MXPA96004683A - Motion bearing lin - Google Patents

Abstract

The present invention relates to a linear motion bearing assembly, characterized in that it comprises: a rail assembly including an elongated base member, having a pair of vertical arms, the vertical arms having respective inner surfaces and outer surfaces, the arms verticals are flexible with respect to the base member, the bearing carriage assembly includes a bearing carriage, a pair of hanging legs extending therefrom, the hanging legs have their respective surfaces and opposite sides, the surface sides define a longitudinal channel for housing the rail assembly, the hanging legs are flexible with respect to the bearing carriage, a plurality of load bearing inserts, each of the inserts defining a portion of at least one load bearing track on them , the inserts are placeable on the sides in front of the hanging legs to define a plurality of car bearing tracks. between the vertical arms and the hanging legs, and a plurality of bearing elements placed on the bearing tracks of the bearing

Description

LINEAR MOVEMENT BEARING BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to bearings of linear movement, antifriction and more particularly, with bearing assemblies of linear movement, which facilitates the manufacture and installation while optimizing the contact angle with the bearing elements. 2 . Description of Related Art The linear motion bearing assemblies are > well known in the art and widely used in a wide variety of machines, machine tools, transfer systems and other equipment, where the machine elements move with respect to each other. These assemblies typically include a bearing carriage mounted for movement along a rail in the form of a Y-beam, a I-shaped beam, or a modified T-beam. The load bearing and return tracks are provided in * association with the bearing carriage for a plurality of REF: 23269 recirculating bearing elements such as for example balls or rollers. These bearing elements move alternately through the load bearing tracks and return tracks to facilitate movement of the bearing carriage along the rail with minimal friction. The end layers are usually placed on the ends of the bearing carriage and may have spaces formed therein for transferring the bearing elements of the load bearing tracks to the return tracks. The spaces for turning, typically comprise 'a track in semitoroidal shape, dimensioned and configured for the particular bearing element that is used. In the semi-toroidal center, an internal guide can be provided for the uniform movement of the bearing elements in the spaces for turning. The return tracks take the form of holes or channels that conform in size to the dimensions of the bearing elements, which are cut or punched in the legs that depend on the bearing carriage. See, for example, U.S. Patent Nos. 4,932,067 to Pester et al. The general structure of this type of linear motion bearing assembly typically requires the extensive use of high quality, expensive bearing steel to produce a bearing of sufficient strength and duration.

This is at least partially necessary, in that the load bearing portions require strength and rigidity of the bearing steel and are usually monolithically formed directly in the structure of the bearing carriage and / or the rail. See, for example, U.S. Patent No. 4,637,739 to Hattori. The manufacture of the rails and / or carriages from such material requires numerous precision machining steps, as well as hardening processes in designated areas such as, for example, contact portions of the load bearing tracks on both of the carriage. and the lane. This process is extremely expensive and, depending on the structure of the bearing assembly, requires elaborate and expensive machining equipment. In addition, a feature of high quality bearing steel is its rigidity. This feature results in a requirement for extreme precision in grinding the load bearing tracks and the highly accurate installation of the linear motion bearing assembly to avoid placing tension on the contact portions. Attempts have been made in the past to isolate the highly stressed contact points within the linear motion bearing assemblies by providing inserts which are mounted to the conventional carriage structure or rail. See, for example, U.S. Patent Nos. 3,900,233 and 4,025,995 to Thomson. The load bearing track inserts were also shown in U.S. Patent No. 4, 515,413, 4,527,841, 4,531,788 and 4,576,421 of Teramachi and U.S. Patent No. 4,576,420 to Lehmann et al. However, these linear motion bearings do not address or overcome the inherent stiffness problem characteristic of these materials. In this way, extreme precision and exact placement are still very definitive factors that affect the operation and duration of the linear motion bearing assembly. Attempts have also been made in the past to reduce this inherent rigidity of the structures formed entirely of high quality bearing steel. For example, U.S. Patent No. 5,217,308 to Schroeder discloses an internal carriage structure for a linear motion bearing assembly. The carriage is configured to be supported within a frame structure by four steel rails that face inwardly mounted on the frame structure. The frame structure is constructed of aluminum and is configured to allow the flexing of the upper rails to incorporate spaces within. of the assembly.

Therefore, it would be highly advantageous to have an easily manufactured linear motion bearing assembly which reduces the need for extensive precision drilling, hardening and / or grinding of the contact surfaces on the carriage and on the rail, while providing a reliable bearing assembly, which is capable of a high degree of flexional movement when placed under load to optimize the contact angle of the bearing elements on the load bearing tracks. Accordingly, it is an object of the present invention to provide an easily manufactured linear motion bearing assembly, which minimizes the use of expensive, high quality bearing steel while providing the ability to optimize the contact angle of the bearing. the bearing elements and the load bearing tracks. It is another object of the present invention to provide a linear motion bearing in which the contact loading bearing portions of the carriage and the rail are formed of high quality steel inserts, which are fitted into a relatively flexible carrier structure. . It is also an object of the present invention to provide a reliable, linear motion bearing assembly which can be easily manufactured with a minimum of steel bearing elements, without the need for precision grinding and hardening directly on the carriage block. and / or the lane. These and other highly desirable objects are realized by the present invention in a linear motion bearing having bearing steel track inserts adapted to the hanging legs of the bearing carriage and the rail. The balance of the bearing assembly is constructed of more flexible material such as, for example, machine grade aluminum, plastics or less expensive grades of steel to aid in the easy and accurate assembly of the linear motion bearing assembly. The parts are, configured without the need for the precision grinding or hardening of tracks directly on the carriage and / or rail. The objects and advantages of the invention are set forth in part in the present and in part will be obvious from it, many can be learned by practice with the invention, which is done and achieved by means of the instruments and combinations indicated in the claims annexes. The invention consists of new parts, constructions, arrangements, combinations, steps and improvements shown and described herein.

COMPENDIUM OF THE INVENTION In accordance with the present invention, there is provided a linear motion bearing, which has load bearing tracks formed of load bearing track inserts, of high quality bearing steel mounted on the bearing carriage assembly and / or the rail assembly. Axial grooves are also formed in both of the bearing carriage assembly and / or the rail assembly to optimize the contact angle of the bearing elements under load. This construction simplifies manufacturing and avoids the need for difficult and expensive grinding and hardening of the load bearing tracks directly on the carriage and bearing rail. In addition, less expensive construction materials such as for example aluminum, plastic or non-bearing quality steel can be used to mount the inserts. The construction material can also be selected based on its desirable bending characteristics without being restricted to the use of relatively rigid, high-quality bearing steel. This structure provides a cheap and safe bearing and linear motion assembly that is easy to manufacture, assemble and install.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, mentioned herein which constitute a part thereof, illustrate the preferred embodiments of the apparatus of the present invention and together with the description, serve to explain the principles of the invention. FIGURE 1 is a perspective view of a linear motion bearing assembly, assembled according to a preferred embodiment of the present invention. FIGURE 2 is a perspective view similar to FIGURE 1 with one of the cart end caps removed. FIGURE 3 is a perspective view, with separate parts of the carriage of the linear motion bearing assembly in FIGURE 1. FIGURE 4 is a perspective view with the separate portions of the rail assembly of the linear motion bearing assembly of FIG. FIGURE 1. FIGURE 5 is an end view with the end cap removed from the assembled linear motion bearing assembly of FIGURE 1.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES Now with reference to the drawings in detail, and initially with FIGURES 1 and 2, a fully assembled linear motion bearing assembly 20 according to the present invention is shown. The assembly includes a substantially inverted U-shaped bearing carriage 22, configured and sized to move along a rail assembly 24 on bearing elements 25. Although they are shown here as balls, other bearing elements are also contemplated including the rollers. The end caps 26 are positioned at each longitudinal end of the bearing carriage 22. The end caps 26 include a semi-rotating space 29 formed integrally in each of the end caps 26 and serve to enclose and connect the corresponding load bearing. and return tracks 28 and 30, respectively located on the hanging legs 32 of the bearing carriage 22. As best seen in FIGURE 2, the return tracks 28 consist of parallel, longitudinal holes drilled axially through the hanging legs 32. of the bearing carriage 22. The mounting holes 34 are formed in the upper flat surface of the bearing carriage 22 and facilitate the coupling of the bearing assembly to the desired machine components. The longitudinal mounting holes 36 are formed on each longitudinal end surface of the bearing carriage 22 and serve to attach the end caps 26. The inner guides 27 are positioned between the ends of the load bearing tracks 28 and the return tracks 30. These inner guides 27 facilitate the movement of the bearing elements 25 between the respective tracks. Now with reference to FIGURE 3, the individual components of the bearing carriage are shown in detail. The bearing carriage 22 is preferably formed of a relatively flexible machine grade material, such as, for example, aluminum, plastic or steel. The surfaces 38 facing the interior of the hanging legs 32 are configured and sized to receive the load bearing track inserts 40. These inserts 40 are formed of high quality bearing steel and include a pair of parallel grooves 42 formed in an inner surface 44. These grooves 42 form a portion of the load bearing tracks 28 and are configured and sized in an appropriate cross-sectional shape to conform to the bearing elements 25 employed in the bearing assembly 22. The load bearing track inserts 40 can be formed easily and efficiently in long sections by known cold drawing processes and subsequently cut to the desired length before assembly. To facilitate manufacturing, the cross-sectional area of the load bearing track inserts is preferably substantially uniform in thickness. The hanging legs 32 are further provided with a longitudinal reinforcement 66 on their outer surface adjacent to the intersection of the hanging legs 32, with the remainder of the carriage 22. This reinforcement 66 provides additional bending characteristics for the hanging legs 32 as discussed in FIG. the next. With reference to FIGURE 4, the rail assembly 24 according to a preferred embodiment of the present invention, includes a base member 46 in substantially U-shape, formed of machine grade aluminum and extruded using known production techniques. The base member 46 includes a pair of vertical, parallel arms 48 defining an axial slot 50 along the longitudinal length of the base member 46. This configuration provides an advantageous degree of flexibility to the vertical arms 48. The dovetail-shaped channels 52 are formed on opposite sides of the vertical arms 48 substantially parallel to the axial slot 50. The load bearing track insert 54 is configured and sized to fit within each of the channels 52 and defines a portion of the load bearing tracks 28. As in the carriage load bearing track inserts 40 discussed in the above, the track of the load bearing track inserts 54 are produced from a hardenable, high quality bearing steel using known cold drawing processes. The inserts are hardened in line by known techniques such as, for example, heating and induction cooling. The inserts 54 are preferably formed with a longitudinal reinforcement 56 on an inner surface thereof. This reinforcement 56 gives the insert 54 a degree of flexibility, which increases its final assembly to the rail. The inserts 54 preferably have a substantially uniform thickness in cross section and include parallel bearing grooves 58. The load bearing track inserts 54 are easily mounted to the base member 46 by configuring the relative dimensions of the dovetail channels 52 and the insert 54, such that the inserts fit within the channels with something Of space. The upper projection 60 of the channel 52 is plastically deformed on the uppermost portion of the insert 54, effectively holding it in place on the base member 46. During this process of plastic deformation, the insert 54 will deform, such as a spring, by virtue of the shape and design of the longitudinal reinforcement 56. The tendency of the insert 54 to return to its original tensionless configuration produces a secure connection between the insert 54 and the base 46. With reference to FIGURE 5, the advantageous features of this construction are presented graphically. With the application of a load or force "F", in the direction of the arrow, the load is transmitted through the carriage 22, the load bearing tracks 28 and bearing elements to the fixed rail assembly 24. The axial slot 50 formed in the base member 46 allows the rail assembly to deform in response to the applied load. This allows resilience and correct orientation of each of the vertical arms 48 and allows translation of the center line 62 of the carriage bearing track. As this center line 62 moves with respect to the center line 64 of the rail loading bearing, the contact angle rotates from its initial position represented by the angle "A" to its loaded position represented by the angle "B" . Since the final angle "B" is more aligned with the orientation of the applied load, the contact angle is effectively optimized. When a load is applied in an opposite direction, that is, a "lifting" force, a similar reaction occurs. Because the carriage is formed of a relatively flexible material such as, for example, aluminum, the hanging legs 32 can flex outwards to optimize again the contact angle. In addition, the reinforcement 66 mentioned above, can be formed on the opposite outer surfaces of the hanging legs 32 at the intersection between the legs 32 and the carriage 22. This reinforcement 66 provides a bending line to allow realignment and / or reorientation of the portions of the carriage load bearing track formed in the insert 40. In addition to the optimization of the contact angle provided by this construction, the manufacture and assembly of this linear motion bearing assembly is greatly simplified on the technique previous. This results from the optimization of the docility described in the foregoing, which allows the use of materials, processes and tolerances that are much less expensive than those in the manufacture of the existing product. To the extent that has not been indicated, it will be understood by those with ordinary skill in the art, that any of several specific modalities in it, described and illustrated may be further modified, to incorporate characteristics shown in other of the specific modalities.

The invention in its broader aspects are therefore not limited to the specific embodiments of the present, shown and described, but separations from them can be made within the scope of the appended claims, without departing from the principles of the invention and without Sacrifice your main advantages. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, property is claimed as contained in the following:

Claims (12)

1. A linear motion bearing assembly, characterized in that it comprises: a rail assembly including an elongate base member, having a pair of vertical arms, the vertical arms having respective inner surfaces and outer surfaces, the vertical arms being flexible with respect to the Blaster member Bearing carriage assembly includes a bearing carriage, a pair of hanging legs extending therefrom, the hanging legs have their respective surfaces and opposite sides, the surface sides define a longitudinal channel for housing the rail assembly , the hanging legs are flexible with respect to the bearing carriage; a plurality of load bearing inserts, each of the inserts defining a portion of at least one load bearing track thereon, the inserts are movable on the sides in front of the hanging legs to define a plurality of tracks of load bearing between the vertical arms and the hanging legs; and a plurality of bearing elements positioned on the load bearing tracks.

2. The linear motion bearing assembly according to claim 1, characterized in that the load bearing inserts each contain a plurality of parallel grooves, which define a portion of a plurality of load bearing tracks.

3. The linear motion bearing assembly according to claim 1, further characterized in that it comprises a pair of longitudinal reinforcements formed adjacent one end of the hanging legs, the reinforcements effect a narrowing of the cross-sectional area of the hanging legs to facilitate their characteristics of ? flexion.

4. The linear motion bearing assembly according to claim 1, further characterized in that it comprises a plurality of load bearing inserts, each of the inserts defining a portion of at least one load bearing track thereon, the inserts they can be placed on the outer surfaces of the vertical arms.

5. The linear motion bearing assembly according to claim 1, characterized in that the bearing carriage is made of a machine grade material, selected from the group consisting of aluminum, plastic and steel.

6. The linear motion bearing assembly according to claim 1, characterized in that the base member of the rail assembly is made of a machine grade material, selected from the group consisting of aluminum, plastic and steel.

7. The linear motion bearing assembly according to claim 1, characterized in that two of the load bearing inserts are placed in the bearing carriage and two of the load bearing inserts are placed in the rail assembly.

8. The linear motion bearing assembly according to claim 6, characterized in that each of the two load bearing inserts positioned in the rail assembly further includes a longitudinal groove formed in a surface adjacent to the outer surfaces of the arms vertical, the longitudinal groove increases the transverse flexibility for the inserts.

9. A linear motion bearing assembly characterized in that it comprises: an elongated rail assembly, including an aluminum base member having a pair of substantially parallel arm members, extending the longitudinal distance of the rail assembly, the members of arm have respective inner surfaces and outer surfaces, the inner surfaces define a longitudinal groove, the outer surfaces defining the structure that receives the insert of the rail assembly; a plurality of rail mounting load bearing inserts, the inserts have an outer surface and an inner surface, the outer surface having a plurality of parallel grooves formed therein, which define a portion of a plurality of load bearing tracks , the load bearing inserts of the rail assembly are placed in the structure receiving the insert formed on the outer surfaces of the parallel arm members; a bearing carriage assembly, including an aluminum bearing carriage, a pair of hanging legs extending therefrom, the hanging legs having respective opposite surface sides and sides, the surface sides defining a longitudinal channel for housing the rail assembly, the surface sides further include a structure that receives the carriage assembly insert; a plurality of carriage loading bearing inserts, each of the inserts includes a plurality of parallel grooves formed therein, defining a portion of a plurality of load bearing tracks, the carriage load bearing inserts are positioned in the structure that receives the insert of the carriage assembly from the sides facing the hanging legs; and a plurality of bearing elements positioned on the load bearing tracks, such that by loading the bearing carriage assembly, the load bearing inserts are flexible at an optimized contact angle with respect to the bearing elements. tread .

10. The linear motion bearing assembly according to claim 9, characterized in that the rail mounting load bearing inserts include a longitudinal groove formed on an inner surface thereof, the longitudinal groove increases the flexibility of the inserts.

11. The bearing assembly, linear movement according to claim 9, characterized in that the bearing elements are balls.

12. The linear motion bearing assembly according to claim 9, characterized in that the structure that receives the rail mounting insert is a longitudinal groove configured and sized to receive and retain the load bearing inserts of the rail assembly.