Thickening structure for reducing heat treatment deformation of oversize tapered roller bearing ring
By locally thickening the inner and outer rings of the bearing, the deformation problem caused by the difference in wall thickness during the induction heating process of the wind turbine main bearing was solved, achieving uniform heating and rotational stability of the workpiece during the heat treatment process, improving the processing qualification rate and reducing costs.
Patent Information
- Application Number
- CN202520052079.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-10
- Publication Date
- 2025-10-21
- Estimated Expiration
- 2035-01-10
AI Technical Summary
With the increase in the size of wind turbine main bearings, the workpieces are severely deformed during the traditional carburizing heat treatment process, resulting in low processing qualification rate, high cost and long cycle. In addition, the temperature rise in thin-walled areas during induction heating leads to a decrease in strength, and the workpieces are prone to deformation or scrap during rotation.
By calculating the depth of the hardened layer, the thickened structure of the inner and outer rings of the bearing was improved, increasing the wall thickness at thin-walled sections to ensure uniform heating of all parts during induction heating and avoid deformation caused by thermal stress differences. Local thickening of the inner and outer rings was adopted to ensure the stability of the workpiece rotation.
This technology achieves uniform heating of the workpiece during induction heating, reduces heat treatment deformation, ensures the stability of the workpiece during rotation, improves the processing qualification rate, and reduces costs.
Smart Images
Figure CN223459734U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to bearing part heat treatment technical field, concretely relates to a kind of extra-large taper roller bearing ring thickening structure for reducing heat treatment deformation. BACKGROUND
[0002] In recent years with the sustained high-speed development of wind power industry, wind turbine is towards larger megawatt level, and gradually from land to sea, wind power main bearing size is larger and larger, and the structure type of wind power main bearing is changed from the type of self-aligning roller bearing (SRB) to the type of taper roller bearing (TRB), and the maximum size of wind power main bearing has reached 3.5 meters. The increase of bearing size makes the difficulty of traditional carburizing heat treatment process increase several times, and the low first-time processing yield, high cost and long cycle time become important factors restricting the manufacturing process.
[0003] As an alternative to the traditional carburizing heat treatment method, a new workpiece rotating induction heating whole quenching soft band-free induction quenching equipment is used, which is heated by multiple large inductors at the same time. The heating time is shortened by more than 70% compared with the traditional scanning heating time, and the layer depth uniformity and microstructure uniformity are better. When the steel is heated, the atomic thermal vibration in the steel increases, which causes the grain in the steel to expand and thermal creep to occur, resulting in a decrease in the strength of the steel. Generally, the strength of the steel remains unchanged in the temperature range of 0-250℃, and when the temperature exceeds 300℃, the strength of the steel begins to decrease significantly. Due to the structure of TRB bearing ring, the wall thickness at different positions is different, which leads to different heating rates during induction heating. The temperature rises faster in the thin-walled part, and the temperature of the non-heating surface of the workpiece continues to rise due to heat conduction. When the temperature of the non-heating surface of the thin-walled part exceeds 300℃, the strength of this part decreases significantly, which will cause the workpiece to deform. Once the workpiece deforms during heating, it will cause the workpiece to swing during rotation, causing the workpiece to touch the inductor, resulting in shutdown or workpiece scrap due to fire. SUMMARY
[0004] The utility model discloses in order to solve above-mentioned technical problem, provide a kind of extra-large taper roller bearing ring thickening structure for reducing heat treatment deformation, the minimum wall thickness of workpiece is calculated when different quenching layer depth, the thickening structure of ring before improvement induction heat treatment is locally increased the wall thickness of bearing inner ring, bearing outer ring thin-walled part, realize the uniform heating temperature of ring workpiece induction heating, avoid the thermal stress difference caused by wall thickness difference during induction heating, reduce workpiece heat treatment deformation, ensure the stability of workpiece rotation during heating.
[0005] The utility model discloses a technical scheme adopted is: a kind of extra-large taper roller bearing ring reduces the thickening structure of heat treatment deformation, including annular bearing inner race and bearing outer ring, the outer circumferential surface of bearing inner race is equipped with inner ring conical raceway, the big end of inner ring conical raceway is equipped with the big baffle of cooperation with the big end surface of taper roller, the small end of inner ring conical raceway is equipped with the small baffle of cooperation with the small end surface of taper roller, inner ring conical raceway is inclined from top to bottom to inner circumferential direction;The inner circumferential surface upper end of bearing outer ring is equipped with toric surface, and the inner circumferential surface of bearing outer ring is also equipped with outer ring conical raceway in connection toric surface;Bearing inner race and bearing outer ring are matched and assembled, and taper roller is equipped between inner ring conical raceway and outer ring conical raceway, and outer ring conical raceway is inclined from top to bottom to outer circumferential direction;From the center height position of bearing inner race, the same taper of bearing inner race conical raceway is equipped with inner ring thickening portion, and from the center height position of bearing outer ring, the same taper of bearing outer ring conical raceway is equipped with outer ring thickening portion.
[0006] The inner ring thickening portion is arranged on the inner circumferential surface of the bearing inner race, and the inner ring thickening portion comprises an inner circular taper surface and an inner circular ring surface. The starting point of the inner circular taper surface is the center height position of the inner circumferential surface of the bearing inner race. The connecting line between the ending point of the inner circular taper surface and the bottom end point of the outer circumferential surface of the bearing inner race is perpendicular to the taper line of the inner ring conical raceway. The taper between the starting point and the ending point of the inner circular taper surface is inclined inward.
[0007] The ending point of the inner circular taper surface is connected to the inner circular ring surface. The starting point of the inner circular taper surface and the connecting point between the ending point of the inner circular taper surface and the inner circular ring surface are smoothly connected. The bottom end surface of the inner circular ring surface is flush with the bottom end surface of the bearing inner race.
[0008] The outer ring thickening portion is arranged on the outer circumferential surface of the bearing outer race. The outer ring thickening portion comprises an outer circular taper surface and an outer circular ring surface. The starting point of the outer circular taper surface is the center height position of the outer circumferential surface of the bearing outer race. The connecting line between the ending point of the outer circular taper surface and the bottom end point of the inner circumferential surface of the bearing outer race is perpendicular to the taper line of the outer ring conical raceway. The taper between the starting point and the ending point of the outer circular taper surface is inclined outward.
[0009] The ending point of the outer circular taper surface is connected to the outer circular ring surface. The starting point of the outer circular taper surface and the connecting point between the ending point of the outer circular taper surface and the outer circular ring surface are smoothly connected. The bottom end surface of the outer circular ring surface is flush with the bottom end surface of the bearing outer race.
[0010] The minimum wall thickness of the bearing inner race after the inner ring thickening portion is added is twice the sum of the quenching layer depth and 30 mm.
[0011] The minimum wall thickness of the bearing outer race after the outer ring thickening portion is added is twice the sum of the quenching layer depth and 30 mm.
[0012] The inner ring thickening part is arranged at the same taper as the tapered raceway of the bearing inner ring from the central height position of the bearing inner ring, and the outer ring thickening part is arranged at the same taper as the tapered raceway of the bearing outer ring from the central height position of the bearing outer ring.
[0013] The beneficial effects of the present application are as follows: the suitable wall thickness of workpieces with different hardened layer depths is calculated, then the weak parts of the inner circumferential surface of the bearing inner ring and the outer circumferential surface of the bearing outer ring are locally thickened in combination with the taper of the raceway of the sleeve ring, the thickening structure of the sleeve ring before induction heat treatment is improved, the wall thickness of the thin-walled part of the bearing inner ring and the bearing outer ring is increased, uniform heating and temperature rising of the sleeve ring workpiece during induction heating are realized, the different thermal stresses caused by the wall thickness difference during induction heating are avoided, the workpiece heat treatment deformation is reduced, the stability of the workpiece rotation during heating is ensured, the deformation of the workpiece during quenching and cooling is reduced, and the hardened layer depth of the finished part raceway is more uniform. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 Fig. 1 is a structure schematic view of a finished bearing inner ring of the present application;
[0015] Figure 2 Fig. 2 is a thickening structure schematic view of the bearing inner ring before heat treatment of the present application;
[0016] Figure 3 Fig. 3 is a structure schematic view of a finished bearing outer ring of the present application;
[0017] Figure 4 Fig. 4 is a thickening structure schematic view of the bearing outer ring before heat treatment of the present application.
[0018] Markings in the figure: 1, bearing inner ring; 2, bearing outer ring; 3, inner tapered raceway; 4, large flange; 5, small flange; 6, outer tapered raceway; 7, inner ring thickening part; 8, outer ring thickening part; 9, annular surface; 10, inner conical surface; 11, inner annular surface; 12, outer conical surface; 13, outer annular surface. DETAILED DESCRIPTION
[0019] The utility model discloses further make detailed description of the specific implementation of the utility model below in combination with the drawings.
[0020] As Figures 1-4 As shown in a kind of thickening structure for reducing heat treatment deformation of extra-large tapered roller bearing ring, including annular bearing inner ring 1 and bearing outer ring 2, the outer circumferential surface of bearing inner ring 1 is equipped with inner ring conical raceway 3, the big end of inner ring conical raceway 3 is equipped with the big baffle 4 being cooperated with the big end surface of tapered roller, the small end of inner ring conical raceway 3 is equipped with the small baffle 5 being cooperated with the small end surface of tapered roller, and inner ring conical raceway 3 is inclined to inner circumferential direction from top to bottom;The inner circumferential surface of bearing outer ring 2 upper end is equipped with circular surface 9, and the inner circumferential surface of bearing outer ring 2 is also equipped with outer ring conical raceway 6 in addition to connecting circular surface 9;Bearing inner ring 1 and bearing outer ring 2 are matched and assembled, and tapered roller is arranged between inner ring conical raceway 3 and outer ring conical raceway 6, and outer ring conical raceway 6 is inclined to outer circumferential direction from top to bottom;From the central height position of bearing inner ring 1, inner ring thickening portion 7 with the same taper of inner ring conical raceway 3 is equipped, and from the central height position of bearing outer ring 2, outer ring thickening portion 8 with the same taper of outer ring conical raceway 6 is equipped.
[0021] The inner ring thickening portion 7 is arranged on the inner circumferential surface of bearing inner ring 1, and the inner ring thickening portion 7 includes inner circular conical surface 10 and inner circular ring surface 11, the starting point of the inner circular conical surface 10 is the central height position of the inner circumferential surface of the bearing inner ring 1, the connecting line between the ending point of the inner circular conical surface 10 and the bottom end point of the outer circumferential surface of the bearing inner ring 1 is perpendicular to the conical line of the inner ring conical raceway 3, and the starting point to the ending point of the inner circular conical surface 10 forms a taper that is inclined inward.
[0022] The ending point of the inner circular conical surface 10 is connected with the inner circular ring surface 11, and the starting point of the inner circular conical surface 10 and the ending point of the inner circular conical surface 10 are both smoothly connected with the bearing inner ring 1 and the inner circular ring surface 11, and the bottom end surface of the inner circular ring surface 11 is flush with the bottom end surface of the bearing inner ring 1.
[0023] The outer ring thickening portion 8 is arranged on the outer circumferential surface of bearing outer ring 2, and the outer ring thickening portion 8 includes outer circular conical surface 12 and outer circular ring surface 13, the starting point of the outer circular conical surface 12 is the central height position of the outer circumferential surface of the bearing outer ring 2, the connecting line between the ending point of the outer circular conical surface 12 and the bottom end point of the inner circumferential surface of the bearing outer ring 2 is perpendicular to the conical line of the outer ring conical raceway 6, and the starting point to the ending point of the outer circular conical surface 12 forms a taper that is inclined outward.
[0024] The ending point of the outer circular conical surface 12 is connected with the outer circular ring surface 13, and the starting point of the outer circular conical surface 12 and the ending point of the outer circular conical surface 12 are both smoothly connected with the bearing outer ring 2 and the outer circular ring surface 13, and the bottom end surface of the outer circular ring surface 13 is flush with the bottom end surface of the bearing outer ring 2.
[0025] The minimum wall thickness of the bearing inner ring 1 after the inner ring thickened portion 7 is added is twice the sum of the hardened layer depth + 30 mm.
[0026] The minimum wall thickness of the bearing outer ring 2 after the outer ring thickening portion 8 is added is twice the sum of the hardened layer depth + 30 mm.
[0027] The bearing ring is made of 42CrMo steel with a density of ρ = 7850 kg / m³, a specific heat capacity of c = 466 J / (kg·K), and a thermal conductivity of λ = 42.7 W / (m·K). During induction heating, the temperature of a 1mm thick mass m at a certain cross-sectional area A on the ring is raised from room temperature of 20°C to 300°C. The required heat is:
[0028] Q=cmΔt=466×A×(1 / 1000) ×7850×(300-20)=1024268A J·m 2 .
[0029] According to the heat conduction formula: Q = λAΔT / ι, ι is the heat conduction distance, and ΔT = 680°C is the temperature difference between the induction heating surface and the non-heating surface. Combining these two formulas, we can calculate that the heat conduction distance ι ≈ 30mm, which means that the ferrule temperature at a depth of about 30mm from the induction heating surface can reach 300°C.
[0030] Assuming that the induction hardening workpiece requires a hardened layer depth of X, we can roughly assume that the distance from induction heating
[0031] If the temperature at depth X from the surface is the same as the surface temperature, then the depth exceeding 300°C is 30 + X. At this depth, the temperature is high and the workpiece strength is extremely low. To ensure overall strength during rotational heating, a thickness twice as great is required: 2 × (30 + X). This allows us to calculate the thickness of the workpiece that needs to be thickened. For example, if the hardened layer depth is 10mm, the minimum wall thickness should be no less than 80mm.
[0032] By measuring the minimum wall thickness of the workpiece with different hardened layer depths, and then combining the taper of the ring raceway, the inner circumference of the bearing inner ring 1 and the outer circumference of the bearing outer ring 2 are locally thickened, and then the raceway surface of the ring is induction heated and overall quenched to ensure the strength of the workpiece during the rotation heating process. At the same time, after the workpiece is locally thickened, the wall thickness difference of each part is reduced, which is conducive to uniform heating and temperature rise of the workpiece during induction heating, reduces the deformation of the workpiece during the heating process, and ensures the stability of the workpiece rotation during the heating process. After the raceway induction heat treatment is completed, the inner ring thickening part 7 and the outer ring thickening part 8 are machined and removed. The position of the thickened part is also convenient for machining and removal, and does not affect the machining accuracy of the finished ring workpiece.
[0033] In addition to the above embodiments, the utility model can have other implementation manners, and any technical scheme formed by equivalent replacement or equivalent transformation falls within the protection scope required by the utility model.
Claims
1. A heavy-duty tapered roller bearing cup with a thickened structure to reduce heat treatment distortion, characterized by: The bearing comprises an annular inner ring and an annular outer ring, an inner ring tapered raceway is arranged on an outer circumferential surface of the inner ring, a large flange matched with a large end surface of a tapered roller is arranged at a large end of the inner ring tapered raceway, a small flange matched with a small end surface of the tapered roller is arranged at a small end of the inner ring tapered raceway, and the inner ring tapered raceway is inclined to the inner circumferential direction from top to bottom; a circular ring surface is arranged at an upper end of an inner circumferential surface of the outer ring, and an outer ring tapered raceway is further arranged on the inner circumferential surface of the outer ring and connected with the circular ring surface; the inner ring and the outer ring are assembled in a matched mode, the tapered roller is arranged between the inner ring tapered raceway and the outer ring tapered raceway, and the outer ring tapered raceway is inclined to the outer circumferential direction from top to bottom; an inner ring thickened portion is arranged at the same taper as the inner ring tapered raceway from a central height position of the inner ring, and an outer ring thickened portion is arranged at the same taper as the outer ring tapered raceway from a central height position of the outer ring.
2. A heavy duty tapered roller bearing ring deformation reducing thickening structure of heat treatment according to claim 1, characterized in that: The inner ring thickened portion is arranged on the inner circumferential surface of the inner ring, the inner ring thickened portion comprises an inner circular tapered surface and an inner circular ring surface, the starting point of the inner circular tapered surface is the central height position of the inner circumferential surface of the inner ring, the connecting line between the ending point of the inner circular tapered surface and the bottom end point of the outer circumferential surface of the inner ring is perpendicular to the tapered line of the inner ring tapered raceway, and the taper between the starting point and the ending point of the inner circular tapered surface is inclined to the inside.
3. A heavy duty tapered roller bearing ring deformation reducing thickening structure of heat treatment according to claim 2, characterized in that: The ending point of the inner circular tapered surface is connected with the inner circular ring surface, the starting point of the inner circular tapered surface and the ending point of the inner circular tapered surface are smoothly connected with the inner ring and the inner circular ring surface, and the bottom end surface of the inner circular ring surface is flush with the bottom end surface of the inner ring.
4. A heavy duty tapered roller bearing ring deformation reducing thickening structure of heat treatment according to claim 1, characterized in that: The outer ring thickened portion is arranged on the outer circumferential surface of the outer ring, the outer ring thickened portion comprises an outer circular tapered surface and an outer circular ring surface, the starting point of the outer circular tapered surface is the central height position of the outer circumferential surface of the outer ring, the connecting line between the ending point of the outer circular tapered surface and the bottom end point of the inner circumferential surface of the outer ring is perpendicular to the tapered line of the outer ring tapered raceway, and the taper between the starting point and the ending point of the outer circular tapered surface is inclined to the outside.
5. A heavy duty tapered roller bearing ring deformation reducing thickening structure of a heat treatment according to claim 4, characterized in that: The ending point of the outer circular tapered surface is connected with the outer circular ring surface, the starting point of the outer circular tapered surface and the ending point of the outer circular tapered surface are smoothly connected with the outer ring and the outer circular ring surface, and the bottom end surface of the outer circular ring surface is flush with the bottom end surface of the outer ring.
6. A heavy-duty taper roller bearing ring deformation reducing thickening structure of heat treatment according to claim 1, characterized in that: The minimum wall thickness of the inner ring after the inner ring thickened portion is added is twice the sum of the hardening layer depth and 30 mm.
7. A heavy duty tapered roller bearing ring deformation reducing thickening structure of heat treatment according to claim 1, characterized in that: The minimum wall thickness of the outer ring after the outer ring thickened portion is added is twice the sum of the hardening layer depth and 30 mm.