly thinner than the maximum thickness. The contour shape is defined by using the curved groups 223 and 224 so that the change of the thickness becomes smooth as a whole. By arranging the thin portions 221 and defining the thickness of the diaphragm 23 as described above, it is possible to alleviate the concentration of cohesive force at the inner and outer circumferential ends and to smooth the stress distribution. Therefore, it is possible to realize a silk-hat type warping-type gear device in which both axial length and outer diameter dimensions are reduced.