Bearing seat for new energy automobile and machining method of bearing seat

Abstract

The invention discloses a bearing seat for a new energy automobile and a machining method of the bearing seat, and belongs to the technical field of bearing seat machining, the bearing seat comprises a shaft core seat, extension seats are arranged on the two sides of the shaft core seat, the surfaces of the extension seats are in an arc shape, the shaft core seat and the extension seats are integrally cast, a bearing mounting groove is formed in the inner side of the shaft core seat, and a bearing is arranged in the bearing mounting groove. The bearing mounting groove is used for fixing a bearing outer ring, a leather collar clamping groove is formed in the inner side of the shaft core seat, surrounds the outer side of the bearing mounting groove and extends to the extension seat, the depth of the leather collar clamping groove is higher than that of the bearing mounting groove, and the shaft core seat is used for directly fixing a bearing inner ring and transmitting motor torque. On the basis of machining the bearing seat, the structural mechanical property, material selection and heat treatment process of the bearing seat can be optimized, and precision machining and online compensation can be carried out.

Description

Technical Field

[0001] This invention relates to the field of bearing housing processing technology, and more specifically, to a bearing housing for new energy vehicles and its processing method. Background Technology

[0002] Bearing housings, also called bearing boxes, are the outer support for shafts and bearings. They are widely used in machinery and equipment as important transmission components. Bearings also need support when rotating, and the support components required for bearing transmission are what we commonly call bearing housings. With the development of new energy vehicles, electric motor-driven new energy vehicles also require specially designed bearing housings to ensure the stable operation of the motor shaft. The bearing housings for electric vehicles need to take into account the high-speed operation and lightweight design of the motor, and consider using one-piece aluminum castings as bearing housings. The aluminum castings need to consider strength, toughness, and stability.

[0003] Traditional split bearing housings are prone to stress concentration at welded or riveted joints, leading to a high rate of cracking under long-term vibration, which can cause the bearing to loosen or even fall off. Ordinary machining processes typically have a bore diameter tolerance of ±0.03mm and a roundness error of >0.05mm, resulting in a radial runout of >0.02mm after bearing assembly. This causes excessive noise and accelerated wear during high-speed operation. In addition, insufficient groove depth of the rubber ring results in a seal compression of <15%, increasing the grease leakage rate. Traditional quenching processes are prone to producing network carbides, resulting in an impact toughness of <5J / cm², making the bearing susceptible to fracture under impact loads. Summary of the Invention

[0004] 1. Technical problems to be solved To address the problems existing in the prior art, the present invention aims to provide a bearing housing for new energy vehicles and its processing method. In addition to realizing the processing of the bearing housing, the present invention can also optimize the structural mechanical properties, material selection and heat treatment process of the bearing housing, and can perform precision machining and online compensation.

[0005] 2. Technical Solution

[0006] To solve the above problems, the present invention adopts the following technical solution: A bearing housing for new energy vehicles includes: a shaft core housing, with an extension seat on both sides of the shaft core housing. The surface of the extension seat is arc-shaped, and the shaft core housing and the extension seat are integrally cast. A bearing mounting groove is formed on the inner side of the shaft core housing for fixing the outer ring of the bearing. A leather ring retaining groove is formed on the inner side of the shaft core housing, surrounding the outer side of the bearing mounting groove and extending to the extension seat. The shaft core seat is used to directly fix the inner ring of the bearing and transmit the motor torque. The wall thickness of the shaft core seat is ≤12mm, the outer diameter is ≤250mm, and the surface hardness is 58–65HRC. The outer seat is used to distribute the bearing load. The bearing mounting groove has a hole diameter tolerance of ±0.019mm, a surface roughness of ≤Ra1.6μm, and a roundness error of ≤0.02mm. The rubber ring groove is used to install the NBR rubber ring, and the groove depth of the rubber ring groove is greater than the wall height of the bearing mounting groove to ensure that the sealing ring is pressed tightly.

[0007] A method for machining bearing housings for new energy vehicles includes the following steps: S1, Cast blank; S2, Rough machining and datum surface forming; S3, Semi-finishing and hole preforming; S4, Heat Treatment Strengthening: S5. Finishing and precision control; S6. Surface treatment and inspection.

[0008] As a preferred embodiment of the present invention, step S1 includes: Material smelting: GCr15 high carbon chromium bearing steel molten material was smelted with a C content of 0.95–1.05% and a Cr content of 1.40–1.65%; Continuous casting: Electromagnetic stirring with a frequency of 7–8 Hz and a current of 350–380 A is used to control the superheat of the molten steel to ≤25℃, forming a steel billet and reducing the formation of banded carbides; Cooling: The steel billet is further cooled by crystallizer cooling water with parameters of 2400–2440 L / min for the wide face and 400–410 L / min for the narrow face. Drawing: The billet is drawn at a drawing speed of 0.9–1.1 m / min and a secondary cooling water volume of 0.6–0.8 L / kg, while avoiding cracking at the edges and corners, so that the billet diameter is ≤250 mm and the wall thickness is ≤12 mm, and a machining allowance of 2–3 mm is reserved on each side.

[0009] As a preferred embodiment of the present invention, step S2 includes: Aging treatment: Use an aging furnace and set the parameters to maintain the temperature at 550±10℃ for 4–6 hours to treat the blank, eliminate casting stress, and stabilize the hardness of the blank to 179–207HBW. Reference surface machining: Position the blank bearing hole on both sides, mill the bottom surface to a thickness of 30±0.1mm, position the bottom surface, mill the top surface and the left and right sides of the bearing hole to 42±0.1mm, simultaneously machine a 2mm×1mm stress relief groove, clamp the 42mm side, and mill the four sides to dimensions of 38±0.05mm and 82±0.05mm.

[0010] As a preferred embodiment of the present invention, step S3 includes: Rough turning of bearing mounting slot: The bearing mounting slot is machined using a horizontal lathe with a bending plate type special fixture, and the hole diameter is machined to Φ29.5±0.1mm, surface roughness ≤Ra6.3μm and roundness error ≤0.05mm, while reserving a finishing allowance of 0.5mm; Rough milling of bearing ring grooves: Use a CNC milling machine and a special groove milling cutter to mill the bearing ring grooves. Leave a 0.2mm finishing allowance for the groove depth and a 0.1mm allowance for the groove width. The groove depth is greater than the height of the bearing mounting groove wall.

[0011] As a preferred embodiment of the present invention, step S4 includes: Quenching: The semi-finished product is quenched at a temperature of 840±10℃, and the holding time is the wall thickness of the semi-finished product x 2.5min / mm, and the holding time is greater than or equal to 30 minutes, followed by oil cooling; Low-temperature tempering: Temper the semi-finished product at a temperature of 160±10℃ and hold for 2 hours, then air cool it to make the hardness of the semi-finished product 58–65HRC and free of network carbides.

[0012] As a preferred embodiment of the present invention, step S5 includes: Precision machining of bearing mounting slots: The bearing mounting slots are machined a second time using a PCD guide bar reamer. After machining, the mounting slot diameter is Φ30±0.019mm, the surface roughness is ≤Ra1.6μm, the roundness error is ≤0.02mm, and the coaxiality is ≤0.02mm. The cutting parameters of the PCD guide bar reamer are a speed of 2000rpm and a feed rate of 0.05mm / r. The reamer is cooled by emulsion and online detection and compensation are performed. Finish milling of the rubber ring groove; use a PCD slot milling cutter to mill the rubber ring groove, with a groove width tolerance of ±0.05mm, a groove depth tolerance of ±0.03mm, and a surface roughness of ≤Ra3.2μm; Auxiliary hole machining: The positioning pin hole is made by drilling first and then reaming. The diameter of the pin hole is Φ8H8 and the perpendicularity is ≤0.03mm.

[0013] As a preferred embodiment of the present invention, step S6 includes: Insulation protection: A 5–8 μm thick nickel plating is applied to the surface of the machined bearing housing to prevent electrical corrosion on the 800V platform.

[0014] Aperture accuracy: The aperture accuracy is tested using a pneumatic gauge, and an aperture tolerance of ±0.019mm is considered acceptable. Geometric tolerances: Use a mandrel and dial indicator to check the parallelism and perpendicularity of the bearing housing. Parallelism / perpendicularity ≤ 0.03mm is acceptable.

[0015] Roundness inspection; The bearing housing is inspected using a roundness tester, and a roundness of ≤0.02mm is considered acceptable; Hardness testing: The bearing housings were randomly inspected using a Rockwell hardness tester.

[0016] As a preferred embodiment of the present invention, the online detection compensation method in step S5 includes: Detection element creation: Define detection elements in CAD software, including points, lines, circles, planes and curved surfaces, and plan the probe movement path; Coordinate system calibration: The workpiece reference features are collected by the probe to establish a machining coordinate system, compensate for clamping deviations, and set the detection threshold to a tolerance of ±0.02mm; Real-time data acquisition: The diameter, roundness, and coaxiality dimensions of the bearing mounting groove are collected using a ruby ​​probe, and the contour image is obtained by laser scanning. The dimensions are extracted through image processing. Multi-location measurement: Multiple sampling points are performed on the bearing mounting groove and the ring retainer groove; Temperature monitoring: Integrated thermocouples monitor the thermal deformation of the machine tool in real time, providing data for thermal error compensation; Data processing and deviation calculation: Compare the measured data d1 with the theoretical value d, and calculate the deviation Δd = d1 - d; Thermal deformation compensation: Based on the temperature field model, predict the amount of thermal expansion and generate compensation values; Tiered compensation strategy: dynamically adjust the compensation amount according to the tolerance; Compensation decision: Based on a preset threshold, compensation is triggered. A neural network is used to learn historical data, predict tool wear trends, and adjust the compensation amount in advance. Compensation command generation: Corrects tool radius / length compensation values ​​and dynamically adjusts the workpiece coordinate system or path trajectory; Compensation execution: The CNC system receives compensation instructions, updates the machining program in real time, and performs remapping; Effect verification: After repair, remeasure to confirm whether the deviation is ≤ ±0.01mm; Process monitoring: Statistical process capability index (CPK) ≥ 1.33 to ensure batch consistency.

[0017] As a preferred embodiment of the present invention, the tolerance zone dynamic adjustment compensation amount and the deviation range compensation decision compensation amount are as follows: If d≤d1<d+δ, the size is too small and needs to be compensated by +2δ; If d+δ≤d1<d+2δ, the size is too small and needs to be compensated by +δ. If d+2δ≤d1≤d+5δ, then it is qualified and no compensation is needed; If d+5δ<d1≤d+6δ, the size is too large and needs to be compensated by -δ. If d+6δ<d1≤d+7δ, the size is too large and needs to be compensated by -2δ. Where δ = tolerance Δ / 7, δ is the standard deviation of the error distribution, and Δ is the tolerance.

[0018] 3. Beneficial effects

[0019] Compared with the prior art, the advantages of this invention are: (1) The present invention forms a closed frame structure by integrally casting the shaft core seat and the outer extension seat. The arc-shaped surface of the outer extension seat disperses the radial load transmitted by the bearing and avoids local stress concentration. The high-precision machining of the bearing mounting groove ensures that the bearing outer ring fits tightly with the groove wall. Combined with the design that the depth of the rubber ring groove is greater than the height of the bearing mounting groove wall, the NBR rubber ring forms an effective sealing barrier to prevent grease leakage and dust intrusion. The lightweight design reduces weight while ensuring strength, reduces motor load energy consumption, and increases range. The high-precision bearing seat, motor shaft, and sealing ring form a collaborative system, with low vibration reducing motor energy consumption and long service life reducing maintenance costs.

[0020] (2) This invention reduces banded carbides through electromagnetic stirring continuous casting, followed by quenching at 840±10℃ and tempering at 160±10℃ to obtain a uniform and refined martensitic structure, which improves wear resistance. The absence of network carbides improves impact toughness, enabling it to withstand the instantaneous impact load during motor startup. A 0.5mm allowance is reserved during the roughing stage. After semi-finishing, the bearing mounting groove is finished by PCD guide bar reamer. Combined with laser scanning to collect diameter and roundness data in real time, the neural network is used to predict the tool wear trend and dynamically adjust the compensation amount. Thermal deformation compensation is based on the temperature field model to predict the machine tool expansion amount, correct the coordinate system offset, and ensure coaxiality ≤0.02mm. The nickel plating layer blocks the electro-corrosion of the 800V high-voltage platform and reduces the risk of insulation failure by 90%. Multiple methods such as pneumatic gauges and roundness testers are used to ensure that the hole diameter tolerance and geometric tolerance are 100% qualified. The process capability of CPK≥1.33 ensures batch consistency. Attached Figure Description

[0021] Figure 1 This is an exploded view of a bearing housing for new energy vehicles according to the present invention; Figure 2 This is a flowchart illustrating the steps of a method for processing a bearing housing for new energy vehicles according to the present invention.

[0022] Explanation of the labels in the diagram: 1. Shaft core seat; 2. Outer seat; 3. Bearing mounting groove; 4. Leather ring groove. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0024] Please see Figure 1 A bearing housing for new energy vehicles includes: a shaft core seat (1), with an extension seat (2) on both sides of the shaft core seat (1). The surface of the extension seat (2) is arc-shaped, and the shaft core seat (1) and the extension seat (2) are integrally cast. A bearing mounting groove (3) is provided on the inner side of the shaft core seat (1), which is used to fix the outer ring of the bearing. A leather ring retaining groove (4) is provided on the inner side of the shaft core seat (1), surrounding the outer side of the bearing mounting groove (3) and extending to the extension seat (2). The groove depth of the leather ring retaining groove (4) is higher than that of the bearing mounting groove (2). 3) The shaft core seat (1) is used to directly fix the inner ring of the bearing and transmit the motor torque. The wall thickness of the shaft core seat (1) is ≤12mm, the outer diameter is ≤250mm, and the surface hardness is 58–65HRC. The outer extension seat (2) is used to distribute the bearing load. The hole diameter tolerance of the bearing mounting groove (3) is ±0.019mm, the surface roughness is ≤Ra1.6μm, and the roundness error is ≤0.02mm. The rubber ring groove (4) is used to install the NBR rubber ring, and the groove depth of the rubber ring groove (4) is > the wall height of the bearing mounting groove (3) to ensure that the sealing ring is pressed tightly.

[0025] In a specific embodiment of the present invention, a closed frame structure is formed by integrally casting the shaft core seat (1) and the extension seat (2). The arc-shaped surface of the extension seat (2) disperses the radial load transmitted by the bearing and avoids local stress concentration. The high-precision machining of the bearing mounting groove (3) ensures that the bearing outer ring fits tightly with the groove wall. With the design that the depth of the rubber ring groove (4) is greater than the height of the bearing mounting groove (3), the NBR rubber ring forms an effective sealing barrier to prevent grease leakage and dust intrusion. The lightweight design reduces weight while ensuring strength, reduces motor load energy consumption, and increases driving range. The high-precision bearing seat, motor shaft, and sealing ring form a collaborative system. Low vibration reduces motor energy consumption, and long life reduces maintenance costs. Example 1:

[0026] A method for processing bearing housings for new energy vehicles, comprising: S1, Cast blank; S2, Rough machining and datum surface forming; S3, Semi-finishing and hole preforming; S4, Heat Treatment Strengthening: S5. Finishing and precision control; S6. Surface treatment and inspection.

[0027] Specifically, step S1 includes: Material smelting: GCr15 high carbon chromium bearing steel molten liquid was smelted with a C content of 0.95% and a Cr content of 1.40%; Continuous casting: Electromagnetic stirring with a frequency of 7Hz and a current of 350A is used to control the superheat of the molten steel to ≤25℃, forming a steel billet and reducing the formation of banded carbides; Cooling: The steel billet was further cooled using crystallizer cooling water with parameters of 2400 L / min for the wide face and 400 L / min for the narrow face. Laboratory tests showed that the insulation failure rate after nickel plating decreased from 10% to 1%, reducing the risk by 90%. Drawing: The steel billet is drawn at a drawing speed of 0.9 m / min and a secondary cooling water volume of 0.6 L / kg, and cracking at the edges and corners is avoided. The billet diameter is ≤250 mm and the wall thickness is ≤12 mm, with a machining allowance of 2–3 mm on each side reserved. Step S2 includes: Aging treatment: The blank is treated by using an aging furnace with the parameters set to a holding temperature of 540℃ and a holding time of 4 hours to eliminate casting stress and stabilize the hardness of the blank to 179HBW. Machining of the reference surface: Position the blank bearing hole on both sides, mill the bottom surface to a thickness of 30±0.1mm, position the bottom surface, mill the top surface and the left and right sides of the bearing hole to 42±0.1mm, simultaneously machine a 2mm×1mm stress relief groove, clamp the 42mm side, and with the bottom surface as the reference, mill the four sides to a size of 38±0.05mm×82±0.05mm, which is its length×width dimension; Step S3 includes: Rough turning of bearing mounting slot: The bearing mounting slot is machined using a horizontal lathe with a bending plate type special fixture, and the hole diameter is machined to Φ29.5±0.1mm, surface roughness ≤Ra6.3μm and roundness error ≤0.05mm, while reserving a finishing allowance of 0.5mm; Rough milling of bearing ring grooves: Use a CNC milling machine and a special groove milling cutter to mill the bearing ring grooves. Leave a 0.2mm finishing allowance for the groove depth and a 0.1mm allowance for the groove width. The groove depth is greater than the height of the bearing mounting groove wall. Step S4 includes: Quenching: The semi-finished product is quenched at 830℃ for 30 minutes, with a holding time of 2.5 min / mm (semi-finished product wall thickness). It is then oil-cooled. Low-temperature tempering: Temper the semi-finished product at 150℃ for 2 hours, then air cool it to make the hardness of the semi-finished product 58HRC and free of network carbides. Step S5 includes: Precision machining of bearing mounting slots: The bearing mounting slots are machined a second time using a PCD guide bar reamer. After machining, the mounting slot diameter is Φ30±0.019mm, the surface roughness is ≤Ra1.6μm, the roundness error is ≤0.02mm, and the coaxiality is ≤0.02mm. The cutting parameters of the PCD guide bar reamer are a speed of 2000rpm and a feed rate of 0.05mm / r. The reamer is cooled by emulsion and online detection and compensation are performed. Finish milling of the rubber ring groove; use a PCD slot milling cutter to mill the rubber ring groove, with a groove width tolerance of ±0.05mm, a groove depth tolerance of ±0.03mm, and a surface roughness of ≤Ra3.2μm; Auxiliary hole machining: The positioning pin hole is made by drilling first and then reaming. The diameter of the pin hole is Φ8H8 and the perpendicularity is ≤0.03mm. Step S6 includes: Insulation protection: A 5μm thick nickel plating is applied to the surface of the machined bearing housing to prevent electrical corrosion from the 800V platform.

[0028] Aperture accuracy: The aperture accuracy is tested using a pneumatic gauge, and an aperture tolerance of ±0.019mm is considered acceptable. Geometric tolerances: Use a mandrel and dial indicator to check the parallelism and perpendicularity of the bearing housing. Parallelism / perpendicularity ≤ 0.03mm is acceptable.

[0029] Roundness inspection; The bearing housing is inspected using a roundness tester, and a roundness of ≤0.02mm is considered acceptable; Hardness testing: The bearing housings were randomly inspected using a Rockwell hardness tester. Implementation: 2:

[0030] A method for processing bearing housings for new energy vehicles, comprising: S1, Cast blank; S2, Rough machining and datum surface forming; S3, Semi-finishing and hole preforming; S4, Heat Treatment Strengthening: S5. Finishing and precision control; S6. Surface treatment and inspection.

[0031] Specifically, step S1 includes: Material smelting: GCr15 high carbon chromium bearing steel molten material was smelted with a C content of 1.00% and a Cr content of 1.52%; Continuous casting: Electromagnetic stirring with a frequency of 7.5Hz and a current of 365A is used to control the superheat of the molten steel to ≤25℃, forming steel billets and reducing the formation of banded carbides; Cooling: The steel billet was further cooled with crystallizer cooling water with parameters of 2420 L / min for the wide face and 405 L / min for the narrow face. Laboratory tests showed that the insulation failure rate after nickel plating decreased from 10% to 1%, and the risk of electro-corrosion decreased by 90%. Drawing: The steel billet is drawn at a drawing speed of 1.0 m / min and a secondary cooling water volume of 0.7 L / kg, and cracking at the edges and corners is avoided. The billet diameter is ≤250 mm and the wall thickness is ≤12 mm, with a machining allowance of 2–3 mm on each side reserved. Step S2 includes: Aging treatment: Use an aging furnace and set the parameters to a holding temperature of 550℃ and a holding time of 5 hours to treat the blank, eliminate the casting stress of the blank, and stabilize the hardness of the blank to 193HBW. Machining of the reference surface: Position the blank bearing hole on both sides, mill the bottom surface to a thickness of 30±0.1mm, position the bottom surface, mill the top surface and the left and right sides of the bearing hole to 42±0.1mm, simultaneously machine a 2mm×1mm stress relief groove, clamp the 42mm side, and with the bottom surface as the reference, mill the four sides to a size of 38±0.05mm×82±0.05mm, which is its length×width dimension; Step S3 includes: Rough turning of bearing mounting slot: The bearing mounting slot is machined using a horizontal lathe with a bending plate type special fixture, and the hole diameter is machined to Φ29.5±0.1mm, surface roughness ≤Ra6.3μm and roundness error ≤0.05mm, while reserving a finishing allowance of 0.5mm; Rough milling of bearing ring grooves: Use a CNC milling machine and a special groove milling cutter to mill the bearing ring grooves. Leave a 0.2mm finishing allowance for the groove depth and a 0.1mm allowance for the groove width. The groove depth is greater than the height of the bearing mounting groove wall. Step S4 includes: Quenching: The semi-finished product is quenched at 840℃ for a holding time of 2.5 min / mm (semi-finished product wall thickness) and the holding time is greater than or equal to 35 minutes, followed by oil cooling. Low-temperature tempering: Temper the semi-finished product at 160℃ for 2 hours, then air cool it to make the hardness of the semi-finished product 61HRC and free of network carbides. Step S5 includes: Precision machining of bearing mounting slots: The bearing mounting slots are machined a second time using a PCD guide bar reamer. After machining, the mounting slot diameter is Φ30±0.019mm, the surface roughness is ≤Ra1.6μm, the roundness error is ≤0.02mm, and the coaxiality is ≤0.02mm. The cutting parameters of the PCD guide bar reamer are a speed of 2000rpm and a feed rate of 0.05mm / r. The reamer is cooled by emulsion and online detection and compensation are performed. Finish milling of the rubber ring groove; use a PCD slot milling cutter to mill the rubber ring groove, with a groove width tolerance of ±0.05mm, a groove depth tolerance of ±0.03mm, and a surface roughness of ≤Ra3.2μm; Auxiliary hole machining: The positioning pin hole is made by drilling first and then reaming. The diameter of the pin hole is Φ8H8 and the perpendicularity is ≤0.03mm. Step S6 includes: Insulation protection: A 6.5μm thick nickel plating is applied to the surface of the machined bearing housing to prevent electrical corrosion from the 800V platform.

[0032] Aperture accuracy: The aperture accuracy is tested using a pneumatic gauge, and an aperture tolerance of ±0.019mm is considered acceptable. Geometric tolerances: Use a mandrel and dial indicator to check the parallelism and perpendicularity of the bearing housing. Parallelism / perpendicularity ≤ 0.03mm is acceptable.

[0033] Roundness inspection; The bearing housing is inspected using a roundness tester, and a roundness of ≤0.02mm is considered acceptable; Hardness testing: The bearing housings were randomly inspected using a Rockwell hardness tester. Implementation: 3:

[0034] A method for processing bearing housings for new energy vehicles, comprising: S1, Cast blank; S2, Rough machining and datum surface forming; S3, Semi-finishing and hole preforming; S4, Heat Treatment Strengthening: S5. Finishing and precision control; S6. Surface treatment and inspection.

[0035] Specifically, step S1 includes: Material smelting: GCr15 high carbon chromium bearing steel molten liquid was smelted with a C content of 1.05% and a Cr content of 1.65%; Continuous casting: Electromagnetic stirring with a frequency of 8Hz and a current of 380A is used to control the superheat of the molten steel to ≤25℃, forming a steel billet and reducing the formation of banded carbides; Cooling: The steel billet was further cooled using crystallizer cooling water with parameters of 2440 L / min for the wide face and 410 L / min for the narrow face. Laboratory tests showed that the insulation failure rate after nickel plating decreased from 10% to 1%, reducing the risk by 90%. Drawing: The steel billet is drawn at a drawing speed of 1.1m / min and a secondary cooling water volume of 0.8L / kg, and cracking at the edges and corners is avoided. The billet diameter is ≤250mm and the wall thickness is ≤12mm, with a machining allowance of 2-3mm on each side reserved. Step S2 includes: Aging treatment: The blank is treated by using an aging furnace with the parameters set to a holding temperature of 560℃ and a holding time of 6 hours to eliminate casting stress and stabilize the hardness of the blank to 207HBW. Machining of the reference surface: Position the blank bearing hole on both sides, mill the bottom surface to a thickness of 30±0.1mm, position the bottom surface, mill the top surface and the left and right sides of the bearing hole to 42±0.1mm, simultaneously machine a 2mm×1mm stress relief groove, clamp the 42mm side, and with the bottom surface as the reference, mill the four sides to a size of 38±0.05mm×82±0.05mm, which is its length×width dimension; Step S3 includes: Rough turning of bearing mounting slot: The bearing mounting slot is machined using a horizontal lathe with a bending plate type special fixture, and the hole diameter is machined to Φ29.5±0.1mm, surface roughness ≤Ra6.3μm and roundness error ≤0.05mm, while reserving a finishing allowance of 0.5mm; Rough milling of bearing ring grooves: Use a CNC milling machine and a special groove milling cutter to mill the bearing ring grooves. Leave a 0.2mm finishing allowance for the groove depth and a 0.1mm allowance for the groove width. The groove depth is greater than the height of the bearing mounting groove wall. Step S4 includes: Quenching: The semi-finished product is quenched at 850℃ for 49 minutes, with a holding time of 2.5 min / mm (semi-finished product wall thickness). It is then oil-cooled. Low-temperature tempering: Temper the semi-finished product at 170℃ for 2 hours, then air cool it to make the hardness of the semi-finished product 65HRC and free of network carbides. Step S5 includes: Precision machining of bearing mounting slots: The bearing mounting slots are machined a second time using a PCD guide bar reamer. After machining, the mounting slot diameter is Φ30±0.019mm, the surface roughness is ≤Ra1.6μm, the roundness error is ≤0.02mm, and the coaxiality is ≤0.02mm. The cutting parameters of the PCD guide bar reamer are a speed of 2000rpm and a feed rate of 0.05mm / r. The reamer is cooled by emulsion and online detection and compensation are performed. Finish milling of the rubber ring groove; use a PCD slot milling cutter to mill the rubber ring groove, with a groove width tolerance of ±0.05mm, a groove depth tolerance of ±0.03mm, and a surface roughness of ≤Ra3.2μm; Auxiliary hole machining: The positioning pin hole is made by drilling first and then reaming. The diameter of the pin hole is Φ8H8 and the perpendicularity is ≤0.03mm. Step S6 includes: Insulation protection: The surface of the machined bearing housing is plated with nickel with a thickness of 8μm to block the electrical corrosion of the 800V platform.

[0036] Aperture accuracy: The aperture accuracy is tested using a pneumatic gauge, and an aperture tolerance of ±0.019mm is considered acceptable. Geometric tolerances: Use a mandrel and dial indicator to check the parallelism and perpendicularity of the bearing housing. Parallelism / perpendicularity ≤ 0.03mm is acceptable.

[0037] Roundness inspection; The bearing housing is inspected using a roundness tester, and a roundness of ≤0.02mm is considered acceptable; Hardness testing: The bearing housings were randomly inspected using a Rockwell hardness tester.

[0038] The bearing housings prepared in Examples 1-3 above were tested and compared with industry standard requirements. The comparison results are shown in the table below.

[0039] In specific embodiments of the present invention, the embodiments adopt a stepped composition design with C: 0.95%~1.05% and Cr: 1.40%~1.65%, both conforming to the GCr15 standard range. The high Cr content of the embodiments improves hardenability and is suitable for high-torque electric drive scenarios. During the continuous casting stage, electromagnetic stirring and low-temperature superheating reduce banded carbides, resulting in material uniformity superior to traditional casting. The hole diameter tolerance of all three embodiments reaches IT6 level. PCD guide bar reamers are used instead of traditional boring tools, with roundness error ≤0.02mm, improving accuracy by 60% compared to traditional processes. The coaxiality of the form and position tolerances is ≤0.02mm, which is superior to industry standards. Deformation is reduced through stress relief groove design and aging treatment, increasing the pass rate to 99%. Nickel plating purity: gradient plating blocks 800V electro-corrosion, reducing the failure rate to 1%, which is 90% lower than traditional plating risk. The plating adhesion is improved through crystallizer cooling water optimization. Segmented quenching and tempering avoid network carbides, and the hardness stability reaches 100%, which is superior to traditional processes.

[0040] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concept, should be covered within the scope of protection of the present invention.

Claims

1. A bearing housing for new energy vehicles, characterized in that, include: The shaft core seat has an extension seat on both sides. The surface of the extension seat is arc-shaped, and the shaft core seat and the extension seat are integrally cast. The inner side of the shaft core seat has a bearing mounting groove for fixing the outer ring of the bearing. The inner side of the shaft core seat, surrounding the outer side of the bearing mounting groove and extending to the extension seat, has a rubber ring retaining groove. The shaft core seat is used to directly fix the inner ring of the bearing and transmit the motor torque. The wall thickness of the shaft core seat is ≤12mm, the outer diameter is ≤250mm, and the surface hardness is 58–65HRC. The outer seat is used to distribute the bearing load. The bearing mounting groove has a hole diameter tolerance of ±0.019mm, a surface roughness of ≤Ra1.6μm, and a roundness error of ≤0.02mm. The rubber ring groove is used to install the NBR rubber ring, and the groove depth of the rubber ring groove is greater than the wall height of the bearing mounting groove to ensure that the sealing ring is pressed tightly.

2. A method for processing a bearing housing for new energy vehicles, applied to the bearing housing for new energy vehicles described in claim 1, characterized in that, Including the following steps: S1, Cast blank; S2, Rough machining and reference surface forming; S3, Semi-finishing and hole preforming; S4, Heat Treatment Strengthening: S5. Finishing and precision control; S6. Surface treatment and inspection.

3. The method for processing a bearing housing for new energy vehicles according to claim 2, characterized in that, Step S1 includes: Material smelting: GCr15 high carbon chromium bearing steel molten material was smelted with a C content of 0.95–1.05% and a Cr content of 1.40–1.65%; Continuous casting: Electromagnetic stirring with a frequency of 7–8 Hz and a current of 350–380 A is used to control the superheat of the molten steel to ≤25℃, forming a steel billet and reducing the formation of banded carbides; Cooling: The steel billet is further cooled by crystallizer cooling water with parameters of 2400–2440 L / min for the wide face and 400–410 L / min for the narrow face. Drawing: The billet is drawn at a drawing speed of 0.9–1.1 m / min and a secondary cooling water volume of 0.6–0.8 L / kg, while avoiding cracking at the edges and corners, so that the billet diameter is ≤250 mm and the wall thickness is ≤12 mm, and a machining allowance of 2–3 mm is reserved on each side.

4. A method for processing a bearing housing for new energy vehicles according to claim 3, characterized in that, Step S2 includes: Aging treatment: Use an aging furnace and set the parameters to maintain the temperature at 550±10℃ for 4–6 hours to treat the blank, eliminate casting stress, and stabilize the hardness of the blank to 179–207HBW. Reference surface machining: Position the blank bearing hole on both sides, mill the bottom surface to a thickness of 30±0.1mm, position the bottom surface, mill the top surface and the left and right sides of the bearing hole to 42±0.1mm, simultaneously machine a 2mm×1mm stress relief groove, clamp the 42mm side, and mill the four sides to dimensions of 38±0.05mm and 82±0.05mm.

5. A method for processing a bearing housing for new energy vehicles according to claim 4, characterized in that, Step S3 includes: Rough turning of bearing mounting slot: The bearing mounting slot is machined using a horizontal lathe with a bending plate type special fixture, and the hole diameter is machined to Φ29.5±0.1mm, surface roughness ≤Ra6.3μm and roundness error ≤0.05mm, while reserving a finishing allowance of 0.5mm; Rough milling of bearing ring grooves: Use a CNC milling machine and a special groove milling cutter to mill the bearing ring grooves. Leave a 0.2mm finishing allowance for the groove depth and a 0.1mm allowance for the groove width. The groove depth is greater than the height of the bearing mounting groove wall.

6. A method for processing a bearing housing for new energy vehicles according to claim 5, characterized in that, Step S4 includes: Quenching: The semi-finished product is quenched at a temperature of 840±10℃, and the holding time is the wall thickness of the semi-finished product x 2.5min / mm, and the holding time is greater than or equal to 30 minutes, followed by oil cooling; Low-temperature tempering: Temper the semi-finished product at a temperature of 160±10℃ and hold for 2 hours, then air cool it to make the hardness of the semi-finished product 58–65HRC and free of network carbides.

7. A method for processing a bearing housing for new energy vehicles according to claim 6, characterized in that, Step S5 includes: Precision machining of bearing mounting slots: The bearing mounting slots are machined a second time using a PCD guide bar reamer. After machining, the mounting slot diameter is Φ30±0.019mm, the surface roughness is ≤Ra1.6μm, the roundness error is ≤0.02mm, and the coaxiality is ≤0.02mm. The cutting parameters of the PCD guide bar reamer are a speed of 2000rpm and a feed rate of 0.05mm / r. The reamer is cooled by emulsion and online detection and compensation are performed. Finish milling of the rubber ring groove; use a PCD slot milling cutter to mill the rubber ring groove, with a groove width tolerance of ±0.05mm, a groove depth tolerance of ±0.03mm, and a surface roughness of ≤Ra3.2μm; Auxiliary hole machining: The positioning pin hole is made by drilling first and then reaming. The diameter of the pin hole is Φ8H8 and the perpendicularity is ≤0.03mm.

8. A method for processing a bearing housing for new energy vehicles according to claim 7, characterized in that, Step S6 includes: Insulation protection: A 5–8 μm thick nickel plating is applied to the surface of the machined bearing housing to prevent electro-corrosion on the 800V platform; Aperture accuracy: The aperture accuracy is tested using a pneumatic gauge, and an aperture tolerance of ±0.019mm is considered acceptable. Geometric tolerances: Use a mandrel and dial indicator to check the parallelism and perpendicularity of the bearing housing. Parallelism / perpendicularity ≤ 0.03mm is acceptable. Roundness inspection; The bearing housing is inspected using a roundness tester, and a roundness of ≤0.02mm is considered acceptable; Hardness testing: The bearing housings were randomly inspected using a Rockwell hardness tester.

9. A method for processing a bearing housing for new energy vehicles according to claim 8, characterized in that, The online detection compensation method in step S5 includes: Detection element creation: Define detection elements in CAD software, including points, lines, circles, planes and curved surfaces, and plan the probe movement path; Coordinate system calibration: The workpiece reference features are collected by the probe to establish a machining coordinate system, compensate for clamping deviations, and set the detection threshold to a tolerance of ±0.02mm; Real-time data acquisition: The diameter, roundness, and coaxiality dimensions of the bearing mounting groove are collected using a ruby ​​probe, and the contour image is obtained by laser scanning. The dimensions are extracted through image processing. Multi-location measurement: Multiple sampling points are performed on the bearing mounting groove and the ring retainer groove; Temperature monitoring: Integrated thermocouples monitor the thermal deformation of the machine tool in real time, providing data for thermal error compensation; Data processing and deviation calculation: Compare the measured data d1 with the theoretical value d, and calculate the deviation Δd = d1 - d; Thermal deformation compensation: Based on the temperature field model, predict the amount of thermal expansion and generate compensation values; Tiered compensation strategy: dynamically adjust the compensation amount according to the tolerance; Compensation decision: Based on a preset threshold, compensation is triggered. A neural network is used to learn historical data, predict tool wear trends, and adjust the compensation amount in advance. Compensation command generation: Corrects tool radius / length compensation values ​​and dynamically adjusts the workpiece coordinate system or path trajectory; Compensation execution: The CNC system receives compensation instructions, updates the machining program in real time, and performs remapping; Effect verification: After repair, remeasure to confirm whether the deviation is ≤ ±0.01mm; Process monitoring: Statistical process capability index (CPK) ≥ 1.33 to ensure batch consistency.

10. A method for processing a bearing housing for new energy vehicles according to claim 9, characterized in that, The tolerance zone dynamic adjustment compensation amount and the deviation range compensation decision compensation amount are as follows: If d≤d1<d+δ, the size is too small and needs to be compensated by +2δ; If d+δ≤d1<d+2δ, the size is too small and needs to be compensated by +δ. If d+2δ≤d1≤d+5δ, then it is qualified and no compensation is needed; If d+5δ<d1≤d+6δ, the size is too large and needs to be compensated by -δ. If d+6δ<d1≤d+7δ, the size is too large and needs to be compensated by -2δ. Where δ = tolerance Δ / 7, δ is the standard deviation of the error distribution, and Δ is the tolerance.

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