Linear guide

A slider has a slider main body which has a circulation sleeve whose inner portion forms a rolling element passage by being inserted into a hole penetrating in an axial direction, an end cap which has an outer peripheral track face of a direction changing passage in a curved shape for communicating a load track between two rolling element rolling grooves and the rolling element passage, and is fixed to an axial end portion of the slider main body, and an inner peripheral track member which has an inner peripheral track face of the direction changing passage, and is fitted to the end cap. An end portion of the circulation sleeve is provided with a plurality of positioning projected portions, and the end cap and the inner peripheral track member are provided with recess portions fitted with the positioning projected portions.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a linear guide used in, for example, a machine tool, an industrial machine field or the like.

2. Description of the Related Art

There is known a linear guide of this kind of a related art as shown in, for example,FIG. 35.

The linear guide is provided with a guide rail1extending in an axial direction and a slider2being laid across the guide rail1so as to relatively move along the axial direction. Two side faces in a width direction of the guide rail1are formed with rolling element rolling grooves3respectively extended in the axial direction by two upper and two lower streaks thereof on one side, that is, four streaks in total, and a slider main body2A of the slider2is formed with rolling element rolling grooves5respectively opposed to the rolling element rolling grooves3at inner side faces of two sleeve portions4thereof. A number of rollers6as rolling elements are rollably charged between the two rolling element rolling grooves3,5and the slider2is made to be able to move on the guide rail1relatively along the axial direction through rolling movement of the rollers6.

In accordance with the movement, the rollers6interposed between the guide rail1and the slider2are rolled to move to end portions in the axial direction of the slider2and in order to continuously move the slider2in the axial direction, it is necessary to infinitely circulate the rollers6. For that purpose, there are formed two upper and two lower (a total of four) of holes7penetrated respectively in the axial direction into the sleeve portions4on both sides of the slider main body2A and the holes7are inserted with circulation sleeves8whose inner portions form passages (rolling element passages) of the rollers6, two ends in the axial direction of the slider main body2A are fixed with a pair of end cap9respectively functioning rolling element circulating parts by screws or the like, and the end caps9are formed with direction changing passages9a(referred toFIG. 3andFIG. 4) curved in a shape of a semicircular arc for communicating intervals between the two rolling element rolling grooves3,5and the rolling element passages8ato thereby form infinite circulation tracks of the rollers6.

The direction changing passages9aprovided at the end cap9for communicating the rolling element passages8aon an upper side and the intervals between the two rolling element rolling grooves3,5on a lower side and the direction changing passages9afor communicating the rolling element passages8aon a lower side and the intervals between the two rolling element rolling grooves3,5on an upper side are formed to intersect such that the direction changing passages9ado not interfere with each other. Meanwhile, in fixing the end cap9to the end face of the slider main body2A, positioning of the circulation sleeve8(rolling element passage8a) on a side of the slider main body2A and the direction changing passage9aon a side of the end cap9becomes important in ensuring smooth circulation of the rollers6.

There is proposed a technology with regard to positioning in this way, in which, for example, two ends of a sleeve (circulation tube) are formed with chipped wall portions in a shape of a chipped circle, opening ends of direction changing passages of side plates (end caps) are formed with projected portions coinciding with the chipped wall portions of the sleeve, and the projected portions are fitted to insides of circular holes (inserting holes of the sleeve) of a casing (slider main body) and the chipped wall portions of the sleeve to thereby position the casing and the sleeves and the side plates each other (for example, refer to Japanese Patent Publication No. 2865854).

In this case, the casing, the sleeve and the side plate are constituted by separate members. Therefore, in integrating the sleeve, one end face of the casing is attached with the side plate, the sleeve is inserted into the circular hole penetrated to the casing from other end face thereof, and at that occasion, a phase is matched such that a shape of an inner periphery of the sleeve and a shape of an opening end of the direction changing passage of the side plate coincide with each other.

Japanese Patent Publication No. 2865854, JP-A-5-209617 and JP-A-9-72335 are referred to as related arts.

However, according to Japanese Patent Publication No. 2865854, when positioning of connecting portions of the circulation sleeve (rolling element passage) and the direction changing passage on the side of the end cap is going to be carried out accurately in order to make circulation of rollers smooth, it is necessary to promote an accuracy of fitting together the projected portion and the chipped wall portion. Therefore, unless the phase of the circulation sleeve is matched accurately, the end cap and the circulation sleeve are not integrated. Therefore, in inserting the circulation sleeve into the hole of the slider main body, the phase of the circulation sleeve needs to match accurately. In this case, operability is deteriorated and time is taken in integrating operation, which amounts to an increase in cost.

Further, in Japanese Patent Publication No. 2865854, the chipped wall portion provided at the circulation sleeve and the projected portion provided at the end cap are fitted together only at one location. Therefore, when the circulation sleeve is shifted by play by a clearance at the fitting portion, there is a concern that positioning of the rolling element passage in the circulation sleeve and the direction changing passage on the side of the end cap is not carried out accurately.

Further, it is difficult to determine the phase in a peripheral direction of the circulation sleeve at a glance and there is a concern of attaching the circulation sleeve to the hole of the slider main body by shifting the phase of the circulation sleeve by 180°. In this case, the chipped wall portion of the end portion of the circulation sleeve and the projected portion on the side of the opening end of the direction changing passage of the side plate (end cap) cannot be fitted together. Therefore, the integration cannot be carried out. Therefore, it is necessary to draw the circulation sleeve temporarily from the hole of the slider main body and reattach the circulation sleeve thereto by making the phase of the circulation sleeve correct again.

In this way, when the circulation sleeve is attached to the hole of the slider main body, it is necessary to pay close attention such that the direction of the circulation sleeve is not mistaken and integrating operation becomes complicated.

Further, in the case of the linear guide of the related art explained in reference toFIG. 35, when a circular arc track of a direction changing passage10provided at the end cap9and a linear track of the rolling element passage8ain the circulation sleeve8are connected, since normally, the end cap9and the circulation sleeve8are die molded products of resin, a corner portion is provided with facing to prevent burr from being produced in molding or in using at the corner portion. Particularly, when facing11is provided at a part of an inner peripheral guide face10aof the direction changing passage10connected with the rolling element passage8a, as shown byFIG. 36, even when the end cap9is positioned to a regular position with respect to the circulation sleeve8, a stepped difference is brought about at the facing portion11. In this case, smooth circulation of the roller6is hampered and the operability is deteriorated.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a linear guide which is capable of ensuring smooth circulation of a roller by enabling to accurately positioning of a circulation sleeve on a side of a slider main body and a direction changing passage on a side of an end cap, and is capable of promoting integration operability.

Further, it is an object of the invention to provide a linear guide which is capable of achieving an excellent operability by ensuring smooth circulation of a roller.

The invention provides a linear guide having a guide rail which has a rolling element rolling groove extending in an axial direction; and a slider which has a rolling element rolling groove opposed to the rolling element rolling groove of the guide rail, and is laid across the guide rail so as to relatively move along the axial direction through rolling movements of a number of rolling elements inserted into a load track formed between the two rolling element rolling grooves, wherein the slider has: a slider main body which has a circulation sleeve whose inner portion forms a rolling element passage by being inserted into a hole penetrating in the axial direction, an end cap which has an outer peripheral track face of a direction changing passage in a curved shape for communicating the load track and the rolling element passage, and is fixed to an axial end portion of the slider main body, and an inner peripheral track member which has an inner track face of the direction changing passage, and is fitted to a side of the end cap directed to a side of an end face of the slider main body, and wherein at least one of end portions of the circulation sleeve is provided with a plurality of positioning locking portions, and the end cap and the inner peripheral track member are provided with locked portions fitted with the positioning locking portions.

Therefore, the plurality of positioning locking portions on a side of the circulation sleeve are respectively fitted to the locked portion on a side of the end cap and the locked portion on a side of the inner peripheral track member. Therefore, positioning of the circulation sleeve and an end cap and the inner peripheral track member can accurately and firmly be carried out. As a result, smooth circulation of the roller is ensured and the operability of the linear guide can be improved.

In the linear guide, the plurality of positioning locking portions are arranged to be respectively axis-symmetrical with respect to a center axis of the rolling element passage. Therefore, even when a phase of the circulation sleeve is shifted by 180°, the positioning locking portions of the circulation sleeve and the locked portions provided at the end cap and the inner peripheral track member can be fitted with each other. Therefore, it is not necessary to paying attention to the phase of the circulation sleeve when the linear guide is integrated. As a result, the integrating operation can be facilitated.

In the linear guide, another end portion of the circulation sleeve is integrally formed with the inner peripheral track member. Therefore, the phase of the circulation sleeve is known at a glance by the inner peripheral track member. Therefore, the linear guide is not integrated by mistaking the phase of the circulation sleeve. Therefore, the integrating operation can further be facilitated.

In the linear guide, the locking portion has a projected portion at either one of a side of an end cap/a return guide and a side of the circulation sleeve, and a recess portion to be engaged with the projected portion at another side thereof, and at least one of the projected portion and the recess portion has an inclined face along a peripheral direction of an end face of the circulation sleeve. Therefore, positioning of the circulation sleeve on the side of the slider main body and the direction changing passage on the side of the end cap can accurately be carried out. As a result, smooth circulation of the roller can be ensured. Further, when the phase of the circulation sleeve is shifted within a range of inclination of the inclined face, accurate positioning can be carried out by engaging the projected portion with the recess portion easily by pushing the circulation sleeve. As a result, an integration operability can be promoted.

In the linear guide, the load tracks are formed by two upper and two lower streaks on one side, four streaks in total, the rolling element passages are formed by two upper and two lower passages on one side, four passages in total, the inner peripheral track member is formed by a first return guide and a second return guide which are fitted to a side of the end cap member directed to the side of the end face the slider main body, a side of one return guide of the first return guide and the second return guide is formed with the direction changing passage for communicating the rolling element passage on an upper side and the load track on a lower side, and a side of another return guide is formed with the direction changing passage for communicating the rolling element passage on a lower side and the load track on an upper side.

Further, In the linear guide, the first return guide and the second return guide are fitted in the axial direction of the guide rail in a state of being arranged substantially orthogonal to each other by constituting substantially a rectangular shape on a short side thereof provided with the inner peripheral track face of the rolling element in view from the axial direction of the guide rail.

Therefore, a request for high molding accuracy can be avoided by simplifying shapes of the first return guide and the second return guide, and operation of fitting the first return guide and the second return guide in the axial direction can easily be carried out. As a result, efficient formation of the integrating operation. Therefore, a reduction in fabrication cost can be achieved.

The invention also provides a linear guide having a guide rail which has a rolling element rolling groove extending in an axial direction, and a slider which has a rolling element rolling groove opposed to the rolling element rolling groove of the guide rail, and is laid across the guide rail so as to relatively move along the axial direction through rolling movements of a number of rolling elements inserted into a load track formed between the two rolling element rolling grooves, wherein the slider has: a slider main body which has a circulation sleeve whose inner portion forms a rolling element passage by being inserted into a hole penetrating in the axial direction, an end cap which has an outer peripheral track face of a direction changing passage in a curved shape for communicating the load track and the rolling element passage, and is fixed to an axial end portion of the slider main body, and an inner peripheral track member which has an inner track face of the direction changing passage, and is fitted to a side of the end cap directed to a side of an end face of the slider main body, wherein an opening end of the direction changing passage is formed with a part of the circulation sleeve.

Therefore, a stepped difference can be avoided to be produced at a part of connecting the end cap and the circulation sleeve. As a result, smooth circulation of the rolling element is ensured and an excellent operability can be achieved.

In the linear guide, it is preferable that the part of the circulation sleeve is formed integrally with the end cap, and is in a projected shape.

Further, in the linear guide, the circulation sleeve is shorter in length than the slider main body.

Further, in the linear guide, the circulation sleeve is shorter in length of the axial direction than the slider main body, and the part of the circulation sleeve formed integrally with the end cap is inserted into the hole of the slider main body.

Therefore, as thickness in the axial direction of the end cap can be minimized. Therefore, a length of a total of the slider can be shortened. As a result, compact formation of the linear guide can be achieved.

The invention also provides a linear guide having a guide rail which has a rolling element rolling groove extending in an axial direction, and a slider which has a rolling element rolling groove opposed to the rolling element rolling groove of the guide rail, and is laid across the guide rail so as to relatively move along the axial direction through rolling movements of a number of rolling elements inserted into a load track formed between the two rolling element rolling grooves, wherein the slider has: a slider main body which has a circulation sleeve whose inner portion forms a rolling element passage by being inserted into a hole penetrating in the axial direction, an end cap which has an outer peripheral track face of a direction changing passage in a curved shape for communicating the load track and rolling element passage, and is fixed to an axial end portion of the slider main body, and an inner peripheral track member which has an inner track face of the direction changing passage, and is fitted to a side of the end cap directed to a side of an end face of the slider main body, wherein an axial end portion of the circulation sleeve is provided with a plurality of fitting portions for positioning, the end cap is provided with a fitted portion which fits with the fitting portion by recess and projection fitting, and a projected portion of the fitting portion or the fitted portion is arranged to be unable to fit to an inner portion of the circulation sleeve on a side of a counter member.

Therefore, positioning of the circulation sleeve and the end cap can accurately and firmly be carried out. As a result, smooth circulation of the rolling element is ensured and the operability of the linear guide can be improved. Further, the projected portion of the fitting portion or the fitted portion for positioning is arranged to be unable to fit to the inner portion of the circulation sleeve. Therefore, in positioning, the projected portion can firmly be prevented from being erroneously fitted to the inner portion of the circulation sleeve.

Further, in the linear guide, it is preferable that the rolling element is a roller.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

First Embodiment

A first embodiment of the invention will be explained in reference toFIG. 1throughFIG. 9.FIG. 1is an explanatory view for explaining a projected portion on a side of a circulation sleeve of a linear guide according to the first embodiment,FIG. 2is a sectional view taken along a line A-A ofFIG. 1,FIG. 3is an explanatory view for explaining a recess portion on a side of an end cap,FIG. 4is a sectional view taken along a line B-B ofFIG. 3,FIG. 5AandFIG. 5Bare explanatory views for explaining an example of a structure of engaging a projected portion and a recess portion,FIG. 6AandFIG. 6Bare explanatory views for explaining a modified example of a structure of engaging a projected portion and a recess portion,FIG. 7AandFIG. 7Bare explanatory views for explaining a modified example of a projected portion, andFIG. 8andFIG. 9are explanatory views for explaining examples of forming inclined faces.

A linear guide of the embodiment is provided with a guide rail11extending in an axial direction and a slider12being laid across the guide rail11so as to relatively move along an axial direction. Two side faces in a width direction of the guide rail11are formed with rolling element rolling grooves13respectively extended in the axial direction by two upper and two lower streaks on one side, that is, four streaks in total, a slider main body12A of the slider12is formed with rolling element rolling grooves15respectively opposed to the rolling element rolling grooves13at inner side faces of two sleeve portions14thereof. A number of rollers16as rolling elements are rollably charged between the two rolling element rolling grooves13,15, and the slider12is made to be able to relatively move on the guide rail11along the axial direction through rolling of the rollers16.

Although the rollers16interposed between the guide rail11and the slider12are rolled to move to end portions in the axial direction of the slider12in accordance with the movement, in order to continuously move the slider12in the axial direction, it is necessary to infinitely circulate the rollers16. For that purpose, two upper and two lower (a total of four) of holes17respectively penetrating in the axial direction are formed at insides of the sleeve portions14on the both sides of the slider main body12A and circulation sleeves18inner portions of which are made to constitute passages (rolling element passages)18aof the rollers16are inserted into the holes17, a pair of end caps19as rolling element circulating parts are fixed respectively to both ends in the axial direction of the slider main body12A via screws or the like, the end caps19are formed with direction changing passages curved in a shape of a semicircular arc for communicating intervals between the two rolling element rolling grooves13,15and the rolling element passages18ato thereby form an infinite circulation track of the rollers16.

According to the linear guide110of the embodiment, as shown byFIG. 1, the circulation sleeves18made of resin are inserted into the holes17at four locations penetrated to the slider main body12A, and inner peripheral portions of the circulation sleeves18are formed with the rolling element passages18ahaving a square section through which the roller16can pass with more or less clearances therebetween. The circulation sleeve18is brought into a state of being mounted with members in a half divided shape in a diameter direction. A length of the circulation sleeve18is made to be a length substantially the same as that of the slider main body12A, further, as shown byFIG. 2, clearances17aare provided between an outer peripheral face of the circulation sleeve18and an inner peripheral face of the hole17.

Holding members111for holding the upper and lower rollers16are interposed between the two rolling element rolling grooves13,15on upper sides and the two rolling element rolling grooves13,15on lower sides and end portions in the axial direction of the holding members111are provided with grooves112for positioning the end caps19. As shown byFIG. 3andFIG. 4, direction changing passages19aof the end caps19for communicating the rolling element passages18aon upper sides and intervals between the two rolling element rolling grooves13,15on lower sides and direction changing passages19afor communicating the rolling element passages18aon lower sides and intervals between the two rolling element rolling grooves13,15on upper sides are formed to intersect three-dimensionally such that the direction changing passages19ado not interfere with each other. Further, faces of the end caps19directed to sides of the slider main body12A are projected with positioning projections113fitted to the positioning grooves112.

Here, according to the embodiment, projected portions114are provided at both end portions of the circulation sleeve18, recess portions115engaged with the projected portion114are provided at surroundings of opening ends of the direction changing passages19aof the end cap19, further, as shown byFIG. 5AandFIG. 5B, inclined faces116along peripheral directions of end faces of the circulation sleeve18are provided at the projected portions114and the recess portions115. Further, the positioning projection113of the end cap19is fitted to the positioning groove112on one end face of the slider main body12A, under the state, the circulation sleeve18is inserted into the hole17from other end face of the slider main body12A, and the projected portion114of one end portion of the circulation sleeve18is engaged with the recess portion115on a side of the end cap19to thereby support the circulation sleeve18in a state of providing the clearances17abetween the circulation sleeve18and the hole17.

Thereby, positioning of the rolling element passage18ain the circulation sleeve18and the direction changing passage19aon the side of the end cap19can accurately be carried out and smooth circulation of the rollers16can be ensured. Further, since the projected portion114and the recess portion115are provided with the inclined faces116along the peripheral direction of the end face of the circulation sleeve18, when the phase of the circulation sleeve18is constituted by a shift within a range of inclination of the inclined face116, accurate positioning can be carried out by engaging the projected portion114with the recess portion115easily by pushing the circulation sleeve18. As a result, integrating operability can be promoted.

Further, the linear guide of the embodiment is not limited to the above-described embodiment but can pertinently be changed within the range not deviated from the gist of the invention. For example, although according to the above-described embodiment, there is adopted the case in which a total face of the face along the peripheral direction of the projected portion114is constituted by the inclined face116as an example, in place thereof, as shown byFIG. 6AandFIG. 6B, a further stable engaging structure can be constituted by constituting the inclined face116only by a front end of the face along the peripheral direction of the projected portion114and providing a linear portion117at a base end portion thereof.

Further, although according to the above-described embodiment, there is adopted the case of providing the projected portion114at a part of the end portion of the circulation sleeve18as an example, in place thereof, as shown byFIG. 7AandFIG. 7B, a total of the end portion of the circulation sleeve18may be provided with the projected portion114having the inclined face116. Thereby, a larger shift of the face of the circulation sleeve18can be dealt with. Further, the inclined faces116provided to the projected portion114and the recess portion115may be provided at a portion in the peripheral direction as shown byFIG. 8, further, may be provided at a total periphery in the peripheral direction.

Further, although according to the above-described embodiment, there is adopted a case of providing the inclined faces116to both of the projected portion114and the recess portion115as an example, the embodiment is not limited thereto but the inclined face116may be provided to either of the projected portion114and the recess portion115. Further, although according to the above-described embodiment, there is adopted the case of providing the projected portion114to the side of the circulation sleeve18and providing the recess portion115to the side of the end cap19as the example, in place thereof, the recess portion115may be provided to the side of the circulation sleeve18and the projected portion114may be provided to the side of the end cap.

Second Embodiment

A second embodiment of the invention will be explained in reference toFIG. 10thoroughFIG. 18.FIG. 10is a sectional view of an essential portion of a slider for explaining a linear guide according to the second embodiment,FIG. 11is a disassembled view of an end cap, an inner peripheral track member and a circulation sleeve,FIG. 12AandFIG. 12Bare views viewing a circulation sleeve from an axial direction,FIG. 13is a view viewing an end cap from a side of an end face of a slider main body,FIG. 14is a left side view ofFIG. 13, andFIG. 15throughFIG. 18are views for explaining a linear guide which is other example of the embodiment.

The linear guide of the embodiment is provided with a guide rail21extending in an axial direction and a slider22being laid across the guide rail21so as to relatively move along the axial direction. Two side faces in a width direction of the guide rail21are formed with rolling element rolling grooves23respectively extended in the axial direction by two upper and two lower streaks on one side, that is, four streaks in total, and a slider main body22A of the slider22is formed with rolling element rolling grooves25respectively opposed to the rolling element rolling grooves23at inner side faces of two sleeve portions24thereof. A number of rollers26as rolling elements are rollably charged between the two rolling element rolling grooves23,25and the slider22is made to be able to relatively move on the guide rail21along the axial direction through rolling of the rollers26.

Although the rollers26interposed between the guide rail21and the slider22are moved to end portions in the axial direction of the slider22in accordance with the movement, in order to continuously move the slider22in the axial direction, it is necessary to infinitely circulate the rollers26. For that purpose, two upper and two lower (a total of four) of holes27respectively penetrated in the axial direction are formed in the sleeve portions24on both sides of the slider main body22A and the holes27are inserted with circulation sleeves28inner portions of which are made to constitute passages (rolling element passages)28aof the rollers26, a pair of end caps29as rolling element circulating parts are respectively fixed to both ends in the axial direction of the slider main body22A by screws or the like, and the end caps29are formed with direction changing passages curved in a shape of a semicircular arc for communicating intervals between the two rolling element rolling grooves23,25and the rolling element passages28ato thereby form an infinite circulation track of the rollers26.

According to the linear guide of the embodiment, as shown byFIG. 10,FIG. 13andFIG. 14, a first return guide (inner peripheral track member)230is fitted in the axial direction of the guide rail1to a side of the end cap29directed to an end face of the slider main body22A, a second return guide240(inner peripheral track member) is fitted in the axial direction of the guide rail21to the first return guide230, and the first return guide230and the second return guide240are arranged substantially orthogonal to each other by constituting substantially a rectangular shape provided with an inner peripheral track face26aof the cylindrical roller26on a side of a short side in view from the axial direction of the guide rail21(referred toFIG. 13).

Further, according to the embodiment, the one direction changing passage of the direction changing passage210afor communicating the rolling element passage28aon an upper side and a load track between the two rolling element rolling grooves23,25on a lower side and a direction changing passage210bfor communicating the rolling element passage28aon a lower side and a load track between the two rolling element rolling grooves23,25on an upper side, is formed by the inner peripheral track face26aof the first return guide230and an outer peripheral track face26bof the end cap29on a left end side ofFIG. 10of the slider main body22A, on a right end side ofFIG. 10of the slider main body22A, one direction changing passage is formed by the inner peripheral track face26aof the second return guide240, the outer peripheral track face26bof the first return guide230and the outer peripheral track face26bof the end cap29, another direction changing passage is formed by the inner peripheral track face26aof the second return guide240, the outer peripheral track face26bof the first return guide230and the outer peripheral track face26bof the end cap29on a left end side ofFIG. 10of the slider main body22A, and on a right end side ofFIG. 10of the slider main body22A, another direction changing passage is formed by the inner peripheral track face26aof the first return guide and the outer peripheral track face26bof the end cap29.

Further, as shown byFIG. 10, the circulation sleeves28made of resin are inserted into holes27at four locations penetrating the slider main body22A in the axial direction, and an inner peripheral portion of the circulation sleeve28is formed with the rolling element passage28ahaving a square section through which the roller26can pass with more or less clearances therebetween. As shown byFIG. 12AandFIG. 12B, the circulation sleeve28is brought into a state of bonding members in a half divided shape in a diameter direction to facilitate fabrication by injection molding, further, a length in the axial direction of the circulation sleeve28is made to be a length substantially the same as that of the slider main body22A.

Here, according to the embodiment, both end portions of the circulation sleeve28are provided to arrange with positioning projected portions (positioning locking portions)220in a taper shape respectively at two locations to be axis-symmetrical with respect to a center axis of the rolling element passage28a, the first return guide230, the second return guide240and the end cap19are provided with recess portions (locked portions)221in a taper shape fitted with the positioning projected portions220, the positioning projected portions220at two locations of one end portion of the circulation sleeve28are fitted to the respective recess portions221of the second return guide240and the end cap29, and the positioning projected portions220at two locations of another end portion are fitted to the respective recess portions221of the first return guide230and the end cap29.

In this way, according to the embodiment, positioning of the circulation sleeve28and the end cap29as well as the first return guide230and the second return guide240can be carried out by simply fitting recesses and projections of the plurality of positioning projected portions220provide at end portions of the circulation sleeve28and the recess portions221provided at the end cap29, the first return guide230and the second return guide240. Therefore, it is not necessary to provide the end portions of the circulation sleeve28and the opening ends of the direction changing passages on the sides of the end caps29with recessed and projected portions having a complicated shape as in the related art. Thereby, time and labor of fabrication can be saved and low cost formation can be achieved.

Further, since the plurality of positioning projected portion220on the sides of the circulation sleeves28are respectively fitted to the recess portions221on the sides of the end caps29as well as the respective recess portions221of the first return guide230and the second return guide240. Therefore, positioning of the circulation sleeves28and the end caps29, the first return guide230and the second return guide240can accurately and firmly be carried out. Thereby, smooth circulation of the rollers26is ensured and operability of the linear guide can be improved.

Further, the positioning projected portion220and the recess portion221are formed in a taper shape. Therefore, even when there is more or less shift in the phase of the circulation sleeve28, so far as the phase of the circulation sleeve28is constituted by a shift within the ranges of inclination of the taper faces of the positioning projected portions220and the recess portions221, accurate positioning can be carried out by engaging the positioning projected portion220with the recess portion221easily by pushing the circulation sleeve28. Further, the plurality of positioning projected portions220provided at the end portion of the circulation sleeve28are arranged to be axis-symmetrical with respect to the center axis of the rolling element passage28ain the circulation sleeve28. Therefore, even when the face of the circulation sleeve28is shifted by 180°, the positioning projected portion220on the side of the circulation sleeve28and the end cap29can be fitted to the respective recess portions210of, the first return guide230and the second return guide240. Therefore, it is not necessary to paying attention to the face of the circulation sleeve28when the linear guide is integrated. Therefore, the integrating operation can be facilitated.

Further, the first return guide230fitted to the end cap29and the second return guide240fitted to the first return guide230are arranged substantially orthogonally to each other by constituting substantially the rectangular shape provided with the inner peripheral track face26aof the roller26on the side of the short side in view from the axial direction of the slider main body22A. Therefore, the shapes of the first return guide230and the second return guide240are simplified and a request for high mold accuracy can be avoided and operation of fitting the first return guide230and the second return guide240in the axial direction can easily be carried out. Therefore, efficient formation of the integrating operation. Therefore, low cost formation of fabrication cost can be achieved.

Further, the linear guide of the inventing is not limited to the above-described embodiment but can pertinently be changed within the range not deviated from the gist of the invention. For example, although according to the above-described embodiment, there is adopted the case of providing the plurality of positioning projected portions220at both end portions of the circulation sleeve28as an example, in place thereof, as shown byFIG. 15andFIG. 16, the positioning projected portions220in the taper shape at two locations are provided only at one end portion (right end portion ofFIG. 15andFIG. 16) of the circulation sleeve28by being arranged to be axis-symmetrical with respect to the center axis of the rolling element passage28a, and another end portion (left end portion ofFIG. 15andFIG. 16) of the circulation sleeve28may be integrally formed with a second return guide240(referred toFIG. 17) constituted by a half divided shape along with the circulation sleeve28and may be provided with the positioning projected portion220in the taper shape at one location.

In this case, as shown byFIG. 15,FIG. 16andFIG. 18, the recess portions221fitted with the positioning projected portions220are provided at the first return guide230and the end cap29, the positioning projected portions220at two locations of one end portion of the circulation sleeve28are fitted to the respective recess portions221of the first return guide230and the end cap29, the positioning projected portion220at one location of another end portion thereof is fitted to the recess portion221of the end cap29, and the second return guide240integral with the circulation sleeve28is fitted to the first return guide230fitted to the end cap29.

By integrally forming the second return guide240at another end portion of the circulation sleeve28in this way, the phase of the circulation sleeve28can be known at a glance by the second return guide240. Therefore, the linear guide is not integrated by mistaking the phase of the circulation sleeve28and the integrating operation can further be facilitated. Further, according to the embodiment, by providing a projection223fitted to a fitting hole222provided at the end face of the slider main body22A at the second return guide240provided integrally with the circulation sleeve28and fitting the projection223of the second return guide240to the fitting hole222of the slider main body22A, the phase of the circulation sleeve28is determined.

Further, although according to the above-described embodiment, there is adopted the case of providing the positioning projected portions at the circulation sleeve and providing the recess portions fitted with the positioning projected portions at the end cap and the inner peripheral track member as the example, it is not necessarily needed to constitute in this way but the circulation sleeve may be provided with the positioning recess portions and the end cap and the inner peripheral track member may be provided with the projected portions fitted with the positioning recess portions, further, the circulation sleeve may be provided with the positioning projected portion and the positioning recess portion and the end cap and the inner peripheral track member may be provided with recessed and projected portions in correspondence therewith.

Third Embodiment

A third embodiment of the invention will be explained in reference toFIG. 19throughFIG. 28.FIG. 19is a sectional view of an essential portion of a slider for explaining a linear guide according to a third embodiment,FIG. 20is a view showing a side of an end face of a slider main body,FIG. 21is a sectional view taken along a line A-A ofFIG. 20,FIG. 22is a view viewing an end cap from a side of an end face of a slider main body,FIG. 23is a sectional view taken along a line B-B ofFIG. 22,FIG. 24is a view showing a half divided member of a circulation sleeve,FIG. 25is a view viewing from an arrow mark C direction ofFIG. 24,FIG. 26is a right side view ofFIG. 25,FIG. 27is a view viewing from an arrow mark D direction ofFIG. 25, andFIG. 28is a sectional view of an essential portion of a slider for explaining a linear guide according to the other embodiment of the invention.

A linear guide of the embodiment is provided with a guide rail31extending in an axial direction and a slider32being laid across the guide rail31so as to relatively move along an axial direction. Two side faces in a width direction of the guide rail31are formed with rolling element rolling grooves33respectively in the axial direction by two upper and two lower streaks on one side, that is, four streaks in total, a slider main body32A of the slider32is formed with rolling element rolling grooves35opposed to the rolling element rolling grooves33respectively at inner side faces of two sleeve portions34thereof. A number of rollers36as rolling elements are rollably charged between the two rolling element rolling grooves33,35and the slider32can be moved relatively along the axial direction on the guide rail31through rolling of the rollers36.

Although the rollers36interposed between the guide rail31and the slider32are rolled to move to end portions in the axial direction of the slider32in accordance with the movement, in order to continuously move the slider32in the axial direction, it is necessary to infinitely circulate the rollers36. For that purpose, two upper and two lower (total of four) of holes37penetrated respectively in the axial direction are formed at insides of sleeve portions34on both sides of a slider main body32A and the holes37are inserted with circulation sleeves38inner portions of which are made to constitute passages (rolling element passages)38aof the rollers36, a pair of end caps39respectively as rolling element circulating parts are fixed to both ends in the axial direction of the slider main body32A via screws or the like and the end caps39are formed with direction changing passages curved in a shape of a semicircular arc for communicating intervals of the rolling element rolling grooves33,35and the rolling element passages38ato thereby form infinite circulation tracks of the rollers36.

According to the linear guide of the embodiment, as shown byFIG. 19andFIG. 20, the circulation sleeves38made of resin are inserted to the holes37at four locations penetrated in the axial direction of the slider main body32A with clearances312therebetween, and inner peripheral portions of the circulation sleeves38are formed with the rolling element passages38ahaving a square shape through which the rollers36can pass with more or less clearances therebetween. As shown byFIG. 20andFIG. 21, the circulation sleeve38is formed by bonding half divided members320ahaving substantially the same shape divided in two along the axial direction respectively in a diameter direction, specifically, as shown byFIG. 24throughFIG. 27, by fitting together projections321and recess portions322disposed at faces of overlapping the respective half divided member320a, a single piece of the circulation sleeve38is formed. Further, a wall thickness of the half divided member320ais made to be substantially constant and the half divided member320ais provided with build-up portions323at respective locations for reinforcement. Further, a plurality of positioning projected portions324are projected from both end portions of the circulation sleeve38as an example of means for positioning with the end caps39.

Holding members325(refer toFIG. 20) for holding the upper and lower rollers36are interposed between the two rolling element rolling grooves33,35on an upper side and the two rolling element rolling grooves33,35on a lower side, and positioning grooves326(refer toFIG. 22) of the end cap39are provided at end portions in the axial directions of the holding member325. As shown byFIG. 22andFIG. 23, inside of the end cap39is arranged with a direction changing passage330afor communicating the rolling element passage38aon an upper side and a load track between the two rolling element rolling grooves33,35on a lower side and a direction changing passage330bfor communicating the rolling element passage38aon a lower side and a load track between the two rolling element rolling grooves33,35on upper side by being intersected three-dimensionally such that the direction changing passages do not interfere with each other.

The direction changing passage330ais formed with an inner side track passage of the roller36at inside of the end cap39on an inner side of the direction changing passage330bon a left end side ofFIG. 19and is formed with an outer side track passage of the roller36at inside of the end cap39on an outer side of the direction changing passage330bon a right end side thereof. On the other hand, the direction changing passage330bis formed with an outer side track passage of the roller36at inside of the end cap39on an outer side of the direction changing passage330aon a left end side ofFIG. 19and is formed with an inner side track passage of the roller36at inside of the end cap39on an inner side of the direction changing passage330aon a right end side thereof. Thereby, track lengths of the direction changing passages330a,330bare made to be the same track length.

Further, as shown byFIG. 22, a face of the end cap39directed to the side of the slider main body32A is projected with a positioning projection327fitted to the positioning groove326provided at an end portion of the holding member325. Here, according to the embodiment, respective opening ends of the direction changing passages330a,330bof the end cap39are formed with projections331inner portions of which are made to constitute portions of the rolling element passages38a, the projections331are formed with recess portions332(refer toFIG. 22) in correspondence with the plurality of positioning projected portion324at the end portion of the circulation sleeve38, a length in the axial direction of the circulation sleeve38is made to be shorter than a length in the axial direction of the slider main body32A and the projection331is inserted into the hole37of the slider main body32A, and the recess portion332is fitted to the positioning projected portion324to thereby accurately position the rolling element passage38aof the circulation sleeve38and the direction changing passages330a,330b, thereby, the circulation sleeve38is positioned and supported at a regular position in a state of providing clearances312between the circulation sleeve38and the hole37.

In this way, according to the embodiment, the opening ends of the direction changing passages330a,330bof the end cap39are integrally formed with the projections331inner portions of which are made to constitute portions of the rolling element passage38a. Therefore, linear tracks constituting portions of the rolling element passage38aare integrally formed with the opening ends of the direction changing passages330a,330bsubstantially in the circular arc shape on the side of the end cap39. Therefore, a stepped difference can be avoided to be produced at portions of connecting with the linear tracks on the side of the circulation sleeve38, smooth circulation of the roller36can be ensured and excellent operability can be achieved.

Further, since the length in the axial direction of the circulation sleeve38is made to be shorter than the length in the axial direction of the slider main body32A, the projections331at the opening ends of the direction changing passages330a,330bare inserted into the holes37of the slider main body32A. Therefore, a thickness in the axial direction of the end cap39can be minimized. Therefore, compact formation of the linear guide can be achieved by shortening the length of the total of the slider32.

Further, the linear guide of the invention is not limited to the above-described embodiment but can pertinently be changed within the range not deviated of the gist of the invention. For example, as shown byFIG. 28, in the respective direction changing passages330a,330b, members340forming inner peripheral guide faces of the inner side track passages of the roller36may integrally be formed with the circulation sleeves38. Thereby, the phase of the circulation sleeve38can be known at a glance by the member340. Therefore, the linear guide is not integrated by mistaking the phase of the circulation sleeve38. Therefore, the integrating operation can be facilitated.

Fourth Embodiment

A fourth embodiment of the invention will be explained in reference toFIG. 29throughFIG. 34.FIG. 29is an explanatory view for explaining a linear guide of a fourth embodiment,FIG. 30is a sectional view of an essential portion of a slider, andFIG. 31throughFIG. 34are views showing modified examples of a projected portion.

The linear guide of the embodiment is provided with a guide rail41extending in an axial direction and a slider42being laid across the guide rail41so as to relatively move along the axial direction. Two side faces in a width direction of the guide rail41are formed with rolling element rolling grooves43respectively extended in the axial direction by two upper and two lower streaks on one side, that is, four streaks in total, and inner side faces of two sleeve portions44of a slider main body42A of the slider42are respectively formed with rolling element rolling grooves45opposed to the rolling element rolling grooves43. A number of rollers46as rolling elements are rollably charged between the two rolling element rolling grooves43,45and the slider42is made to be able to move on the guide rail41relatively along the axial direction.

Although the rollers46interposed between the guide rail41and the slider42are rolled to move to end portions in the axial direction of the slider42in accordance with the movement, in order to continuously move the slider42in the axial direction, it is necessary to infinitely circulate the rollers46. For that purpose, insides of sleeve portions44on both sides of the slider main body42A are formed with two upper and two lower (a total of four) of holes47respectively penetrated in the axial direction and the holes47are inserted with circulation sleeves48inner portions of which are made to constitute passages (rolling element passages)48aof the rollers46, both ends in the axial direction of the slider main body42A are fixed with a pair of end caps49as rolling element circulation parts via screws or the like, and the end caps49are formed with direction changing passages curved in a shape of a semicircular arc for communicating intervals between the two rolling element rolling grooves43,45and the rolling element passages48ato thereby form infinite circulation tracks of the rollers46.

According to the linear guide of the embodiment, as shown byFIG. 29andFIG. 30, the end cap49is provided with an end cap main body49a, a first return guide430and a second return guide440, the first return guide430is fitted to a side of the slider main body42A of the end cap main body49adirected to an end face of the slider main body42A in the axial direction of the guide rail41, and the first return guide430is fitted with the second return guide440in the axial direction of the guide rail41.

Further, according to the embodiment, by the end cap main body49a, the first return guide430and the second return guide440, there are formed a direction changing passage410for communicating the rolling element passage48aon an upper side and a load track between the two rolling element rolling grooves43,45on a lower side and a direction changing passage410for communicating the rolling element passage48aon a lower side and a load track between the two rolling element rolling grooves43,45on an upper side. Further, circulation sleeves48made of resin are inserted into the holes47at four locations penetrated through the slider main body42A in the axial direction, and inner peripheral portions of the circulation sleeves48are formed with rolling element passages48ahaving a square section through which the rollers46of the rolling elements can pass with more or less clearances therebetween.

Here, according to the embodiment, both end portions of the circulation sleeve48are respectively provided with positioning projected portions (fitting portions)450in a taper shape at two locations to be axis-symmetrical in a direction of a short side of the rolling element passage48awith respect to a center axis of the rolling element passage48a, the end caps49are provided with recess portions (fitted portions)451in a taper shape fitted to the positioning projected portions450, and the positioning projected portions450at two locations on a side of the circulation sleeve48are fitted to the respective recess portions451on a side of the end cap49.

Meanwhile, in reference toFIG. 29, when a dimension between bottom portions of guide grooves424constituting portions of the circulation sleeve opposed to each other is designated by notation A and a dimension between outer side faces of the projected portions450at two locations provided at an end portion of the circulation sleeve48is designated by notation B, in the case of A≧B, in fitting the projected portion450on the side of the circulation sleeve48to the recess portion451on the side of the end cap49, there is a possibility that a failure in integration is brought about by erroneously fitting the projected portion450to the guide groove424on the side of the end cap49. The failure in integration is found after the slider42has been finished to integrate and the rollers46are inserted. Therefore, when the integration is carried out again thereafter, enormous time and labor are wasted. In this case, an operational efficiency is lowered and integration cost is increased.

Hence, according to the embodiment, when the dimension between the bottom portions of the guide groove424opposed to each other is designated by notation A and the dimension between the outer guide faces of the projected portions450at two locations provided at the end portion of the circulation sleeve48is designated by notation B, by constituting A<B, the projected portion450is arranged to be unable to fit to the guide groove424on the side of the end cap49. Thereby, the possibility of bringing about the failure in integration is eliminated by firmly preventing the projected portion450from being erroneously fitted to the guide groove424on the side of the end cap49when the projected portion450on the side of the circulation sleeve48is fitted to the recess portion451on the side of the end cap49.

In this way, according to the embodiment, by simply fitting recesses and projections of the plurality of positioning projected portions450provided at the end portion of the circulation sleeve48and the recess portions451on the side of the end cap49, positioning of the circulation sleeve48and the end cap49can be carried out. Therefore, positioning of the circulation sleeve48and the end cap49can accurately and firmly be carried out. Thereby, smooth circulation of the rollers46can be ensured and the operability of the linear guide can be improved.

Further, since the projected portions450on the side of the circulation sleeve48are arranged to be unable to fit to the guide grooves424on the side of the end cap49, when the projected portions450on the side of the circulation sleeve48are fitted to the recess portions451on the side of the end cap49, the projected portions450can firmly be prevented from being erroneously fitted to the guide grooves424on the side of the end cap49. Thereby, the possibility of bringing about the failure in integration is eliminated and promotion of the operational efficiency and a reduction in integration cost can be achieved.

Further, the linear guide of the invention is not limited to the above-described embodiment but can pertinently be changed within the range not deviated from the gist of the invention. For example, although according to the above-described embodiment, there is adopted the case in which the both end portions of the circulation sleeve48are provided with the positioning projected portions450respectively at two locations to be axis-symmetrical in the direction of the short side of the rolling element passage48awith respect to the center axis of the rolling element passage48aas an example, in place thereof, as shown byFIG. 31, one of the projected portions450at two locations may be arranged to shift, further, as shown byFIG. 32andFIG. 33, the projected portions450may be arranged at three locations and four locations, or five or more locations.

Further, although according to the above-described embodiment, there is exemplified the case of constituting the projected portion450by the section in the circular shape, the sectional shape of the projected portion450is not particularly limited but the section may be constituted by an oval shape as shown by, for example,FIG. 34. In any cases ofFIG. 31throughFIG. 34, when a line passing center O of the circulation sleeve48and connecting the bottom portions of the guide groove424opposed to each other is defined as a center line L1, a line passing the center O of the circulation sleeve48and orthogonal to the center line L1is defined as a center line L2, a dimension from center line L1to an inner side face of the guide groove424is designated by notation C, and a longest dimension from the center line L2to the projected portion450is designated by notation D, in the case of C≧D, there is a possibility of bringing about a failure in integration by erroneously fitting the projected portion450to the guide groove424on the side of the end cap49when the projected portion450on the side of the circulation sleeve48is fitted to the recess portion451on the side of the end cap49. When C<D is constituted, the projected portion450is made to be unable to fit to the guide groove424on the side of the end cap49and when the projected portion450on the side of the circulation sleeve48is fitted to the recess portion451on the side of the end cap49, the projected portion450can firmly be prevented from being erroneously fitted to the guide groove424on the side of the end cap49. Thereby, the possibility of bringing about the failure in integration is eliminated and operation and effect similar to those of the above-described embodiment can be achieved.

Further, although according to the above-described embodiment, there is adopted the case in which the projected portion450is provided on the side of the circulation sleeve48and the recess portion451is provided on the side of the end cap49as an example, in place thereof, the recess portion451may be provided on the side of the circulation sleeve48and the projected portion450may be provided on the side of the end cap49. Furthermore, although according to the above-described embodiment, there is shown an example of arranging the projected portion450on the side of the circulation sleeve48to be unable to fit to the guide groove424on the side of the end cap49, when the guide groove424is not provided, the projected portion450may be arranged to be unable to fit to the rolling element passage on the side of the end cap49.

Although according to the four embodiments explained above, an explanation has been given by taking an example of the roller as the rolling element, the rolling element may be a ball.