Constant-velocity rotary linear bearing

Abstract

This invention relates to the field of bearing technology and discloses a fixed-stroke rotary linear bearing, including an outer ring, a cage rotating and translating within the outer ring, and stops located at both ends of the outer ring to prevent the cage from disengaging. A plurality of rolling elements are mounted on the cage. A bidirectional dynamic buffer module is provided on the outer ring. The bidirectional dynamic buffer module includes two sets of telescopic pressure chambers and a medium delivery channel disposed inside the outer ring. The telescopic pressure chamber includes a hard chamber, a hard abutment ring, and a telescopic ring member sealingly connecting the hard chamber and the hard abutment ring. The hard chamber has a medium channel communicating with the medium delivery channel and an annular pressure transformer chamber. The telescopic ring member, the annular pressure transformer chamber, and the medium delivery channel are filled with medium. When the cage presses against the hard abutment ring, the hard abutment ring squeezes the medium in the annular pressure transformer chamber until it contacts the hard chamber. This bearing has the functions of rotation and reciprocating translation within a fixed stroke, with smooth rotation and good translational buffering performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bearings, in particular to a constant rotation linear bearing. BACKGROUND

[0002] The constant rotation linear bearing is a bearing capable of realizing linear and rotary compound motion, which can be applied to mechanical equipment requiring multi-directional motion.

[0003] The prior application with publication number CN105952794B discloses a linear motion bearing, which is essentially a constant rotation linear bearing. The bearing comprises an outer ring, a retainer ring arranged at both ends of the outer ring, a retainer located in the outer ring, and balls arranged on the retainer. The retainer can rotate and move along the axial direction of the outer ring under the action of the balls. The one-way stroke of the retainer along the axial direction of the outer ring is the difference between the distance between the two retainer rings and the axial thickness of the retainer.

[0004] The existing retainer lacks a buffering structure during its movement along the axial direction of the outer ring. Good buffering can reduce impact and vibration during operation and improve the stability of operation. However, conventional buffering structures may cause the established stroke of the retainer to change during operation. Therefore, there is a good market prospect for providing buffering performance while ensuring the established stroke of the retainer. SUMMARY

[0005] The present application provides a constant rotation linear bearing that can provide buffering performance while ensuring the established stroke of the retainer, aiming at the lack of buffering performance of the existing constant rotation linear bearing when the retainer moves to the maximum stroke.

[0006] To solve the above technical problems, the present application provides the following technical solutions:

[0007] A constant rotation linear bearing comprises an outer ring, a retainer rotating and translating in the outer ring, and a stopper arranged at both ends of the outer ring to limit the retainer from coming out. The retainer is provided with a plurality of rolling bodies that are in contact with the inner wall of the outer ring and partially protrude from the inner wall of the retainer. The outer ring is provided with a bidirectional dynamic buffering module that provides buffering force when the retainer moves to the end of the outer ring. The bidirectional dynamic buffering module comprises two groups of telescopic pressure chambers and a medium conveying channel arranged in the inner part of the outer ring. The telescopic pressure chamber comprises a hard chamber limited by the first ring groove bottom of the retainer ring and the end of the outer ring, a hard resistance ring located in the inner part of the outer ring, and a telescopic ring member sealingly connecting the hard chamber and the hard resistance ring and forming a sealed annular pressure-changing chamber with both. The hard chamber is provided with a medium channel in communication with the medium conveying channel and the annular pressure-changing chamber. The annular pressure-changing chamber, the medium channel, and the medium conveying channel are filled with a medium. When the retainer presses the hard resistance ring, the hard resistance ring extrudes the medium in the annular pressure-changing chamber until it comes into contact with the hard chamber.

[0008] By the above scheme, the bidirectional dynamic buffering module is added, when the cage moves axially to abut against the hard abutting ring, the hard abutting ring is extruded, the telescopic ring member is contracted, the medium in the annular pressure changing chamber gradually enters the telescopic pressure chamber at the other end through the medium channel and the medium conveying channel, the cage is buffered in the process, and the telescopic pressure chamber at the other end is reset from the contracted state to the expanded state, waiting for providing buffering performance for the cage after reversing, and the amount of the medium inside is in a non-saturated state, that is, when the cage abuts against the abutting ring, the abutting ring can move to abut against the hard chamber with the contraction of the telescopic ring member, so that the stroke amount of the single translation of the cage is determined, and the rotary linear bearing has good buffering performance while the stroke is determined in linear motion.

[0009] Preferably, the telescopic ring member is a corrugated ring pipe that is axially telescopic and deformed, and an anti-deformation structure is arranged between the hard abutting ring and the hard chamber to avoid torsional deformation of the corrugated ring pipe.

[0010] Preferably, the anti-deformation structure comprises at least one telescopic pipe assembly that is completely shrunk into the hard abutting ring and the hard chamber when contracted and is arranged between the hard abutting ring and the hard chamber, and the telescopic pipe assembly comprises at least two telescopic pipe members that are telescopically arranged.

[0011] By the above scheme, the telescopic pipe member is arranged, which can avoid the circumferential deflection of the hard abutting ring and ensure that the corrugated ring pipe always telescopes in the axial direction.

[0012] Preferably, the medium is lubricating oil, and the corrugated ring pipe is provided with a stage oil infiltration structure.

[0013] Preferably, the stage oil infiltration structure comprises an oil infiltration hole that is opened when the corrugated ring pipe is expanded and closed when the corrugated ring pipe is contracted and is arranged at a local trough part of an outer ring pipe of the corrugated ring pipe.

[0014] Preferably, the oil infiltration hole has a hole diameter ranging from 100 μm to 200 μm.

[0015] By the above scheme, the design of the oil infiltration hole can realize trace intermittent reciprocating oil infiltration, lubricate the inner ring wall of the outer ring, and have a lubricating effect when the cage runs to the rolling body on the cage and contacts the lubricating oil. When the corrugated ring pipe is contracted, the oil infiltration hole at the trough part is closed, so that only trace oil infiltration exists for a short time in the process of each contraction or expansion of the corrugated ring pipe. The setting can provide bidirectional buffering and also has a long-time lubricating effect.

[0016] Preferably, the hard chamber comprises a large ring segment and a small ring segment which are integrally arranged and have different outer diameters, the large ring segment is overlapped at 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 comprises a first oil groove recessed at one end of the large ring segment towards the bottom of the first ring groove and connected with the medium conveying channel, a second oil groove recessed at the part of the small ring segment located in the annular pressure chamber, and an oil passing ring groove recessed on the outer ring wall of the large ring segment and in communication with the first oil groove and the second oil groove, and a first sealing ring is embedded on 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 passing ring groove.

[0017] By the above scheme, the medium channel needs to be arranged in the hard chamber, and the medium channel is arranged by the first oil groove, the second oil groove, the oil passing ring groove and the first sealing ring, which is easy to process, and the first sealing ring can seal the oil passing ring groove and avoid the exudation of lubricating oil to the direction of the stop piece.

[0018] Preferably, the bottom of the first ring groove is concentrically recessed with a second ring groove, and the two ends of the medium conveying channel are located at the groove bottoms of the two second ring grooves, respectively, and after the hard chamber is inserted into the first ring groove, the first oil groove is opposite to the second ring groove.

[0019] By the above scheme, the second ring groove is arranged, which can avoid the trouble of butt joint of the first ring groove and the medium conveying channel, and after the hard chamber is inserted into the first ring groove and limited by the stop piece, it can be ensured that the lubricating oil flowing out of the first oil groove enters the second ring groove and flows to the medium conveying channel.

[0020] Preferably, the two ends of the retainer are uniformly and circumferentially embedded with balls or protruded with hemispherical protrusions.

[0021] By the above scheme, the balls or hemispherical protrusions can reduce the friction generated by the rotation of the retainer after abutting against the pressing ring, and reduce the circumferential torsion received by the pressing ring.

[0022] Preferably, a one-way valve is arranged at one end of the large ring segment towards the outer end of the outer ring, which allows one-way oil injection from the outside to the oil passing ring groove.

[0023] By the above scheme, the one-way valve is convenient for adding lubricating oil at any time.

[0024] The present application has the following technical effects:

[0025] The bidirectional dynamic buffering module is added, when the retainer moves axially to abut against the hard abutting ring, the hard abutting ring is extruded, the corrugated ring pipe is contracted, the medium in the annular variable pressure chamber enters the annular variable pressure chamber at the other end through the medium channel and the medium conveying channel, the retainer is buffered in the process, and the annular variable pressure chamber at the other end is reset from the contracted state to the expanded state, waiting for providing buffering performance for the retainer after reversing, the amount of the internal lubricating oil is in a non-saturated state, when the retainer abuts against the abutting ring, the abutting ring can move to abut against the hard chamber with the contraction of the telescopic ring piece, so that the stroke amount of the single translation of the retainer is determined, and the rotary linear bearing has good buffering performance while the stroke is determined in linear motion;

[0026] The telescopic pipe assembly is additionally arranged, which is used for preventing the deflection of the hard abutting ring and providing guidance for the telescoping of the corrugated ring pipe;

[0027] After the hard chamber is assembled, the lubricating oil is sealed and moved between the annular variable pressure chamber and the medium conveying channel under the cooperation of the first sealing ring and the second sealing ring, and the medium channel is arranged in a mode facilitating production.

[0028] The oil seepage hole is arranged at the outer ring pipe trough of the corrugated ring pipe, intermittent micro oil seepage in the buffering process is realized, buffering and lubrication are simultaneously provided, and the one-way valve facilitating lubricating oil addition is further arranged. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a front view of a fixed-stroke rotary linear bearing of the embodiment;

[0030] Figure 2 It is a sectional view of A-A of Figure 1

[0031] Figure 3 It is an enlarged view of A of Figure 2

[0032] Figure 4 It is an exploded view of a fixed-stroke rotary linear bearing of the embodiment;

[0033] Figure 5 It is a front view of the telescopic pressure chamber when the telescopic pressure chamber is expanded;

[0034] Figure 6 It is a sectional view of B-B of Figure 5

[0035] Figure 7 It is a sectional view of C-C of Figure 6

[0036] Figure 8 It is a sectional view of the retainer of the embodiment; ​​​​

[0037] Figure 9 This is a cross-sectional view of the ball bearings after they are inserted into the pocket in this embodiment.

[0038] The parts referred to by the numbers in the above attached diagrams are as follows: 1. Outer ring; 101. First annular groove; 102. Second annular groove; 103. Annular groove; 104. Medium conveying channel; 2. Retaining ring; 3. Telescopic pressure chamber; 301. Rigid chamber; 3011. First oil tank; 3012. Second oil tank; 3013. Oil passage annular groove; 302. Rigid abutment ring; 303. Corrugated ring pipe; 3031. 3032, Annular transformer chamber; 4, First sealing ring; 5, Cage; 501, Pocket; 5011, Cylindrical section; 5012, Conical section; 6, Ball bearing; 7, Hemispherical protrusion; 8, One-way valve; 801, Spherical plug; 802, Spring; 9, Telescopic pipe assembly; 901, Fixed pipe fitting; 902, "T" shaped pipe fitting; 903, "I" shaped pipe fitting; 10, Second sealing ring. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0040] A fixed-stroke rotary linear bearing, referenced Figures 1-9 As shown, it includes an outer ring 1, a cage 5, rolling elements, and a retainer. The retainer is an open-type retaining ring 2, and the rolling elements are balls 6. See details. Figures 8-9 As shown, the retainer 5 is cylindrical and, after being inserted into the outer ring 1, has a clearance fit with the inner wall of the outer ring 1. The retainer 5 is provided with several pocket groups at intervals along its axial direction. Each pocket group includes four pockets 501 evenly spaced around the circumference of the retainer 5. The pockets 501 of adjacent pocket groups are staggered. From the outside to the inside, each pocket 501 includes an integrally formed 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 outside the inner ring wall of the retainer 5, and the side of the ball 6 closest 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°.

[0041] A bidirectional dynamic buffer module is provided on the outer ring 1 to provide buffering force when the cage 5 moves to the end of the outer ring 1. See details. Figures 2-3 As shown, the bidirectional dynamic buffer module includes two sets of telescopic pressure chambers 3 and a medium conveying channel 104 disposed inside the outer ring 1. The diameter of the medium conveying channel 104 is 0.5-1mm.

[0042] The outer ring 1 is concave on both sides to form a first ring groove 101, the bottom of the first ring groove 101 is concave to form a second ring groove 102, the outer ring wall of the first ring groove 101 is concave to form a ring-shaped clamping groove 103 for clamping the retainer 2, and the medium conveying channel 104 is uniformly and spacedly provided with 1-4 medium conveying channels around the outer ring 1, and the two ends of the medium conveying channel 104 respectively penetrate the second ring groove 102.

[0043] The telescopic pressure chamber 3 comprises a hard chamber 301, a hard stop ring 302 and a corrugated ring pipe 303, and specifically referring to Figures 5-7 The hard chamber 301 comprises a large ring segment and a small ring segment which are integrally arranged and have different outer diameters, the large ring segment is overlapped on 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 corrugated ring pipe 303 is formed by sleeving two corrugated pipes with different diameters, the two ends of the inner corrugated pipe are sealingly and fixedly connected with the inner ring wall of the small ring segment and the large ring segment, the two ends of the outer corrugated pipe are sealingly and fixedly connected with the outer ring wall of the small ring segment and the large ring segment, and the small ring segment, the corrugated ring pipe 303 and the hard stop ring 302 form a ring-shaped pressure changing chamber 3032, and the hard chamber 301 is provided with a medium channel which communicates the medium conveying channel 104 and the ring-shaped pressure changing chamber 3032.

[0044] The medium channel comprises a first oil groove 3011 which is recessed on one end of the large ring segment and connected with the medium conveying channel 104, a second oil groove 3012 which is recessed on the part of the small ring segment located in the ring-shaped pressure changing chamber 3032, and an oil passing ring groove 3013 which is recessed on the outer ring wall of the large ring segment and communicates with the first oil groove 3011 and the second oil groove 3012, the first sealing ring 4 is embedded on the outer ring wall of the large ring segment and elastically abuts against the inner ring wall of the first ring groove 101 while sealing the oil passing ring groove 3013, and the second sealing ring 10 is concentrically embedded on the end face of the large ring segment facing the small ring segment and elastically abuts against the bottom of the first ring groove 101 when the retainer 2 is clamped with the ring-shaped clamping groove 103.

[0045] The two groups of ring-shaped pressure changing chambers 3032, the medium channel and the medium conveying channel 104 are filled with 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, the length of the telescopic pressure chamber 3 after contraction to the maximum stroke accounts for 1 / 3-1 / 2 of the length after expansion, and the total oil volume of the lubricating oil needs to be kept below the preset maximum oil volume, the volume corresponding to the preset maximum oil volume is 1-1.25 times the volume of the telescopic pressure chamber 3 after expansion, that is, when the retainer 5 abuts against the hard stop ring 302, the hard stop ring 302 extrudes the medium in the ring-shaped pressure changing chamber 3032 and can move to contact the end face of the small ring segment, so as to ensure that the retainer 5 moves in the outer ring 1 and always keeps in the fixed range.

[0046] An anti-deformation structure is provided between the small ring segment and the rigid abutment ring 302 to prevent torsional deformation of the bellows ring pipe 303. See details. Figure 7 As shown, the anti-deformation structure includes a telescopic tube assembly 9 disposed between the small ring segment and the rigid abutment ring 302. Two sets of telescopic tube assemblies 9 are symmetrically arranged, and each set of telescopic tube assemblies 9 includes at least two telescopic tubes. In this embodiment, there are 5 telescopic tubes, 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 rigid abutment ring 302 are respectively recessed on opposite sides to fix and accommodate one 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 rigid abutment ring 302 from deflecting and guide the telescopic direction of the corrugated ring tube 303.

[0047] To further reduce the circumferential torsion experienced by the rigid abutment ring 302, see [reference needed]. Figure 2 or Figure 4 As shown, hemispherical protrusions 7 are evenly spaced at both ends of the cage 5.

[0048] The corrugated ring pipe 303 is equipped with a staged oil seepage structure, see [link / reference]. Figure 2 As shown, the staged oil seepage structure includes an oil seepage hole 3031 set in the local trough of the outer ring pipe of the corrugated ring pipe 303. The hole opens when the corrugated ring pipe 303 expands and closes when it contracts. The diameter of the oil seepage hole 3031 ranges from 100μm to 200μm. A one-way valve 8 is set at the end of the large ring section facing the outer end of the outer ring 1, which allows one-way oil injection into the oil ring groove 3013 from the outside. The one-way valve 8 in this scheme is a ball valve structure, including a spring 802 and a ball plug 801. When the oil injector presses against the ball plug 801, oil can be injected into the medium channel. The amount of oil injected is evaluated by observing the expansion state of the telescopic pressure chamber 3 and the maximum stroke of the cage 5.

[0049] The aforementioned corrugated ring tube 303 is made of PU polyurethane steel wire hose, and its fixed connection with the rigid abutment ring 302 and the small ring segment is by adhesive bonding. The retaining ring 2, the rigid abutment ring 302 and the rigid chamber 301 are made of 65Mn, and the retainer 5 and the outer ring 1 are made of aluminum alloy.

[0050] During use, oil is injected at preset intervals to ensure sufficient lubrication for buffering. The phased oil seepage also continuously provides lubrication for the ball bearings 6, ensuring the smoothness and stability of the cage 5's rotation and translation.

[0051] The running principle is as follows: when the retainer 5 moves axially to abut against the hard abutting ring 302, the hard abutting ring 302 is extruded, the corrugated ring pipe 303 is contracted, the lubricating oil in the annular variable pressure chamber 3032 gradually enters the annular variable pressure chamber 3032 at the other end through the medium channel and the medium conveying channel 104, the retainer 5 is buffered in the process, and the annular variable pressure 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 commutation, and the amount of internal lubricating oil is in a non-saturated state, when the retainer 5 abuts against the abutting ring, the abutting ring can move with the contraction of the telescopic ring member to abut against the hard chamber 301, so as to ensure that the stroke amount of the single translation of the retainer 5 is a certain stroke; in addition, the oil infiltration hole 3031 provided on the outer ring pipe of the corrugated ring pipe 303 is located at the wave trough part, and in the contraction or expansion process of the corrugated ring pipe 303, the wave crests are slowly infiltrated for a short time in the wave unfolding stage, and the wave crests pause to infiltrate outward, so that the wave crests can be repeatedly and stage-by-stage infiltrated in a small amount, the buffering performance of the retainer 5 is provided, and the lubricating balls 6 are lubricated at the same time.

[0052] The above is only the preferred embodiment of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments. Any technical solution falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that, for ordinary skilled persons in the art, some improvements and decorations without departing from the principles of the present application shall also be considered as the protection scope of the present application.

Claims

1. A constant-velocity rotary linear bearing comprising an outer ring (1), a cage (5) rotating and translating in the outer ring (1), and a stopper at both ends of the outer ring (1) for limiting the cage (5) from coming out, the cage (5) being equipped with a plurality of rolling elements which are in contact with the inner wall of the outer ring (1) while partially protruding out of the inner wall of the cage (5), characterized in that: The outer ring (1) is provided with a bidirectional dynamic buffering module for providing buffering force when the retainer (5) runs to the end of the outer ring (1), the bidirectional dynamic buffering module comprises two groups of telescopic pressure chambers (3) and a medium conveying channel (104) arranged in the inner part of the outer ring (1), the telescopic pressure chamber (3) comprises a hard chamber (301) limited to the bottom of the first ring groove (101), a hard abutment ring (302) located in the inner part of the outer ring (1), and a telescopic ring member for sealingly connecting and forming a seal between the hard chamber (301) and the hard abutment ring (302), the hard chamber (301) is provided with a medium channel in communication with the medium conveying channel (104) and the annular variable pressure chamber (3032), the annular variable pressure chamber (3032), the medium channel and the medium conveying channel (104) are filled with a medium, and when the retainer (5) abuts against the hard abutment ring (302), the hard abutment ring (302) extrudes the medium in the annular variable pressure chamber (3032) until it contacts the hard chamber (301).

2. A constant velocity rotary linear bearing according to claim 1, wherein: The telescopic ring member is a corrugated ring tube (303) capable of axial telescopic deformation, and an anti-deformation structure is arranged between the hard abutment ring (302) and the hard chamber (301) to prevent the corrugated ring tube (303) from being twisted and deformed.

3. A constant velocity rotary linear bearing according to claim 2, wherein: The anti-deformation structure comprises at least one telescopic pipe assembly (9) arranged between the hard abutment ring (302) and the hard chamber (301) and capable of being completely retracted into the inner part of the hard abutment ring (302) and the hard chamber (301) when contracted, and the telescopic pipe assembly (9) comprises at least two telescopic pipe members telescopically arranged.

4. A constant velocity rotary linear bearing according to claim 3, wherein: The medium is lubricating oil, and the corrugated ring tube (303) is provided with a staged oil infiltration structure.

5. A constant velocity rotary linear bearing according to claim 4, wherein: The staged oil infiltration structure comprises oil infiltration holes (3031) arranged at local valley parts of the outer ring tube of the corrugated ring tube (303) and capable of being opened when the corrugated ring tube (303) is expanded and closed when the corrugated ring tube (303) is contracted.

6. A constant velocity rotary linear bearing according to claim 5, wherein: The diameter of the oil infiltration hole (3031) ranges from 100 μm to 200 μm.

7. A constant velocity rotary linear bearing according to any one of claims 1 to 6, wherein: The hard chamber (301) comprises a large ring segment and a small ring segment which are integrally arranged and have different outer diameters, the large ring segment is overlapped on 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) connected with the medium conveying channel (104) and recessed at one end of the large ring segment towards the bottom of the first ring groove (101), a second oil groove (3012) recessed at the part of the small ring segment located in the annular variable pressure chamber (3032), and an oil passing ring groove (3013) recessed on the outer ring wall of the large ring segment and in communication with the first oil groove (3011) and the second oil groove, and a first sealing ring (4) is embedded on the outer ring wall of the large ring segment and elastically abuts against the inner ring wall of the first ring groove (101) while sealing the oil passing ring groove (3013).

8. A constant velocity rotary linear bearing according to claim 7, wherein: The bottom of the first ring groove (101) is concentrically recessed with a second ring groove (102), and the two ends of the medium conveying channel (104) are located at the groove bottoms of the two second ring grooves (102), respectively, and after the hard chamber (301) is inserted into the first ring groove (101), the first oil groove (3011) is opposite to the second ring groove (102).

9. A constant velocity rotary linear bearing according to any one of claims 1 to 6, wherein: The two ends of the cage (5) are embedded with balls or protrude with hemispherical protrusions (7) in a circumferential uniform interval.

10. The constant stroke rotary linear bearing of claim 7, wherein: A one-way valve (8) for one-way oil injection from outside to the oil ring groove (3013) is arranged at one end of the large ring section towards the outer ring (1) end.

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