Large-size shaft end nut locking anti-loosening structure and method

Abstract

The application relates to the field of high-end equipment manufacturing technology, in particular to a large-size shaft end nut locking anti-loosening structure and method. The anti-loosening structure comprises a snap ring fixed in the circumferential direction of a main shaft, a locking nut abutting against the end face of the snap ring and a limiting pin. The bottom of the limiting pin abuts against an elastic pad, and the top of the limiting pin protrudes from the end face of the snap ring. A plurality of pin holes are formed in the locking nut. When the locking nut is screwed on the main shaft close to the snap ring, the limiting pin is axially compressed and moves close to the side of the elastic pad along the groove. When the locking nut abuts against the snap ring, the limiting pin is embedded in the pin hole under the elastic force of the elastic pad, the reverse rotation of the locking nut is limited, the size of the axial pre-tightening force of the wheel hub bearing is stabilized, the bearing clearance of the wheel hub bearing is kept within the set value, the mechanical performance of the wheel hub bearing unit is improved, the service life of the wheel hub bearing unit is prolonged, and the driving safety of the automobile is improved.

Description

Technical Field

[0001] This application relates to the technical field of high-end equipment manufacturing industry, and in particular to a locking and anti-loosening structure and method for large-size shaft end nuts. Background Technology

[0002] As a key and core component of automobiles, wheel hub bearing units provide precise guidance for the rotation of the wheel hub. Their manufacturing precision, working performance, service life and reliability play a decisive role in the transmission, driving, braking and steering performance of automobiles.

[0003] Reference Figure 1 The hub bearing unit mainly includes a hub 1, an adjustable inner bearing 2 installed in the hub 1 and sleeved on the outer circumference of the main shaft 5, an adjustable outer bearing 3, and an elastic spacer 4 whose inner ring of the adjustable outer bearing 3 abuts against the inner ring of the outer bearing 3. One end of the elastic spacer 4 abuts against the inner ring of the outer bearing 3. The locking nut 64 is screwed onto the main shaft 5 and abuts against the elastic spacer 4. When the screwing torque reaches the set value, the screwing of the locking nut 5 is stopped. The locking nut 64 compresses the elastic spacer 4 by pressing it. The elastic spacer 4 transmits the axial force to the outer bearing 3, which is then transmitted to the inner bearing 2 through the hub 1. The axial force applied by the locking nut 64 achieves axial preload on the inner bearing 2 and the outer bearing 3, thereby achieving the adjustment of the clearance.

[0004] The clearance of a wheel hub bearing is a major factor affecting its lifespan. Insufficient clearance increases rolling friction, reduces vehicle coasting performance, and can even cause overheating and high-temperature sintering. Excessive clearance causes wheel wobble during driving, increasing abnormal wear on tires and related parts, and in severe cases, leading to a "flywheel" phenomenon. Therefore, ensuring the bearing clearance is within a certain range is a crucial technical issue.

[0005] However, in practical applications, under impact, vibration, and variable load, as well as when the wheel hub bearing unit heats up, the friction between the threaded pair of the locking nut and the main shaft will decrease. Sometimes, due to creep and stress relaxation of the materials of the threaded connector and the connected parts, the preload of the connection between the two decreases, causing the locking nut connection to loosen, resulting in the failure of the wheel hub bearing preload. This leads to excessive clearance between the inner and outer bearings, abnormal wear and scrapping of the wheel hub bearing unit, and even driving safety hazards.

[0006] Several common shaft end locking structures exist: (1) Snap ring locking structure, that is, the teeth on the inner side of the snap ring are locked in the groove on the shaft; the teeth on the outer side of the snap ring are plastically deformed and locked in the groove of the nut. This traditional structure has a good locking effect, but the disadvantages are that it is inconvenient to disassemble and assemble, there are few lockable phases, the clearance is inconvenient to adjust, and the snap ring is used only once; (2) Double nut locking structure, that is, there is mutual pressure between the two nuts to ensure that the threads do not loosen. Its disadvantages are that the structure is not compact, it is easy to loosen after high frequency vibration, and it is not easy to disassemble and assemble after corrosion; (3) Shaft end pin or wire locking structure, that is, a hole is made on the shaft outside the nut to insert a pin or wire. Its disadvantages are that the locking position and bearing clearance cannot be adjusted, and the hole on the shaft can easily reduce the bearing capacity of the shaft. Therefore, in most cases, the commonly used nut locking and anti-loosening methods are not adopted in the vehicle wheel hub bearing unit under high load and complex alternating load conditions.

[0007] Solutions for locking and preventing loosening of nuts in wheel hub bearing units, both domestically and internationally, include: For example, Chinese patents "201820216638.2" and "202020424661.8" describe a type of automotive wheel hub bearing unit. The anti-loosening structure of this bearing unit uses a thin stamped outer sleeve to fix the shaft end retaining ring, thereby fixing the bearing's axial direction. This method results in a non-removable wheel hub bearing unit with non-adjustable clearance. This type of structure is only suitable for small vehicles and not for large vehicles. For wheel hub bearing units in medium and large vehicles, there are four generations of technology. The first three generations are integral structures with non-adjustable clearance. The fourth generation features a detachable structure with adjustable clearance and reliable locking. ConMet, an American company specializing in fourth-generation technology, possesses a unique patented structure for bearing locking. ConMet's international patent number, "EP11250547.4," describes a wheel hub bearing nut locking device. This device combines a hooked retaining ring, a grooved special nut, and a multi-hole chuck. When the nut is tightened to a suitable clearance adjustment position, the hook of the retaining ring passes through the nut and engages with the hole in the multi-hole chuck, thus achieving locking and preventing loosening. This assembly consists of three components, each with a relatively complex structure and a complex installation process.

[0008] Therefore, limiting the reverse rotation of the lock nut and providing it with anti-loosening capability is crucial for vehicle driving safety. Maintaining the bearing preload clearance of the wheel hub bearing unit within the set value has become an urgent technical problem that needs to be solved. Summary of the Invention

[0009] To overcome the shortcomings of existing technologies, this invention proposes a large-size shaft end nut locking and anti-loosening structure and method, which can stabilize the magnitude of the axial preload of the wheel hub bearing, always keep the bearing clearance of the wheel hub bearing within the set value, improve the mechanical performance of the wheel hub bearing unit, extend the service life of the wheel hub bearing unit, and improve the driving safety of the vehicle.

[0010] The large-size shaft end nut locking and anti-loosening structure and method provided by this invention adopts the following technical solution:

[0011] A large-size shaft end nut locking and anti-loosening structure includes a retaining ring fixed circumferentially to the main shaft, a locking nut abutting against the end face of the retaining ring, and a limiting pin. The retaining ring has several grooves on the side near the locking nut, and the grooves are provided with elastic pads.

[0012] The limiting pin passes through the groove, the bottom of the limiting pin abuts against the elastic pad, and the top of the limiting pin protrudes from the end face of the retaining ring. The height of the limiting pin protruding from the end face of the retaining ring is h1, and the rebound amount of the elastic pad is h2. The relationship between the height of the limiting pin protruding from the end face of the retaining ring and the rebound amount of the elastic pad is: h1≤h2.

[0013] The locking nut has several pin holes. When the locking nut is screwed onto the main shaft and close to the retaining ring, the limiting pin moves axially along the groove near the elastic pad.

[0014] When the locking nut abuts against the retaining ring, the limiting pin is embedded in the pin hole under the elastic force of the elastic pad to restrict the reverse rotation of the locking nut;

[0015] When the locking nut rotates in the reverse direction, the contact surface between the limiting pin and the pin hole is the working surface, the angle between the working surface and the axis of the limiting pin is the working angle α, the side away from the working surface is the screw-in surface, the angle between the screw-in surface and the axis of the limiting pin is the screw-in angle β, and α < β.

[0016] By adopting the above technical solution, the retaining ring and the main shaft are connected by a key to achieve circumferential fixation of the retaining ring, and the retaining ring and the locking nut are connected by a limiting pin to achieve circumferential limitation of the locking nut and prevent reverse rotation of the locking nut; the limiting pin passes through the groove and the bottom of the limiting pin abuts against the elastic pad. Under the elastic force of the elastic pad, the limiting pin can reciprocate along the axis of the groove; when the elastic pad is not compressed, the limiting pin protrudes from the end face of the retaining ring. When the elastic pad is compressed, under the action of the elastic potential energy of the elastic pad, the limiting pin can move outward along the axis of the groove until it protrudes from the end face of the retaining ring. The height of the locating pin protruding from the end face of the retaining ring is less than or equal to the rebound amount of the elastic pad, reducing the difference in the reciprocating stroke of the locating pin, ensuring the height of the locating pin protruding from the end face of the retaining ring, and improving the reliability of the locating pin in circumferentially limiting the locking nut. The contact surface between the locating pin and the pin hole is the working surface. When the locking nut rotates in the opposite direction, the working surface abuts against the inner wall of the pin hole, restricting the reverse rotation of the locking nut. The working angle is less than the screw-in angle. The central cross section of the locating pin is asymmetrical. The locating pin on the side closer to the working surface has a larger slope than the locating pin on the side farther from the working surface, and the locating pin on the side away from the working surface has a smaller slope, which facilitates the installation when tightening the locking nut. When the pin hole of the locking nut is aligned with the limiting pin, the limiting pin is embedded in the pin hole under the elastic force of the elastic pad, restricting the circumferential rotation of the locking nut and achieving the anti-loosening effect of the locking nut; under the action of the elastic pad, the limiting pin achieves self-locking by limiting the circumferential movement of the locking nut. By pressing the limiting pin along the axis of the groove and moving it to the bottom of the groove, the locking nut can be loosened by rotating it in the opposite direction, thus achieving the disassembly of the locking nut.

[0017] This shaft end nut locking and anti-loosening structure has the advantages of simple structure, unique design, and convenient installation and disassembly. It maintains the axial preload of the wheel hub bearing, keeps the bearing clearance within the set value, improves the mechanical performance of the wheel hub bearing unit, extends the service life of the wheel hub bearing unit, and improves the driving safety of the vehicle.

[0018] Optionally, the working surface and the screw-in surface have a circular arc transition; the working angle ranges from 15° to α to 5°; the screw-in angle ranges from 35° to β to 25°; and the height of the limiting pin protruding from the end face of the retaining ring...

[0019] By adopting the above technical solution, the working surface and the screw-in surface have a rounded transition, which makes it easier to screw in the locking nut. The smaller the working angle, the greater the shear strength when the limit pin abuts against the pin hole, and the greater the torque that can withstand the reverse rotation of the locking nut; the size of the screw-in angle determines the ease with which the locking nut screws in against the limit pin. The larger the screw-in angle, the smoother the limit pin, and the less resistance to screwing the locking nut when it is close to the retaining ring, making it easier to install; the relationship between the groove diameter D and the height of the limit pin protruding from the end face of the retaining ring, when... At this time, the height of the limit pin protruding from the end face of the retaining ring is optimal, which facilitates the screwing in and disassembly of the lock nut.

[0020] Optionally, the elastic pad includes a working part and a cylindrical anti-slip part, the anti-slip part abutting against the side wall of the groove, the limiting pin passing through the elastic pad, and the side wall of the limiting pin abutting against the anti-slip part.

[0021] By adopting the above technical solution, the bottom of the limiting pin abuts against the working part of the elastic pad, the side wall of the limiting pin abuts against the anti-slip part, and the limiting pin abuts against the elastic pad circumferentially. On the one hand, this improves the coaxiality of the limiting pin and the groove, reducing the risk of the limiting pin dislodging from the groove during equipment operation vibration. On the other hand, it avoids rigid contact between the limiting pin and the groove hole wall, improving the stability of the reciprocating motion of the limiting pin.

[0022] Optionally, the circumferential sidewall of the limiting pin is provided with a plurality of strip grooves, the length direction of the strip grooves being parallel to the axis of the limiting pin, and the sidewall of the elastic pad is provided with a plurality of strip protrusions embedded in the strip grooves.

[0023] By adopting the above technical solution, the strip-shaped protrusion of the elastic pad is embedded in the strip-shaped groove of the limiting pin. On the one hand, the strip-shaped protrusion restricts the circumferential rotation of the limiting pin and reduces the probability of the limiting pin moving out of control. On the other hand, the strip-shaped protrusion realizes the guiding role of the axial movement of the limiting pin.

[0024] Optionally, an annular square groove is provided on the peripheral wall of the limiting pin, and a convex ring is provided on the inner circumferential side of the anti-slip part of the elastic pad, which is embedded in the annular square groove.

[0025] By adopting the above technical solution, the convex ring of the elastic pad is embedded in the annular square groove, reducing the risk of the limit pin dislodging from the groove and improving the reliability of the limit pin installation.

[0026] Optionally, the cross-section of the convex ring is quadrilateral, and the convex ring includes a first end face away from the working part and a second end face close to the working part. The first end face makes an angle of θ1 with the axial direction of the convex ring, and the second end face makes an angle of θ2 with the axial direction of the convex ring, and θ1 < θ2.

[0027] By adopting the above technical solution, when the limiting pin moves towards the bottom of the groove, the degree of the first pressure angle and the second pressure angle continuously increases. Since the first pressure angle of the convex ring is smaller than the second pressure angle, when the limiting pin is subjected to the axial pressure of the locking nut, the compression of the second end face of the convex ring is greater than the compression of the first end face of the convex ring when the limiting pin loses the axial pressure of the locking nut. Under the action of the elastic potential energy accumulated by the elastic pad at the bottom and the second end face of the convex ring, the time for the convex ring to move outward is shortened, and the installation efficiency of the locking nut is improved. The structural design of the convex ring reduces the possibility of insufficient rebound of the limiting pin when the elastic pad rebounds, ensures the height value of the limiting pin protruding from the end face of the retaining ring, and improves the reliability of the limiting pin in circumferentially limiting the locking nut.

[0028] Optionally, the range of the first pressure angle is 45°>θ1>30°, the range of the second pressure angle is 60°>θ2>45°, and the relationship between the depth T of the annular square groove and the first pressure angle is: T=h1tanθ1.

[0029] By adopting the above technical solution, the relationship between the depth of the annular square groove and the first pressing angle is T = h1tanθ1. That is, the first end face of the convex ring abuts against the side wall of the annular square groove near the bottom of the groove, and the second end face of the convex ring abuts against the side wall of the annular square groove near the top of the groove. When the limiting pin moves towards the bottom of the groove, the side wall of the groove of the limiting pin continuously presses against the first end face until the first pressing angle reaches 90°, at which point the limiting pin stops moving. The establishment of this relationship between the depth of the annular square groove, the first pressing angle, and the stroke of the limiting pin improves the reliability of the limiting pin in preventing the locking nut from loosening.

[0030] Optionally, the elastic pad is provided with an elastic element on the side near the limiting pin, and one end of the elastic element is disposed between the elastic pad and the limiting pin.

[0031] By adopting the above technical solution, the elastic element helps to reduce the error in the height value of the limit pin protruding from the end face of the retaining ring, reduces the risk of elastic failure due to fatigue damage of the elastic washer, and improves the service life and reliability of the locking nut structure.

[0032] Optionally, the elastic element is a wave spring.

[0033] By adopting the above technical solution, on the one hand, the wave spring has good mechanical properties and can compensate for the stroke difference when the limit pin rebounds insufficiently when the elastic pad rebounds; on the other hand, the wave spring has a small radial dimension, which can save installation space.

[0034] The present invention also provides a method for locking and preventing loosening of large-size shaft end nuts, which includes the following steps:

[0035] S1. The retaining ring is connected to the main shaft by a key to achieve circumferential positioning of the retaining ring;

[0036] S2. The elastic pad is installed in the groove of the retaining ring, and the elastic element is embedded in the elastic pad and abuts against the bottom of the elastic pad;

[0037] S3. The limiting pin is embedded in the elastic pad, and the bottom of the limiting pin is fixed to the elastic element;

[0038] S4. When the locking nut is screwed onto the main shaft near the retaining ring, the locking nut is pressed in along the second end face of the limiting pin, and the limiting pin compresses the elastic element along the axis of the groove. When the limiting hole of the limiting pin is aligned with the limiting pin, the limiting pin is embedded in the pin hole under the elastic force of the elastic element, thereby achieving axial limiting of the locking nut.

[0039] By adopting the above technical solution, a retaining ring is sleeved on the spindle, and the retaining ring and the spindle are connected by a key to achieve circumferential positioning of the spindle. An elastic pad is embedded in the bottom of the groove through an interference fit. An elastic element is installed between the elastic pad and the limiting pin. The convex ring of the elastic pad is embedded in the annular square groove of the limiting pin to restrict the movement of the elastic element. The locking nut is screwed onto the spindle. During the screwing of the locking nut, the positioning pin is pressed and moves along the axis of the groove. When the pin hole is aligned with the positioning pin, the positioning pin is embedded in the pin hole under the action of the elastic element and the elastic pad, realizing reverse anti-loosening of the locking nut. When the locking nut rotates in the opposite direction, the working surface abuts against the inner wall of the pin hole, restricting the reverse rotation of the locking nut. By pressing the limiting pin along the axis of the groove to move towards the bottom of the groove, the locking nut is loosened in the opposite direction, thus realizing the disassembly of the locking nut.

[0040] Compared with the prior art, the present invention has the following beneficial technical effects:

[0041] (1) The limiting pin of the present invention is inserted into the groove and the bottom of the limiting pin abuts against the elastic pad. When the elastic pad is not compressed, the limiting pin protrudes from the end face of the retaining ring. When the elastic pad is compressed, under the action of the elastic potential energy of the elastic pad, the limiting pin can move outward along the groove axis to protrude from the end face of the retaining ring. Since the height of the limiting pin protruding from the end face of the retaining ring is less than or equal to the rebound amount of the elastic pad, the difference in the reciprocating stroke of the limiting pin can be reduced, ensuring the height value of the limiting pin protruding from the end face of the retaining ring and improving the reliability of the limiting pin in circumferentially limiting the locking nut.

[0042] (2) In this invention, the limiting pin has a working surface and a screw-in surface. The contact surface between the limiting pin and the pin hole is the working surface. The angle between the working surface and the axis of the limiting pin is the working angle α, and the angle between the screw-in surface and the axis of the limiting pin is the screw-in angle β. The relationship between the working angle and the screw-in angle is: α < β. When the locking nut rotates in the opposite direction, the working surface abuts against the inner wall of the pin hole, restricting the reverse rotation of the locking nut. The central cross section of the limiting pin is asymmetrical. The limiting pin on the side closer to the working surface has a larger slope than the limiting pin on the side farther from the working surface, and the limiting pin on the side away from the working surface has a smaller slope. Both the working surface and the screw-in surface are set as rounded transitions, which facilitates the installation when the locking nut is screwed in.

[0043] (3) When the pin hole of the locking nut is aligned with the limiting pin, on the one hand, under the elastic force of the elastic pad, the limiting pin is embedded in the pin hole, restricting the circumferential rotation of the locking nut and achieving the anti-loosening effect of the locking nut. On the other hand, under the action of the elastic pad, the limiting pin achieves self-locking by limiting the circumferential movement of the locking nut. By pressing the limiting pin along the groove axis and moving it to the bottom of the groove, the locking nut can be loosened in the opposite direction, thus achieving the disassembly of the locking nut, which is convenient.

[0044] (4) The strip-shaped protrusion of the elastic pad of the present invention is embedded in the strip-shaped groove of the limiting pin. On the one hand, the strip-shaped protrusion restricts the circumferential rotation of the limiting pin and reduces the probability of the limiting pin moving out of control. On the other hand, the strip-shaped protrusion realizes the guiding role of the axial movement of the limiting pin, thereby improving the safety and reliability of use.

[0045] (5) The protruding ring of the present invention is provided with a first pressing angle and a second pressing angle, and the first pressing angle is smaller than the second pressing angle. When the limiting pin moves to the bottom of the groove, the degree of the first pressing angle and the second pressing angle continuously increases. When the limiting pin is subjected to the axial pressure of the locking nut, under the action of the elastic potential energy accumulated by the elastic pad at the bottom and the second end face of the protruding ring, the time for the protruding ring to move outward can be shortened, and the installation efficiency of the locking nut can be improved. The structural design of the protruding ring reduces the possibility of insufficient rebound of the limiting pin when the elastic pad rebounds, and improves the reliability of the limiting pin in circumferentially limiting the locking nut.

[0046] (6) The elastic element used in this invention is a wave spring. On the one hand, the good mechanical properties of the wave spring can compensate for the insufficient travel difference of the limit pin when the elastic pad rebounds, reduce the risk of elastic failure due to fatigue damage of the elastic washer, and improve the service life and reliability of the locking nut structure. On the other hand, the wave spring has a small radial dimension, which saves installation space.

[0047] (7) The relationship between the depth of the annular square groove, the first pressure angle and the stroke of the limiting pin in this invention is established as T=h1tanθ1, which satisfies the stroke requirements of the limiting pin and improves the anti-loosening reliability of the limiting pin for the locking nut.

[0048] (8) The shaft end nut locking and anti-loosening structure of the present invention has the advantages of simple structure, unique design, convenient installation and disassembly, safety and reliability, high efficiency and green environmental protection. It maintains the axial preload of the wheel hub bearing, so that the bearing clearance of the wheel hub bearing is within the set value, improves the mechanical performance of the wheel hub bearing unit, extends the service life of the wheel hub bearing unit, and improves the driving safety of the vehicle. Attached Figure Description

[0049] Figure 1 This is a structural schematic diagram of an existing hub bearing unit;

[0050] Figure 2 This is a schematic diagram of the shaft end nut locking and anti-loosening structure in Embodiment 1 of the present invention;

[0051] Figure 3 This is the present invention. Figure 2 The main view;

[0052] Figure 4 This is the present invention. Figure 3 AA section view;

[0053] Figure 5 This is a cross-sectional schematic diagram of the anti-loosening structure of the shaft end nut after compression of the elastic pad in Embodiment 1 of the present invention;

[0054] Figure 6 This is a front view of the elastic pad in Embodiment 1 of the present invention;

[0055] Figure 7 This is the present invention. Figure 6 BB section view;

[0056] Figure 8 This is a schematic diagram of the limiting pin in Embodiment 1 of the present invention;

[0057] Figure 9 This is a schematic diagram of the locking nut structure in Embodiment 1 of the present invention;

[0058] Figure 10 This is a schematic cross-sectional view of the elastic pad before compression in Embodiment 2 of the present invention;

[0059] Figure 11 This is a schematic cross-sectional view of the elastic pad after compression in Embodiment 2 of the present invention;

[0060] Figure 12 This is a cross-sectional schematic diagram of the elastic pad in Embodiment 2 of the present invention;

[0061] Figure 13 This is an explosion-proof schematic diagram of the shaft end nut locking and anti-loosening structure in Embodiment 3 of the present invention;

[0062] Figure 14 This is a schematic cross-sectional view of the elastic pad before compression in Embodiment 3 of the present invention;

[0063] Figure 15 This is a schematic cross-sectional view of the elastic pad after compression in Embodiment 3 of the present invention;

[0064] Figure 16 This is a schematic diagram of the wave spring in Embodiment 3 of the present invention.

[0065] Explanation of reference numerals in the attached drawings: 1-Hub; 2-Inner bearing; 3-Outer bearing; 4-Elastic spacer; 5-Main shaft; 6-Anti-loosening structure; 61-Snap ring; 611-Groove; 612-Protruding tongue; 62-Elastic pad; 621-Working part; 6211-Pressure relief hole; 622-Anti-slip part; 623-Strip-shaped protrusion; 624-Protruding ring; 6241-First end face; 6242-Second end face; 63-Limiting pin; 631-Pin head; 6311-Working surface; 6312-Screw-in surface; 632-Pin body; 6321-Strip-shaped groove; 6322-Annular square groove; 64-Locking nut; 641-Flange; 642-Pin hole; 643-Nut body; 65-Wave spring. Detailed Implementation

[0066] The following is in conjunction with the appendix Figure 2-16 This application will be described in further detail.

[0067] Example 1:

[0068] like Figure 2 and Figure 3 As shown, Embodiment 1 of this application discloses a large-size shaft end nut locking and anti-loosening structure, including a retaining ring 61, a locking nut 64, and a limiting pin 63. The retaining ring 61 is connected to the main shaft 5 by a key to achieve circumferential limiting of the retaining ring 61. A groove 611 is provided on the end face of the retaining ring 61 near the locking nut 64. An elastic pad 62 is provided in the groove 611. The limiting pin 63 is embedded in the groove 611 and the bottom of the limiting pin 63 abuts against the elastic pad 62. When the elastic pad 62 is not compressed, the limiting pin 63 protrudes from the end face of the retaining ring 61. The locking nut 64 has 6 pin holes 642 on the side near the retaining ring 61.

[0069] like Figure 4 and Figure 5As shown, the locking nut 64 is screwed onto the main shaft 5. When the locking nut 64 approaches the retaining ring 61 and presses against the limiting pin 63, the limiting pin 63 can move along the axis of the groove 611. When the pin hole 642 of the locking nut 64 is aligned with the limiting pin 63, under the elastic force of the elastic pad 62, the limiting pin 63 can move into the retaining groove along the axis of the groove 611. The limiting pin 63 restricts the locking nut 64 from rotating in the opposite direction. This shaft end nut locking and anti-loosening structure has the advantages of simple structure and convenient installation and disassembly. It maintains the axial preload of the wheel hub bearing, so that the bearing clearance of the wheel hub bearing is within the set value, improves the mechanical performance of the wheel hub bearing unit, extends the service life of the wheel hub bearing unit, and improves the driving safety of the vehicle.

[0070] Specifically, such as Figure 2 and Figure 4 As shown, the retaining ring 61 is annular, and the inner circumference of the retaining ring 61 is provided with a protruding tongue 612 that is connected to the main shaft 5 key. The end face of the retaining ring 61 near the locking nut 64 is provided with multiple circular grooves 611, which are arranged opposite to the protruding tongue 612, and the depth of the groove 611 is t.

[0071] like Figure 6 and Figure 7 As shown, the elastic pad 62 is made of hydrogenated nitrile rubber. The elastic pad 62 includes a working part 621 and an anti-slip part 622, which are integrally machined.

[0072] Specifically, such as Figure 4 and Figure 5 As shown, the working part 621 is disc-shaped, and the relationship between the thickness δ of the working part 621 and the compression rebound amount h2 is: δ>2h2;

[0073] like Figure 7 As shown, the anti-slip part 622 is cylindrical, and its outer periphery abuts against the inner wall of the groove 611 of the retaining ring 61. Several strip-shaped protrusions 623 are arranged circumferentially on the inner periphery of the anti-slip part 622, and the length direction of the strip-shaped protrusions 623 is parallel to the axis of the groove 611. To facilitate the installation of the limiting pin 63, a pressure relief hole 6211 is provided in the center of the working part 621.

[0074] like Figure 4 and Figure 8 As shown, the limiting pin 63 includes a pin head 631 and a pin body 632. When the elastic pad 62 is not compressed, the length of the pin head 631 is the height h1 of the limiting pin 63 protruding from the end face of the retaining ring 61. The length L of the limiting pin 63 is L = t + h1 - δ. The relationship between the groove diameter D and the height of the limiting pin protruding from the end face of the retaining ring is as follows: At this time, the height of the limit pin protruding from the end face of the retaining ring is optimal, which facilitates the screwing in and disassembly of the lock nut.

[0075] Specifically, the bottom of the pin 632 abuts against the working part 621 of the elastic pad 62, and the side wall of the pin 632 abuts against the anti-slip part 622 of the elastic pad 62. The pin 632 is embedded in the elastic pad 62 to avoid rigid contact between the limiting pin 63 and the wall of the groove 611, thereby improving the smoothness and safety of the reciprocating motion of the limiting pin 63 and reducing the risk of the limiting pin 63 dislodging from the groove 611 during equipment operation vibration.

[0076] The relationship between the height h1 of the pin head 631 and the springback amount h2 of the working part 621 is: h1≤h2. This setting can reduce the difference in the reciprocating stroke of the limit pin 63, ensure the height of the limit pin 63 protruding from the end face of the retaining ring 61, and improve the reliability of the limit pin 63 in circumferentially limiting the locking nut 64.

[0077] The contact surface between the pin head 631 and the pin hole 642 is the working surface 6311. The angle between the working surface 6311 and the axis of the limiting pin 63 is the working angle α. The side away from the working surface 6311 is the screw-in surface 6312. The angle between the screw-in surface 6312 and the axis of the limiting pin 63 is the screw-in angle β. The value range of the working angle α is 15°>α>5°, and the value range of the screw-in angle β is 35°>β>25°. The working angle α is greater than the screw-in angle β. That is, the pin head 631 on the side closer to the working surface 6311 has a larger slope than the limiting pin 63 on the side farther from the working surface 6311, and the limiting pin 63 on the side away from the working surface 6311 has a smaller slope. In addition, the working surface 6311 and the screw-in surface 6312 are arc transitions, which makes it easier to install the locking nut 64 when screwing it in. When the pin hole 642 of the locking nut 64 is aligned with the limiting pin 63, under the elastic force of the elastic pad 62, the pin head 631 is embedded in the pin hole 642, which restricts the circumferential rotation of the locking nut 64 and achieves the anti-loosening effect of the locking nut 64.

[0078] The inner diameter of the anti-slip part 622 of the elastic pad 62 is D. The relationship between the inner diameter of the anti-slip part 622 of the elastic pad 62 and the height of the limit pin 63 protruding from the end face of the retaining ring 61 is as follows: when h1=0.75D, the height of the limit pin 63 protruding from the end face of the retaining ring 61 is optimal, which facilitates the screwing in of the locking nut 64 and the disassembly of the locking nut 64.

[0079] To improve the smoothness of the axial movement of the limiting pin 63, the pin body 632 is provided with several strip grooves 6321 that are adapted to the strip protrusion 623 in the circumferential direction. The length of the strip groove is the sum of the length of the strip protrusion 623 and the height of the pin head 631, which ensures the smooth sliding of the limiting pin 63 when it is pressed. The strip protrusion 623 of the elastic pad 62 is embedded in the strip groove 6321 of the limiting pin 63. The strip protrusion 623 can restrict the circumferential rotation of the limiting pin 63 and reduce the probability of the limiting pin 63 moving out of control. At the same time, the strip protrusion 623 plays a guiding role in the axial movement of the limiting pin 63.

[0080] like Figure 2 and Figure 9 As shown, the locking nut 64 includes a flange portion 641 and a nut body 643. The flange portion 641 is located on the side of the nut body 643 near the retaining ring 61, and six pin holes 642 are formed on the end face of the flange portion 641.

[0081] On the other hand, the present invention provides a method for locking and preventing loosening of a large-size shaft end nut, comprising the following steps:

[0082] The first step is to fit the retaining ring 61 onto the spindle 5, and slide the tongue 612 of the retaining ring 61 into the keyway of the spindle 5.

[0083] The second step is to embed the elastic pad 62 into the groove 611 of the retaining ring 61, and embed the strip-shaped protrusion 624 of the elastic pad 62 into the strip-shaped groove 6321 of the limiting pin 63.

[0084] Third, when the pin hole 642 of the locking nut 64 is aligned with the limiting pin 63, the limiting pin 63 is embedded in the pin hole 642 under the elastic force of the elastic pad 62, restricting the circumferential rotation of the locking nut 64 and achieving the anti-loosening effect of the locking nut 64; under the elastic action of the elastic pad 62, the limiting pin 63 achieves self-locking by limiting the circumferential position of the locking nut 64. By pressing the pin head 631 along the axial direction of the groove 611 to move it to the bottom of the groove 611, the locking nut 64 is loosened in the opposite direction, thus achieving the disassembly of the locking nut 64.

[0085] This shaft end nut locking and anti-loosening structure has the advantages of simple structure and convenient installation and disassembly. It maintains the axial preload of the wheel hub bearing, keeps the bearing clearance of the wheel hub bearing within the set value, improves the mechanical performance of the wheel hub bearing unit, extends the service life of the wheel hub bearing unit, and improves the driving safety of the vehicle.

[0086] Example 2:

[0087] like Figure 10 and Figure 11 As shown, in this embodiment, an annular square groove 6322 is formed on the peripheral wall of the pin 632, and a protruding ring 624 is provided on the inner circumferential side of the anti-slip part 622 of the elastic pad 62, which is embedded in the annular square groove 6322. The protruding ring 624 of the elastic pad 62 is embedded in the annular square groove 6322, which reduces the risk of the limiting pin 63 disengaging from the groove 611 and improves the reliability of the installation of the limiting pin 63.

[0088] like Figure 12 As shown, the cross-section of the convex ring 624 is quadrilateral. The convex ring 624 includes a first end face 6241 on the side away from the working part 621 and a second end face 6242 on the side closer to the working part 621.

[0089] The angle between the first end face 6241 and the axial direction of the convex ring 624 is the first pressing angle θ1, and the value range of the first pressing angle is 45°>θ1>30°. The angle between the second end face 6242 and the axial direction of the convex ring 624 is the second pressing angle θ2, and the value range of the second pressing angle is 60°>θ2>45°.

[0090] like Figure 10 and Figure 11 As shown, when the limiting pin 63 moves towards the bottom of the groove 611, the angle values ​​of the first pressure angle and the second pressure angle continuously increase. Since the first pressure angle of the convex ring 624 is smaller than the second pressure angle, when the limiting pin 63 is subjected to the axial pressure of the locking nut 64 and the stroke distance reaches h1, the compression amount of the second end face 6242 of the convex ring 624 is greater than the compression amount of the first end face 6241 of the convex ring 624. When the limiting pin 63 loses the axial pressure of the locking nut 64, under the action of the elastic potential energy accumulated by the elastic pad 62 at the bottom and the second end face 6242 of the convex ring 624, the time for the convex ring 624 to move outward is shortened, and the installation efficiency of the locking nut 64 is improved. The structural design of the convex ring 624 reduces the possibility of insufficient rebound of the limiting pin 63 when the elastic pad 62 rebounds, ensures the height value of the limiting pin 63 protruding from the end face of the retaining ring 61, and improves the reliability of the limiting pin 63 in circumferentially limiting the locking nut 64.

[0091] like Figure 10-12 As shown, the relationship between the depth T of the annular square groove 6322 and the first pressing angle is: T = h1tanθ1, that is, the first end face 6241 of the convex ring 624 abuts against the side wall of the annular square groove 6322 near the bottom of the groove, and the second end face 6242 of the convex ring 624 abuts against the side wall of the annular square groove 6322 near the top of the groove. When the limiting pin 63 moves towards the bottom of the groove 611, the side wall of the groove 611 of the limiting pin 63 continuously presses against the first end face 6241 until the first pressing angle reaches 90°, at which point the limiting pin 63 stops moving. The establishment of this relationship between the depth of the annular square groove 6322, the first pressing angle, and the travel of the limiting pin 63 improves the reliability of the limiting pin 63 in preventing the locking nut 64 from loosening.

[0092] Example 3:

[0093] like Figure 13 and Figure 14 As shown, compared to Embodiment 2, this embodiment has an elastic element on the side of the elastic pad 62 near the limiting pin 63. The elastic element is a wave spring 65, which is disposed between the elastic pad 62 and the limiting pin 63.

[0094] like Figure 15 and Figure 16As shown, the wave spring 65 has good mechanical properties, which can compensate for the insufficient stroke difference of the limit pin 63 when the elastic pad 62 rebounds. On the other hand, the wave spring 65 has a small radial dimension, saving installation space. In addition, the wave spring 65 reduces the risk of elastic failure due to fatigue damage of the elastic pad 62, thus improving the service life and reliability of the locking nut 64 structure.

[0095] The method for locking and preventing loosening of the large-size shaft end nut in this embodiment consists of five steps:

[0096] First, the retaining ring 61 is fitted onto the spindle 5, and the protrusion 612 of the retaining ring 61 slides into the keyway of the spindle 5.

[0097] In the second step, the elastic pad 62 is embedded in the groove 611 of the retaining ring 61, and the protruding ring 624 of the elastic pad 62 is embedded in the strip groove 6321 of the limiting pin 63.

[0098] Third, the elastic pad 62 is installed in the groove 611 of the retaining ring 61, and the wave spring is embedded in the elastic pad 62 and pressed against the bottom of the elastic pad 62.

[0099] Fourth step, the pin 632 is embedded in the elastic pad 62, and the bottom of the pin 632 is welded and fixed to the wave spring.

[0100] Fifth step: When the locking nut 64 is screwed onto the main shaft 5 near the retaining ring 61, the locking nut 64 is pressed in along the second end face 6242 of the pin head 631. The limiting pin 63 compresses the wave spring along the axis of the groove 611. When the pin hole 642 is aligned with the limiting pin 63, the limiting pin 63 is embedded in the pin hole 642 under the elastic force of the wave spring, restricting the reverse rotation of the locking nut 64 and realizing the circumferential limitation of the locking nut 64. By pressing the limiting pin 63 along the axis of the groove 611 and moving it to the bottom of the groove 611, the locking nut 64 is loosened in the reverse direction, thus realizing the disassembly of the locking nut 64.

[0101] The embodiments described in this invention are preferred embodiments of the invention and are not intended to limit the scope of protection of the invention. Therefore, all equivalent changes made to the structure, shape, and principle of the invention should be included within the scope of protection of the invention.

Claims

1. A large-size shaft end nut locking and anti-loosening structure, comprising a retaining ring (61) circumferentially fixed to the main shaft (5), a locking nut (64) abutting against the end face of the retaining ring (61), and a limiting pin (63), characterized in that: The retaining ring (61) has several grooves (611) on the side near the locking nut (64), and an elastic pad (62) is provided in the groove (611); The limiting pin (63) passes through the groove (611), the bottom of the limiting pin (63) abuts against the elastic pad (62), and the top of the limiting pin (63) protrudes from the end face of the retaining ring (61). The height of the limiting pin (63) protruding from the end face of the retaining ring (61) is h1, and the rebound amount of the elastic pad (62) is h2. The relationship between the height of the limiting pin (63) protruding from the end face of the retaining ring (61) and the rebound amount of the elastic pad (62) is: h1≤h2; The locking nut (64) has several pin holes (642). When the locking nut (64) is screwed onto the main shaft (5) near the retaining ring (61), the limiting pin (63) moves axially along the groove (611) near the elastic pad (62). When the locking nut (64) abuts against the retaining ring (61), the limiting pin (63) is embedded in the pin hole (642) under the elastic force of the elastic pad (62) to restrict the reverse rotation of the locking nut (64); When the locking nut (64) rotates in the reverse direction, the contact surface between the limiting pin (63) and the pin hole (642) is the working surface (6311), the angle between the working surface (6311) and the axis of the limiting pin (63) is the working angle α, the side away from the working surface (6311) is the screw-in surface (6312), the angle between the screw-in surface (6312) and the axis of the limiting pin (63) is the screw-in angle β, and α < β; The elastic pad (62) includes a working part (621) and a cylindrical anti-slip part (622). The anti-slip part (622) abuts against the side wall of the groove (611). The limiting pin (63) passes through the elastic pad (62), and the side wall of the limiting pin (63) abuts against the anti-slip part (622). The limiting pin (63) has an annular square groove (6322) on its peripheral wall, and the inner circumferential side of the anti-slip part (622) of the elastic pad (62) is provided with a protruding ring (624) embedded in the annular square groove (6322); The cross-section of the convex ring (624) is quadrilateral. The convex ring (624) includes a first end face (6241) on the side away from the working part (621) and a second end face (6242) on the side close to the working part (621). The angle between the first end face (6241) and the axial direction of the convex ring (624) is a first pressure angle θ1, and the angle between the second end face (6242) and the axial direction of the convex ring (624) is a second pressure angle θ2, and θ1 < θ2.

2. The large-size shaft end nut locking and anti-loosening structure according to claim 1, characterized in that: The working surface (6311) and the screw-in surface (6312) are both arc transitions. The working angle α ranges from 15° to 5°. The screw-in angle β ranges from 35° to 25°. The diameter of the groove (611) is D. The height of the limiting pin (63) protruding from the end face of the retaining ring (61) is h1=D.

3. The large-size shaft end nut locking and anti-loosening structure according to claim 1, characterized in that: The limiting pin (63) has a plurality of strip grooves (6321) on its circumferential sidewall. The length direction of the strip grooves (6321) is parallel to the axis of the limiting pin (63). The elastic pad (62) has a plurality of strip protrusions (623) embedded in the strip grooves (6321) on its sidewall.

4. The large-size shaft end nut locking and anti-loosening structure according to claim 1, characterized in that: The first pressure angle has a range of 45°>θ1>30°, and the second pressure angle has a range of 60°>θ2>45°. The relationship between the depth T of the annular square groove (6322) and the first pressure angle is: T=h1tanθ1.

5. The large-size shaft end nut locking and anti-loosening structure according to claim 1, characterized in that: The elastic pad (62) has an elastic element on the side near the limiting pin (63), and one end of the elastic element is disposed between the elastic pad (62) and the limiting pin (63).

6. The large-size shaft end nut locking and anti-loosening structure according to claim 5, characterized in that: The elastic element is a wave spring (65).

7. A locking method for a large-size shaft end nut locking and anti-loosening structure according to any one of claims 1-6, characterized in that: The steps are as follows: S1. The retaining ring (61) is sleeved on the main shaft (5) to achieve circumferential positioning of the retaining ring (61); S2, The elastic pad (62) is installed in the groove (611) of the retaining ring (61); S3, the limiting pin (63) is embedded in the elastic pad (62); S4. When the locking nut (64) is screwed onto the main shaft (5) near the retaining ring (61), the locking nut (64) is pressed in along the second end face (6242) of the limiting pin (63), and the limiting pin (63) compresses the elastic pad (62) along the axis of the groove (611). When the pin hole (642) of the locking nut (64) is aligned with the limiting pin (63), the limiting pin (63) is embedded in the pin hole (642) under the elastic force of the elastic pad (62), thereby achieving circumferential limiting of the locking nut (64).

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