Deep groove ball bearing

Abstract

The utility model relates to the technical field of traction motor bearing manufacturing, in particular to a deep groove ball bearing which comprises an outer ring, an inner ring, a plurality of rolling bodies and a retainer, the outer surface of the inner ring and the inner surface of the outer ring are respectively provided with a roller path for the rolling body to roll; the rolling body is located between the outer ring and the inner ring, and the retainer is located between the outer ring and the inner ring; the guide mode of the deep groove ball bearing is rolling body guide; the groove curvature coefficient of the outer ring is 0.520 Dw, and the groove curvature coefficient of the inner ring is 0.510 Dw. The curvature coefficient of the inner and outer ring channels is reduced by 0.005 Dw compared with a conventional bearing, and the contact area of the raceway and a rolling body is increased under the condition, so that the load borne by the unit area is reduced, the stress concentration and fatigue crack possibility is reduced, the operation temperature rise and vibration of the bearing under the high-speed working condition are reduced, and the fatigue life of the bearing is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of manufacturing of traction motor bearings for vehicles, and particularly relates to a deep groove ball bearing. Background Art

[0002] The traction motor is the main equipment in the locomotive drive system, and the bearing is a key component of the traction motor. In addition to bearing the weight of the motor rotor, the bearing also has to bear the traction force and braking force generated by frequent starting and braking, and at the same time has to bear the impact load during the operation of the locomotive and the force generated by gear meshing, etc. Under such complex working conditions, the bearing must also meet the requirements of high running reliability and long service life, so higher requirements are put forward for the design and manufacturing quality of the bearing.

[0003] The original design method was used for the design of the raceway radius curvature and the rib of the inner ring and the outer ring of the original traction motor bearing of the locomotive, and a steel plate stamping cage was used. This structure is suitable for ordinary bearings with low rotational speed and no special requirements for the vibration speed and vibration acceleration of the bearing, and cannot meet the industry requirements. Summary of the Utility Model

[0004] The utility model aims to overcome the above technical defects and provides a deep groove ball bearing with high rotational speed, good insulation and long service life.

[0005] To achieve the above purpose, the technical solution adopted by the utility model is: a deep groove ball bearing, comprising an outer ring, an inner ring, a plurality of rolling elements and a cage; raceways for the rolling elements to roll are provided on the outer surface of the inner ring and the inner surface of the outer ring;

[0006] The rolling elements are located between the outer ring and the inner ring, and the cage is located between the outer ring and the inner ring; the guiding mode of the deep groove ball bearing is rolling element guiding;

[0007] The groove curvature coefficient of the outer ring is 0.520 Dw, and the groove curvature coefficient of the inner ring is 0.510 Dw.

[0008] The groove curvature coefficients of the inner and outer rings are reduced by 0.005 Dw compared with conventional bearings. In this case, the contact area between the raceway and the rolling elements increases, thereby reducing the load borne per unit area, reducing the possibility of stress concentration and fatigue cracks, reducing the operating temperature rise and vibration of the bearing under high-speed conditions, and improving the fatigue life of the bearing; the increase in the contact area between the raceway and the rolling elements also improves the running stability of the bearing at high rotational speeds; and improves the vibration speed and vibration acceleration of the complete set of bearings.

[0009] Furthermore, the cage comprises two semi-riveted solid cages, and the two semi-riveted solid cages are connected by rivets.

[0010] Further, the pocket of the cage is an arc pocket, and the center of rotation of the rolling element, the center of the rivet, and the center of the arc pocket are not on the same center.

[0011] This design of the arc pocket ensures the running stability of the rolling elements in the cage. The pocket is arc-shaped, which can effectively improve the lubrication state during the high-speed operation of the bearing. The cage has good machinability and high forming accuracy, which can reduce the vibration during the operation of the bearing, meet the requirement of the bearing for high-speed rotation, improve the vibration speed and vibration acceleration of the complete bearing, reduce the bearing noise, avoid the strengthening of the bearing vibration when the bearing bears impact acceleration, and improve the service life of the bearing.

[0012] Further, the radius of curvature of the arc pocket is 0.6 times the diameter of the rolling element.

[0013] Further, the outer surface of the outer ring and the side surface of the outer ring are transitioned by a chamfer. The chamfer is an arc-shaped chamfer, and the outer surface of the outer ring is smoothly transitioned with the chamfer. The conventional chamfer has an angle of 15° with the outer surface of the outer ring 1 and an angle of 30° with the side surface of the outer ring 1. Therefore, it is easy to form a cusp at the joint of the outer surface and the side surface of the conventional bearing outer ring 1. In this application, the chamfer is set as a smoothly transitioned chamfer, which not only improves the impact work at the rounded corner, but also solves the problem of coating peeling at the rounded corner because there is no cusp on the outer ring of the bearing.

[0014] Further, an insulating ceramic coating is applied on the outer ring, and the insulating ceramic coating is composed of Al2O3 and TiO2. Through experimental verification, the designed insulating bearing has the same design and insulating performance as the in-use bearing, meeting the requirements of the insulating performance that when the voltage of the bearing is 1000V (DC), the insulation resistance ≥ 500MΩ and the static capacitance ≤ 5nF.

[0015] Further, the thickness of the insulating ceramic coating is greater than 0.35mm. Adding a small amount of TiO2 can make up for the performance decline of the bonding strength and impact function caused by the increase in the coating thickness. When sealing the holes of the coating, two-hole sealing processes are adopted, which can effectively increase the environmental adaptability of the insulating coating. At the same time, the bonding strength and impact resistance of the coating are also improved.

[0016] Further, the rib coefficient of the inner ring is 0.4 Dw, and the rib coefficient of the outer ring is 0.4 Dw. Since the bearing bears axial force, a rib coefficient of 0.4 Dw is adopted in the design to prevent shoulder crossing and rib crushing when the axial load increases, and improve the fatigue life of the bearing.

[0017] Further, the material of the bearing ring is high-carbon chromium bearing steel.

[0018] The present application also provides a manufacturing method for the above deep groove ball bearing ring, including quenching - cryogenic treatment - tempering; the quenching adopts a salt bath martensite quenching process, and the salt bath martensite quenching temperature is 175°C; the cryogenic treatment temperature is -70°C; the tempering temperature is 200°C. The bearing ring adopts an austenitizing process plan with high hardness. After heat treatment processing, the retained austenite content of the bearing ring can reach ≤3%, forming a compressive stress on the surface of the bearing ring. The material metallographic structure is delicate, uniform and stable, and has high strength and toughness, ensuring the wear resistance and impact resistance of the bearing and improving the service life of the bearing.

[0019] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0020] (1) The curvature coefficient of the inner and outer ring raceways is reduced by 0.005 compared with conventional bearings. In this case, the contact area between the raceway and the rolling elements increases, thereby reducing the load borne per unit area, reducing the possibility of stress concentration and fatigue cracks, and reducing the operating temperature rise and vibration of the bearing under high-speed conditions, and improving the fatigue life of the bearing.

[0021] (2) The outer ring fillet is a large arc chamfer, which improves the impact energy at the fillet and solves the problem of coating peeling at the fillet.

[0022] (3) It has good insulation effect and meets the insulation performance requirements of the bearing with an insulation resistance ≥500 MΩ and a static capacitance ≤5 nF when the voltage is 1000 V (DC).

[0023] (4) The cage adopts a double half-riveted solid cage, which can reduce the bearing operation vibration, meet the high-speed rotation of the bearing, improve the vibration speed and vibration acceleration of the complete set of bearings, reduce the bearing noise, avoid the bearing vibration strengthening when the bearing bears the impact acceleration, and improve the service life of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Among them:

[0026] Figure 1 is a schematic structural diagram of a deep groove ball bearing;

[0027] Figure 2 is a three-dimensional view of a deep groove ball bearing;

[0028] Figure 3 is a sectional view of a deep groove ball bearing;

[0029] Figure 4 It is the top view of a deep groove ball bearing;

[0030] Figure 5 It is a schematic diagram of the contact structure between the rolling elements and the cage in the top view state of the deep groove ball bearing;

[0031] Figure 6 It is a schematic diagram of the positional relationship among the center of the pocket of the deep groove ball bearing, the center of rotation of the rolling element, and the center of the rivet;

[0032] Figure 7 It is Figure 6 a partial enlarged view of.

[0033] Figure 8 It is the arc chamfer of the outer ring of the present application;

[0034] Figure 9 It is the arc chamfer of the outer ring of the conventional design.

[0035] In the figure: 1 is the outer ring; 2 is the inner ring; 3 is the rolling element; 4 is the cage; 5 is the rivet; 6 is the insulating coating; 7 is the arc pocket; 8 is the first pocket center; 9 is the second pocket center; 10 is the center of rotation of the steel ball; 11 is the center of the rivet. Specific embodiments

[0036] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0037] As Figures 1 - 9 shown, a deep groove ball bearing includes an outer ring 1, an inner ring 2, a plurality of rolling elements 3 and a cage 4; raceways for the rolling elements 3 to roll are provided on both the outer surface of the inner ring 2 and the inner surface of the outer ring 1;

[0038] The rolling elements 3 are located between the outer ring 1 and the inner ring 2, and the cage 4 is located between the outer ring 1 and the inner ring 2; the guiding mode of the deep groove ball bearing is the guiding of the rolling elements 3;

[0039] The groove curvature coefficient of the outer ring 1 is 0.520 Dw, and the groove curvature coefficient of the inner ring 2 is 0.510 Dw.

[0040] The curvature coefficient of the inner and outer raceway grooves is reduced by 0.005 Dw compared with conventional bearings. In this case, the contact area between the raceway and the rolling elements increases, thereby reducing the load borne per unit area, decreasing the stress concentration and the possibility of fatigue cracks, reducing the operating temperature rise and vibration of the bearing under high-speed conditions, and improving the fatigue life of the bearing; the increase in the contact area between the raceway and the rolling elements also improves the running stability of the bearing at high speeds; and it improves the vibration velocity and vibration acceleration of the assembled bearing.

[0041] Furthermore, the cage 4 includes two semi-riveted solid cages, and the two semi-riveted solid cages are connected by a rivet 5.

[0042] Furthermore, the pocket of the cage 4 is an arc-shaped pocket, and the center of rotation of the rolling element 3, the center of the rivet 5, and the center of the arc-shaped pocket are not on the same center.

[0043] This design of the arc-shaped pocket ensures the running stability of the rolling elements in the cage. The pocket is arc-shaped, which can effectively improve the lubrication state of the bearing during high-speed operation. The cage has good machinability and high forming accuracy, can reduce the vibration during bearing operation, meet the requirement for the bearing to achieve high-speed rotation, improve the vibration velocity and vibration acceleration of the assembled bearing, reduce the bearing noise, avoid the strengthening of bearing vibration when the bearing is subjected to impact acceleration, and improve the service life of the bearing.

[0044] Furthermore, the radius of curvature of the arc-shaped pocket is 0.6 times the diameter of the rolling element 3.

[0045] Furthermore, the outer surface of the outer ring 1 and the side surface of the outer ring 1 are transitioned by a chamfer, and the chamfer is an arc-shaped chamfer, and the outer surface of the outer ring 1 is smoothly transitioned with the chamfer. The conventional chamfer has an angle of 15° with the outer surface of the outer ring 1 and an angle of 30° with the side surface of the outer ring 1. Therefore, the outer surface of the outer ring 1 of the conventional bearing and the side surface of the outer ring 1 are prone to form sharp points. In this application, the chamfer is set as a smoothly transitioned chamfer, which not only improves the impact work at the rounded corner, but also, since there are no sharp points on the outer ring of the bearing, can solve the problem of coating peeling at the rounded corner.

[0046] Furthermore, an insulating ceramic coating is applied on the outer ring 1, and the insulating ceramic coating is composed of Al2O3 and TiO2. Through experimental verification, the designed insulated bearing has the same design and insulation performance as the in-use bearing, meeting the requirements of insulation performance when the voltage of the bearing is 1000V (DC), the insulation resistance ≥ 500MΩ, and the static capacitance ≤ 5nF.

[0047] Furthermore, the thickness of the insulating ceramic coating is greater than 0.35 mm. Adding a small amount of TiO2 can compensate for the performance degradation of the bonding strength and impact function caused by the increase in coating thickness; when sealing the coating, a two-step sealing process can effectively improve the environmental adaptability of the insulating coating. At the same time, the bonding strength and impact resistance of the coating are also enhanced.

[0048] Furthermore, the rib coefficient of the inner ring 2 is 0.4 Dw, and the baffle coefficient of the outer ring 1 is 0.4 Dw. Since the bearing bears axial force, a rib coefficient design of 0.4 Dw is adopted to prevent shoulder climbing and rib crushing when the axial load increases, and to improve the fatigue life of the bearing.

[0049] Furthermore, the material of the bearing ring is high-carbon chromium bearing steel.

[0050] This application also provides a manufacturing method for the above-mentioned deep groove ball bearing ring, including quenching - cold treatment - tempering; the quenching adopts a salt bath martensite quenching process, and the salt bath martensite quenching temperature is 175°C; the cold treatment temperature is -70°C; the tempering temperature is 200°C. The bearing ring adopts an austenitizing process plan with high hardness. After heat treatment, the retained austenite content of the bearing ring can reach ≤3%, forming a compressive stress on the surface of the bearing ring. The material metallographic structure is delicate, uniform and stable, and has high strength and toughness, ensuring the wear resistance and impact resistance of the bearing and improving the service life of the bearing.

[0051] It should be noted that all directional indicators (such as up, down, left, right, front, back...) in the embodiments of this application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indicators will also change accordingly.

[0052] In addition, the descriptions involving "first", "second", etc. in this application are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the said features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0053] The above-disclosed are only the preferred embodiments of this application. Of course, the scope of rights of this application cannot be limited by this. Therefore, equivalent changes made according to the claims of this application still fall within the scope covered by this application.

Claims

1. A deep groove ball bearing, characterized in that, It includes an outer ring, an inner ring, a number of rolling elements and a cage; raceways for the rolling elements to roll are provided on the outer surface of the inner ring and the inner surface of the outer ring; The rolling elements are located between the outer ring and the inner ring, and the cage is located between the outer ring and the inner ring; the guiding method of the deep groove ball bearing is rolling element guiding; The groove curvature coefficient of the outer ring is 0.520 Dw, and the groove curvature coefficient of the inner ring is 0.510 Dw; The cage includes two semi-riveted solid cages, and the two semi-riveted solid cages are connected by rivets; The pocket holes of the cage are arc-shaped pocket holes, and the center of rotation of the rolling elements, the center of the rivets and the center of the arc-shaped pocket holes are not on the same center.

2. A deep groove ball bearing according to claim 1, characterized in that, The radius of curvature of the arc-shaped pocket holes is 0.6 times the diameter of the rolling elements.

3. A deep groove ball bearing according to claim 1, characterized in that, An insulating ceramic coating is applied to the outer ring.

4. A deep groove ball bearing according to claim 3, characterized in that, The thickness of the insulating ceramic coating is greater than 0.35 mm.

5. A deep groove ball bearing according to claim 1, characterized in that, The rib coefficient of the inner ring is 0.4 Dw, and the baffle coefficient of the outer ring is 0.4 Dw.

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