Curvilinear motion rolling guide unit

1. A curvilinear motion rolling guide unit comprising:

a raceway rail having first raceway grooves formed in arcuate inner and outer side surfaces having predetermined radiuses of curvature, respectively;

an arcuate slider having second raceway grooves formed in opposition to the respective first raceway grooves and moving on the raceway rail in a relative manner while straddling the raceway rail; and

a plurality of rolling elements rolling in infinite circulation passages each being composed of a raceway passage formed between the first raceway groove and the second raceway groove, a return passage provided in the slider and extending along the raceway passage, and direction changing passages provided in the slider and establishing communication between the raceway passage and the return passage,

wherein the slider has an arcuate casing which has an upper section and wings extending from inner and outer sides of the upper section along the inner and outer side surfaces of the raceway rail and having the respective second raceway grooves formed therein, end caps fixed to respective opposite end surfaces of the casing and having the respective direction changing passages formed therein, and arcuate cover members having respective grooves which extend along longitudinal directions of the wings of the casing and into which respective arcuate pipe members adapted to form the respective return passages are fitted,

the cover members are fixed to the casing and/or the end caps, and

wherein the end caps in contact with the end surfaces of the casing have connection pipe portions extending from the direction changing passages and protruding toward the casing, and communicating with the return passages of the pipe members, and opposite end portions of the cover members are fitted to the respective connection pipe portions, whereby the cover members are fixed to the end caps.

2. The curvilinear motion rolling guide unit according to claim 1 , wherein the opposite end surfaces of the pipe members abut end surfaces of the connection pipe portions of the end caps, respectively, whereby the direction changing passages and the return passages communicate with each other.

3. The curvilinear motion rolling guide unit according to claim 2 , wherein fitting grooves formed at opposite ends of the grooves of the cover members are fitted to the respective connection pipe portions formed in wings of the end caps, whereby the cover members are fixed to the casing in position.

4. A curvilinear motion rolling guide unit comprising:

a raceway rail having first raceway grooves formed in arcuate inner and outer side surfaces having predetermined radiuses of curvature, respectively;

an arcuate slider having second raceway grooves formed in opposition to the respective first raceway grooves and moving on the raceway rail in a relative manner while straddling the raceway rail; and

a plurality of rolling elements rolling in infinite circulation passages each being composed of a raceway passage formed between the first raceway groove and the second raceway groove, a return passage provided in the slider and extending along the raceway passage, and direction changing passages provided in the slider and establishing communication between the raceway passage and the return passage,

wherein the slider has an arcuate casing which has an upper section and wings extending from inner and outer sides of the upper section along the inner and outer side surfaces of the raceway rail and having the respective second raceway grooves formed therein, end caps fixed to respective opposite end surfaces of the casing and having the respective direction changing passages formed therein, and arcuate cover members having respective grooves which extend along longitudinal directions of the wings of the casing and into which respective arcuate pipe members adapted to form the respective return passages are fitted,

the cover members are fixed to the casing and/or the end caps, and

wherein at least the outer cover member disposed at the wing of the casing has first hook portions provided respectively at its opposite end portions and extending toward the casing, and the first hook portions are fitted respectively into and engaged with first hook fixation recesses formed in the opposite end surfaces of the casing, whereby the cover member is fixed to the casing in position.

5. A curvilinear motion rolling guide unit comprising,

a raceway rail having first raceway grooves formed in arcuate inner and outer side surfaces having predetermined radiuses of curvature, respectively;

an arcuate slider having second raceway grooves formed in opposition to the respective first raceway grooves and moving on the raceway rail in a relative manner while straddling the raceway rail; and

a plurality of rolling elements rolling in infinite circulation passages each being composed of a raceway passage formed between the first raceway groove and the second raceway groove, a return passage provided in the slider and extending along the raceway passage, and direction changing passages provided in the slider and establishing communication between the raceway passage and the return passage,

wherein the slider has an arcuate casing which has an upper section and wings extending from inner and outer sides of the upper section along the inner and outer side surfaces of the raceway rail and having the respective second raceway grooves formed therein, end caps fixed to respective opposite end surfaces of the casing and having the respective direction changing passages formed therein, and arcuate cover members having respective grooves which extend along longitudinal directions of the wings of the casing and into which respective arcuate pipe members adapted to form the respective return passages are fitted,

the cover members are fixed to the casing and/or the end caps, and

wherein at least the outer cover member disposed at the wing of the casing has, at its opposite end portions, hook portions extending toward the casing and provided at its inclined surface corresponding to an inclined surface of the undercut of the casing and located above the pipe member, and the hook portions are fitted respectively into and engaged with a second hook fixation recesses formed in the opposite end surfaces of the casing, whereby the cover member is fixed to the casing in position.

6. A curvilinear motion rolling guide unit comprising:

a raceway rail having first raceway grooves formed in arcuate inner and outer side surfaces having predetermined radiuses of curvature, respectively;

an arcuate slider having second raceway grooves formed in opposition to the respective first raceway grooves and moving on the raceway rail in a relative manner while straddling the raceway rail; and

a plurality of rolling elements rolling in infinite circulation passages each being composed of a raceway passage formed between the first raceway groove and the second raceway groove, a return passage provided in the slider and extending along the raceway passage, and direction changing passages provided in the slider and establishing communication between the raceway passage and the return passage,

wherein the slider has an arcuate casing which has an upper section and wings extending from inner and outer sides of the upper section along the inner and outer side surfaces of the raceway rail and having the respective second raceway grooves formed therein, end caps fixed to respective opposite end surfaces of the casing and having the respective direction changing passages formed therein, and arcuate cover members having respective grooves which extend along longitudinal directions of the wings of the casing and into which respective arcuate pipe members adapted to form the respective return passages are fitted,

the cover members are fixed to the casing and/or the end caps, and

wherein at least the outer cover member disposed at the wing of the casing has, at its opposite end portions, attachment bracket portions each having a through hole corresponding to an end cap fixing threaded hole formed in the casing, and the end caps have respective attachment holes corresponding to the end cap fixing threaded holes, and screws are inserted through the respective attachment holes and the through holes and screwed into the end cap fixation threaded holes, respectively, thereby fixing the end caps to the casing; as a result, the cover member is fixed to the casing in position.

7. A curvilinear motion rolling guide unit comprising:

a raceway rail having first raceway grooves formed in arcuate inner and outer side surfaces having predetermined radiuses of curvature, respectively;

an arcuate slider having second raceway grooves formed in opposition to the respective first raceway grooves and moving on the raceway rail in a relative manner while straddling the raceway rail; and

a plurality of rolling elements rolling in infinite circulation passages each being composed of a raceway passage formed between the first raceway groove and the second raceway groove, a return passage provided in the slider and extending along the raceway passage, and direction changing passages provided in the slider and establishing communication between the raceway passage and the return passage,

wherein the slider has an arcuate casing which has an upper section and wings extending from inner and outer sides of the upper section along the inner and outer side surfaces of the raceway rail and having the respective second raceway grooves formed therein, end caps fixed to respective opposite end surfaces of the casing and having the respective direction changing passages formed therein, and arcuate cover members having respective grooves which extend along longitudinal directions of the wings of the casing and into which respective arcuate pipe members adapted to form the respective return passages are fitted,

the cover members are fixed to the casing and/or the end caps,

wherein at least the outer wing of the casing has intersecting holes which are formed at each of positions located axially apart from each other, to thereby form engagement portions on its wall surface at the positions where the intersecting holes are present, at least the outer cover member disposed at the wing of the casing has hook portions extending toward the casing, having respective barbs, and provided in respective regions located in opposition to the engagement portions, and each of the hook portions is inserted into one of the intersecting holes, and the barbs are engaged with the respective engagement portions, whereby the cover member is fixed to the casing in position.

8. The curvilinear motion rolling guide unit according to claim 7 , wherein in the casing, one of the intersecting holes extends in the longitudinal direction, and the barbs of the hook portions provided in at least the outer cover member are engaged with the longitudinally extending holes, respectively, whereby the cover member is fixed to the casing in position.

9. The curvilinear motion rolling guide unit according to claim 8 , wherein the longitudinally extending holes formed in the casing are pilot holes for the end cap fixing threaded holes formed in the casing for fixing the end caps to the casing.