Ball-bearing guide device with adjustable preload

Abstract

Guide device with rolling elements for slide arrangements having a first and a second slide element (11, 12) that are coupled and guided to each other, wherein a slide element (12) is capable of alternating linear movements with respect to the other slide element (11) by means of two linear rows of balls (31, 31') interposed, characterized in that one of the slide elements (12) has an opening on at least one of its sides parallel to the direction of movement, into which a side cheek insert (28) is fitted, wherein a preload prevailing on the two rows of balls (31, 31') between the first and the second slide element can be adjusted by means of a variably definable locking force with which the side cheek insert (28) is attached to the slide element (12).

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The invention generally relates to slide arrangements having two coupled and guided elements, one element being capable of alternating linear movements relative to the other, which are brought about by a preferably pneumatic control unit. In particular, the invention relates to a guide device with rolling elements, typically balls, for such slide arrangements, especially when the slide arrangement has small dimensions. 2. Description of the state of the art

[0002] The slide arrangements under consideration can be pneumatically actuated and are widely used in numerous areas, particularly, but not exclusively, in the automated gripping and handling of various components and elements to be positioned and assembled. They can be equipped with a gripping element such as a suction cup, which is actuated via a channel extending through both parts of the slide arrangement.

[0003] According to the prior art, the two parts of a slide assembly can be coupled by means of rolling elements, usually balls, allowing one to slide relative to the other. The presence of these elements facilitates sliding even at minimal pneumatic control pressure. However, their assembly requires high-precision work and is therefore time-consuming, resulting in considerable implementation costs.

[0004] Often, there is no way to adjust the coupling preload.

[0005] However, a linear guide is known from GB 703 762 A in which an inner support of a first guide element is supported against an outer side wall by a spring. This preloads the inner support in the direction of the balls located further inside and a second guide element, also located inside. The preload can be adjusted by changing the spring or its contact point via a screw.

[0006] Furthermore, DE 36 38 968 A1 discloses a slide guide in which a bearing body extending completely along the guide direction is connected to one of the slide parts via fastening screws. The fastening screws are received in the slide part with lateral play, and the preload of the bearing body against rolling elements can be adjusted via a series of pressure screws.

[0007] Furthermore, a pneumatic or hydraulic working cylinder with a ball guide is known from DE 35 13 214 A1.

[0008] For some applications, it is also important that the slide assembly has small dimensions and a low weight. These conditions are not currently met in this area. TASK AND SUMMARY OF THE INVENTION

[0009] Therefore, it is an object of the present invention to provide a guide device for a slide assembly of the type mentioned above, designed in such a way that both the construction and assembly are simplified, the need for precision work is eliminated, the adjustment of the preload of the guide means is facilitated from the outside to ensure correct operation, and the overall dimensions of the device, in particular its width, are reduced. The width is considered to be the thickness measured at the narrow sides of the slide assembly that extend in the direction of movement of the movable element.

[0010] This objective and the resulting implicit advantages are achieved according to the invention by a guide device for pneumatically controlled slide arrangements according to the preamble of claim 1, in which a slide element has an opening on at least one of its sides parallel to the direction of movement and is completed by a side cheek insert which is fastened in the opening, the closing force of which is variable in order to provide an adjustable preload on two rows of balls between the two coupled slide elements.

[0011] Accordingly, and advantageously, this side cheek insert ensures that the assembly of the slide is facilitated, the structure of the latter is completed, and that, with the inclusion of appropriate fastening means, a fine adjustment of the preload of the coupling of the guide device is made possible from the outside. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The invention will be explained in more detail with reference to the continuation of the present description, which refers to the attached drawings, which serve for illustration and not for limitation, in which: Fig. 1 shows an exploded view of the components of a slide arrangement with a guide device according to the invention; Fig. 2 shows a perspective view of the composite sled arrangement; Fig. 3 shows a side view of the arrangement; Fig. 4 shows an enlarged longitudinal section of the arrangement; and Fig. Figure 5 shows a cross-section of the arrangement, highlighting the guide device. DETAILED DESCRIPTION OF THE INVENTION

[0013] The drawings show a slide arrangement comprising a first stationary element 11 and a second movable element 12, which are complementarily coupled and guided to each other by means of the guide device 13 of the invention.

[0014] The slide element 12 is capable of alternating linear displacements relative to the stationary slide element 11, the displacements being effected by means of a pneumatic control unit 14. This control unit 14 comprises a fluid chamber 15, which is provided along the length of the stationary slide element 11, and a piston 16, which is received and sealed in the chamber 15 and slides within it. The piston 16 is provided with a rod 17 that penetrates at least one guide ring 18, which is held in the chamber 15 by a pin 19. The rod 17 extends to such an extent that it connects with the slide element 12. The chamber 15 is supplied with a pressurized fluid, in particular air, which enters and exits through inlet and outlet channels 20, 20' to cause the aforementioned displacements of the movable slide element relative to the stationary element.

[0015] The movable slide element 12 can be equipped with a gripping element such as a suction cup (not shown), which is arranged correspondingly to a fluid channel 21 parallel to the chamber 15 of the piston 16. The fluid channel 21 runs longitudinally through both slide elements and can be connected on the side of the stationary slide element 11 to a vacuum unit (not shown) configured to control the function of the gripping element. To ensure that the channel 21 remains open during the movements of the movable element 12 relative to the stationary element 11, a tube 22 is arranged between the two slide elements, which engages telescopically in one of the elements, in this case the stationary element 11.

[0016] The slide element 11 is provided with means 23 for attachment to a manipulator or similar device. A spring 24 is arranged along the rod 17 of the piston 16, designed to push the movable slide element 12 towards the component to be picked up, thereby ensuring that the gripping element is in contact with the component itself each time. A shock absorber 12' is arranged between the two opposing parts of the two slide elements 11, 12.

[0017] The guide device 13 proposed in the illustrated embodiment has a guide rib 25 that is an integral part of the stationary slide element 11 and extends along at least part of the latter's length. The guide rib 25 has two linear raceways 26, 26' along its opposite flanks.

[0018] The movable slide element 12 has a wall 27 on one side, parallel to the direction of movement, which runs along an adjacent flank of the guide rib 25 of the stationary element 11. On the opposite side, the movable slide element 12 has an opening and is completed by a side cheek insert 28, which runs along the opposite flank of the guide rib 25. The side cheek insert 28 is fastened to the slide element 12 by means of screws 29.

[0019] On the inside of the side wall 27 of the stationary slide element 11, a linear running groove 30 is machined, which faces the opposite linear running groove 26, located on the adjacent flank of the guide rib 25 of the mobile element 12. The same applies to the inside of the inserted side cheek insert 28, where a linear running groove 30' faces the opposite linear running groove 26', which is arranged on the other flank of the guide rib 25.

[0020] A first linear row of rolling elements, in particular balls 31, is arranged between the side wall 27 of the movable slide element 12 and the adjacent flank of the guide rib 25 of the stationary slide element 11. These balls are spaced apart from one another by a corresponding ball retaining cage 32 and guided between the two opposing raceways 26, 30 on this side of the slide. Similarly, a second linear row of balls 31 is arranged between the side cheek insert 28 and the adjacent flank of the guide rib 25 of the stationary slide element 11. These balls are also spaced apart from one another by a corresponding ball retaining cage 32' and guided between the two opposing raceways 26', 30' on the other side of the slide.

[0021] Thanks to the configuration described above, the ball rows 31, 31' can be connected to the fixed and movable elements 11, 12 of the slide before the side panel insert 28 is attached to the movable slide element 12. This simplifies assembly, and it is also possible to vary the preload of the coupling between the two elements 11, 12 with the two interposed ball rows 31, 31' by simply tightening / loosening the fastening screws 29 of the side panel insert 28, thus adjusting the smoothness of movement of the movable element 12 relative to the fixed element 11 according to the respective requirements.

Claims

[1] Guide device with rolling elements for slide arrangements having a first and a second slide element (11, 12) that are coupled and guided to each other, wherein a slide element (12) is capable of alternating linear movements with respect to the other slide element (11) by means of two linear rows of balls (31, 31') characterized by , that one of the slide elements (12) has an opening on at least one of its sides parallel to the direction of movement, into which a side cheek insert (28) is fitted, wherein a preload prevailing on the two rows of balls (31, 31') between the first and the second slide element can be adjusted by means of a variably definable locking force with which the side cheek insert (28) is attached to the slide element (12). [2] Guide device according to claim 1, characterized by, that a guide rib (25) is an integral part of the first slide element (11), which extends along at least a part of the length of the latter and which has two linear running grooves (26, 26') along two opposite flanks, that a side wall (27) is an integral part of the second slide element (12), which runs along a first flank of the guide rib (25) of the first slide element (11) and which is provided with a linear running groove (30) opposite the linear running groove (26) on this first flank of the guide rib (25), that the side cheek insert (28) is attached in the region of the opening which is arranged on the second slide element (12) on the part opposite the side wall (27), which runs along a second flank of the guide rib (25) and has a linear running groove (30') opposite the linear running groove (26') on the second flank of the Guide rib (25) opposite,and that a first row of balls (31) is guided in the guide grooves (26, 30) between the side wall and the first flank of the guide rib (25) and a second row of balls (31) is guided in the guide grooves (26', 31') between the side cheek insert (28) and the second flank of the guide rib (25). [3] Guide device according to claim 1 or 2, characterized by , that the side cheek insert (28) is attached to the second slide element (12) by means of screws (29) with adjustable tightness. [4] Guide device according to any one of the preceding claims, characterized by , that the side wall (27) and the side cheek insert (28) of the second slide element (12) run parallel to each other, are arranged on opposite sides of the guide rib (25) of the first slide element (11) and the two rows of balls thereby contain an adjustable preload. [5] Guide device according to any one of the preceding claims, characterized by that the rolling elements are spheres. [6] Pneumatically controlled slide, characterized by a guide device with rolling elements according to one of the preceding claims.

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