CN118640225A - A fixed section retainer and a manufacturing method thereof - Google Patents

Abstract

The invention discloses a fixed joint retainer and a manufacturing method thereof, wherein the fixed joint retainer specifically comprises a rigid framework and a flexible coating layer, concave areas are respectively arranged on the inner avoidance surface and the outer wall surface of the framework, the concave areas at least cover the areas on the inner avoidance surface and the outer wall surface, which are contacted with the outer spherical surface of an inner star wheel and the inner spherical surface of an outer star wheel, and a first coating layer is solidified in the concave areas; the skeleton has evenly offered a plurality of spacing window along its circumference, and every spacing window is all cured and is provided with the second coating at two lateral walls of skeleton circumference. According to the invention, on the basis of the original skeleton structure of the retainer, the first coating layer is arranged on the inner and outer surfaces of the retainer in a curing way in a region matched with the spherical surface, so that the friction coefficient is reduced, the friction of the spherical surface pair is reduced, and the torque transmission loss is reduced; meanwhile, the second coating layers are arranged on two opposite limiting structures of the limiting window, so that vibration and noise generated by the fact that the steel balls directly strike side beams on two sides in the limiting window are reduced, and the vehicle experience of a user is improved.

Description

A fixed section retainer and a manufacturing method thereof

Technical Field

The invention relates to the technical field of vehicle parts, and in particular to a fixed-joint retainer and a manufacturing method thereof.

Background Art

The cage is a part used to partially wrap all or part of the rolling elements and move with them. It is an important component in the fixed joint of the vehicle's constant velocity drive shaft. After assembly, the cage can constrain the movement trajectory of the steel balls in the fixed joint, allowing the fixed joint to run smoothly. However, during the actual operation of the fixed joint, the cage will be subjected to a large axial force, which will concentrate the axial clearance of the components in the fixed joint on the wheel side, causing the inner and outer spherical areas of the cage to contact and rub against the outer spherical surface of the inner star wheel and the inner spherical surface of the outer star wheel respectively, which will cause partial torque power loss. At the same time, under the large turning angle condition of the fixed joint, the steel ball always rolls in the cage window, and in the circumferential direction of the cage, the side beam of the window will collide with the moving steel ball to limit it, and generate noise at the same time. Although the internal structure and grease of the fixed joint will absorb and weaken the sharp abnormal noise, a muffled sound similar to a gurgling sound can still be heard inside and outside the car, affecting the customer's car experience and willingness to buy a car.

Therefore, how to optimize the structure of the cage to reduce torque loss and operating noise is a technical problem that needs to be solved urgently by those skilled in the art.

Summary of the invention

The invention provides a fixed-joint retainer and a manufacturing method thereof, so as to reduce torque loss and operation noise during operation of the retainer.

In order to achieve the above object, the present invention provides the following technical solutions:

In the first aspect, the present invention provides a fixed joint retainer, comprising a rigid frame and a flexible coating layer, wherein recessed areas are respectively provided on the inner wall surface and the outer wall surface of the frame, the recessed areas at least cover the areas on the inner and outer wall surfaces that avoid contact with the outer spherical surface of the inner star wheel and the inner spherical surface of the outer star wheel, the coating layer comprises a first coating layer and a second coating layer, the first coating layer is solidified in the recessed area; the frame is uniformly provided with a plurality of limit windows along its circumference, and each limit window is solidified with a second coating layer on both side walls in the circumferential direction of the frame.

Optionally, in the above-mentioned fixed node retainer, the frame includes reference portions at both ends thereof in the axial direction, the reference portions are annular structures with exposed exteriors, and each reference portion includes an axial end surface area of the frame.

Optionally, in the above-mentioned fixed node retainer, the first coating layer completely fills the area between the reference portions at both ends in the axial direction of the skeleton.

Optionally, in the above-mentioned fixed section retainer, the combining structure of the skeleton and the first coating layer is composed of a first arc segment, a second arc segment and a third arc segment arranged in sequence along their axial direction, the first arc segment and the third arc segment have the same diameter and arc length and are symmetrically arranged about the second arc segment, and the diameter of the first arc segment is greater than the diameter of the second arc segment.

Optionally, in the above-mentioned fixed-section retainer, the diameter of the first arc segment is 0.015 mm-0.02 mm larger than the diameter of the second arc segment.

Optionally, in the above-mentioned fixed node retainer, the second coating layer includes a contact layer and a buffer layer, the buffer layer is a granular structure and is vulcanized and fixed on the skeleton, and the contact layer is cured and arranged on the buffer layer.

In a second aspect, the present invention provides a manufacturing method for manufacturing the fixed section retainer provided by any of the above embodiments, comprising at least the following steps:

Shot blasting: Shot blast the skeleton after carburizing heat treatment, using a crawler shot blasting machine, the shot blasting time is 4min-6min, the diameter of the steel shot is 1mm, and the oxide scale and some residual stress on the skeleton surface after carburizing are removed;

Cleaning: After the shot blasted skeleton is subjected to degreasing cleaning, cleaning, pickling, neutralization cleaning, phosphating and cleaning processes, a rough oxide film is formed on the surface of the skeleton;

Coating: Place the phosphated skeleton on the coating tooling, preheat to 100℃-160℃, and then combine the medium of the coating layer with the skeleton of the cage by extrusion injection molding or spraying. The extrusion or spraying temperature is 360℃-380℃, and the temperature is quickly lowered after coating;

Grinding: Use a grinder to grind the inner and outer spherical surfaces of the cage. After the grinding wheel is dressed with a diamond roller, the inner and outer spherical surfaces of the cage are further ground. The inner and outer spherical surfaces of the cage are ground into a three-segment arc structure with a diameter of the two end areas larger than the diameter of the middle area in the axial direction.

Optionally, in the above manufacturing method, in the cleaning step, the degreasing cleaning process uses an ultrasonic cleaning machine to ultrasonically clean the skeleton using a degreasing cleaning liquid at 45° C.-55° C. as a medium;

The pickling process uses 8%-12% hydrochloric acid and pickles for 1 minute at a temperature not higher than 30°C;

The phosphating process uses zinc or manganese phosphating solution with a concentration of 5%-7% and a pH of 2.0-3.0, and the phosphating treatment is carried out for 10min-15min in a treatment environment of not less than 10°C.

Optionally, in the above manufacturing method, three independent water tanks, namely a neutralization tank, a soaking tank and a rinsing tank, are used in the neutralization cleaning process and the cleaning process after phosphating. A 3% sodium hydroxide solution is configured in the neutralization tank for acid-base neutralization, and running water with a flow rate of 4L/min-6L/min is passed into the rinsing tank to clean impurities.

Optionally, in the above manufacturing method, the hardness of the skeleton body is HRC60-HRC64, and the surface hardness of the coated area on the skeleton is HRC58-HRC62.

It can be seen from the above technical scheme that the fixed joint retainer provided by the present invention is structurally combined by a rigid skeleton and a flexible coating layer. Specifically, on the basis of the skeleton structure, in combination with the working condition of the fixed joint running at a large angle, a recessed area is set on the skeleton in the area that may contact the spherical surface of the inner star wheel and the outer star wheel in the fixed joint, and a first coating layer is filled and solidified in the recessed area. The filling setting of the first coating layer enables the inner wall surface and the outer wall surface of the skeleton to still maintain a complete spherical structure, and can maintain the contact effect with the inner star wheel and the outer star wheel under the working condition of the fixed joint with a large angle. At the same time, the first coating layer replaces the rigid skeleton structure to contact and slide with the inner star wheel and the outer star wheel. The first coating layer The flexible structure can reduce the friction coefficient between it and the inner and outer star wheels, thereby reducing the loss of torque transmission and improving the transmission efficiency; at the same time, the limit window opened on the skeleton is also solidified with a second coating layer on the two side walls in the circumferential direction of the skeleton. The steel ball rolls in the limit window under the normal operating condition of the fixed joint, and collides with the side wall of the limit window, that is, the position where the second coating layer is provided, when the fixed joint is in a large turning angle condition. Compared with the rigid collision structure in the prior art, it not only has less vibration and generates less noise, but also can absorb part of the noise through the second coating layer and the first coating layer, so that the NVH performance of the whole vehicle is better, and customers have a better car experience.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some examples or embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without creative work, and the present invention can also be applied to other similar scenarios based on the provided drawings. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

FIG1 is a schematic diagram of the structure of a fixed section retainer provided in an embodiment of the present invention;

FIG2 is a schematic diagram of a front cross-sectional structure of a retainer in one embodiment of the present invention;

FIG3 is a schematic diagram of a top cross-sectional structure of the retainer in FIG2 ;

Fig. 4 is a detailed view of area A in Fig. 3;

5 is a schematic diagram of a front cross-sectional structure of a retainer in another embodiment of the present invention;

FIG6 is a schematic diagram of a top cross-sectional structure of the retainer in FIG5 ;

FIG7 is a detailed view of area B in FIG6;

Fig. 8 is a side view of the retainer;

FIG. 9 is a schematic cross-sectional view of the structure of FIG. 8 .

Among them, 10 is a skeleton; 110 is a limiting window; 120 is a reference part; 210 is a first coating layer; 220 is a second coating layer; 310 is a first arc segment; 320 is a second arc segment; 330 is a third arc segment; 40 is a steel ball.

DETAILED DESCRIPTION

The cage is an important component assembled in the fixed joint of the constant velocity drive shaft. At present, in order to meet the strength requirements of the cage, its material is generally low-carbon alloy steel, and it is manufactured through processes such as turning, punching, heat treatment, grinding, and finishing. However, there will be sliding friction between the spherical structure on the inner and outer wall surfaces and the gear train, and torque loss will be generated due to the large friction coefficient of rigid contact. At the same time, the rigid fit between the steel ball and the cage will also produce a large collision noise under large turning angle conditions, affecting the user's car experience.

In order to make the technical personnel in this field better understand the scheme of the present invention, the embodiments of the present invention are described below with reference to the accompanying drawings. In addition, the embodiments shown below do not limit the content of the invention recorded in the claims. In addition, the entire contents of the structures represented by the following embodiments are not limited to those necessary for the solutions of the invention recorded in the claims.

1 and 2, the fixed joint retainer provided by the embodiment of the present invention is mainly composed of a skeleton 10 and a coating layer, wherein the skeleton 10 is a structure of a rigid material, the same as that in the prior art, to provide a basic bearing structure for the retainer, and the coating layer is a flexible material and solidified on the wall surface of the skeleton 10, and the coating layer includes at least a first coating layer 210 and a second coating layer 220. Specifically, the skeleton 10 is provided with recessed areas on its inner wall surface and outer wall surface, respectively, and the recessed areas at least cover the spherical areas on the inner wall surface and the outer wall surface of the skeleton 10. It should be noted that the spherical areas of the inner wall surface and the outer wall surface on the skeleton 10 are areas where the skeleton 10 may contact the outer spherical surface of the inner star wheel and the inner spherical surface of the outer star wheel during the operation of the fixed joint, and the spherical area is determined according to the size of the fixed joint in the actual application process, and the recessed area covers the inner wall surface. The first coating layer 210 is solidified in the recessed area while the area on the surface and the outer wall surface that contacts the outer spherical surface of the inner star wheel and the inner spherical surface of the outer star wheel. The first coating layer 210 fills the area where the recessed area is set on the skeleton 10. It is not only tightly combined with the skeleton 10, but also the first coating layer 210 makes the inner wall surface and the outer wall surface of the skeleton 10 a complete structural surface without defects, so as to meet the good connection between the retaining frame and the outer star wheel of the inner star wheel, that is, in the operating condition of the fixed joint with a large rotation angle, the first coating layer 210 replaces the original skeleton 10 structure to contact and slide with the inner star wheel and the outer star wheel. It should be noted that, in the same spherical fitting clearance, the first coating layer 210 has a smaller friction coefficient with the inner star wheel and the outer star wheel than the rigid skeleton 10 structure, and can reduce the spherical pair friction and reduce the torque transmission loss.

At the same time, similar to the currently common retaining frame structure, in the fixed joint retaining frame provided by the embodiment of the present invention, a plurality of limit windows 110 are evenly opened on the skeleton 10 along its circumference, which are used for setting and limiting the operation of the steel ball 40, and it should be noted that in the axial direction of the skeleton 10, the two wall surfaces of a single limit window 110 are interference fit with the steel ball 40, and they are always in contact, so the above two wall surfaces are exposed metal structures and maintain the connection effect with the steel ball 40, and in the circumferential direction of the skeleton 10, the two side wall surfaces of the single limit window 110 are solidified with a second coating layer 220, and when the fixed joint is in a large-angle operating condition, the limit The walls on both sides of the window 110 withstand the collision of the steel ball 40, and partially absorb the impact of the steel ball 40 through the flexible second coating layer 220 to reduce the noise caused by the steel ball 40 hitting the side wall of the limit window 110. At the same time, compared with the rigid skeleton 10 structure, the second coating layer 220 and the first coating layer 210 have weaker noise transmission performance, but can reduce the transmission of the impact noise of the steel ball 40, thereby achieving the effect of improving the NVH performance of the whole vehicle. It should be noted that the skeleton 10 is a regular rotating body structure. The axial direction of the skeleton 10 in this article is parallel to the center line of the skeleton 10 structure, and the circumferential direction of the skeleton 10 is the rotation direction of the rotating body structure.

It should be further explained that the second coating layer 220 on the skeleton 10 can be set to cover the original structure. Similarly, a recessed structure can be set at the position where the second coating layer 220 is set, so that the second coating layer 220 is filled in the corresponding area to improve the stability of its connection.

The fixed joint retainer provided in the embodiment of the present invention is structurally combined by a rigid skeleton 10 and a flexible coating layer. Specifically, on the basis of the structure of the skeleton 10, in combination with the working condition of the fixed joint running at a large angle, a recessed area is set on the skeleton 10 in the area that may contact the spherical surface of the inner star wheel and the outer star wheel in the fixed joint, and a first coating layer 210 is filled and solidified in the recessed area. The filling setting of the first coating layer 210 allows the inner wall surface and the outer wall surface of the skeleton 10 to still maintain a complete spherical structure, and can maintain the contact effect with the inner star wheel and the outer star wheel under the working condition of the fixed joint with a large angle. At the same time, the first coating layer 210 replaces the rigid skeleton 10 structure and contacts and slides with the inner star wheel and the outer star wheel. The flexible structure of the first coating layer 210 can The friction coefficient between it and the inner star wheel and the outer star wheel is reduced, thereby reducing the loss of torque transmission and improving the transmission efficiency; at the same time, the limit window 110 opened on the skeleton 10 is also solidified with a second coating layer 220 on the two side walls in the circumferential direction of the skeleton 10. The steel ball 40 rolls in the limit window 110 under the normal operation condition of the fixed joint, and collides with the side wall of the limit window 110, that is, the position where the second coating layer 220 is provided, when the fixed joint is in a large turning angle condition. Compared with the rigid collision structure in the prior art, it not only has small vibration and small noise, but also can absorb part of the noise through the second coating layer 220 and the first coating layer 210, so that the NVH performance of the whole vehicle is better, and customers have a better car experience.

Furthermore, considering that in the actual production process of the fixed joint retainer, uniform design, process and inspection reference surfaces are required to ensure its structural accuracy, see Figures 2 and 8. Therefore, in some embodiments of the present invention, the skeleton 10 includes reference portions 120 at both ends in its axial direction, and a single reference portion 120 is an annular metal structure that is not coated with a coating layer and has a bare surface, and each reference portion 120 includes an end face area of the skeleton 10 in its axial direction, so that the two end faces of the skeleton 10 in the axial direction can be used as reference surfaces to enable the retainer to be calibrated and tested, that is, when observed from the axial direction of the skeleton 10, the areas on both sides are exposed metal structures, and the first coating layer 210 is arranged in the area between the reference portions 120 on both sides and on the inner and outer wall surfaces of the skeleton 10.

On the basis of the above-mentioned embodiments, the setting of the first coating layer 210 is suitable for filling the recessed area on the skeleton 10, and contacts and rubs with the inner star wheel and the outer star wheel under the large rotation angle working condition of the fixed joint. Therefore, referring to Figures 5-7, the first coating layer 210 can be set only on the spherical area structure on both sides of the axial direction of the skeleton 10, and it is not necessary to set it in the middle area, so as to maintain the rigidity effect of the skeleton 10 and reduce the structural damage effect of the recessed area setting on the skeleton 10; and referring to Figures 2-4, in other embodiments of the present invention, on the basis of checking that the strength of the skeleton 10 meets the use conditions required by the operation of the fixed joint, in order to improve the convenience of opening the recessed area on the skeleton 10, And the curing convenience of the first coating layer 210, the first coating layer 210 completely fills the area between the reference parts 120 at both ends in the axial direction of the skeleton 10, that is, the structure of the skeleton 10 in the axial direction, its inner wall surface or outer wall surface is a structure in which the first coating layer 210 is sandwiched between the reference parts 120 at both ends, and the recessed area on the single side wall of the skeleton 10 and the first coating layer 210 are both an integral structure without the need for segmented arrangement, which reduces the difficulty of processing and production of the skeleton 10. At the same time, the larger area of the first coating layer 210 enables the retaining frame to have a greater ability to absorb noise during the collision of the steel ball 40, which can improve the NVH performance of the vehicle to a certain extent.

In order to improve the coordination effect between the retaining frame and the outer star wheel and the inner star wheel during the operation of the fixed joint, referring to Figures 8 and 9, in some embodiments of the present invention, the integrated structure after the skeleton 10 and the first coating layer 210 are combined is a segmented structure in its axial direction, specifically including a first arc segment 310, a second arc segment 320 and a third arc segment 330 arranged in sequence along the axial direction, wherein the diameter and arc length of the first arc segment 310 and the third arc segment 330 are the same, and the first arc segment 310 and the third arc segment 330 are symmetrically arranged with respect to the second arc segment 320, and the diameters of the first arc segment 310 and the third arc segment 330 are both larger than the diameter of the second arc segment 320, and the above structure is formed on the inner wall surface of the skeleton 10 and the inner star wheel, so as to achieve the desired effect. When the outer wall surface is spherically matched with the outer star wheel, the structure of the first arc segment 310 and the third arc segment 330 protruding toward the center line of the skeleton 10 compared with the second arc segment 320 can make the inner star wheel and the outer star wheel have a tendency to move toward the bisector plane of the second arc segment 320 after contacting the spherical surface of the retainer, thereby realizing self-centering of the outer star wheel and the inner star wheel. At the same time, it should be noted that since the spherical area where the retainer contacts the inner and outer star wheels is solidified with the first coating layer 210, the flexible first coating layer 210 has a certain toughness and can compensate for the tolerance fluctuations generated by the skeleton 10 during grinding, thereby reducing the spherical matching clearance between the spherical structure of the inner and outer wall surfaces of the retainer and the outer and inner star wheels, and improving the problem of abnormal noise caused by axial movement of the whole vehicle.

Furthermore, in some embodiments of the present invention, the diameters of the first arc segment 310 and the third arc segment 330 are increased by 0.015mm-0.02mm compared to the second arc segment 320, so that the retaining frame has a self-centering effect on the inner star wheel and the outer star wheel while having a relatively smooth and integrated appearance structure, avoiding the generation of obvious convex points and the risk of stress concentration.

In the fixed joint retainer provided in an embodiment of the present invention, the coating layer is a nylon coating, which contains a low-friction, high-load-bearing capacity material such as polytetrafluoroethylene, and the nylon coating layer can be cured on the metal skeleton 10 by extrusion injection molding, powder spraying, light curing and other technical means, and the fully cured retainer structure is machined by grinding the surface to achieve the required size requirements. In a specific embodiment of the present invention, the second coating layer 220 specifically includes a contact layer and a buffer layer, wherein the buffer layer is preferably provided with a structure of multiple particles so as to be fixed on the skeleton 10 by fluidization. The particle structure enables the buffer layer to have a better buffering and vibration reduction effect, and the contact layer is cured and arranged on the buffer layer. The contact layer is used to directly contact the steel ball 40, and it can be made of a more wear-resistant material. The second coating layer 220 is layered to apply different materials, so that the second coating layer 220 has good buffering performance while achieving its wear resistance and service life through the contact layer.

Some embodiments of the present invention further provide a manufacturing method, which is used to successfully prepare the fixed section retainer provided by any of the above embodiments. The manufacturing method will be described in detail below. It should be noted that the following steps are post-processes based on the skeleton 10 with a recessed area. Since the production and manufacturing of the rigid skeleton 10 is similar to the prior art, and the recessed area is provided on the structure of the skeleton 10 is a common technical means, the corresponding steps are not described in detail here. The manufacturing method provided by the present invention includes at least the following steps:

S01: Shot blasting: Shot blast the skeleton after carburizing heat treatment, using a crawler shot blasting machine, the shot blasting time is 4min-6min, the diameter of the steel shot is 1mm, and the oxide scale and some residual stress on the skeleton surface after carburizing are removed;

It should be noted that the purpose of carburizing heat treatment is to form a layer of high-carbon compounds on the surface of the skeleton 10 to improve the hardness and wear resistance of the skeleton 10, and the skeleton 10 after carburizing needs to undergo quenching and low-temperature tempering processes. Therefore, the shot blasting step can remove part of the residual stress caused by quenching while removing the oxide scale.

S02: Cleaning: After the shot blasted skeleton is subjected to degreasing cleaning, cleaning, pickling, neutralization cleaning, phosphating and cleaning processes, a rough oxide film is formed on the surface of the skeleton.

It should be noted here that degreasing cleaning is the removal of grease, dirt, etc. adhered to the surface of the metal substrate by a degreasing agent. Specifically, in some embodiments of the present invention, the degreasing cleaning process uses an ultrasonic cleaning machine, and uses the configured degreasing cleaning liquid as the medium. The degreasing cleaning liquid is heated to 45°C-55°C and then ultrasonic cleaning is performed.

It should also be noted that, based on the above-mentioned embodiment, the pickling process is used to remove scale, rust and other contaminants on the metal surface to clean and prepare the metal surface. The pickling process specifically uses 8%-12% hydrochloric acid and pickles for 1 minute at a temperature not higher than 30°C. In this embodiment, the hydrochloric acid concentration, pickling temperature and pickling time must be strictly controlled to avoid hydrogen ions from penetrating into the gaps in the material, which may cause the risk of hydrogen embrittlement of the skeleton 10.

Furthermore, the phosphating process is used to form a phosphating film on the surface of the skeleton 10, thereby providing protection for the skeleton 10 and preventing the skeleton 10 from being corroded to a certain extent. The phosphating process uses a zinc-based or manganese-based phosphating solution with a concentration of 5%-7% and a pH of 2.0-3.0. At the same time, the skeleton 10 is phosphated for 10 minutes to 15 minutes in a treatment environment of not less than 10°C.

S03: Coating: Place the phosphated skeleton on the coating tooling, preheat to 100℃-160℃, and then combine the medium of the coating layer with the skeleton of the cage by extrusion injection molding or spraying. The extrusion or spraying temperature is 360℃-380℃, and the temperature is quickly lowered after coating.

It should be noted that the coating layer is preferably made of nylon material to adapt to commonly used equipment and temperature requirements, and the coated retaining frame needs to be cooled quickly to avoid the risk of reducing the quenching hardness or hardening layer depth of the retaining frame skeleton 10 due to metallographic transformation caused by high temperature, resulting in a reduction in the hardening layer depth and surface hardness and affecting product performance.

S04: Grinding: Use a grinder to grind the inner and outer spherical surfaces of the cage. After the grinding wheel is dressed with a diamond roller, the inner and outer spherical surfaces of the cage are further ground. The inner and outer spherical surfaces of the cage are ground into a three-segment arc structure with a diameter of the two end areas larger than the diameter of the middle area in the axial direction.

It should be noted that in step S04, the inner and outer spherical surfaces of the retaining frame are ground into three arc structures with the diameters of the two end areas in the axial direction being larger than the diameter of the middle area, so as to satisfy the self-centering effect of the inner and outer star wheels when they cooperate with the spherical surface of the retaining frame.

Furthermore, in the manufacturing method provided in an embodiment of the present invention, in step S02, three independent water tanks are used in the neutralization cleaning process and the cleaning process after phosphating to ensure the cleaning effect, specifically a neutralization tank, a soaking tank and a rinsing tank, wherein the neutralization tank is configured with a sodium hydroxide solution with a concentration of 3% for acid-base neutralization cleaning, and the rinsing tank is passed with industrial running water with a flow rate of 4L/min-6L/min to clean impurities.

It should also be noted that in step S03, the quenching hardness and hardened layer depth of the skeleton 10 of the retaining frame can be adjusted according to the actual process requirements. Specifically, the hardness of the main body of the skeleton 10 is HRC60-HRC64, and the surface hardness of the area coated with the coating layer on the skeleton 10 is HRC58-HRC62, so that the coating layer can also meet the contact support requirements of the steel ball 40, the inner star wheel and the outer star wheel.

It should be noted that, for the convenience of description, only the parts related to the invention are shown in the drawings. In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

As shown in the present invention and claims, unless the context clearly indicates an exception, the words "a", "an", "a kind" and/or "the" do not specifically refer to the singular, but may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of clearly identified steps and elements, and these steps and elements do not constitute an exclusive list, and the method or device may also include other steps or elements. The elements defined by the sentence "includes a..." do not exclude the existence of other identical elements in the process, method, commodity or device that includes the elements.

In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

The above description is only a preferred embodiment of the present invention and an explanation of the technical principles used, and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. The scope of the invention involved in the present invention is not limited to the technical solution formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the above-mentioned inventive concept. For example, the above-mentioned features are replaced with the technical features with similar functions disclosed in the present invention (but not limited to) to form a technical solution.

Claims (10)

1. A fixed joint retainer, characterized in that it includes a rigid skeleton and a flexible coating layer, wherein the inner wall surface and the outer wall surface of the skeleton are respectively provided with recessed areas, wherein the recessed areas at least cover the areas on the inner wall surface and the outer wall surface that are in contact with the outer spherical surface of the inner star wheel and the inner spherical surface of the outer star wheel, wherein the coating layer includes a first coating layer and a second coating layer, wherein the first coating layer is solidified in the recessed area; the skeleton is uniformly provided with a plurality of limiting windows along its circumference, and each limiting window is solidified with the second coating layer on both side walls of the skeleton in the circumferential direction. 2. The fixed joint retainer as described in claim 1 is characterized in that the skeleton includes a reference portion at both ends thereof in the axial direction, the reference portion is an annular structure with an exposed outer surface, and each of the reference portions includes an axial end surface area of the skeleton. 3 . The fixed node retainer according to claim 2 , wherein the first coating layer completely fills the area between the reference portions at both ends in the axial direction of the skeleton. 4. The fixed section retainer as described in claim 3 is characterized in that the combining structure of the skeleton and the first coating layer is composed of a first arc segment, a second arc segment and a third arc segment arranged in sequence along their axial direction, the first arc segment and the third arc segment have the same diameter and arc length and are symmetrically arranged about the second arc segment, and the diameter of the first arc segment is greater than the diameter of the second arc segment. 5. The fixed node retainer as described in claim 4 is characterized in that the diameter of the first arc segment is 0.015mm-0.02mm larger than the diameter of the second arc segment. 6. The fixed node retainer according to any one of claims 1 to 5, characterized in that the second coating layer includes a contact layer and a buffer layer, the buffer layer is a granular structure and is vulcanized and fixed on the skeleton, and the contact layer is cured and arranged on the buffer layer. 7. A manufacturing method for manufacturing the fixed node retainer according to any one of claims 1 to 6, characterized in that it comprises at least the following steps: Shot blasting: Shot blast the skeleton after carburizing heat treatment, using a crawler shot blasting machine, the shot blasting time is 4min-6min, the diameter of the steel shot is 1mm, and the oxide scale and some residual stress on the skeleton surface after carburizing are removed; Cleaning: After the shot blasted skeleton is subjected to degreasing cleaning, cleaning, pickling, neutralization cleaning, phosphating and cleaning processes, a rough oxide film is formed on the surface of the skeleton; Coating: Place the phosphated skeleton on the coating tooling, preheat to 100℃-160℃, and then combine the medium of the coating layer with the skeleton of the cage by extrusion injection molding or spraying. The extrusion or spraying temperature is 360℃-380℃, and the temperature is quickly lowered after coating; Grinding: Use a grinder to grind the inner and outer spherical surfaces of the cage. After the grinding wheel is dressed with a diamond roller, the inner and outer spherical surfaces of the cage are further ground. The inner and outer spherical surfaces of the cage are ground into a three-segment arc structure with a diameter of the two end areas larger than the diameter of the middle area in the axial direction. 8. The manufacturing method according to claim 7, characterized in that in the cleaning step, the degreasing cleaning process uses an ultrasonic cleaning machine to perform ultrasonic cleaning on the skeleton using a degreasing cleaning liquid at 45°C-55°C as a medium; The pickling process uses 8%-12% hydrochloric acid and pickles for 1 minute at a temperature not higher than 30°C; The phosphating process uses zinc or manganese phosphating solution with a concentration of 5%-7% and a pH of 2.0-3.0, and performs phosphating treatment for 10min-15min at a treatment environment of not less than 10°C. 9. manufacture method as claimed in claim 8, is characterized in that, in the cleaning process after the neutralization cleaning process and phosphating, a total of three independent water tanks are used, namely, a neutralization tank, an immersion tank and a rinse tank, wherein a sodium hydroxide solution having a concentration of 3% is configured in the neutralization tank to carry out acid-base neutralization, and the flowing water having a flow rate of 4L/min-6L/min is passed into the rinse tank to carry out impurity cleaning. 10. The manufacturing method according to claim 7, characterized in that, in the coating step, the hardness of the skeleton body is HRC60-HRC64, and the surface hardness of the coated area on the skeleton is HRC58-HRC62.