Deep groove ball bearing for special working conditions

Abstract

The invention discloses a deep groove ball bearing for special working conditions, which comprises an outer ring, an inner ring, a rolling body and a retainer, the rolling body is movably arranged between the outer ring and the inner ring, the inner peripheral wall of the outer ring and the outer peripheral wall of the inner ring are both provided with raceways for the rolling body to move, and the retainer is composed of two opposite and attached frame bodies. A plurality of pocket grooves are annularly formed in the inner walls of the frame bodies, when the two frame bodies are attached, each pocket groove and the adjacent pocket groove are combined to form a pocket hole for containing a rolling body, a plurality of sleeves are detachably connected between the two frame bodies, reinforcing rings are embedded in the frame bodies, the outer ring and the inner ring are both made of high-nitrogen stainless steel materials, and the outer ring and the inner ring are made of high-nitrogen stainless steel materials. The rolling bodies are ceramic balls, the sleeves and the reinforcing rings are made of stainless steel materials, and the frame body is made of PTFE materials. The deep groove ball bearing solves the problem that in the prior art, a deep groove ball bearing suitable for the liquid ammonia environment at the temperature of minus 40 DEG C is lacked.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bearings, in particular to a deep groove ball bearing for special working conditions. BACKGROUND

[0002] With the transformation of global energy structure to clean energy, green ammonia has become a key carrier of new energy system due to its core values of coupling wind and light power consumption, breaking through the bottleneck of hydrogen energy storage and transportation, and promoting industrial decarbonization. As the core equipment for green ammonia storage and application, the liquid ammonia pump needs to operate stably in a liquid ammonia environment of minus 40 DEG C for a long time. The performance of the bearing as the core transmission component of the liquid ammonia pump directly determines the service life and reliability of the liquid ammonia pump.

[0003] However, the existing deep groove ball bearing cannot adapt to this special working condition: first, the ring is usually made of ordinary bearing steel, which is prone to hydrogen embrittlement and corrosion in liquid ammonia, and the wear resistance is insufficient without oil lubrication. If the rolling element is made of steel, it is easy to cause galvanic corrosion with the ring, and the friction coefficient is significantly increased at low temperature. Second, the cage is usually made of a single material and integrally formed, or the pocket hole is jammed with the rolling element due to poor low-temperature resistance, or the steel ball wear is aggravated due to the lack of self-lubricating performance. Although some cages are provided with metal support members, the connection structure does not consider the difference in thermal expansion coefficient between PTFE and metal at low temperature, which is prone to looseness. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a deep groove ball bearing for special working conditions to solve the problem that there is no deep groove ball bearing for minus 40 DEG C liquid ammonia environment in the prior art.

[0005] To achieve the above purpose, the present application provides a deep groove ball bearing for special working conditions, which comprises an outer ring, an inner ring, a rolling element movably arranged between the outer ring and the inner ring, and a cage. The inner wall of the cage is circumferentially provided with a plurality of pockets. When the two cage bodies are combined, each pocket is combined with the adjacent pocket to form a pocket hole for accommodating the rolling element. A plurality of sleeves are detachably connected between the two cage bodies. The cage body is embedded with a reinforcing ring. The outer ring and the inner ring are made of high-nitrogen stainless steel. The rolling element is a ceramic ball. The sleeve and the reinforcing ring are made of stainless steel. The cage body is made of PTFE.

[0006] The beneficial effects of the above technical scheme are: in the above technology, the outer ring and the inner ring are made of high-nitrogen stainless steel material, which can adapt to the liquid ammonia environment below-40 DEG C, has excellent corrosion resistance and wear resistance, avoids the erosion of liquid ammonia to the sleeve ring and the excessive wear under oil-free lubrication; the rolling element is a ceramic ball, which can effectively avoid the electric corrosion problem between the steel rolling element and the sleeve ring, and reduce the rolling friction loss; the above retainer is composed of two oppositely attached frame bodies, the pocket groove of the frame body is combined to form a pocket hole for accommodating the rolling element, which can stably separate and guide the rolling element, reduce the collision and friction between the rolling elements, and the frame body is made of PTFE material, which has self-lubricating performance and can supplement the lubrication demand in the oil-free environment; the two frame bodies are detachably connected to the sleeve, which facilitates the bearing assembly and the replacement of parts during later maintenance, and the embedded stainless steel reinforcing ring in the frame body can enhance the overall structural strength of the retainer, prevent the PTFE frame body from being deformed due to low temperature shrinkage or stress, and solve the problem that the existing deep groove ball bearing cannot adapt to the special working condition of liquid ammonia below-40 DEG C, so as to ensure the stable operation of the bearing.

[0007] The present application further provides: a plurality of openings are annularly formed on each of the two frame bodies, the plurality of openings on one frame body correspond to the plurality of openings on the other frame body one by one, and each opening and the corresponding opening form a connecting hole, a plurality of connecting holes correspond to a plurality of sleeves one by one and are detachably arranged, the sleeve is axially provided with a through hole, and a rivet is arranged in the through hole.

[0008] The beneficial effects of the above technical scheme are: the openings annularly formed on the two frame bodies correspond to each other and form connecting holes, and the connecting holes and the sleeves are detachably arranged, which can ensure the positioning accuracy of the sleeve on the frame body, avoid misalignment when the two frame bodies are attached, and maintain the coaxiality of the overall structure of the retainer; the through hole axially formed in the sleeve is provided with a rivet, and the rivet is connected with the through hole through a stamping process, which can improve the connection firmness of the rivet and the sleeve compared with the traditional connection method, prevent the connection from loosening due to the difference in material thermal expansion coefficient in a low-temperature environment, and simplify the assembly process through the stamping connection process, thereby improving the assembly efficiency; the detachable connection structure facilitates the replacement of damaged sleeves or frame bodies during later bearing maintenance, without the need to replace the entire retainer, thereby reducing maintenance costs, ensuring that the retainer can stably separate and guide the rolling elements for a long time, reducing the friction loss of the rolling elements, and ensuring the reliability of the bearing operation.

[0009] The sleeve is further provided with a first clamping groove in the outer peripheral wall of each end, a second clamping groove in the inner peripheral wall of the opening, each first clamping groove is arranged opposite to the adjacent second clamping groove, a spring ring is arranged in the second clamping groove, the spring ring is made of elastic metal material, the spring ring is arranged in a spiral shape and has a shaft hole, the inner peripheral wall of the shaft hole of each spring ring is clamped and matched with the adjacent first clamping groove, and the outer peripheral wall of each spring ring is clamped and matched with the inner peripheral wall of the corresponding second clamping groove.

[0010] The first clamping groove in the outer peripheral wall of each end of the sleeve is arranged opposite to the second clamping groove in the inner peripheral wall of the opening of the frame body, the elastic metal spiral spring ring in the second clamping groove is clamped and matched with the first clamping groove and the second clamping groove respectively, an elastic connection structure is formed, the difference in thermal expansion coefficients between the PTFE frame body and the stainless steel sleeve can be compensated, the structural internal stress caused by the different shrinkage amounts of the two at low temperature can be avoided, and the cracking of the frame body or the sleeve can be prevented; the elastic property of the spring ring can absorb the impact load borne by the bearing during the operation of the liquid ammonia pump, the damage of the impact to the overall structure of the retainer can be reduced, the cracking of the sleeve can be prevented, the spiral structure ensures that the spring ring itself has stable elastic recovery capacity, is not easy to fail in long-term use, always maintains the close connection between the sleeve and the frame body, avoids the loosening of the retainer, ensures the stable operation of the rolling element in the pocket, and improves the overall operation stability of the bearing.

[0011] The present application further provides that the end wall and the outer peripheral wall of the rivet are connected by a smooth inclined surface and form a positioning surface, the protrusion on the inner peripheral wall of one end of the through hole is connected to the inner peripheral wall of the through hole by a smooth inclined surface and forms a matching surface, and the positioning surface and the matching surface are in tight fit when the rivet is connected to the through hole by the stamping process.

[0012] The smooth inclined surface between the end wall and the outer peripheral wall of the rivet forms a positioning surface, and the smooth inclined surface between the protrusion on the inner peripheral wall of one end of the through hole and the through hole forms a matching surface, which are in tight fit when connected by stamping, can increase the contact area of the rivet and the sleeve, improve the sealing property of the connection, prevent impurities in the liquid ammonia or the environment from entering the inside of the through hole, and avoid the connection failure of the rivet and the sleeve due to corrosion; the tight fit mode can enhance the connection strength of the rivet and the sleeve, prevent the rivet from loosening due to material shrinkage in a low-temperature environment, and ensure the long-term stability of the retainer connection structure; the smooth inclined surface design can reduce stress concentration in the stamping process, avoid damage of the rivet or the sleeve due to excessive local stress during assembly, ensure the assembly quality, ensure that the retainer continuously plays the function of separating and guiding the rolling element in the liquid ammonia environment, and maintain the normal operation of the bearing.

[0013] The present application further provides that the protrusions in the adjacent through holes are arranged in a staggered manner.

[0014] The technical scheme has the beneficial effects that: the protrusions in the adjacent through holes are arranged in a staggered manner, which can avoid stress superposition of the through holes of the adjacent sleeves when bearing load, disperse the stress points of the retainer to different positions, prevent local area cracking of the sleeve or the retainer due to stress concentration, and improve the load resistance of the overall structure of the retainer; the dispersion of the stress points makes the retainer bear force more evenly during rotation with the bearing, reduces vibration caused by uneven force, reduces the influence of vibration on the contact state of the rolling element and the raceway, and avoids the aggravation of component wear caused by vibration; the uniform stress and low vibration characteristics can improve the smoothness of the bearing operation, reduce operation noise, ensure long-term reliable operation of the bearing under complex working conditions of the liquid ammonia pump, prolong the overall service life of the bearing, and reduce the equipment maintenance frequency.

[0015] The application further provides that the inner circumferential wall of the pocket is provided with a deformation groove, the deformation groove is provided with a fitting plate at the opening, the radial section of the fitting plate is arranged in an arc shape, the outer wall surface of the fitting plate is a contact surface for contacting the rolling element, the deformation groove is provided with a deformation spring piece, the deformation spring piece is composed of two end portions and a deformation portion, the two end portions are respectively connected to the top wall and the bottom wall of the deformation groove, the radial section of the deformation portion is arranged in an arc shape, the outer wall of the deformation portion is connected to the inner wall of the fitting plate, the deformation portion is made of a shape memory alloy material, the deformation portion has a first shape at a first temperature range, the deformation portion has a second shape at a second temperature range, the contact surface of the fitting plate is flush with the inner circumferential wall of the pocket in the first shape of the deformation portion, and the deformation portion is bent and pushes the fitting plate to move towards the pocket in the second shape of the deformation portion.

[0016] The beneficial effects of the above technical solution are: the deformation groove of the inner circumferential wall of the pocket provides installation space for the deformation spring and the matching plate, the arc outer wall surface of the matching plate is adapted to the shape of the rolling body, and the contact friction with the rolling body can be reduced; the two ends of the deformation spring are connected with the top wall and the bottom wall of the deformation groove respectively, ensuring stable installation of the deformation spring, the deformation part is made of shape memory alloy material, and different shapes are presented in different temperature ranges: in a first temperature range, the deformation part presents a first shape, the matching plate is flush with the inner circumferential wall of the pocket, and the protrusion of the matching plate is avoided to cause the rolling body to be stuck; and in a second temperature range, the deformation part presents a second shape and is bent to push the matching plate to move, so that the increase of the gap between the pockets caused by the contraction of the PTFE frame body at low temperature is compensated, and the rolling body is prevented from shaking in the pocket; the elastic properties of the deformation spring can also absorb the impact of the rolling body during operation, improve the adaptability of the retainer to temperature changes, and ensure stable operation of the bearing in a liquid ammonia environment with temperature fluctuations. The above-mentioned shape memory alloy is a prior art, and a nickel-titanium alloy can be used, which has a phase transition temperature of minus 30 DEG C, and is in a contracted state at minus 40 DEG C. At a low temperature of minus 40 DEG C, the deformation part expands and drives the matching plate to move slightly in the direction of the deformation groove, providing a "compensation space" for the contraction of the PTFE pocket, avoiding the pocket becoming smaller and causing the steel ball to be stuck; when the bearing is heated during operation (the temperature of the bearing may rise to -10 DEG C to 0 DEG C when the liquid ammonia pump is working), the deformation part is in the second shape, the curvature of the deformation part is smaller, the matching plate is slightly pushed in the direction of the pocket, and the matching plate is matched with the steel ball, avoiding the gap being too large to cause the steel ball to shake, and ensuring the stability of the gap between the pocket and the steel ball in the whole temperature range. Since the shape memory alloy is a prior art, its structure and function will not be described in detail.

[0017] The present application further provides: a plurality of fine recesses for storing PTFE debris generated by wear of the retainer to form a lubricating layer are uniformly distributed on the inner circumferential wall of the raceway in a ring shape, and a plurality of the fine recesses are combined to be arranged in a honeycomb shape.

[0018] The beneficial effects of the above technical solution are: the honeycomb-shaped fine recesses uniformly distributed on the inner circumferential wall of the raceway in a ring shape can effectively store PTFE debris generated by wear of the retainer, avoid the loss of debris with liquid ammonia, form a continuous lubricating layer on the surface of the raceway, supplement the lubrication demand in an oil-free environment, and reduce the dry friction between the rolling body and the raceway; and the honeycomb structure ensures uniform distribution of the fine recesses, so that the lubricating layer can cover the entire raceway, and the contact area between the rolling body and the raceway is protected by lubrication, avoiding excessive wear caused by local insufficient lubrication; the fine recesses can also accommodate trace impurities that may exist in the liquid ammonia, prevent the impurities from producing grinding action between the rolling body and the raceway, avoid scratching the surface of the raceway, protect the precision of the raceway, improve the wear resistance of the bearing, ensure long-term stable operation of the bearing in a liquid ammonia environment at minus 40 DEG C, and prolong the service life.

[0019] The fine concave is coated with a solid lubricating film, and the solid lubricating film is composed of PTFE powder and a molybdenum disulfide composite coating.

[0020] The PTFE powder and the molybdenum disulfide composite solid lubricating film coated in the fine concave can form a synergistic lubricating effect with the PTFE debris stored in the concave, further enhancing the lubricating performance of the raceway, reducing the friction loss of the rolling element and the raceway, and improving the smoothness of the bearing operation. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a three-dimensional view of the present application; Figure 2 is a three-dimensional view of the present application in a partially separated state; Figure 3 is a sectional view of the present application after removing the outer ring and the inner ring; Figure 4 is a three-dimensional view of the present application in a partially separated state after removing the outer ring and the inner ring; Figure 5 is a three-dimensional view of the present application in a deformed elastic sheet and a fitted plate cooperation state; Figure 6 is a simple sectional view of the raceway of the present application. DETAILED DESCRIPTION

[0022] The application provides a deep groove ball bearing for special working conditions, which comprises an outer ring 1, an inner ring 11, rolling bodies 12 movably arranged between the outer ring 1 and the inner ring 11, and a retainer 2, a raceway 13 for the rolling bodies 12 is arranged on the inner circumferential wall of the outer ring 1 and the outer circumferential wall of the inner ring 11, the retainer 2 is composed of two opposite and adhered retainer bodies 21, a plurality of pockets 22 are annularly arranged on the inner wall of the retainer body 21, each pocket 22 is combined with the adjacent pocket 22 to form a pocket hole for accommodating the rolling body 12 when the two retainer bodies 21 are adhered, a plurality of sleeves 3 are detachably connected between the two retainer bodies 21, a reinforcing ring is embedded in the retainer body 21, the outer ring 1 and the inner ring 11 are made of high-nitrogen stainless steel, the rolling body 12 is a ceramic ball, the sleeve 3 and the reinforcing ring are made of stainless steel, the retainer body 21 is made of PTFE, a plurality of openings 211 are annularly arranged on the two retainer bodies 21, the plurality of openings 211 on one of the retainer bodies 21 correspond to the plurality of openings 211 on the other retainer body 21 one by one, and each opening 211 is combined with the corresponding opening 211 to form a connecting hole, the plurality of connecting holes correspond to the plurality of sleeves 3 one by one and are arranged in clamping mode, the sleeve 3 is axially provided with a through hole 31, a rivet 32 is arranged in the through hole 31, the rivet 32 is connected with the through hole 31 through a stamping process, first clamping grooves 33 are annularly arranged on the outer circumferential walls at both ends of the sleeve 3, second clamping grooves 212 are annularly arranged on the inner circumferential walls at the openings of the openings 211, each first clamping groove 33 is arranged opposite to the adjacent second clamping groove 212, a spring ring 23 is arranged in the second clamping groove 212, the spring ring 23 is made of elastic metal material, the spring ring 23 is arranged in a spiral shape and is provided with a shaft hole, the inner circumferential wall of the shaft hole of each spring ring 23 is arranged in clamping mode with the adjacent first clamping groove 33, the outer circumferential wall of each spring ring 23 is arranged in clamping mode with the inner circumferential wall of the corresponding second clamping groove 212, the initial end wall of the rivet 32 is connected with the outer circumferential wall in a smooth inclined surface and is provided with a positioning surface 321, a protrusion 34 is arranged on the inner circumferential wall of one end of the through hole 31, and the outer wall of the protrusion 34 is connected with the inner circumferential wall of the through hole 31 in a smooth inclined surface and is provided with a matching surface 341, the positioning surface 321 and the matching surface 341 are arranged in expansion fit mode when the rivet 32 is connected with the through hole 31 through the stamping process, the protrusions 34 in the adjacent through holes 31 are arranged in a staggered mode, a deformation groove 24 is arranged on the inner circumferential wall of the pocket 22, a adhered plate 4 is arranged at the opening of the deformation groove 24, the adhered plate 4 is arranged in an arc shape in the radial section and the outer wall surface thereof is a contact surface 41 for contacting the rolling body 12, a deformation spring piece 25 is arranged in the deformation groove 24, the deformation spring piece 25 is composed of two end parts and a deformation part 251, the two end parts are arranged in connection with the top wall and the bottom wall of the deformation groove 24, the deformation part 251 is arranged in an arc shape in the radial section and the outer wall of the deformation part 251 is arranged in connection with the inner wall of the adhered plate 4, the deformation part 251 is made of shape memory alloy material,The deformation part 251 has a first shape at a first temperature range and a second shape at a second temperature range. The deformation part 251 is arranged flush with the inner circumferential wall of the groove 22 in the first shape. The deformation part 251 is bent and pushes the fitting plate 4 to move towards the groove 22 in the second shape. The inner circumferential wall of the raceway 13 is uniformly distributed with a plurality of fine pits 131 for storing the PTFE debris generated by the wear of the retainer 2 to form a lubricating layer. The plurality of fine pits 131 are combined and arranged in a honeycomb shape. The fine pits 131 are coated with a solid lubricating film 132. The solid lubricating film is composed of a composite coating of PTFE powder and molybdenum disulfide.

[0023] The basic principles and main features of the present application and the advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application. These changes and improvements fall within the scope of the present application. The scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A deep groove ball bearing for special working conditions, comprising an outer ring, an inner ring, rolling elements movably arranged between the outer ring and the inner ring, and a cage, a raceway for the rolling elements is formed on the inner peripheral wall of the outer ring and the outer peripheral wall of the inner ring, characterized in that: The holder is composed of two opposite and abutting holder bodies, a plurality of pockets are annularly arranged on the inner walls of the holder bodies, each pocket is combined with the adjacent pocket to form a pocket hole for accommodating the rolling element when the two holder bodies are abutted, a plurality of sleeves are detachably connected between the two holder bodies, a reinforcing ring is embedded in the holder body, the outer ring and the inner ring are made of high-nitrogen stainless steel, the rolling element is a ceramic ball, the sleeve and the reinforcing ring are made of stainless steel, and the holder body is made of PTFE.

2. A deep groove ball bearing for special operating conditions according to claim 1, characterized in that A plurality of holes are annularly arranged on the two holder bodies, the holes on one of the holder bodies correspond to the holes on the other holder body one by one, and each hole is combined with the corresponding hole to form a connecting hole, the connecting holes correspond to the sleeves one by one and are clamped and arranged, the sleeve is axially provided with a through hole, the through hole is provided with a rivet, and the rivet is connected with the through hole through a stamping process.

3. A deep groove ball bearing for special operating conditions according to claim 2, characterized in that: First clamping grooves are annularly arranged on the outer peripheral walls at the two ends of the sleeve, second clamping grooves are annularly arranged on the inner peripheral walls of the hole openings, each first clamping groove is oppositely arranged with the adjacent second clamping groove, a spring ring is arranged in the second clamping groove, the spring ring is made of elastic metal material, the spring ring is arranged in a spiral shape and is provided with a shaft hole, the inner peripheral wall of the shaft hole of each spring ring is clamped and arranged with the adjacent first clamping groove, and the outer peripheral wall of each spring ring is clamped and arranged with the inner peripheral wall of the corresponding second clamping groove.

4. A deep groove ball bearing for special operating conditions according to claim 3, characterized in that: The rivet is connected with the through hole through a stamping process, and a positioning surface is formed between the smooth inclined surface connecting the end wall and the outer peripheral wall at the starting end of the rivet.

5. A deep groove ball bearing for special operating conditions according to claim 4, characterized in that: The protrusions in the adjacent through holes are arranged in a staggered manner.

6. The deep groove ball bearing for special working conditions according to claim 1, characterized in that: A deformation groove is arranged on the inner peripheral wall of the pocket, a abutting plate is arranged at the opening of the deformation groove, the radial section of the abutting plate is arranged in an arc shape, and the outer wall surface thereof is a contact surface for contacting the rolling element, a deformation spring piece is arranged in the deformation groove, the deformation spring piece is composed of two end portions and a deformation portion, the two end portions are respectively connected and arranged with the top wall and the bottom wall of the deformation groove, the radial section of the deformation portion is arranged in an arc shape, and the outer wall of the deformation portion is connected with the inner wall of the abutting plate, the deformation portion is made of a shape memory alloy material, the deformation portion has a first form at a first temperature range, and the deformation portion has a second form at a second temperature range, the contact surface of the abutting plate is flush with the inner peripheral wall of the pocket in the first form of the deformation portion, and the deformation portion is bent and pushes the abutting plate to move towards the direction of the pocket in the second form of the deformation portion.

7. The deep groove ball bearing for special working conditions according to claim 1, characterized in that: A plurality of fine recesses for storing PTFE debris generated by wear of the holder to form a lubricating layer are uniformly arranged annularly on the inner peripheral wall of the raceway, and the fine recesses are combined in a honeycomb shape.

8. A deep groove ball bearing for special operating conditions according to claim 7, characterized in that The fine recesses are coated with a solid lubricating film, and the solid lubricating film is composed of a PTFE powder and a molybdenum disulfide composite coating.

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