High-speed ball bearing and machining process thereof

Abstract

The invention provides a high-speed ball bearing and a machining process thereof, and relates to the technical field of mechanical engineering, the high-speed ball bearing comprises an outer ring and an inner ring, a group of steel balls are arranged between the outer ring and the inner ring, the outer ring comprises a bearing steel layer, a metal transition layer and a ceramic layer, and a vibration sensor and a temperature sensor are mounted in the ceramic layer; two metal retainers are arranged on the surfaces of a set of steel balls, two sets of inclined oil holes are formed in the annular side face of the inner ring, a set of wave-shaped oil grooves are formed in the inner wall of the ceramic layer, and through the collaborative design of the inner ring inclined oil holes and the outer ring wave-shaped oil grooves, the problem that lubricating oil is prone to being thrown out by centrifugal force at a high speed is solved, the friction coefficient is remarkably reduced, and heating is reduced; the hexagonal hollow holder further optimizes the distribution of lubricating oil and improves the lubrication uniformity, the built-in sensor realizes real-time acquisition of temperature and vibration signals through wireless transmission, and stainless steel sheet sealing and epoxy resin encapsulation ensure that the sensor works stably for a long time in an oil and dust environment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of mechanical engineering, more particularly, relates to a high-speed ball bearing and a processing technology thereof. BACKGROUND

[0002] As an important mechanical basic part, the high-speed ball bearing can stably operate in a high-speed environment and is widely used in high-end equipment such as machine tool spindles, aero-engines, high-speed motors and train axle boxes. The high-speed ball bearing replaces sliding friction with rolling friction between rolling elements and rings, effectively reduces energy loss during mechanical operation and ensures high-precision and high-efficiency operation of the equipment. In practical applications, the high-speed ball bearing usually needs to use the following structure:

[0003] 1. The inner ring is matched with the shaft and rotates at high speed together with the shaft, and the groove thereof is in contact with the rolling element to transmit the load;

[0004] 2. The outer ring is matched with the bearing seat and is usually fixed or rotates at low speed to provide support and guidance for the rolling element;

[0005] 3. The rolling element (steel ball) is a core component for bearing and transmitting force, and rolls between the inner and outer ring grooves to reduce friction;

[0006] 4. The retainer is used to separate the rolling elements to avoid mutual collision and ensure uniform distribution of the rolling elements.

[0007] At present, manufacturers use various designs and processing methods to achieve good performance of the high-speed ball bearing. Some manufacturers use high-purity bearing steel to manufacture the rings and rolling elements, and improve the surface quality through precision grinding. Some manufacturers use ceramic materials as the rolling elements to reduce weight and improve high-temperature resistance. Some manufacturers design the retainer to be lightweight and use brass, engineering plastics and other materials.

[0008] However, the above-mentioned embodiments still have the following problems: in terms of lubrication, high-speed ball bearings mostly rely on traditional straight oil holes or smooth oil grooves for oil supply, but in the case of train axle boxes, aircraft engines and the like, the bearing needs to withstand continuous high-speed rotation of more than 10,000 r / min, under such special conditions, the lubricating oil will be thrown to the outside of the bearing due to the strong centrifugal force, and a stable oil film cannot be formed in the contact area between the raceway and the steel ball, which is manifested as uneven oil film thickness, local dry friction, and thus a sharp increase in friction coefficient, which not only reduces the transmission efficiency, but also may cause the lubricating oil to deteriorate due to overheating, thereby shortening the service life of the bearing, in terms of state monitoring, in the case of aerospace, high-speed rail and other scenarios with extremely high reliability requirements, the bearing needs to be continuously operated for thousands of hours under high-speed and high-pressure environment, under such special conditions, the small damage (such as steel ball peeling and groove scratch) in the bearing will accumulate over time, which is manifested as abnormal increase of vibration amplitude and local temperature rise, and since these signals cannot be captured in real time, it is difficult to provide early warning at the initial stage of failure, which may eventually lead to sudden failure of the bearing, causing major safety accidents and huge economic losses, in view of the above problems, the present application provides a solution, and designs a high-speed ball bearing with efficient lubrication, high temperature resistance, stable structure and real-time monitoring function, which optimizes the lubrication through the synergistic effect of the inclined oil hole of the inner ring and the wavy spiral oil groove of the outer ring, improves the high temperature resistance and structural stability by using the gradient structure of the ring, and realizes real-time monitoring and failure warning by the built-in sensor, thereby improving the performance and reliability of the high-speed ball bearing. SUMMARY

[0009] In order to solve the above technical problems, the present application provides a high-speed ball bearing and its processing technology to solve the above problems.

[0010] A high-speed ball bearing, comprising an outer ring and an inner ring, a group of steel balls being arranged between the outer ring and the inner ring, the outer ring comprising a bearing steel layer, a metal transition layer and a ceramic layer, a vibration sensor and a temperature sensor being installed in the ceramic layer, two metal retainers being arranged on the surface of the group of steel balls, two groups of inclined oil holes being arranged on the annular side surface of the inner ring, a group of wavy oil grooves being arranged on the inner wall of the ceramic layer, two sealing rings being arranged between the inner ring and the ceramic layer, the two sealing rings being respectively arranged at the ports on both sides of the inner ring and the ceramic layer, the two sealing rings being made of fluorine rubber or polytetrafluoroethylene, the two sealing rings being embedded in the outer ring and being installed on the inner wall of the ceramic layer, gaps being formed between the two sealing rings and the inner ring, and the two sealing rings being flush with the end faces of the outer ring on the opposite sides.

[0011] Preferably, both of the metal retainer surfaces are provided with a set of hexagonal hollow grids, both of the metal retainers are symmetrically installed, both of the metal retainers are provided with a plurality of semispherical pocket grooves on the opposite sides, the size of the semispherical pocket grooves is larger than that of the steel balls, the gap width between the inner wall of the pocket groove of the metal retainer and the outer wall of the steel ball is 1% of the diameter of the steel ball, both of the metal retainers are made of brass, and the steel balls are sintered from high-purity silicon nitride powder.

[0012] Preferably, a plurality of screws for fixing are threadedly installed between the two metal retainers, the plurality of screws are respectively located at the separation between two adjacent semispherical pocket grooves of the metal retainer, the plurality of screws are made of brass, the two ends of the plurality of screws respectively penetrate through the two metal retainers, and the protruding parts at the two ends of the plurality of screws are respectively welded to the two metal retainers for reinforcement.

[0013] Preferably, the inner wall of the ceramic layer is provided with two sealing grooves, and the sealing grooves are covered by a wear-resistant ceramic coating.

[0014] Preferably, the vibration sensor and the temperature sensor are respectively installed in the two sealing grooves, and the two sealing grooves are located close to the port of the ceramic layer.

[0015] Preferably, the vibration sensor and the temperature sensor are fixed by high-temperature resistant epoxy resin pouring, and the surfaces of the vibration sensor and the temperature sensor are respectively covered by a stainless steel sheet one and a stainless steel sheet two.

[0016] Preferably, the inner wall of the ceramic layer is provided with two guide grooves, the ceramic layer is made of silicon nitride, the metal transition layer is made of titanium alloy, the ceramic layer and the metal transition layer are connected by active brazing, the metal transition layer and the bearing steel layer are fixed by friction welding, and the two guide grooves are respectively located on the two sides of the set of wave-shaped oil grooves and are in communication with the set of wave-shaped oil grooves.

[0017] A processing technology of a high-speed ball bearing, the processing technology of the high-speed ball bearing comprises the following steps:

[0018] S1: raw material preparation and inspection: the core material adopts high-carbon chromium bearing steel, the bar stock is subjected to ultrasonic flaw detection and surface magnetic particle flaw detection, the surface of the bar stock is subjected to sand blasting or pickling to remove the oxide scale, and the bar stock is subjected to alkali washing and water washing to remove oil stains.

[0019] S2: bar stock cutting: the raw material is cut into a fixed-length blank by using a numerical control sawing machine, and deburring is performed after cutting.

[0020] S3: forging forming: the blank is heated by medium frequency induction, the temperature uniformity is controlled within ±10℃, the forging temperature is controlled within 880-950℃, then forging is carried out, slow cooling, the cooling speed is ≤50℃ / h, finally annealing is carried out.

[0021] S4: high-precision numerical control lathe is adopted, and the end face, inner hole and outer circle and channel are processed in sequence: the parallelism of the end face is ≤0.005mm / 100mm, and Ra is 3.2μm; the inner hole size tolerance is IT11 level, and Ra is 1.6μm; the channel is pre-processed according to the channel curvature radius R=steel ball diameter / 2+0.01-0.02mm.

[0022] S5: heat treatment: first, the blank is ultrasonically cleaned by using neutral cleaning agent, and then dried; the blank is heated by using a vacuum furnace, heated to 840-850℃, and then tempered, the temperature is controlled within 160-180℃, and the blank is kept for 3-4h to eliminate quenching residual stress, stabilize the structure, and then taken out from the furnace when the temperature is below 100℃.

[0023] S6: fine grinding: the end face is fine ground by using a double-end surface grinder, the parallelism is ≤0.002mm / 100mm, and Ra is 0.8μm; the inner hole is fine ground by using a numerical control inner hole grinder, the roundness is ≤0.0005mm, the cylindrical degree is ≤0.001mm, the size tolerance is IT5 level; the channel is fine ground by using a numerical control channel grinder, the error is ≤0.001mm, the channel roundness is ≤0.0003mm, the channel curvature radius tolerance is ±0.001mm, and Ra is 0.04μm.

[0024] S7: steel ball processing: high-purity silicon nitride powder is adopted, the powder is first filled into a spherical mold and is static-pressed, the pressure is controlled within 100-300MPa, the powder is first sintered to near density by using normal pressure, and then the internal pores are eliminated by using high-temperature (1600-1800℃) and high-pressure (100-200MPa) nitrogen gas, and the fine grinding is carried out by using a grinding liquid, the roundness is controlled within ≤0.1μm, and Ra is ≤0.02μm.

[0025] S8: retainer processing: brass H62 is adopted, the blank is annealed after forging, kept for 2h at 600-650℃, and then the inner and outer circles are turned, and the tolerance is IT9 level; the pocket is processed by using a numerical control punch, the pocket size tolerance is IT8 level, the pocket pitch circle runout is ≤0.03mm, and the pocket edge is rounded with R0.1-0.2mm.

[0026] S9: assembling and assembling: the blank is ultrasonically cleaned by using 40℃ aviation kerosene for 15min to remove the grinding liquid and iron scraps, and then dried and immediately transferred into a clean assembly room; the assembling is carried out by using a special tool to uniformly put the steel balls into the inner and outer circle channels, and the number is accurately ensured, and the error needs to be ≤0.001mm by using a laser gap detector.

[0027] Compared with the prior art, the present application has the following beneficial effects:

[0028] In the application, through the collaborative design of the inner ring inclined oil hole and the outer ring wave-shaped oil groove, the problem that lubricating oil is easily thrown out by centrifugal force at high speed is solved, the oil film retention time is prolonged, the friction coefficient is significantly reduced, the heat generation is reduced, and the hexagonal hollow retainer further optimizes the lubricating oil distribution and improves the lubricating uniformity.

[0029] In the application, in the gradient structure of the outer ring, the inner layer of silicon nitride ceramic can resist high temperature above 300 DEG C, adapt to the continuous heating environment during train operation, the metal transition layer eliminates the difference in material thermal expansion, avoids the risk of cracking, and the outer layer of bearing steel ensures the assembly strength, and the heat resistance and structural reliability of the bearing are improved as a whole.

[0030] In the application, the built-in sensor realizes real-time acquisition of temperature and vibration signals through wireless transmission, and the stainless steel sheet sealing and epoxy resin filling ensure that the sensor works stably in the oil and dust environment for a long time, and the potential faults such as hot shaft and abnormal sound are warned in advance, and the train operation risk is reduced.

[0031] In the application, the low-friction design reduces the wear of parts, the gradient material improves the fatigue resistance, and the precise state monitoring prolongs the service life of the bearing, reduces the maintenance frequency and cost of the train, and improves the operation efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is the overall structure schematic diagram of the application;

[0033] Figure 2 It is the overall explosion structure schematic diagram of the application;

[0034] Figure 3 It is the overall front view structure schematic diagram of the application;

[0035] Figure 4 It is the inner ring structure schematic diagram of the application;

[0036] Figure 5 It is the ceramic layer structure schematic diagram of the application;

[0037] Figure 6 It is the inclined oil hole structure schematic diagram of the application;

[0038] Figure 7 It is the metal retainer structure schematic diagram of the application;

[0039] Figure 8 It is the application Figure 5 A enlarged structure diagram in the application.

[0040] Correspondence between component names and figure numbers in the figure is as follows: 1, bearing steel layer; 2, inner ring; 3, sealing ring; 4, metal retainer; 5, steel ball; 6, inclined oil hole; 7, metal transition layer; 8, ceramic layer; 9, wavy oil groove; 10, guide groove; 11, hexagonal hollow grid; 12, vibration sensor; 13, stainless steel sheet 1; 14, stainless steel sheet 2; 15, temperature sensor; 16, screw; 17, sealing groove. DETAILED DESCRIPTION

[0041] The embodiments of the present application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0042] Please refer to Figure 1 - Figure 8 The present application provides a high-speed ball bearing, comprising an outer ring and an inner ring 2, a group of steel balls 5 is arranged between the outer ring and the inner ring 2, the outer ring comprises a bearing steel layer 1, a metal transition layer 7 and a ceramic layer 8, a vibration sensor 12 and a temperature sensor 15 are installed in the ceramic layer 8, two metal retainers 4 are arranged on the surface of the group of steel balls 5, two groups of inclined oil holes 6 are arranged on the annular side surface of the inner ring 2, a group of wavy oil grooves 9 are arranged on the inner wall of the ceramic layer 8, two sealing rings 3 are arranged between the inner ring 2 and the ceramic layer 8, the two sealing rings 3 are respectively located at the ports on both sides of the inner ring 2 and the ceramic layer 8, the two sealing rings 3 are made of fluorine rubber or polytetrafluoroethylene, and the two sealing rings 3 are embedded in the outer ring and are embedded and installed on the inner wall of the ceramic layer 8.

[0043] There is a gap between the two sealing rings 3 and the inner ring 2, the back sides of the two sealing rings 3 are flush with the two side end faces of the outer ring, a group of hexagonal hollow grids 11 are arranged on the surface of the two metal retainers 4, the two metal retainers 4 are symmetrically installed, a plurality of semispherical pocket grooves are arranged on the opposite side of the two metal retainers 4, the size of the semispherical pocket grooves is larger than the size of the steel balls 5, the gap width between the inner wall of the pocket groove of the two metal retainers 4 and the outer wall of the steel balls 5 is 1% of the diameter of the steel balls 5, the two metal retainers 4 are made of brass, and the group of steel balls 5 are sintered from high-purity silicon nitride powder.

[0044] A plurality of screws 16 for fixing are threadedly installed between the two metal retainers 4, the plurality of screws 16 are respectively located at the separation between the two adjacent semispherical pocket grooves of the metal retainer 4, the plurality of screws 16 are made of brass, the two ends of the plurality of screws 16 respectively penetrate through the two metal retainers 4, and the protruding parts at the two ends of the plurality of screws 16 are respectively welded and reinforced with the two metal retainers 4.

[0045] Two sealing grooves 17 are arranged on the inner wall of the ceramic layer 8, the two sealing grooves 17 are located close to the side port of the ceramic layer 8, the opening of the two sealing grooves 17 is covered by a wear-resistant ceramic coating, the surface curvature of the ceramic coating is the same as that of the inner wall of the ceramic layer 8, and the ceramic coating is smoothly connected with the inner wall of the ceramic layer 8. During use, the inner ring 2 rotates at high speed with the axle, the outer ring is fixed with the bearing seat, the steel ball 5 rolls in the inner and outer ring channels to transfer the load, the direction of the inclined oil hole 6 radially arranged on the inner ring 2 is opposite to the rotation direction, and the inclined oil hole 6 guides the lubricating oil transported by the shaft end into the channel by means of the centrifugal force generated by rotation, and cooperates with the wavy oil groove 9 on the surface of the outer ring channel to form cooperative lubrication. The wavy structure generates a small vortex in the oil groove, prolongs the contact time of the lubricating oil with the groove wall, and disperses the turbulent flow of the oil under high speed through the fluctuating groove width, so that the lubricating oil is more uniformly attached to the raceway surface, ensures that the contact area between the steel ball 5 and the channel always maintains a stable oil film, and reduces friction and wear.

[0046] The design of the hexagonal hollow grid 11 of the metal retainer 4 not only reduces the influence of centrifugal force through the lightweight structure to avoid rigid collision with the steel ball 5 and the sleeve ring when rotating synchronously with the steel ball 5, but also provides a channel for the flow of lubricating oil through the hollow space to further optimize the lubrication distribution. In the gradient structure of the outer ring, the inner layer of silicon nitride ceramic directly contacts the steel ball 5 by virtue of the characteristics of high temperature resistance and low friction, reduces the heat generated by high-speed friction, the intermediate titanium alloy transition layer alleviates the thermal expansion difference between the ceramic and the outer layer of bearing steel to avoid cracking caused by temperature changes, and the outer layer of bearing steel ensures rigid assembly with the bearing seat, thereby improving the structural stability of the bearing under high speed and variable temperature environment. At the same time, the temperature sensor 15 and the vibration sensor 12 built-in the outer ring monitor the operating state in real time, and the temperature sensor 15 captures the heat change generated by the friction of the channel.

[0047] The vibration sensor 12 and the temperature sensor 15 are respectively installed in the two sealing grooves 17, and are fixed by high-temperature epoxy resin filling. The surfaces of the vibration sensor 12 and the temperature sensor 15 are respectively covered with stainless steel sheet 1 3 and stainless steel sheet 2 14. Two guide grooves 10 are arranged on the inner wall of the ceramic layer 8. The ceramic layer 8 is made of silicon nitride, the metal transition layer 7 is made of titanium alloy, the ceramic layer 8 and the metal transition layer 7 are connected by active brazing, and the metal transition layer 7 and the bearing steel layer 1 are fixed by friction welding.

[0048] Two guide grooves 10 are respectively located on both sides of a set of wave-shaped oil grooves 9 and communicate with the set of wave-shaped oil grooves 9, the vibration sensor 12 senses the abnormal collision signal of the steel ball 5 and the sleeve ring, the data is processed through the sensor module fixed by high-temperature-resistant epoxy resin, and then transmitted to the train control system wirelessly, the sealing structure of the stainless steel sheet one 13 and the stainless steel sheet two 14 on the surface of the sensor can block the invasion of lubricating oil and dust and does not affect the signal penetration, so that reliable data can be continuously output under extreme working conditions and early warning is provided for faults such as hot shaft and abnormal sound.

[0049] The inclined oil hole 6 of the inner ring 2 is cooperatively designed with the wave-shaped oil groove 9 of the outer ring, so that the problem that lubricating oil is easily thrown out by centrifugal force at high speed is solved, the oil film retention time is prolonged, the friction coefficient is significantly reduced, heat generation is reduced, the hexagonal hollow retainer further optimizes the distribution of lubricating oil and improves the uniformity of lubrication, in the gradient structure of the outer ring, the inner layer of silicon nitride ceramic can resist high temperature above 300 DEG C and adapt to the continuous heating environment during train operation, the metal transition layer 7 eliminates the difference in thermal expansion of materials to avoid the risk of cracking, and the outer layer of bearing steel ensures the assembly strength, so that the heat resistance and structural reliability of the bearing are improved as a whole, the built-in sensor realizes real-time acquisition of temperature and vibration signals through wireless transmission, and the stainless steel sheet sealing and epoxy resin filling ensure that the sensor can work stably for a long time in an oil and dust environment, so that potential faults such as hot shaft and abnormal sound are early warned, train operation risks are reduced, low-friction design reduces part wear, gradient materials improve fatigue resistance, and the service life of the bearing is greatly prolonged, train maintenance frequency and cost are reduced, and operation efficiency is improved.

[0050] A processing technology of a high-speed ball bearing, the processing technology of the high-speed ball bearing comprises the following steps:

[0051] S1: raw material preparation and inspection: the core material adopts high-carbon chromium bearing steel, ultrasonic flaw detection is performed on the bar stock, surface magnetic powder flaw detection is performed, sand blasting or pickling is used to remove the oxide scale on the surface of the bar stock, and alkali washing + water washing is used to remove oil stains.

[0052] S2: bar stock cutting: the raw material is cut into a fixed-length blank by using a numerical control sawing machine, the length tolerance of the blank is ±0.3 mm, the end face perpendicularity is ≤0.1 mm / 100 mm, and burrs are removed after cutting.

[0053] S3: forging forming: the blank is heated by using a medium-frequency induction, the temperature uniformity is controlled to be ±10 DEG C, the forging temperature is controlled to be 880-950 DEG C, then forging is performed, the contour tolerance of the blank is ≤±1 mm, slow cooling is performed, the cooling speed is ≤50 DEG C / h, and finally annealing is performed to reduce the hardness and facilitate subsequent processing.

[0054] S4: Using high-precision CNC lathe, in turn processing: end face: parallelism ≤ 0.005 mm / 100 mm, Ra3.2 μm; inner hole / outer circle: inner hole size tolerance IT11 level, Ra1.6 μm; channel: pre-processing according to channel curvature radius R = steel ball diameter / 2+0.01-0.02 mm.

[0055] S5: Heat treatment: first ultrasonic cleaning with neutral cleaning agent, temperature control at 30℃, after drying, heating in vacuum furnace, heating to 840-850℃, holding time = ring wall thickness mm x 1.5-2 min, then tempering, temperature control at 160-180℃, holding for 3-4 h to eliminate quenching residual stress, stabilize the structure, furnace cooling to below 100℃ and discharging.

[0056] S6: Fine grinding: using double-end surface grinder to fine grind end face, parallelism ≤ 0.002 mm / 100 mm, Ra0.8 μm, using numerical control inner hole grinder to fine grind inner hole, roundness ≤ 0.0005 mm, cylindricity ≤ 0.001 mm, size tolerance IT5 level, using numerical control channel grinder to fine grind channel, error ≤ 0.001 mm, channel roundness ≤ 0.0003 mm, channel curvature radius tolerance ± 0.001 mm, Ra0.04 μm.

[0057] S7: Steel ball processing: using high-purity silicon nitride powder, first filling the powder into spherical mold and static pressing, pressure control at 100-300 MPa, first sintering to near density under normal pressure, then eliminating internal pores at 1600℃-1800℃ high temperature and 100 MPa-200 MPa high pressure nitrogen, fine grinding with grinding fluid, controlling roundness ≤ 0.1 μm, Ra ≤ 0.02 μm.

[0058] S8: Cage processing: using brass H62, annealing after forging, holding at 600-650℃ for 2 h, turning inner and outer circles, tolerance IT9 level; using numerical control punch to process pockets, pocket size tolerance IT8 level, pocket pitch circle runout ≤ 0.03 mm, pocket edge rounding R0.1-0.2 mm.

[0059] S9: Assembly and assembly: ultrasonic cleaning with 40℃ aviation kerosene for 15 min to remove grinding fluid and iron filings, drying immediately and then transferring into clean assembly room; assembly: uniformly placing steel balls into inner and outer ring channels with special tooling, ensuring accurate quantity, using laser gap detector for detection, error needs to be ≤ 0.001 mm.

[0060] Working principle:

[0061] The high-speed ball bearing, in use, the inner ring 2 rotates with the axle at high speed, the outer ring is fixed with the bearing seat, the steel ball 5 rolls between the inner and outer ring channels to transfer load, the inclined oil hole 6 (direction opposite to the rotation direction) radially opened in the inner ring 2, by the centrifugal force of rotation, obliquely guides the lubricating oil transported from the shaft end into the channel, cooperates with the wave-shaped oil groove 9 on the surface of the outer ring channel to form lubrication, the wave-shaped structure generates micro eddy current in the oil groove, prolongs the contact time of the lubricating oil with the groove wall, disperses the oil turbulent flow at high speed through the fluctuating groove width, makes the lubricating oil more evenly adhere to the raceway surface, ensures that the contact area of the steel ball 5 and the channel always maintains a stable oil film, reduces friction and wear, the design of the hexagonal hollow grid 11 of the metal retainer 4, when rotating synchronously with the steel ball 5, not only reduces the influence of centrifugal force through the lightweight structure to avoid rigid collision with the steel ball 5 and the sleeve ring, but also provides a channel for the flow of lubricating oil through the space gap to further optimize the lubrication distribution, in the gradient structure of "ceramic layer 8-metal transition layer 7-bearing steel layer 1" of the outer ring, the inner layer of silicon nitride ceramic directly contacts the steel ball 5 by virtue of its high temperature resistance and low friction characteristics to reduce the heat generated by high-speed friction, the intermediate titanium alloy transition layer alleviates the thermal expansion difference between the ceramic and the outer layer of bearing steel to avoid cracking caused by temperature changes, and the outer layer of bearing steel ensures rigid assembly with the bearing seat to improve the structural stability of the bearing in high-speed and variable temperature environments, at the same time, the built-in temperature sensor 15 and vibration sensor 12 of the outer ring monitor the operating state in real time, the temperature sensor 15 captures the heat changes generated by channel friction, and the vibration sensor 12 senses abnormal collision signals of the steel ball 5 and the sleeve ring, after the data is processed by the sensor module fixed by high-temperature resistant epoxy resin, it is transmitted wirelessly to the train control system, the stainless steel sheet one 13 and the stainless steel sheet two 14 sealing structure on the surface of the sensor, not only can block the invasion of lubricating oil and dust, but also does not affect the signal penetration, ensuring the continuous output of reliable data in extreme working conditions to provide early warning for hot shaft and abnormal sound faults, the cooperative design of the inclined oil hole 6 of the inner ring 2 and the wave-shaped oil groove 9 of the outer ring solves the problem of lubricating oil being easily thrown out by centrifugal force at high speed, prolongs the oil film retention time, significantly reduces the friction coefficient, reduces heat generation, the hexagonal hollow retainer further optimizes the lubricating oil distribution and improves the lubricating uniformity, in the gradient structure of the outer ring, the inner layer of silicon nitride ceramic can resist high temperature above 300℃ to adapt to the continuous heat generation environment during train operation, the metal transition layer 7 eliminates the thermal expansion difference of the materials to avoid the risk of cracking, and the outer layer of bearing steel ensures the assembly strength to improve the heat resistance and structural reliability of the bearing, the built-in sensor realizes real-time acquisition of temperature and vibration signals through wireless transmission, the stainless steel sheet sealing and epoxy resin filling ensure that the sensor works stably in the oil and dust environment for a long time, provides early warning for potential hot shaft and abnormal sound faults, reduces the risk of train operation, the low-friction design reduces part wear, the gradient material improves fatigue resistance, combined with accurate state monitoring, significantly prolongs the service life of the bearing, reduces the frequency and cost of train maintenance, and improves the operation efficiency.

[0062] Embodiments of the present application are presented by way of example and description, and are not intended to be exhaustive or to limit the application to the form disclosed. Many modifications and variations will be apparent to those skilled in the art upon reading this disclosure. Embodiments are chosen and described in order to best explain the principles of the application and its practical application to thereby enable others skilled in the art to best utilize the application, various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. A high speed ball bearing comprising an outer ring and an inner ring (2) between which a set of steel balls (5) is arranged, characterized in that: The outer ring comprises a bearing steel layer (1), a metal transition layer (7) and a ceramic layer (8); the vibration sensor (12) and the temperature sensor (15) are installed in the ceramic layer (8); Wherein, the surface of a group of steel balls (5) is provided with two metal retainers (4), the inner ring (2) is provided with two groups of inclined oil holes (6) on the annular side surface, and the inner wall of the ceramic layer (8) is provided with a group of wave-shaped oil grooves (9).

2. The high speed ball bearing of claim 1 wherein, Two sealing rings (3) are arranged between the inner ring (2) and the ceramic layer (8), the two sealing rings (3) are respectively located at the ports on the two sides of the inner ring (2) and the ceramic layer (8), the two sealing rings (3) are made of fluorine rubber or polytetrafluoroethylene, the two sealing rings (3) are embedded in the outer ring, and are embedded and installed on the inner wall of the ceramic layer (8), there is a gap between the two sealing rings (3) and the inner ring (2), and the back sides of the two sealing rings (3) are flush with the two side end faces of the outer ring.

3. The high speed ball bearing of claim 1 wherein, The surfaces of the two metal retainers (4) are provided with a group of hexagonal hollow grids (11), the two metal retainers (4) are symmetrically installed, a plurality of hemispherical pocket grooves are formed on the opposite sides of the two metal retainers (4), the specifications of the hemispherical pocket grooves are larger than the specifications of the steel balls (5), the gap width between the inner walls of the pocket grooves of the two metal retainers (4) and the outer walls of the steel balls (5) is 1% of the diameter of the steel balls (5), the two metal retainers (4) are made of brass, and a group of steel balls (5) are sintered from high-purity silicon nitride powder.

4. The high speed ball bearing of claim 1 wherein, A plurality of screws (16) for fixing are threadedly installed between the two metal retainers (4), the plurality of screws (16) are respectively located at the separation positions of the adjacent two hemispherical pocket grooves in the metal retainers (4), the plurality of screws (16) are made of brass, the two ends of the plurality of screws (16) respectively penetrate through the two metal retainers (4), and the protruding parts at the two ends of the plurality of screws (16) are respectively welded and reinforced with the two metal retainers (4).

5. The high speed ball bearing of claim 1 wherein, The inner wall of the ceramic layer (8) is provided with two sealing grooves (17), and the two sealing grooves (17) are located close to the side ports of the ceramic layer (8); Wherein, the grooves of the two sealing grooves (17) are covered by wear-resistant ceramic coating, the surface curvature of the ceramic coating is the same as that of the inner wall of the ceramic layer (8), and is smoothly connected with the inner wall of the ceramic layer (8).

6. The high speed ball bearing of claim 5 wherein, The vibration sensor (12) and the temperature sensor (15) are respectively installed in the two sealing grooves (17); Wherein, the vibration sensor (12) and the temperature sensor (15) are fixed by high-temperature resistant epoxy resin pouring, and the detection end of the temperature sensor (15) faces one side of the inner wall of the ceramic layer (8).

7. The high speed ball bearing of claim 1 wherein, The surfaces of the vibration sensor (12) and the temperature sensor (15) are respectively covered with stainless steel sheet one (13) and stainless steel sheet two (14), and the stainless steel sheet one (13) and the stainless steel sheet two (14) are in the shape of a box.

8. The high speed ball bearing of claim 1 wherein, Two guide grooves (10) are arranged in the inner wall of the ceramic layer (8), the ceramic layer (8) is made of silicon nitride, the metal transition layer (7) is made of titanium alloy, the ceramic layer (8) and the metal transition layer (7) are connected through active brazing, and the metal transition layer (7) and the bearing steel layer (1) are fixed through friction welding.

9. The high speed ball bearing of claim 8 wherein, Two guide grooves (10) are arranged in the inner wall of the ceramic layer (8), the ceramic layer (8) is made of silicon nitride, the metal transition layer (7) is made of titanium alloy, the ceramic layer (8) and the metal transition layer (7) are connected through active brazing, and the metal transition layer (7) and the bearing steel layer (1) are fixed through friction welding.

10. A process for machining a high-speed ball bearing, characterized in that, The processing technology of the high-speed ball bearing comprises the following steps: S1: raw material preparation and inspection: the core material adopts high-carbon chromium bearing steel, the bar stock is subjected to ultrasonic flaw detection and surface magnetic particle flaw detection, the surface of the bar stock is subjected to sand blasting or pickling to remove the oxide scale, and alkali washing and water washing are adopted to remove oil stains. S2: bar stock cutting: the raw material is cut into fixed-length blanks by using a numerical control sawing machine, and deburring is performed after cutting. S3: forging forming: the blank is heated by using a medium-frequency induction, the temperature uniformity is controlled within ±10℃, the forging temperature is controlled within 880-950℃, then forging and pressing are performed, slow cooling is performed, the cooling speed is ≤50℃ / h, and finally annealing is performed. S4: a high-precision numerical control lathe is adopted to process in sequence: end face: parallelism ≤0.005mm / 100mm, Ra3.2μm; inner hole / outer circle: inner hole size tolerance IT11 level, Ra1.6μm; groove: pre-processing according to groove curvature radius R=steel ball diameter / 2+0.01-0.02mm. S5: heat treatment: first, ultrasonic cleaning is performed by using a neutral cleaning agent, drying is performed, then heating is performed by using a vacuum furnace, heating is performed to 840-850℃, heat preservation is performed, then tempering is performed, the temperature is controlled within 160-180℃, heat preservation is performed for 3-4h to eliminate quenching residual stress, stabilize the organization, and the furnace is cooled to below 100℃ to discharge the furnace. S6: fine grinding: the end face is fine ground by using a double-end surface grinder, the parallelism is ≤0.002mm / 100mm, Ra0.8μm, the inner hole is fine ground by using a numerical control inner circle grinder, the roundness is ≤0.0005mm, the cylindrical degree is ≤0.001mm, the size tolerance is IT5 level, the groove is fine ground by using a numerical control groove grinder, the error is ≤0.001mm, the groove roundness is ≤0.0003mm, the groove curvature radius tolerance is ±0.001mm, and Ra0.04μm. S7: steel ball processing: high-purity silicon nitride powder is adopted, the powder is first filled into a spherical mold and subjected to static pressure, the pressure is controlled within 100-300MPa, the powder is first sintered to near density by using normal pressure, then internal pores are eliminated in a high-temperature and high-pressure nitrogen atmosphere of 1600-1800℃ and 100-200MPa, fine grinding is performed by using a grinding liquid, the roundness is controlled within ≤0.1μm, and Ra≤0.02μm. S8: retainer processing: brass H62 is adopted, annealing is performed after forging, heat preservation is performed at 600-650℃ for 2h, the inner and outer circles are turned, and the tolerance is IT9 level; a numerical control punch is adopted to process the pockets, the pocket size tolerance is IT8 level, the pocket pitch circle runout is ≤0.03mm, and the pocket edge is rounded to R0.1-0.2mm. S9: Assembly and assembly: ultrasonic cleaning with 40℃ aviation kerosene for 15min, remove grinding fluid, iron filings, and immediately transfer to a clean assembly room after drying; assembly: evenly put steel balls into the inner and outer ring channels with special tools, ensure the number is accurate, detect with laser gap meter, error needs to be ≤0.001mm.

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