LINEAR GUIDE DEVICE

Abstract

A linear guide device includes a rail that has a first advancing device extending along a longitudinal direction, a carriage that can be displaced relative to the rail along the longitudinal direction and has a second advancing device extending along the longitudinal direction, a cage that can be displaced relative to the rail and the carriage along the longitudinal direction and a coupling element that is designed for simultaneously engaging into the first and the second advancing device in order to cause a movement of the cage relative to the rail and/or the carriage when the carriage is advanced relative to the rail along the longitudinal direction. The coupling element has at least one projection that interacts with a stopping face formed on the rail and/or the carriage in order to retain the coupling element in the linear guide device.

Claims

1. A linear guide device, comprising a rail (2) that has a first advancing device (8) extending along a longitudinal direction (L), a carriage (3) that can be displaced relative to the rail (2) along the longitudinal direction (L) and has a second advancing device (9) extending along the longitudinal direction (L), a cage (4) that can be displaced relative to the rail (2) and the carriage (3) along the longitudinal direction (L) and a coupling element (6) that is designed for simultaneously engaging into the first and the second advancing device in order to cause a movement of the cage (4) relative to the rail (2) and/or the carriage (3) when the carriage (3) is advanced relative to the rail (2) along the longitudinal direction (L), wherein the coupling element (6) has at least one projection (43, 44) that interacts with a stopping face (13a, 14, 35a, 36) formed on the rail and/or the carriage in order to retain the coupling element (6) in the linear guide device (1).

2. The linear guide device according to claim 1, wherein the coupling element is realized in the form of a gearwheel (6) that is arranged in the linear guide device (1) so as to be rotatable about a rotational axis (A), wherein the rotational axis (A) extends transverse, preferably perpendicular, to the longitudinal direction (L) and the at least one projection (43, 44) extends away from the gearwheel (6) in the direction of the rotational axis (A).

3. The linear guide device according to claim 1, wherein the cage (4) has a recess (7, 51, 52), through which the coupling element (6) extends, and wherein the projection (43, 44) of the coupling element abuts on a boundary of the recess in order to cause the movement of the cage (4) relative to the rail (2) and/or the carriage (3).

4. The linear guide device according to claim 1, wherein the linear guide device (1) has no mounting of the coupling element (6) on the cage (4).

5. The linear guide device according to claim 1, wherein the at least one projection (43, 44) of the coupling element essentially is designed cylindrically, and wherein a diameter (D2, D3) of the cylindrical projection is smaller than a diameter (D1) of the coupling element.

6. The linear guide device according to claim 1, wherein the stopping face is a boundary (11, 14, 34, 36) of the carriage (3) and/or the rail (2) facing the cage (4), particularly an underside (34, 36) of the carriage (3) and/or an upper side (11, 14) of the rail (2), in order to prevent a movement of the coupling element (6) in the direction of the rail (2) and/or the carriage (3).

7. The linear guide device according to claim 1, wherein the rail (2) and/or the carriage (3) has a groove (13, 35), particularly a groove that extends in the longitudinal direction (L) and/or is arranged laterally of the first or second advancing device (8, 9), and wherein the stopping face is formed by a wall (13a, 35a) of the groove in order to limit the movement of the coupling element (6) parallel to the carriage (3) and/or the rail (2).

8. The linear guide device according to claim 6, wherein the coupling element (6) has at least one first projection (43), which abuts on the groove (13, 35) of the rail and/or the carriage, and one second projection (44), which abuts on the boundary (11, 14, 34, 36) of the carriage and/or the rail facing the cage (4), and wherein a dimension, particularly a diameter (D2), of the first projection (43) preferably is greater than a dimension, particularly a diameter (D3), of the second projection (44).

9. The linear guide device according to claim 1, wherein the cage (4) is arranged between the rail (2) and the carriage (3).

10. The linear guide device according to claim 1, wherein the cage (4) has a plurality of rolling bodies (5) that respectively abut on the carriage (3) and on the rail (2) in a rollable manner.

11. The linear guide device according to claim 1, wherein the cage (4) comprises a base body (21), preferably an essentially planar base body, and two legs (22a, 22b) that extend away from the base body (21), preferably perpendicularly, and are designed for receiving the rail (2) in an intermediate space formed between the two legs.

12. The linear guide device according to claim 1, wherein the carriage (3) essentially is designed in a U-shaped manner in a plane extending perpendicular to the longitudinal direction (L), and wherein the legs (32a, 32b) of the U-shaped carriage are designed for receiving the cage (4) in an intermediate space formed between the two legs.

13. The linear guide device according to claim 1, furthermore comprising a limit stop that limits the movement of the cage (4) relative to the rail (2) and/or the carriage (3) in the longitudinal direction (L), wherein the limit stop preferably is realized in the form of an oblong opening (25) in the cage (4) and a screw (10) that extends through the opening and is fastened on the rail (2) or the carriage (3).

14. The linear guide device according to claim 1, wherein the first and/or second advancing structure is realized in the form of a gear rack (8, 9).

15. The linear guide device according to claim 1, furthermore comprising a drive that is designed for driving the carriage (3) in a displaceable manner relative to the rail (2) along the longitudinal direction (L).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

[0030] In the drawings,

[0031] FIG. 1 shows a schematic perspective view of a linear guide device according to an embodiment of the present invention,

[0032] FIG. 2 shows a schematic perspective view of the linear guide device illustrated in FIG. 1 without carriage,

[0033] FIG. 3 shows a schematic and enlarged perspective view of the region of the linear guide device identified by the reference symbol B in FIG. 2,

[0034] FIG. 4 shows a schematic perspective view of a coupling element provided in the linear guide device illustrated in FIGS. 1-3,

[0035] FIG. 5 shows a schematic view of the linear guide device illustrated in FIGS. 1-4 in the form of a top view from the front,

[0036] FIG. 6 shows a schematic and enlarged view of the region of the linear guide device identified by the reference symbol C in FIG. 5,

[0037] FIG. 7 shows a schematic view of the linear guide device illustrated in FIGS. 1-6 in the form of a section along the line F-F in FIG. 1, and

[0038] FIG. 8 shows a schematic and enlarged view of the region of the linear guide device identified by the reference symbol E in FIG. 7.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0039] A linear guide device according to an embodiment of the present invention is described below with reference to FIGS. 1 to 8.

[0040] The linear guide device 1 has a rail 2, a slide or carriage 3 and a cage 4 arranged between the rail 2 and the carriage 3. The rail 2, the carriage 3 and the cage 4 have a common longitudinal axis L. A plurality of rolling bodies 5 is provided on the cage 4, wherein said rolling bodies respectively abut on the carriage 3 and the rail 2 in a rollable manner. Consequently, the cage 4 is arranged on the rail 2 so as to be movable in the longitudinal direction L and the carriage 3 is arranged on the cage 4 so as to be movable in the longitudinal direction L. The cage 4 is concealed by the carriage 3 in the illustration according to FIG. 1.

[0041] The linear guide device 1 furthermore has a coupling element in the form of a gearwheel 6 that extends through a recess 7 formed in the cage 4 in order to engage into respective advancing devices of the rail 2 and the carriage 3, wherein said advancing devices are realized in the form of gear racks 8,9.

[0042] In the present embodiment, the rail 2 has an upper side 11 that respectively faces the cage 4 and the carriage 3. The rail 2 furthermore has two lateral surfaces 12, each one of which respectively faces one of the legs 22a, 22b of the cage 4 described further below.

[0043] The rail 2 has the gear rack 8, into which the gearwheel 6 engages, on its upper side 11. The gear rack 8 extends in the longitudinal direction L on the upper side 11 of the rail 2. The gear rack 8 is not arranged centrally with respect to a center axis of the rail 2 extending in the longitudinal direction L. In other words, the gear rack 8 is with respect to the center axis arranged offset in the direction of one side of the carriage. The rail 2 furthermore has two grooves 13 (see FIGS. 6, 8) extending in the longitudinal direction L on its upper side 11. In the present embodiment, the grooves 13 respectively are arranged laterally of the gear rack 8 on the upper side 11 of the rail. The grooves 13 are designed open in the direction of the cage 4, i.e. toward the top in the present embodiment. They are designed for receiving a first projection 43 of the gearwheel 6 described further below. In this case, a sidewall 13a of the groove serves as a stopping face for the first projection 43 of the gearwheel (see FIGS. 6, 8).

[0044] A respective depression 14 is optionally provided in the upper side 11 laterally of the grooves 13 (see FIGS. 6, 8), wherein said depressions serves as a stopping face for the second projections 44 of the gearwheel 6 as described in greater detail below. Alternatively, the upper side 11 may also be realized without the depressions 14 and the second projections 44 of the gearwheel 6 may directly abut on the upper side 11, which in this case forms the stopping face.

[0045] A respective track 15 extending in the longitudinal direction L is provided on the lateral surfaces 12 of the rail 2, wherein the rolling bodies 5 of the cage 4 abut on said tracks in a rollable manner. In FIGS. 1 and 2, the track 15 is respectively realized in the form of a projection, which is provided on the lateral surface 12 and on which the rolling bodies rest. The cage 4 is supported on the tracks 15 of the rail with its rolling bodies 5.

[0046] The rail 2 preferably is mounted in a fixed manner, e.g. in a machine tool, a measuring system, etc.

[0047] The cage 4 essentially is designed in a U-shaped manner in a cross section through the linear guide device 1 perpendicular to the longitudinal direction L. The cage 4 specifically comprises a base body or a base plate 21, which in the present embodiment essentially is designed in a planar manner, and two legs 22a, 22b that extend away from the base plate 21, preferably perpendicularly. The legs 22a, 22b are designed in such a way that an intermediate space, in which the rail 2 is at least partially received, is formed between the legs. In the present embodiment of the linear guide device 1, the cage 4 is attached to the rail 2 in the form of an inverted U-shape (i.e. with the base plate 21 pointing upward and the opening of the U-shape pointing downward).

[0048] The base plate 21 of the cage 4 has the aforementioned recess 7, through which the gearwheel 6 extends.

[0049] The base plate 21 of the cage 4 furthermore has an opening 25 (see FIG. 2) that is designed in an oblong manner in the longitudinal direction L of the linear guide device 1. A screw 10 (see FIGS. 1, 7) fastened on the rail 2 or the carriage 3 extends through this opening 25. The ends of the oblong opening 25 in the longitudinal direction L form a limit stop that limits the movement of the cage 4 relative to the rail 2 and/or the carriage 3 in the longitudinal direction L.

[0050] The rolling bodies 5 of the cage 4 are respectively arranged on the legs 22a, 22b of the cage. To this end, the rolling bodies 5 are rotatably mounted in the legs 22a, 22b of the cage 4 and spaced apart from one another, preferably equidistantly, along the longitudinal direction L. For example, the rolling bodies 5 may be realized in the form of balls and/or rollers. They protrude from the legs 22a, 22b toward the inner side and also toward the outer side of the U-shaped cage 4 such that they abut on the tracks 15, 33 of the rail 2 and the carriage 3 in a rollable manner. Consequently, the cage 4 is arranged so as to be movable relative to the rail 2 and therefore also relative to the carriage 3 in the longitudinal direction L.

[0051] Similar to the cage 4, the carriage 3 essentially is designed in a U-shaped manner in a cross section of the linear guide device 1 perpendicular to the longitudinal direction L. The carriage 3 specifically comprises a base body or a base plate 31, which in the present embodiment essentially is designed in a planar manner, and two legs 32a, 32b that extend away from the base plate 31, preferably perpendicularly. The legs 32a, 32b are designed in such a way that an intermediate space, in which the cage 4 is at least partially received, is formed between the legs. In the embodiment of the linear guide device 1 illustrated in the figures, the carriage 3 is attached to the cage 4 in the form of an inverted U-shape (i.e. with the base plate 31 pointing upward and the opening of the U-shape pointing downward).

[0052] The carriage 3 has the gear rack 9, into which the gearwheel 6 engages (see FIGS. 6, 8), on the underside 34 of the base plate 31, i.e. on the boundary of the base plate 31 facing the cage 4 and the rail 2. The gear rack 9 extends in the longitudinal direction L on the underside 34 of the base plate 31. The gear rack 9 is not arranged centrally with respect to a center axis of the carriage 3 extending in the longitudinal direction L. In other words, the gear rack 9 is with respect to the center axis arranged offset in the direction of one side of the carriage. The underside 34 of the base plate 31 furthermore has two grooves 35 (see FIGS. 6, 8) extending in the longitudinal direction L. In the present embodiment, the grooves 35 respectively are arranged laterally of the gear rack 9 on the underside 34 of the base plate 31. The grooves 35 are designed open in the direction of the cage 4, i.e. toward the bottom in the present embodiment. They are designed for receiving the first projection 43 of the gearwheel 6 described further below. In this case, a sidewall 35a of the groove serves as stopping face for the first projection 43 of the gearwheel (see FIGS. 6, 8).

[0053] A respective depression 36 is optionally provided in the underside 34 of the base plate 31 laterally of the grooves 35 (see FIGS. 6, 8), wherein said depressions serves as a stopping face for the second projections 44 of the gearwheel 6 as described in greater detail below. Alternatively, the underside 34 of the base plate 31 may also be realized without the depressions 36 and the second projections 44 of the gearwheel 6 may directly abut on the underside 34 of the base plate 31, which in this case forms the stopping face.

[0054] The carriage 3 has tracks 33 extending in the longitudinal direction L on the inner side of the legs 32a, 32b, i.e. on the side of the legs facing the cage 4, wherein the rolling bodies 5 of the cage 4 abut on said tracks in a rollable manner. The carriage is supported on the rolling bodies 5 of the cage 4 with the tracks 33.

[0055] The linear guide device 1 furthermore has a drive that is not illustrated in greater detail in the figures and designed for driving the carriage 3 such that it can be displaced relative to the rail 2 along the longitudinal direction L.

[0056] The gearwheel 6 is described in greater detail below with reference to FIG. 4. The gearwheel 6 is arranged in the linear guide device 1 so as to be rotatable about a rotational axis A, wherein the rotational axis A extends perpendicular to the longitudinal direction L (see also FIG. 2). The gearwheel 6 comprises a plurality of teeth 41 that are spaced apart from one another in the circumferential direction by gaps 42 and designed for engaging into the gear racks 8, 9 of the rail 2 and the carriage 3 (see FIGS. 2, 5-8). The bases of the gaps 42 define a first diameter D1 of the gearwheel 6.

[0057] The gearwheel 6 furthermore has a first projection 43, which is designed for simultaneously abutting on the groove 13 of the rail 2 and on the groove 35 of the carriage 3, and a second projection 44, which is designed for simultaneously abutting on the upper side 11 of the rail 2 or the depression 14 formed therein and on the underside 34 of the carriage 3 or the depression 36 formed therein.

[0058] In the present embodiment, the first projection 43 and the second projection 44 respectively are designed cylindrically with the rotational axis A of the gearwheel as cylinder axes. Each of the projections 43, 44 specifically has a circumferential surface 43a, 44a forming the lateral area of the cylindrical projection and an end face 43b, 44b forming the base area of the cylindrical projection.

[0059] Viewed perpendicular to the rotational axis A, the first projection 43 has a second diameter D2 that is smaller than the first diameter D1 of the gearwheel 6. The second projection 44 has, viewed perpendicular to the rotational axis A, a third diameter D3 that is smaller than the first diameter D1 of the gearwheel 6 and in the present embodiment also smaller than the second diameter D2 of the first projection 43. The first projection 43 is arranged on the gearwheel 6 and extends away from the gearwheel 6 in the direction of the rotational axis A. The second projection 44 is arranged on the first projection 43 and extends away from the first projection 43 in the direction of the rotational axis A.

[0060] A width of the first projection 43 in the direction of the rotational axis A is chosen in such a way that the end face 43b of the first projection abuts or essentially abuts on the sidewall 13a of the groove 13 of the rail 2 and on the sidewall 35a of the groove 35 of the carriage 3 when the gearwheel is arranged in the linear guide device 1. The third diameter D3 of the second projection 44 is chosen in such a way that its circumferential surface 44a abuts on the depression 14 in the upper side 11 of the rail 2 or on the upper side 11 itself and on the depression 36 in the underside 34 of the carriage 4 or on the underside 34 of the carriage itself when the gearwheel 6 is arranged in the linear guide device 1. The sidewalls 13a, 35a of the grooves 13, 35 therefore serve as stopping faces for the first projection 43 or its end face 43b and the depressions 14, 36 or the upper side 11 of the rail 2 and the underside 34 of the carriage 3 serve as stopping faces for the second projection 44 or its circumferential surface 44a.

[0061] In the present embodiment, the gearwheel respectively has two first projections 43 and two second projections 44, which are arranged in pairs on opposite sides of the gearwheel 6 along the rotational axis A. The rear projections are partially concealed by the gearwheel in the illustration according to FIG. 4.

[0062] The recess 7 in the base plate 21 of the cage 4, through which the gearwheel 6 extends, is described in greater detail below with reference to FIGS. 3 and 4. The recess 7 has a first recess section 51 and a second recess section 52, which are respectively designed in an oblong manner and intersect one another perpendicularly or crosswise. The first recess section 51 is designed for receiving the gearwheel 6 with the first projections 43 provided thereon and the second recess section 52 is designed for receiving the second projections 44 of the gearwheel 6.

[0063] The first recess section 51 specifically extends along the longitudinal direction L of the linear guide device 1 over a length M1 that is greater than a width N1 of the first recess section 51 perpendicular to the longitudinal direction L. The length M1 of the first recess section 51 is greater than a maximum diameter of the gearwheel 6, which is defined by the free ends of the teeth 41 of the gearwheel, such that the gearwheel 6 is freely rotatable about its rotational axis A when it is arranged in the recess 7. The width N1 of the first recess section 51 is greater than or equal to a width of the gearwheel 6 between the end faces 43b of the first projections 43, which are arranged on opposite sides of the gearwheel 6, along the rotational axis A.

[0064] The second recess section 52 extends perpendicular to the longitudinal direction L of the linear guide device 1 (i.e. along the rotational axis A of the gearwheel 6) over a length M2 that is greater than a width N2 of the second recess section 52 in the longitudinal direction L. The length M2 of the second recess section 52 is greater than a total width of the gearwheel 6 between the end faces 44b (see FIG. 4) of the second projections 44, which are arranged on opposite sides of the gearwheel 6, along the rotational axis A. The width N2 of the second recess section 52 is greater than or equal to the third diameter D3 of the second projection 44 of the gearwheel 6.

[0065] The second recess section 52 is designed in such a way that the second projections 44 of the gearwheel 6 arranged therein can abut on the wall, i.e. the boundary, of the second recess section 52 in the longitudinal direction L of the linear guide device 1 in order to transmit a movement of the gearwheel 6 in the longitudinal direction L to the cage 4. In other words, the gearwheel 6 acts as a driver for the cage 4 during a movement in the longitudinal direction L.

[0066] The gearwheel 6 is not fastened on the cage 4 in the present embodiment of the linear device 1. In fact, the gearwheel 6 is respectively retained or fastened in the linear guide device 1 in a floating manner solely due to the interaction of the projections 43, 44 with the corresponding stopping faces formed on the rail 2 and the carriage 3.

[0067] FIGS. 6 and 8, in particular, show that the end faces 43b of the two first projections 43 of the gearwheel 6 abut or abut in a spaced-apart manner on the sidewalls 13a, 35a of the grooves 13, 35 formed in the rail 2 and in the carriage 3. This prevents a movement of the gearwheel 6 perpendicular to the longitudinal direction L and parallel to the rail 2 and the carriage 3, namely a lateral movement of the gearwheel 6 in the present embodiment. In addition, the circumferential surfaces 44a of the two first projections 44 abut on the depressions 14, 36 formed in the underside 34 of the carriage 3 and the upper side 11 of the rail. This prevents a movement of the gearwheel 6 perpendicular to the longitudinal direction L and in the direction of the rail 2 or in the direction of the carriage 3, namely a vertical movement of the gearwheel 6 in the present embodiment.

[0068] In other words, the gearwheel 6 is retained in the linear guide device 1 in a floating and stationary manner with respect to movements perpendicular to the longitudinal direction L by the sidewalls 13a, 35a of the grooves 13, 35 and the stopping faces in the form of the depressions 14, 36 (or the underside 34 of the carriage 3 and the upper side 11 of the rail 2 themselves). Additional mounting of the gearwheel on the cage is not required.

[0069] During the operation of the linear guide device, the not-shown drive exerts a driving force upon the carriage 3 such that the carriage 3 moves relative to the rail 2 in the longitudinal direction L by a defined amount, which is also referred to as stroke. In the process, the gearwheel 6 rolls between the gear racks 8, 9 relative to the rail 2 along the longitudinal direction L by half of the travel of the carriage 3 (half stroke). During the movement of the gearwheel 6, its projections 43, 44 roll on the stopping faces of the carriage 3 and the rail 2 in a dragging manner. This makes it possible to prevent a movement of the gearwheel 6 perpendicular to the longitudinal direction L, i.e. in the vertical direction and in the lateral direction of the linear guide device. The circumferential surface 44a of the second projections comes in contact with the wall of the second recess section 52 of the recess 7 of the cage 4 and causes the cage 4 and the gearwheel 6 to be jointly moved relative to the rail 2 in the longitudinal direction L by half of the travel of the carriage 3 (half stroke). The movement of the cage 4 in the longitudinal direction L therefore is coupled with the movement of the carriage 3 along the rail 2. In other words, the gearwheel acts as a driver for the cage 4 during a movement in the longitudinal direction L.

[0070] Alternatively or additionally to providing the oblong opening 25, which interacts with the screw 10 and the ends of which in the longitudinal direction L form a limit stop for the movement of the cage 4 relative to the rail 2 and/or the carriage 3 in the longitudinal direction L, it is also possible to realize a limit stop by designing the grooves 13, 35 accordingly. For example, the grooves may have projections that act as a limit stop in the longitudinal direction L, wherein the gearwheel 6 comes in contact with said projections in order to limit the movement of the gearwheel 6 in the longitudinal direction L.

[0071] The present invention is not limited to the above-described embodiment of the linear guide device illustrated in the figures. Modifications of the linear guide device are in fact possible. For example, the individual elements may deviate from the described elements with respect to their size and/or shape. For example, the shape of the first projection 43 and/or the second projection 44 may deviate from a cylindrical shape.

[0072] Instead of providing the gearwheel, it would also be possible to use a different coupling element that is designed for simultaneously engaging into the first and the second advancing device of the rail and the carriage in order to cause a movement of the cage relative to the rail and/or the carriage during an advance of the carriage relative to the rail. Accordingly, the advancing devices may also be designed differently than the above-describe the gear racks. For example, the coupling element may be designed for a rotary advance in interaction with the advancing devices, wherein a rotational axis of the coupling element preferably extends perpendicular to the longitudinal direction of the rail and/or wherein the rotational axis preferably is fixed relative to the rail and the carriage.

[0073] Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.