HOLLOW-TYPE STRAIN WAVE GEARING UNIT

摘要

A hollow-type strain wave gearing unit (1) has a sealing member (14) for sealing a gap (15) opening to the inner peripheral surface of a unit hollow portion (5) passing through in an axis (1a) direction. The gap (15) includes a gap section (15b) between an outer peripheral side end race (48b) on the wave generator side and a boss side end face (108), both faces opposing each other in the axis (1a) direction, and the sealing member (14) is assembled therein. The gap section (15b) is formed in a state partially entering the inside of the inner ring (11b) of the second bearing (11) supporting the wave generator (4). It is possible to realize a hollow-type strain wave gearing unit with a sealing mechanism that is suitable for increasing the inner diameter of the unit hollow portion and for reducing the unit axial length.

主权项

1. A hollow-type strain wave gearing unit, comprising:
a rigid internally-toothed gear; a cup-shaped flexible externally-toothed gear arranged inside the rigid internally-toothed gear, and capable of meshing with the rigid internally-toothed gear; a wave generator disposed inside the flexible externally-toothed gear and flexes the externally-toothed gear into an ellipsoidal shape to mesh partially with the rigid internally-toothed gear; a boss side hollow part extending and passing through a boss in an axis direction, the boss defining a center portion of a cup bottom of the flexible externally-toothed gear; a wave generator side hollow part extending and passing through the wave generator in the axis direction; and an annular sealing member for sealing an annular gap opening to an inner peripheral surface of a unit hollow portion, the unit hollow portion extending in the axis direction and the unit hollow portion being defined by the boss side hollow part and the wave-generator side hollow part, wherein the gap is formed between a boss side end face that is formed on a side of the boss, and a wave generator side end face that is formed on a side of the wave generator and faces the boss side end surface in the axis direction, the wave generator side end face has an annular inner peripheral side end face, and an annular outer peripheral side end face that is positioned set back in the axis direction from the inner peripheral side end face with respect to the boss side end face, and the sealing member is assembled in an annular gap section formed between the outer peripheral side end face and the boss side end face in the gap.