Ball spline
AssigneeNippon Thompson Co., Ltd.
InventorToyohisa Ishihara
Life of this patent
Estimating the term…
Abstract
This ball spline is capable of omitting ball retaining claws on an outer cylinder, forming by grinding raceway grooves in an inner surface of the outer cylinder easily with a high precision, positioning and fixing retainers simply on the outer cylinder, and reducing the manufacturing cost. In this ball spline, each of the retainers is formed by a pair of ball retaining units, which are fastened to the outer cylinder by engaging outer projections formed on the ball retaining units with grooves formed in the outer cylinder. The locking bores in spacer rings are engaged with locking projections on the ball retaining units, whereby the spacer rings are fixed to the ball retaining units.
Claims10
A ball spline comprising a ball spline shaft provided with first raceway grooves in an outer surface thereof so that said raceway grooves extend in the lengthwise direction of said ball spline shaft;
- an outer cylinder fitted around said ball spline shaft and provided with second raceway grooves in the portions of an inner surface thereof which are opposed to said first raceway grooves, in such a manner that second raceway grooves extend in the lengthwise direction of said outer cylinder, and return bores formed so as to be spaced from said second raceway grooves;
- balls rolling between said first and second raceway grooves;
- retainers holding said balls in cooperation with said outer cylinder;
- spacer rings which are provided with passages respectively communicating with said second raceway grooves and said return bores, and which are disposed at both ends of said outer cylinder;
- end caps which are provided with direction conversion passages communicating with said passages in said spacer rings, and which are disposed on the end surfaces of said spacer rings;
- and end seals disposed on the end surfaces of said end caps, each of said retainers being formed by a pair of ball retaining units provided with ball retaining surfaces extending along said second raceway grooves in said outer cylinder, said ball retaining units arranged on the inner surface of said outer cylinder being engaged with and held by said spacer rings.
Dependencies are inferred from the claim text.