Abstract A linear ball bearing unit for use in machine tools, transportation robots or the like comprises a bearing body having a pair of skirts with opposed inner surfaces. Ball rolling grooves are formed in both inner surfaces of the skirts and constitute parts of the passageways for loaded balls. Passage bores for non-loaded balls are formed in the central portions of the skirts. The bearing unit further comprises a track shaft which is provided in both side surfaces thereof with recesses in face-to-face relationship with the ball rolling grooves of the skirts thus forming passageways for loaded balls. Lids are attached to both ends of the bearing body and adapted to provide ball turn grooves through which the passageways for loaded balls are connected to corresponding passage bores for non-loaded balls thereby permitting ball trains to be recirculated through the passageways for loaded balls and then through the passage bores for the non-loaded balls. The angle of contact between the loaded balls and the ball-rolling grooves in the bearing body and the track shaft is set to be about 45 degrees.
In a linear ball bearing comprising: a bearing body having a horizontal and vertical axis and having a pair of skirts with opposed inner surfaces wherein said skirts are provided on their opposing inner surfaces with two pairs of longitudinally extending ballrolling grooves for loaded balls, and two pairs of passage bores for non-loaded balls extending in the longitudinal direction; a track shaft provided at its opposite side surfaces with two pairs of ball-rolling grooves extending in the longitudinal direction in face-to-face relation with the corresponding ball-rolling grooves in the bearing body; and a pair of lids attached to the both ends of the bearing body and each having four ball-return grooves for connecting the opposed ball-rolling grooves in the bearing body and the track shaft with the corresponding passage bores in the bearing body; the improvement in which (a) said ball rolling grooves are arranged symmetrically with respect to said horizontal and vertical axes and said bearing body and said track shaft are arranged with an angle of contact between the loaded balls and the ball-rolling grooves in the bearing body and the track shaft set to be about 45 degrees; and (b) each skirt has a central portion and the passage bores for the non-loaded balls are disposed substantially in the central portion of each skirt in symmetry with respect to said horizontal and vertical axes and in close proximity to said horizontal axis and near said ball rolling grooves.
Claim 2
Dependent Claim
242 words
In a linear ball bearing comprising: a bearing body having a horizontal and vertical axis and having a pair of skirts with opposed inner surfaces wherein said skirts are provided on their opposing inner surfaces with two pairs of longitudinally extending ballrolling grooves for loaded balls, and two pairs of passage bores for non-loaded balls extending in the longitudinal direction; a track shaft provided at its opposite side surfaces with two pairs of ball-rolling grooves extending in the longitudinal direction in face-to-face relation with the corresponding ball-rolling grooves in the bearing body; and a pair of lids attached to the both ends of the bearing body and each having four ball-return grooves for connecting the opposed ball-rolling grooves in the bearing body and the track shaft with the corresponding passage bores in the bearing body; the improvement in which (a) said ball rolling grooves are arranged symmetrically with respect to said horizontal and vertical axes and said bearing body and said track shaft are arranged with an angle of contact between the loaded balls and the ball-rolling grooves in the bearing body and the track shaft set to be about 45 degrees; and (b) each skirt has a central portion and the passage bores for the non-loaded balls are disposed substantially in the central portion of each skirt in symmetry with respect to said horizontal and vertical axes and in close proximity to said horizontal axis and near said ball rolling grooves.
Claim 3
Dependent Claim
49 words
A linear ball bearing unit according to claim 1, wherein said ball rolling grooves in said bearing body and said track shaft for constituting said passageways for loaded balls are constituted by circular arc grooves having a radius of curvature which is about a half of the ball diameter.
Claim 4
Dependent Claim
24 words
A linear ball bearing unit according to claim 2, wherein tongues are formed in both ends of said slits in each of said retainers.