Circulating ball type steering telescopic shaft with automatic anti-backlash structure

Abstract

The application discloses a circulating ball type steering telescopic shaft with automatic clearance-eliminating structure, which comprises a telescopic rod, a spline sleeve, a universal joint, a dustproof oil seal and a clearance-eliminating mechanism, one end of the telescopic rod is connected with the clearance-eliminating mechanism, the spline sleeve is sleeved on the telescopic rod and the clearance-eliminating mechanism, the other end of the telescopic rod is supported in the spline sleeve through the dustproof oil seal, and the universal joint is welded with the spline sleeve; the clearance-eliminating mechanism comprises a track block, a steel ball, a track sheet, a positioning block, a clearance-eliminating ring and a track pin, the track block, the track pin, the spline sleeve, the positioning block and the track sheet form an annular track, the annular track is divided into an inner track and an outer track, the steel ball is continuously and uniformly distributed in the inner track and the outer track, each steel ball is in contact with two circular arcs on two track sheets and a spline sleeve ball groove; and the clearance-eliminating ring is installed in a groove on the surface of the track block. The application increases the supporting area of the steel ball and the spline sleeve, improves the supporting strength, reduces stress concentration, and reduces the abrasion of the steel ball, the track sheet and the spline sleeve.

Description

Technical Field

[0001] This invention relates to a recirculating ball steering telescopic shaft with an automatic backlash elimination structure, belonging to the technical field of heavy-duty vehicle steering systems. Background Technology

[0002] Driving comfort is increasingly important to drivers of heavy-duty vehicles, and abnormal noises in the cab significantly impact their driving experience. The steering telescopic shaft is a crucial component connecting the steering column and the steering gear, transmitting the torque applied by the driver to the steering gear to achieve the driver's steering intentions. Occasionally, the aftermarket reports abnormal noises from the steering column under certain operating conditions. Replacing different steering telescopic shafts reveals varying degrees of improvement in the noise level, indicating that the torsional clearance of the telescopic shaft has a significant impact on steering column noise. Currently used steering telescopic shafts are ball-type, and they only roll purely within a small range. During most of the telescopic range, the balls slide within the spline sleeve, accelerating wear and hindering torsional clearance control. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the deficiencies of the existing technology by providing a circulating ball type steering telescopic shaft with an automatic backlash elimination structure. The steel ball rolls without slipping throughout the entire range of the telescopic shaft. At the same time, the backlash elimination structure is added to reduce the wear of the steel ball spline sleeve, so that the torsional clearance is kept within the control range for a long time, thus solving the problem that the torsional clearance of the steel ball type steering telescopic shaft is difficult to control.

[0004] To solve this technical problem, the present invention provides a recirculating ball-type steering telescopic shaft with an automatic backlash elimination structure, comprising a telescopic rod, a spline sleeve, a universal joint, a dustproof oil seal, and a backlash elimination mechanism. One end of the telescopic rod is connected to the backlash elimination mechanism, the spline sleeve is fitted onto the telescopic rod and the backlash elimination mechanism, and the other end of the telescopic rod is supported inside the spline sleeve by the dustproof oil seal. The universal joint is welded to the spline sleeve. The backlash elimination mechanism includes a track block, steel balls, track plates, a positioning block, a backlash elimination ring, and track pins. The track block, track pins, spline sleeve, positioning block, and track plates form a ring track, which is divided into an inner track and an outer track. The steel balls are continuously and evenly distributed in the inner and outer tracks. Each steel ball contacts two track plates and two arc segments on the ball groove of the spline sleeve, forming a four-point support structure. The backlash elimination ring is installed in a groove on the surface of the track block. When the telescopic rod is pulled out or compressed, it drives the track block to move together, and the steel balls perform a pure rolling motion in the ring track.

[0005] The inner side of the spline sleeve has three ball grooves evenly distributed at 120°; the outer side of the track block has three grooves evenly distributed at 120°, and its inner side has an irregular through hole with three contact surfaces; the outer side of the track pin has three grooves distributed at 120°, the track pin is inserted from the bottom of the track block, and the track pin is fixed on the track block by six positioning blocks; the positioning blocks, the ball grooves of the spline sleeve, and the grooves of the track block form an outer track, and the positioning blocks, the grooves of the track block, and the grooves of the track pin form an inner track.

[0006] The ball groove of the spline sleeve has a three-segment arc design, which increases the support area between the steel ball and the spline sleeve when the steel ball rolls on the outer track.

[0007] The track piece is placed on the track block and positioned axially by the positioning blocks installed at both ends. During the extension or compression of the telescopic rod, the steel ball rolls purely on the surface of the track piece and makes point contact.

[0008] The gap-eliminating ring is made of rubber material and is set in a groove on the surface of the track block below the track piece. Each steel ball contacts two track pieces and is squeezed between the track piece and the spline sleeve ball groove to eliminate the gap between the steel ball and the spline sleeve.

[0009] The telescopic rod and the track block are welded together by friction welding.

[0010] The aforementioned rail pin has three oil reservoirs evenly distributed at the bottom of the rail to store grease, reducing rolling wear between the steel ball, the rail plate, and the spline sleeve.

[0011] The dustproof oil seal consists of a steel frame and rubber vulcanization, which provides both support strength and dust protection.

[0012] Beneficial effects: The telescopic shaft of this invention features a steel ball that performs a pure rolling motion within a circular track, effectively reducing wear between the steel ball and the spline sleeve. It also incorporates a backlash-eliminating ring, which eliminates the gap between the steel ball and the spline sleeve through elastic deformation. The spline sleeve's ball groove has a three-segment arc design, increasing the support area between the steel ball and the spline sleeve, improving support strength, and reducing stress concentration. The track pin has three evenly distributed oil reservoirs at the bottom of the track for storing grease, reducing rolling wear between the steel ball, the track plate, and the spline sleeve. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the present invention;

[0014] Figure 2 This is a schematic diagram of the structure of the present invention after concealing the spline sleeve and universal joint welding assembly;

[0015] Figure 3 This is a schematic diagram of the assembly at the track block of the present invention;

[0016] Figure 4 This is a schematic diagram of the structure of the circular track of the present invention;

[0017] Figure 5 This is a schematic cross-sectional view of the track block of the present invention;

[0018] Figure 6 This is a schematic diagram illustrating the fit between the steel ball, track piece, and spline sleeve of the present invention.

[0019] Figure 7 This is a schematic diagram of the track block structure of the present invention;

[0020] Figure 8 This is a schematic diagram of the track pin structure of the present invention;

[0021] Figure 9 This is a schematic diagram of the positioning block of the present invention;

[0022] Figure 10 This is a schematic diagram of the gap-eliminating ring of the present invention;

[0023] Figure 11 This is a schematic diagram of the structure of the track piece of the present invention.

[0024] In the diagram: 1. Telescopic rod; 2. Spline sleeve; 3. Universal joint; 4. Dustproof oil seal; 5. Track block; 6. Steel ball; 7. Track piece; 8. Positioning block; 9. Clearance ring; 10. Track pin. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] like Figures 1-11 As shown, this invention provides a recirculating ball-type steering telescopic shaft with an automatic backlash elimination structure, including a telescopic rod 1, a spline sleeve 2, a universal joint 3, a dustproof oil seal 4, and a backlash elimination mechanism. One end of the telescopic rod 1 is connected to the backlash elimination mechanism, the spline sleeve 2 is fitted onto the telescopic rod 1 and the backlash elimination mechanism, and the other end of the telescopic rod 1 is supported inside the spline sleeve 2 by the dustproof oil seal 4. The universal joint 3 is welded to the spline sleeve 2. The backlash elimination mechanism includes a track block 5, a steel ball 6, a track piece 7, a positioning block 8, a backlash elimination ring 9, and a track pin 10. Block 5, track pin 10, spline sleeve 2, positioning block 8, and track piece 7 form a circular track. The circular track is divided into an inner track and an outer track. Steel balls 6 are continuously and evenly distributed in the inner and outer tracks. Each steel ball 6 cooperates with two track pieces 7 and spline sleeve 2, forming a four-point support structure. The backlash elimination ring 9 is installed in the groove on the surface of the track block 5, and its upper part cooperates with the track piece 7. When the telescopic rod 1 is pulled out or compressed, it drives the track block 5 to move together, and the steel balls 6 perform pure rolling motion in the circular track.

[0027] The inner side of the spline sleeve 2 is provided with three ball grooves evenly distributed at 120°; the outer side of the track block 5 is provided with three grooves evenly distributed at 120°, and its inner side is an irregular through hole with three contact surfaces; the outer side of the track pin 10 is provided with three grooves distributed at 120°, the track pin 10 is inserted from the bottom of the track block 5, and the track pin 10 is fixed on the track block 5 by six positioning blocks 8; the positioning blocks 8, the ball grooves of the spline sleeve 2 and the grooves of the track block 5 form an outer track, and the positioning blocks 8, the grooves of the track block 5 and the grooves of the track pin 10 form an inner track.

[0028] The ball groove of the spline sleeve 2 is designed with a three-segment arc. When the steel ball 6 rolls on the outer track, it can increase the support area between the steel ball 6 and the spline sleeve 2, improve the support strength, and reduce stress concentration.

[0029] The track piece 7 is placed on the track block 5 and is positioned axially by the positioning blocks 8 installed at both ends. During the extension or compression of the telescopic rod 1, the steel ball 6 rolls purely on the surface of the track piece 7 and makes point contact.

[0030] The steel ball 6 is positioned by four points of support, and it contacts the two track pieces 7 and the two arcs on the ball groove of the spline sleeve 2 respectively. During the extension or compression of the telescopic rod 1, the steel ball 6 contacts the two track pieces 7 and the two arcs on the ball groove of the spline sleeve 2 respectively and rolls purely.

[0031] The gap-eliminating ring 9 is made of rubber material and is located below the track plate 7 in the groove on the surface of the track block 5. During assembly, it is pre-compressed to a certain amount of deformation, and a certain amount of extrusion force is generated through its elastic deformation. This extrusion force is transmitted to the steel ball 6 through the track plate 7. Each steel ball 6 is in contact with two track plates 7, so each steel ball 6 is subjected to two extrusion forces, which squeeze the steel ball 6 between the track plate 7 and the ball groove of the spline sleeve 2, eliminating the gap between the steel ball 6 and the spline sleeve 2.

[0032] The telescopic rod 1 and the track block 5 are welded together by friction welding.

[0033] The track pin 10 has three oil reservoirs evenly distributed at the bottom of the track for storing grease, which reduces the rolling wear between the steel ball 6, the track piece 7, and the spline sleeve 2.

[0034] The dustproof oil seal 4 consists of a steel frame and rubber vulcanization, which provides dust protection while ensuring support strength.

[0035] During the extension or compression of the telescopic rod, the steel ball remains in a state of pure rolling within the circular track. This pure rolling reduces wear between the steel ball and the track, facilitating gap control between the steel ball and the spline sleeve. Simultaneously, the invention incorporates a rubber-made gap-eliminating ring located below the track plate and within a groove on the track block surface. During assembly, this ring undergoes pre-compression with a certain amount of deformation, generating a compressive force through elastic deformation. This compressive force is transmitted to the steel ball via the track plate. Each steel ball contacts two track plates, thus experiencing two compressive forces, pressing the steel ball between the track plate and the spline sleeve's ball groove, eliminating the gap between the steel ball and the spline sleeve. The spline sleeve's ball groove employs a three-segment arc design, increasing the support area between the steel ball and the spline sleeve, improving support strength, and reducing stress concentration. Three oil reservoirs are evenly distributed at the bottom of the track pin to store grease, further reducing rolling wear between the steel ball, track plate, and spline sleeve. This invention solves the problem of uncontrollable torsional clearance in steel ball-type steering telescopic shafts, improving driver comfort.

[0036] The above embodiments of the present invention are merely illustrative examples and are not the only ones. All modifications within the scope of the present invention or equivalent to the scope of the present invention are encompassed by the present invention.

Claims

1. A recirculating ball-type steering telescopic shaft with an automatic backlash elimination structure, characterized in that: The system includes a telescopic rod (1), a spline sleeve (2), a universal joint (3), a dustproof oil seal (4), and a backlash elimination mechanism. One end of the telescopic rod (1) is connected to the backlash elimination mechanism. The spline sleeve (2) is fitted onto the telescopic rod (1) and the backlash elimination mechanism. The other end of the telescopic rod (1) is supported inside the spline sleeve (2) by the dustproof oil seal (4). The universal joint (3) is welded to the spline sleeve (2). The backlash elimination mechanism includes a track block (5), a steel ball (6), a track piece (7), a positioning block (8), a backlash elimination ring (9), and a track pin (10). The track block (5), the track... The ring track is composed of a pin (10), a spline sleeve (2), a positioning block (8), and a track piece (7). The ring track is divided into an inner track and an outer track. Steel balls (6) are continuously and evenly distributed in the inner and outer tracks. Each steel ball (6) is matched with two track pieces (7) and a spline sleeve (2) to form a four-point support structure. The backlash elimination ring (9) is installed in the groove on the surface of the track block (5). When the telescopic rod (1) is pulled out or compressed, it drives the track block (5) to move together. The steel balls (6) make a pure rolling motion in the ring track. The inner side of the spline sleeve (2) is provided with three ball grooves evenly distributed at 120°; the outer side of the track block (5) is provided with three grooves evenly distributed at 120°, and its inner side is a shaped through hole with three contact surfaces; the outer side of the track pin (10) is provided with three grooves distributed at 120°, the track pin (10) is inserted from the bottom of the track block (5), and the track pin (10) is fixed on the track block (5) by six positioning blocks (8); the positioning blocks (8) and the ball grooves of the spline sleeve (2) and the grooves of the track block (5) form an outer track, and the positioning blocks (8) and the grooves of the track block (5) and the grooves of the track pin (10) form an inner track; The gap-eliminating ring (9) is made of rubber material and is set in the groove on the surface of the track block (5) below the track piece (7). Each steel ball (6) contacts two track pieces (7) and is squeezed between the track piece (7) and the ball groove of the spline sleeve (2) to eliminate the gap between the steel ball (6) and the spline sleeve (2).

2. The circulating ball-type steering telescopic shaft with automatic backlash elimination structure according to claim 1, characterized in that: The ball groove of the spline sleeve (2) is a three-segment arc design, which can increase the support area between the steel ball (6) and the spline sleeve (2) when the steel ball (6) rolls on the outer track.

3. The circulating ball-type steering telescopic shaft with automatic backlash elimination structure according to claim 1, characterized in that: The track piece (7) is set on the track block (5) and is positioned axially by the positioning blocks (8) installed at both ends. During the pulling or compression process of the telescopic rod (1), the steel ball (6) rolls purely on the surface of the track piece (7) and makes point contact.

4. The circulating ball-type steering telescopic shaft with automatic backlash elimination structure according to claim 1, characterized in that: The telescopic rod (1) and the track block (5) are welded together by friction welding.

5. The circulating ball-type steering telescopic shaft with automatic backlash elimination structure according to claim 1, characterized in that: The track pin (10) has three oil reservoirs evenly distributed at the bottom of the track for storing grease, which reduces the rolling wear between the steel ball (6), the track piece (7), and the spline sleeve (2).

6. The circulating ball-type steering telescopic shaft with automatic backlash elimination structure according to any one of claims 1-5, characterized in that: The dustproof oil seal (4) consists of a steel frame and rubber vulcanization, which provides dust protection while ensuring the support strength.

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