Flat linear bearing

Abstract

This utility model discloses a planar linear bearing, including a base, rollers, and an end cap. The base has a groove, and the rollers are disposed within the groove. The groove includes a first groove, a second groove, and a transition groove. The second groove is deeper than the first groove. The first and second grooves are smoothly connected via the transition groove to form a loop. An exposure window is provided on the first groove. The end cap covers the base, shielding the groove. The end cap includes a support portion and a connecting portion. The support portion is positioned corresponding to the first groove, and the connecting portion is positioned corresponding to the second groove. The connecting portion is higher than the support portion, and the connecting portion and the support portion are connected by a transition slope. The base also has a positioning component for positioning the end cap. Its structure is simple, increases bearing load, ensures structural strength, and possesses good toughness, thus improving structural performance.

Description

Technical Field

[0001] This utility model relates to a planar linear bearing. Background Technology

[0002] In linear bearing applications, when long-distance movement is required and the mounting surface is inclined, multiple adverse factors can easily accumulate and have a cumulative effect. Inclined mounting itself subjects the bearing to axial force. If the machining accuracy of mating components (such as guide rails and sliders) is insufficient—for example, due to dimensional deviations, excessive form and position tolerances, or poor surface roughness—it will further compromise the bearing's operational stability. This precision defect can cause significant forward / backward movement or lateral shifting of linear bearings at different positions during movement, resulting in an off-center load. Under off-center load, the stress distribution on the bearing's internal steel balls is severely uneven, with some balls bearing loads far exceeding design values. Since the contact between the steel balls and the end cap is point contact with a small contact area, according to mechanical principles, the stress generated by point contact under the same load is much higher than that of surface contact. This makes the raceway surface of the end cap a weak point. Over time, the raceway surface is prone to permanent indentations due to stress concentration. These indentations exacerbate the impact and vibration of the rolling steel balls. If the off-center load persists or the load is too large, the end cap may even crack due to fatigue stress. These damages significantly increase the internal frictional resistance of the bearing, leading to a sharp drop in transmission efficiency. At the same time, the abnormal contact between the steel balls and the damaged end cap will accelerate the wear of the parts, ultimately causing the linear bearing to have a service life lower than the design standard. It may also cause a chain of problems such as abnormal noise during equipment operation and reduced positioning accuracy. Utility Model Content

[0003] To address the shortcomings of existing technologies, this utility model provides a planar linear bearing with a simple structure, which improves bearing load, ensures structural strength, and has good toughness, thereby improving the structural performance.

[0004] To achieve the above objectives, this utility model provides a planar linear bearing, including a base, rollers, and an end cap. The base has a groove, and the rollers are disposed within the groove. The groove includes a first groove, a second groove, and a transition groove. The second groove is deeper than the first groove. The first and second grooves are smoothly connected via the transition groove to form a loop. The first groove has an exposure window for communication with the outside. The end cap covers the base, shielding the groove. The end cap includes a support portion and a connecting portion. The support portion is positioned corresponding to the first groove, and the connecting portion is positioned corresponding to the second groove. The distance between the connecting portion and the bottom surface of the second groove is greater than the distance between the support portion and the bottom surface of the first groove. The connecting portion is higher than the support portion. The connecting portion and the support portion are connected by a transition slope. The base also has a positioning component for positioning the end cap.

[0005] The beneficial effects of this design are as follows: the stepped design with a high end cap connection and a low load-bearing section ensures precise fit between the load-bearing section and the first groove, physically limiting the rollers to maintain the correct posture during operation, effectively preventing uneven load caused by roller misalignment and reducing local stress concentration. The non-contact space formed by the connection and the second groove not only provides ample room for roller circulation, preventing movement jamming, but also retains lubricating medium, forming a continuous lubrication layer, further reducing frictional loss between the rollers and the groove. The transition slope makes the transition of the rollers between the load-bearing section and the connection section smoother, reducing impact vibration and improving transmission stability. The precision-rolled carbon structural steel, with a surface roughness of less than Ra0.2, reduces the frictional resistance during roller rolling, keeping the frictional torque at an extremely low level and reducing energy loss. The maximum thickness difference of 0.01mm per piece ensures uniform stress distribution after end cap assembly, avoiding stress concentration and deformation caused by local thickness deviations. The high-hardness surface and tough core structure formed by carbonitriding heat treatment, with a surface hardness of HV650 or higher, can resist wear and indentation caused by long-term rolling of rollers, and the effective hardened layer depth of more than 0.1mm ensures the durability of wear resistance. The low hardness and toughness of the core can buffer impact loads and prevent the end cap from failing due to brittle fracture during start-up, shutdown, or load fluctuations. The positioning component ensures the assembly accuracy of the end cap and the base, avoids misalignment of the raceway due to assembly deviations, and improves the bearing positioning accuracy. The reserved space in the connection part facilitates heat dissipation and reduces the risk of lubrication failure caused by frictional heat. The tight fit between the load-bearing part and the first groove body can enhance the overall rigidity of the bearing, making it suitable for high-precision transmission scenarios.

[0006] As a further feature of this utility model, the positioning component is configured as a buckle, the base is provided with a plurality of positioning grooves in the circumference of the end cover, the buckle is disposed in the positioning groove, the edge of the buckle is exposed outside the positioning groove, the side wall of the end cover is provided with a positioning edge, and the contact surface between the buckle and the positioning edge is provided with an inclined surface.

[0007] The advantages of this design are as follows: The buckle is embedded in the base positioning groove, with its edge exposed for easy manual operation without additional tools. During assembly, the end cap's positioning edge slides smoothly into the buckle's inclined surface, allowing for quick positioning and engagement. Disassembly is simple; the exposed buckle can be pried open to separate the parts, enabling convenient assembly and disassembly. Furthermore, the engagement of the buckle with the positioning groove and edge provides stable positioning, preventing the end cap from loosening. The positioning groove's constraint on the buckle limits circumferential movement of the end cap, improving overall assembly accuracy. The tight engagement structure also enhances bearing sealing, preventing external dust and impurities from entering the raceway and ensuring smooth roller operation.

[0008] As a further feature of this utility model, a positioning post is provided on the base between the positioning slots, and an installation slot is provided on the end cover corresponding to the position of the positioning post, and the positioning post is engaged with the installation slot.

[0009] The beneficial effects of this design are as follows: This configuration creates a dual positioning constraint based on the snap-fit ​​positioning, significantly improving structural reliability. The positioning pins can be precisely inserted into the mounting groove, limiting the relative displacement between the end cap and the base radially and circumferentially. This prevents assembly misalignment caused by vibration and impact, ensuring the coaxiality and groove alignment accuracy of the end cap and base, and guaranteeing smooth roller operation. This design assists in assembly positioning, simplifies the installation process, and reduces assembly errors. It also distributes the load borne by the snap-fit, preventing excessive force on a single snap-fit ​​and thus extending the service life of the positioning components. During disassembly, the positioning pins also guide the end cap to separate smoothly, reducing the risk of component impact and improving maintenance convenience.

[0010] As a further feature of this utility model, the positioning column includes a base and a column body, with the base embedded in the mounting groove.

[0011] The advantages of this design are as follows: With the base embedded in the mounting groove, the increased contact area and structural fitting depth significantly enhance the connection strength between the positioning post and the end cap, effectively preventing the positioning post from loosening or falling off due to vibration and impact during bearing operation, thus ensuring long-term stable positioning accuracy. The embedded base allows for pre-positioning during assembly, quickly aligning the post with the mounting groove and improving assembly efficiency. The fitting structure also disperses the radial force borne by the positioning post, preventing localized stress concentration in the mounting groove that could cause cracking. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0013] Figure 2 This is a top view of the base structure in an embodiment of the present utility model;

[0014] Figure 3 This is a schematic diagram of the base structure in an embodiment of the present utility model;

[0015] Figure 4 This is a schematic diagram of the cover structure in an embodiment of the present utility model. Detailed Implementation

[0016] This utility model provides an embodiment of a planar linear bearing, such as... Figures 1 to 4As shown, the device includes a base 1, rollers, and an end cap. The base 1 has a channel 4, and the rollers are disposed within the channel 4. The channel 4 includes a first groove 41, a second groove 42, and a transition groove 43. The second groove 42 is deeper than the first groove 41. The first groove 41 and the second groove 42 are smoothly connected via the transition groove 43 to form a loop. The first groove 41 has an exposure window for communication with the outside. The end cap covers the base 1, shielding the channel 4. The end cap includes a supporting portion 22 and a connecting portion 21. The supporting portion 22 is positioned corresponding to the first groove 41, and the connecting portion 21 is positioned corresponding to the second groove 42. The distance between the connecting portion 21 and the bottom surface of the second groove 42 is greater than the distance between the supporting portion 22 and the bottom surface of the first groove 41. The height of the connecting portion 21 is higher than the supporting portion 22. The connecting portion 21 and the supporting portion 22 are connected by a transition slope. The base 1 also has a positioning assembly for positioning the end cap. The beneficial effects of this design are as follows: the stepped design of the end cap connecting part 21 being high and the bearing part 22 being low, and the precise fit between the bearing part 22 and the first groove 41, ensures that the rollers maintain the correct posture during operation through physical limiting, effectively avoiding the problem of uneven load caused by roller misalignment and reducing local stress concentration; the non-contact space formed by the connecting part 21 and the second groove 42 not only provides sufficient movement margin for roller circulation and avoids movement jamming, but also retains the lubricating medium, forming a continuous lubrication layer, further reducing frictional loss between the rollers and the groove 4. The setting of the transition slope makes the switching of the rollers between the bearing part 22 and the connecting part 21 smoother, reducing impact vibration and improving transmission stability. The precision-rolled carbon structural steel, with a surface roughness of less than Ra0.2, reduces the frictional resistance when the rollers roll, keeping the frictional torque at an extremely low level and reducing energy loss; the maximum thickness difference of 0.01mm per piece ensures uniform stress after the end cap is assembled, avoiding stress concentration and deformation caused by local thickness deviations. The high-hardness surface and tough core structure formed by carbonitriding heat treatment, with a surface hardness of HV650 or higher, can resist wear and indentation caused by long-term rolling of rollers, and the effective hardened layer depth of more than 0.1mm ensures the durability of wear resistance; the low hardness and toughness of the core can buffer impact loads and prevent the end cap from failing due to brittle fracture during start-up, shutdown or load fluctuations. The positioning component ensures the assembly accuracy of the end cap and the base 1, avoids misalignment of the groove 4 due to assembly deviation, and improves the bearing positioning accuracy; the reserved space of the connecting part 21 facilitates heat dissipation and reduces the risk of lubrication failure caused by frictional heat; the tight fit between the bearing part 22 and the first groove 41 can enhance the overall rigidity of the bearing, making it suitable for high-precision transmission scenarios.

[0017] As a further feature of this embodiment, the positioning component is configured as a snap fastener 12. The base 1 has a plurality of positioning grooves 11 circumferentially arranged on the end cap. The snap fastener 12 is disposed in the positioning grooves 11, with its edge exposed outside the positioning grooves 11. A positioning edge is provided on the side wall of the end cap, and the contact surface between the snap fastener 12 and the positioning edge is provided with an inclined surface. The advantages of this configuration are: with this configuration, the snap fastener 12 is embedded in the positioning grooves 11 of the base 1, and its edge is exposed, making it easy to operate by hand without additional tools; during assembly, the positioning edge of the end cap slides smoothly into the snap fastener 12 along its inclined surface, allowing for quick positioning and engagement; during disassembly, the exposed snap fastener 12 can be pried open to separate it, achieving convenient assembly and disassembly operations. Furthermore, the cooperation between the snap fastener 12, the positioning grooves 11, and the positioning edge can form a stable limit, preventing the end cap from loosening. The positioning groove 11 constrains the buckle 12, limiting the circumferential movement of the end cover and improving the overall assembly accuracy; the tight engagement structure also enhances the bearing sealing, preventing external dust and impurities from entering the groove 4 and ensuring smooth operation of the rollers.

[0018] As a further feature of this embodiment, a positioning post 3 is provided on the base 1 between the positioning grooves 11, and an installation groove 24 is provided on the end cap corresponding to the position of the positioning post 3. The positioning post 3 is engaged with the installation groove 24. The beneficial effects of this configuration are: this configuration forms a double positioning constraint based on the positioning of the snap fastener 12, which greatly improves the structural reliability. The positioning post 3 can be accurately inserted into the installation groove 24, which restricts the relative displacement between the end cap and the base 1 in the radial and circumferential directions, avoids assembly offset caused by vibration and impact, ensures the coaxiality of the end cap and the base 1 and the alignment accuracy of the groove 4, and ensures smooth operation of the rollers. This design can assist in assembly positioning, simplify the installation process, and reduce assembly errors; it can also distribute the load borne by the snap fastener 12, avoid the snap fastener 12 from deforming and failing due to excessive force, and extend the service life of the positioning component. During disassembly, the positioning post 3 can also guide the end cap to separate smoothly, reduce the risk of component collision, and improve maintenance convenience.

[0019] As a further feature of this embodiment, the positioning post 3 includes a base 31 and a post 32, with the base 31 embedded in the mounting groove 24. The advantages of this configuration are: by increasing the contact area and structural fitting depth, the base 31 embedded in the mounting groove 24 significantly enhances the connection strength between the positioning post 3 and the end cap, effectively preventing the positioning post 3 from loosening or falling off due to vibration or impact during bearing operation, thus ensuring long-term stable positioning accuracy. The embedded base 31 allows for pre-positioning during assembly, quickly aligning the post 32 with the mounting groove 24 and improving assembly efficiency; the fitting structure disperses the radial force borne by the positioning post 3, preventing localized stress concentration in the mounting groove 24 that could cause cracking.

[0020] The above examples are merely one preferred embodiment of this utility model. Ordinary variations and substitutions made by those skilled in the art within the scope of this utility model's technical solution are all included within the protection scope of this utility model.

Claims

1. A planar linear bearing, comprising a base, rollers, and end caps, wherein the base has a groove, and the rollers are disposed in the groove, characterized in that: The channel includes a first groove, a second groove, and a transition groove. The second groove is deeper than the first groove. The first groove and the second groove are smoothly connected by the transition groove to form a loop. The first groove is provided with an exposure window for communicating with the outside. The end cap is placed on the base to shield the channel. The end cap includes a support part and a connecting part. The support part is positioned corresponding to the first groove, and the connecting part is positioned corresponding to the second groove. The distance between the connecting part and the bottom surface of the second groove is greater than the distance between the support part and the bottom surface of the first groove. The height of the connecting part is higher than that of the support part. The connecting part and the support part are connected by a transition slope. The base is also provided with a positioning component for positioning the end cap.

2. The planar linear bearing according to claim 1, characterized in that: The positioning component is configured as a snap fastener. The base has several positioning grooves around the end cover. The snap fastener is disposed in the positioning grooves. The edge of the snap fastener is exposed outside the positioning groove. The side wall of the end cover is provided with a positioning edge. The contact surface between the snap fastener and the positioning edge is provided with an inclined surface.

3. The planar linear bearing according to claim 2, characterized in that: The base has positioning posts between positioning slots, and the end cap has mounting slots corresponding to the positions of the positioning posts. The positioning posts are engaged with the mounting slots.

4. The planar linear bearing according to claim 3, characterized in that: The positioning column includes a base and a column body, with the base embedded in the mounting groove.

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