Fixed-range rotating linear bearing

Abstract

The invention relates to the technical field of bearings, and discloses a fixed-range rotating linear bearing which comprises an outer ring, a retainer rotationally and horizontally moving in the outer ring and stoppers located at the two ends of the outer ring and used for limiting the retainer from disengaging, a plurality of rolling bodies are assembled on the retainer, and a bidirectional dynamic buffer module is arranged on the outer ring. The two-way dynamic buffering module comprises two sets of telescopic pressure bins and a medium conveying channel arranged in the outer ring, each telescopic pressure bin comprises a hard bin chamber, a hard abutting ring and a telescopic ring piece connected with the hard bin chamber and the hard abutting ring in a sealed mode, and a medium channel communicating with the medium conveying channel and the annular variable pressure bin is arranged in each hard bin chamber; the telescopic ring piece, the annular variable-pressure bin and the medium conveying channel are filled with media, when the holder abuts against the hard abutting ring, the hard abutting ring extrudes the media in the annular variable-pressure bin till the media make contact with the hard bin, the bearing has the functions of rotation and reciprocating translation in a fixed range, rotation is smooth, and the translation buffering performance is good.

Description

Technical Field

[0001] The present invention relates to the technical field of bearings, and in particular to a fixed-stroke rotating linear bearing. Background Art

[0002] Fixed-stroke linear bearings are bearings that can achieve combined linear and rotational motion and are suitable for mechanical equipment that requires multi-directional motion.

[0003] The prior application with publication number CN105952794B discloses a linear motion bearing, which is essentially a fixed-stroke rotating linear bearing. The bearing includes an outer ring, retaining rings arranged at both ends of the outer ring, a retaining frame located inside the outer ring, and balls arranged on the retaining frame. Under the action of the balls, the retaining frame can rotate inside the outer ring and move along the axial direction of the outer ring. The one-way stroke of its axial movement along the outer ring is the difference between the spacing between the two retaining rings and the axial thickness of the retaining frame.

[0004] The existing retaining frame lacks a buffer structure during the axial movement along the outer ring inside the outer ring. Good buffering can reduce the impact and vibration during operation and improve the stability of operation. However, the conventional buffering structure will lead to the risk of changes in the predetermined stroke of the retaining frame. Therefore, there is a good market prospect for ensuring that the retaining frame has a predetermined movement stroke while providing its movement buffering properties. Summary of the Invention

[0005] The present invention aims to solve the problem that the retaining frame of the existing fixed-stroke rotary linear bearing lacks buffering performance when moving to the maximum stroke at both ends, and provides a fixed-stroke rotary linear bearing that can provide buffering performance for its movement while ensuring the retaining frame has a predetermined movement stroke.

[0006] In order to solve the above technical problems, the present invention is solved by the following technical solutions: A fixed-stroke rotary linear bearing comprises an outer ring, a retaining frame that rotates and translates within the outer ring, and stoppers located at both ends of the outer ring for limiting the retaining frame from disengaging. The retaining frame is equipped with a number of rolling bodies that contact the inner wall of the outer ring and partially protrude beyond the inner wall of the retaining frame. The outer ring is provided with a bidirectional dynamic buffer module that provides a buffering force when the retaining frame runs to the end of the outer ring. The bidirectional dynamic buffer module comprises two sets of telescopic pressure chambers and a medium conveying channel arranged inside the outer ring. The telescopic pressure chamber comprises a hard chamber that is restricted by the retaining ring and the bottom of the first annular groove at the end of the outer ring, a hard back ring located inside the outer ring, and a telescopic ring of an annular transformer chamber that seals the hard chamber and the hard back ring and forms a seal with both. A medium channel connected to the medium conveying channel and the annular transformer chamber is provided in the hard chamber. The annular transformer chamber, the medium channel and the medium conveying channel are filled with medium. When the retaining frame presses against the hard back ring, the hard back ring squeezes the medium in the annular transformer chamber until it contacts the hard chamber.

[0007] The above scheme is adopted, and a bidirectional dynamic buffer module is added. When the retaining frame moves axially to abut against the hard abutting ring, the hard abutting ring will be squeezed, the telescopic ring will shrink, and the medium in the annular transformer chamber will gradually enter the telescopic pressure chamber at the other end through the medium channel and the medium conveying channel. The retaining frame is buffered in this process, and the telescopic pressure chamber at the other end is reset from a contracted state to an expanded state, waiting to provide buffering performance for the retaining frame after reversing. The amount of medium inside is in a non-saturated state, that is, when the retaining frame abuts the pressure ring, the pressure ring can move with the contraction of the telescopic ring to abut against the hard chamber, thereby ensuring that the single translation stroke of the retaining frame is a predetermined stroke. The rotary linear bearing has good buffering performance while having a predetermined stroke during linear motion.

[0008] Preferably, the telescopic ring is a corrugated ring tube that is axially telescopically deformable, and an anti-deformation structure is provided between the hard abutment ring and the hard chamber to prevent the corrugated ring tube from torsional deformation.

[0009] Preferably, the anti-deformation structure includes at least one set of telescopic tube assemblies arranged between the hard abutment ring and the hard chamber, which are completely retracted into the hard abutment ring and the hard chamber when contracted, and the telescopic tube assembly includes at least two telescopic tubes that are telescopically sleeved.

[0010] By adopting the above solution, a telescopic pipe is provided, which can prevent the hard anvil ring from circumferential deflection and ensure that the corrugated ring tube always expands and contracts along its axial direction.

[0011] Preferably, the medium is lubricating oil, and a staged oil seepage structure is provided on the corrugated annular tube.

[0012] Preferably, the staged oil seepage structure includes oil seepage holes provided at local troughs of the outer ring tube of the corrugated annular tube, which are opened when the corrugated annular tube is expanded and closed when the corrugated annular tube is contracted.

[0013] Preferably, the pore size of the oil seepage holes ranges from 100 μm to 200 μm.

[0014] By adopting the above solution, the design of the oil seepage hole can carry out micro-intermittent reciprocating oil seepage to lubricate the inner ring wall of the outer ring. When the cage runs to the rolling element on it and contacts the lubricating oil, it has a lubricating effect. When the corrugated ring tube contracts, the trough part is in a folded state, and the oil seepage holes on it will close. Therefore, during each contraction or expansion process of the corrugated ring tube, there will only be a short-term micro-oil seepage. This setting can provide two-way buffering while also achieving a long-term lubrication effect.

[0015] Preferably, the hard chamber includes a large ring segment and a small ring segment which are integrally arranged and have one large and one small outer diameter. The large ring segment overlaps the bottom of the first ring groove and the small ring segment is inserted into the inner ring of the outer ring. The medium channel includes a first oil groove which is recessed at one end of the large ring segment facing the bottom of the first ring groove and is connected to the medium conveying channel, a second oil groove which is recessed in the part of the small ring segment located in the annular transformer chamber, and an oil ring groove which is recessed on the outer ring wall of the large ring segment and is connected to the first oil groove and the second oil groove. A first sealing ring is embedded in the outer ring wall of the large ring segment and elastically abuts against the inner ring wall of the first ring groove while sealing the oil ring groove.

[0016] When adopting the above scheme, a medium channel needs to be set up in the hard chamber. The medium channel adopts the setting method of the first oil groove, the second oil groove, the oil ring groove and the first sealing ring, which is easy to process. The first sealing ring can seal the oil ring groove and prevent the lubricating oil from leaking toward the blocker.

[0017] Preferably, a second annular groove is concentrically provided at the bottom of the first annular groove, and both ends of the medium conveying channel are respectively located at the bottom of the two second annular grooves. After the hard chamber is inserted into the first annular groove, the first oil groove faces the second annular groove.

[0018] By adopting the above solution and setting up a second annular groove, the trouble of docking the first annular groove with the medium conveying channel can be eliminated. It is only necessary to insert a hard chamber into the first annular groove and limit it with a baffle to ensure that the lubricating oil flowing out of the first oil groove enters the second annular groove and flows to the medium conveying channel.

[0019] Preferably, both ends of the retainer are provided with balls embedded therein or hemispherical protrusions at even intervals in the circumferential direction.

[0020] By adopting the above solution, the balls or hemispherical protrusions can reduce the friction force generated by the rotation of the retaining frame after it abuts against the pressure ring, and reduce the circumferential torsional force on the pressure ring.

[0021] Preferably, a one-way valve for one-way oil injection from the outside into the oil ring groove is provided at one end of the large ring segment facing the outer end of the outer ring.

[0022] With the above solution, the one-way valve makes it easy to add lubricating oil at any time.

[0023] The present invention has significant technical effects due to the adoption of the above technical solutions: A bidirectional dynamic buffer module is added. When the retainer moves axially to abut against the hard abutting ring, the hard abutting ring is squeezed, the corrugated ring tube contracts, and the medium in the annular transformer chamber gradually enters the annular transformer chamber at the other end through the medium channel and the medium delivery channel. The retainer is buffered in this process, and the annular transformer chamber at the other end is reset from a contracted state to an expanded state, waiting to provide buffering performance for the retainer after reversing. The amount of lubricating oil inside is in an unsaturated state. When the retainer abuts the pressure ring, the pressure ring can move with the contraction of the telescopic ring to abut against the hard chamber, thereby ensuring that the single translation stroke of the retainer is a predetermined stroke. The rotary linear bearing has good buffering performance while having a predetermined stroke during linear motion. A telescopic tube assembly is added to prevent the hard ring from deflecting and provide guidance for the expansion and contraction of the corrugated ring tube; After the hard chamber is assembled, the first sealing ring and the second sealing ring cooperate to allow the lubricating oil to move in a sealed manner between the annular transformer chamber and the medium conveying channel. The arrangement of the medium channel is convenient for production. Oil seepage holes are set at the trough of the outer ring tube of the corrugated ring tube to achieve intermittent trace oil seepage during the buffering process, providing buffering and lubrication at the same time. A one-way valve is also provided to facilitate the addition of lubricating oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a front view of a fixed-range rotary linear bearing according to this embodiment; Figure 2 yes Figure 1 AA cross-sectional view; Figure 3 yes Figure 2 A magnified view of A; Figure 4 This is a disassembled diagram of a fixed-range rotation linear bearing of this embodiment; Figure 5 This is a front view of the telescopic pressure chamber of this embodiment when expanded; Figure 6 yes Figure 5 Cross-sectional view of BB; Figure 7 yes Figure 6 Cross-sectional view of CC; Figure 8 is a cross-sectional view of the retainer of this embodiment; Figure 9 It is a cross-sectional view of the ball of this embodiment after being placed in the pocket.

[0025] The parts designated by the numbers in the above figures are as follows: 1. Outer ring; 101. First ring groove; 102. Second ring groove; 103. Annular clamping groove; 104. Medium conveying channel; 2. Retaining ring; 3. Telescopic pressure chamber; 301. Hard chamber; 3011. First oil groove; 3012. Second oil groove; 3013. Oil ring groove; 302. Hard back ring; 303. Corrugated ring tube; 3031. Oil seepage hole; 3032, annular transformer chamber; 4, first sealing ring; 5, retaining frame; 501, pocket hole; 5011, cylindrical barrel section; 5012, conical barrel section; 6, ball bearing; 7, hemispherical protrusion; 8, one-way valve; 801, spherical plug; 802, spring; 9, telescopic tube assembly; 901, fixed pipe fitting; 902, "T"-shaped pipe fitting; 903, "I"-shaped pipe fitting; 10, second sealing ring. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0027] A fixed-stroke linear bearing, referring to Figures 1-9 As shown, it includes an outer ring 1, a cage 5, a rolling element and a stopper. The stopper is an open retaining ring 2 and the rolling element is a ball 6. For details, refer to Figure 8-Figure 9 As shown, the retainer 5 is cylindrical and has a clearance fit with the inner wall of the outer ring 1 after being inserted into the outer ring 1. A number of pocket groups are arranged on the retainer 5 along its axial direction. The pocket group includes four pockets 501 evenly spaced around the circumference of the retainer 5. The pockets 501 of adjacent pocket groups are staggered. The pockets 501 include, from the outside to the inside, an integral cylindrical section 5011 and a conical section 5012. The inner diameter of the cylindrical section 5011 is 0.1-0.2 mm larger than the diameter of the ball 6. When the ball 6 is tangent to the conical section 5012, the ball 6 partially protrudes from the inner ring wall of the retainer 5 and the side of the ball 6 close to the outer ring wall of the retainer 5 completely enters the pocket 501. The cone angle β of the conical section 5012 is 70°±10°.

[0028] A bidirectional dynamic buffer module is provided on the outer ring 1 to provide buffering force when the retainer 5 runs to the end of the outer ring 1. Figure 2-Figure 3 As shown, the bidirectional dynamic buffer module includes two sets of telescopic pressure chambers 3 and a medium conveying channel 104 arranged inside the outer ring 1. The diameter of the medium conveying channel 104 is 0.5-1 mm.

[0029] There are first annular grooves 101 concentrically recessed on both sides of the outer ring 1, a second annular groove 102 concentrically recessed at the bottom of the first annular groove 101, and an annular groove 103 concentrically recessed on the outer ring wall of the first annular groove 101 for the retaining ring 2 to be clamped into. There are 1 to 4 medium conveying channels 104 evenly spaced around the circumference of the outer ring 1, and both ends of the medium conveying channels pass through the second annular groove 102 respectively.

[0030] The telescopic pressure chamber 3 includes a hard chamber 301, a hard back ring 302 and a corrugated ring tube 303. Figure 5-Figure 7 As shown, the hard chamber 301 includes an integrally arranged large and small ring segments with different outer diameters. The large ring segment overlaps the bottom of the first annular groove 101, and the small ring segment is inserted into the inner ring of the outer ring 1. The corrugated annular tube 303 is formed by a sleeve of two corrugated tubes, one with a larger diameter and the other with a smaller diameter. The ends of the inner corrugated tube are sealed and fixedly connected to the inner annular walls of the small and large ring segments, respectively. The ends of the outer corrugated tube are sealed and fixedly connected to the outer annular walls of the small and large ring segments, respectively. An annular pressure-transformation chamber 3032 is formed between the small ring segment, the corrugated annular tube 303, and the hard annular ring 302. A medium channel is provided on the hard chamber 301, connecting the medium delivery channel 104 and the annular pressure-transformation chamber 3032.

[0031] The medium channel includes a first oil groove 3011 which is recessed at one end of the large ring segment facing the bottom of the first ring groove 101 and is connected to the medium conveying channel 104, a second oil groove 3012 which is partially recessed in the annular transformer chamber 3032 of the small ring segment, and an oil ring groove 3013 which is recessed on the outer ring wall of the large ring segment and is connected to the first oil groove 3011 and the second oil groove 3012. A first sealing ring 4 is embedded on the outer ring wall of the large ring segment, which elastically abuts against the inner ring wall of the first ring groove 101 and seals the oil ring groove 3013. A second sealing ring 10 is concentrically embedded on the end face of the large ring segment facing the small ring segment. When the retaining ring 2 is engaged with the annular groove 103, the second sealing ring 10 elastically abuts against the bottom of the first ring groove 101.

[0032] The medium filled in the two groups of annular transformer chambers 3032, the medium channel and the medium delivery channel 104 is lubricating oil. The length of the telescopic pressure chamber 3 after expansion accounts for 1 / 4-1 / 3 of the total length of the outer ring 1, and the length of the telescopic pressure chamber 3 after contraction to the maximum stroke accounts for 1 / 3-1 / 2 of its expanded length. The total amount of lubricating oil needs to be kept below the preset maximum oil amount. The volume corresponding to the preset maximum oil amount is 1-1.25 times the volume of the expanded telescopic pressure chamber 3, that is, when the retaining frame 5 presses against the hard back ring 302, the hard back ring 302 squeezes the medium in the annular transformer chamber 3032 and can move to contact the end face of the small ring segment to ensure that the retaining frame 5 always moves within the fixed range in the outer ring 1.

[0033] An anti-deformation structure is provided between the small ring segment and the hard anvil 302 to prevent the corrugated ring tube 303 from torsional deformation. Figure 7As shown, the anti-deformation structure includes a telescopic tube assembly 9 arranged between the small ring segment and the hard anvil 302. The telescopic tube assembly 9 is symmetrically arranged in two groups, and each group of telescopic tube assemblies 9 includes at least two telescopic tubes. In this embodiment, 5 telescopic tubes are included, of which 2 are fixed tubes 901, 2 are "T"-shaped tubes 902, and 1 is an "I"-shaped tube 903. The small ring segment and the hard anvil 302 have corresponding recesses on opposite sides thereof for fixing and accommodating a fixed tube 901. The large ends of the two "T"-shaped tubes 902 are respectively inserted into a fixed tube 901, and the two ends of the "I"-shaped tube 903 are respectively inserted into the "T"-shaped tube 902. The above-mentioned telescopic tube assembly 9 can prevent the hard anvil 302 from deflecting and guide the telescopic direction of the corrugated ring tube 303.

[0034] In order to further reduce the circumferential torsion force on the hard anvil ring 302, see Figure 2 or Figure 4 As shown, hemispherical protrusions 7 are evenly spaced circumferentially on both ends of the retainer 5 .

[0035] The corrugated ring tube 303 is provided with a staged oil leakage structure, see Figure 2 As shown, the staged oil seepage structure includes an oil seepage hole 3031 provided at a local trough portion of the outer ring tube of the corrugated ring tube 303, which opens when the corrugated ring tube 303 is expanded and closes when it is contracted. The aperture range of the oil seepage hole 3031 is 100μm-200μm, and a one-way valve 8 for one-way oil injection from the outside to the oil ring groove 3013 is provided at the end of the large ring segment facing the outer end of the outer ring 1. The one-way valve 8 in this scheme is a ball valve structure, including a spring 802 and a spherical plug 801. When the oiler presses the spherical plug 801, oil can be injected into the medium channel. The oil injection amount is evaluated by observing the expansion state of the telescopic pressure chamber 3 and the maximum stroke of the retaining frame 5.

[0036] The above-mentioned corrugated ring tube 303 adopts PU polyurethane steel wire hose, and the fixed connection between it and the hard back ring 302 and the small ring segment is adhesive fixation. The retaining ring 2, the hard back ring 302 and the hard chamber 301 are made of 65Mn, and the retaining frame 5 and the outer ring 1 are made of aluminum alloy.

[0037] During use, oil is injected at preset intervals to ensure that there is sufficient lubricating oil for buffering. The staged oil seepage can also continuously provide lubrication for the balls 6, ensuring the smoothness and stability of the rotation and translation of the retainer 5.

[0038] The operating principle is as follows: when the retainer 5 moves axially to abut against the hard annular ring 302, it squeezes the hard annular ring 302, the corrugated ring tube 303 contracts, and the lubricating oil in the annular transformer chamber 3032 gradually enters the annular transformer chamber 3032 at the other end through the medium channel and the medium delivery channel 104. The retainer 5 is buffered in this process, and the annular transformer chamber 3032 at the other end is reset from the contracted state to the expanded state, waiting to provide buffering performance for the retainer 5 after reversing. The amount of lubricating oil inside is in a non-saturated state. When the retaining frame 5 abuts against the pressing ring, the pressing ring can move to abut against the hard chamber 301 as the telescopic ring contracts, thereby ensuring that the single translation stroke of the retaining frame 5 is a predetermined stroke; in addition, the oil seepage hole 3031 provided on the outer ring tube of the corrugated ring tube 303 is located in the trough position. During the contraction or expansion process of the corrugated ring tube 303, the oil seeps slowly for a short time during the stage of corrugation expansion, and the oil seepage is suspended as the corrugation folds. Therefore, it can repeatedly seep a small amount of oil in stages, providing the retaining frame 5 with buffering performance while lubricating the ball 6.

[0039] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A fixed-range rotation linear bearing, comprising an outer ring (1), a retainer (5) that rotates and translates within the outer ring (1), and stoppers located at both ends of the outer ring (1) for limiting the retainer (5) from coming out, the retainer (5) being equipped with a plurality of rolling elements that contact the inner wall of the outer ring (1) and partially protrude from the inner wall of the retainer (5), characterized in that: The outer ring (1) is provided with a bidirectional dynamic buffer module for providing a buffer force when the retaining frame (5) runs to the end of the outer ring (1). The bidirectional dynamic buffer module includes two sets of telescopic pressure chambers (3) and a medium conveying channel (104) arranged inside the outer ring (1). The telescopic pressure chamber (3) includes a hard chamber (301) limited by the retaining ring (2) and the bottom of the first ring groove (101) at the end of the outer ring (1), a hard backing ring (302) located inside the outer ring (1), and a sealing member connecting the hard chamber (301) and the hard A retractable ring member of the annular pressure-transforming chamber (3032) is provided in the hard chamber (301) to form a seal with the ring (302) and the annular pressure-transforming chamber (3032). A medium channel is provided in the hard chamber (301) to communicate with the medium delivery channel (104) and the annular pressure-transforming chamber (3032). The annular pressure-transforming chamber (3032), the medium channel and the medium delivery channel (104) are filled with medium. When the retaining frame (5) presses against the hard ring (302), the hard ring (302) squeezes the medium in the annular pressure-transforming chamber (3032) until it contacts the hard chamber (301).

2. The fixed-range rotation linear bearing according to claim 1, characterized in that: The telescopic ring is a corrugated ring tube (303) that is deformed by axial telescopic deformation. An anti-deformation structure is provided between the hard abutting ring (302) and the hard chamber (301) to prevent the corrugated ring tube (303) from torsional deformation.

3. The fixed-range rotation linear bearing according to claim 2, characterized in that: The anti-deformation structure comprises at least one set of telescopic tube components (9) arranged between the hard anvil (302) and the hard chamber (301) and completely retracted into the hard anvil (302) and the hard chamber (301) when contracted, wherein the telescopic tube component (9) comprises at least two telescopic tubes that are telescopically sleeved.

4. The fixed-range rotation linear bearing according to claim 3, characterized in that: The medium is lubricating oil, and a staged oil seepage structure is provided on the corrugated ring tube (303).

5. The fixed-range rotation linear bearing according to claim 4, characterized in that: The staged oil seepage structure comprises an oil seepage hole (3031) provided at a local trough portion of the outer ring tube of the corrugated ring tube (303), which opens when the corrugated ring tube (303) is expanded and closes when it is contracted.

6. The fixed-range rotation linear bearing according to claim 5, characterized in that: The pore size of the oil seepage hole (3031) ranges from 100 μm to 200 μm.

7. A fixed-range rotation linear bearing according to any one of claims 1 to 6, characterized in that: The hard chamber (301) comprises a large ring segment and a small ring segment which are integrally arranged and have a large and a small outer diameter, respectively. The large ring segment is overlapped at the bottom of the first ring groove (101) and the small ring segment is inserted into the inner ring of the outer ring (1). The medium channel comprises a first oil groove (3011) which is recessed at one end of the large ring segment facing the bottom of the first ring groove (101) and is connected to the medium conveying channel (104), a second oil groove (3012) which is recessed at a portion of the small ring segment located within the annular transformer chamber (3032), and an oil ring groove (3013) which is recessed on the outer ring wall of the large ring segment and is connected to the first oil groove (3011) and the second oil groove. A first sealing ring (4) which elastically abuts against the inner ring wall of the first ring groove (101) and seals the oil ring groove (3013) is embedded on the outer ring wall of the large ring segment.

8. The fixed-range rotation linear bearing according to claim 7, characterized in that: A second annular groove (102) is concentrically provided at the bottom of the first annular groove (101), and both ends of the medium conveying channel (104) are respectively located at the bottoms of the two second annular grooves (102). After the hard chamber (301) is inserted into the first annular groove (101), the first oil groove (3011) faces the second annular groove (102).

9. A fixed-range rotation linear bearing according to any one of claims 1 to 6, characterized in that: Both ends of the retaining frame (5) are circumferentially evenly spaced with embedded balls or hemispherical protrusions (7).

10. The fixed-range rotation linear bearing according to claim 7, characterized in that: A one-way valve (8) for one-way oil injection from the outside into the oil ring groove (3013) is provided at one end of the large ring segment facing the outer end of the outer ring (1).

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