A high-speed bearing group structure

Abstract

The present invention provides a high-speed bearing group structure, which relates to the field of bearings. The high-speed bearing group structure includes an outer housing, a rotating inner ring, a rotating outer ring and support bearings. A central through hole is formed in the outer housing, and the rotating inner ring is arranged at the central through hole. The support bearings are circumferentially and evenly arranged on the outer periphery of the rotating inner ring. The support bearing includes an inner bearing ring, an outer bearing ring and a rotating body. A positioning shaft is connected between the outer housing and the inner bearing rings of the respective support bearings. The support bearings are tightly installed in the annular space between the rotating inner ring and the rotating outer ring. When the rotating inner ring rotates at a high speed, it drives the support bearings to follow. The operation of the outer bearing rings and the rotating bodies of the support bearings will generate centrifugal forces, introducing new centrifugal forces. These centrifugal forces cancel out the centrifugal force of the rotating inner ring itself. The rotating outer ring always forms a radially inward tightening force on the outer bearing rings, avoiding excessive pressure on the rollers in the existing bearing structure and improving the integrity and reliability of the bearing structure.

Description

Technical Field

[0001] The present invention relates to the technical field of bearings, and particularly to a high-speed bearing group structure. Background Art

[0002] Bearings are important components in mechanical devices. Their main function is to support rotating components, reduce the friction coefficient during rotation, and ensure the rotational accuracy of the rotating components.

[0003] A common bearing structure, as disclosed in the Chinese utility model patent with the authorization announcement number CN205136374U and the authorization announcement date of April 6, 2016, discloses a high-speed cylindrical roller bearing. Specifically, the high-speed cylindrical roller bearing includes an outer bearing ring, an inner bearing ring, a cage, and rollers. A plurality of rollers are evenly spaced and installed in the cage. The rollers are in contact with the inner walls of the outer bearing ring and the inner bearing ring. The rollers are composed of a steel hollow roller, a polytetrafluoroethylene elastomer, and a silicon nitride ceramic hollow sleeve. The elastomer is filled in the internal hollow part of the roller. The sleeve has a circular arc convexity on its outer surface, and the sleeve is inlaid on the outer surface of the roller. A rib is provided on the inner bearing ring. Since the slip rate of the cage is reduced, the centrifugal force on the outer bearing ring during high-speed rotation is also reduced.

[0004] When using the high-speed cylindrical roller bearing in the prior art, by redesigning the roller to be composed of a steel hollow roller, an elastomer filled in the internal hollow part, and a hollow sleeve, the centrifugal force generated by the roller at high speeds can be reduced. However, under high-speed operating conditions, the inner bearing ring of the existing bearing will exert a greater pressure on the roller due to centrifugal force. Moreover, the redesigned roller cannot ensure a reliable support for the rotating component, resulting in low reliability of the entire bearing, and poor rotational speed and load capacity that the bearing can withstand. Summary of the Invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a high-speed bearing group structure to solve the problem that under high-speed operating conditions, in the prior art, in order to increase the rotational speed and load capacity, multiple bearings are usually installed in series. Although this is better than a single bearing, when the number is too large, the effect weakens, and problems of uneven force will occur.

[0006] The technical solution of the high-speed bearing group structure of the present invention is as follows:

[0007] The high-speed bearing group structure includes a housing, a rotating inner ring, a rotating outer ring, and support bearings installed in the housing. A central through hole is provided on the housing. The rotating inner ring is disposed at the central through hole. The support bearings are circumferentially spaced and arranged on the outer periphery of the rotating inner ring;

[0008] The support bearing includes an inner bearing ring, an outer bearing ring and a rotating body. A positioning shaft is connected between the housing body and the inner bearing rings of the respective support bearings. The support bearings are tightly installed in the annular space between the inner rotating ring and the outer rotating ring.

[0009] Further, the positioning shaft is fixedly connected to the housing body.

[0010] Further, the housing body includes a first half shell and a second half shell that are snap-fitted. The first half shell includes a front shell plate, an outer peripheral edge and a convex shaft. The structure of the second half shell is symmetrically arranged with that of the first half shell; the second half shell includes a rear shell plate, an outer peripheral edge and a convex shaft. The convex shafts of the first half shell and the second half shell are butted to form the positioning shaft.

[0011] Further, the outer peripheral edges of the first half shell and the second half shell are snap-fitted to form the annular outer wall of the housing body. The outer rotating ring is installed in the annular outer wall with a gap, and a lubricating fluid is filled between the outer rotating ring and the annular outer wall.

[0012] Further, there are at least three groups of the support bearings, and at least three groups of support bearing groups are circumferentially spaced and evenly distributed on the outer periphery of the inner rotating ring.

[0013] Further, there are at least six support bearings in total. Two support bearings among at least six support bearings form the support bearing group, and the two support bearings of each support bearing group are respectively installed on the same positioning shaft.

[0014] Further, a positioning inner edge is provided in the middle of the inner wall of the outer rotating ring, and the two support bearings of each support bearing group are respectively arranged on both sides of the positioning inner edge.

[0015] Further, a stop ring is also sleeved on the positioning shaft, and the stop ring is axially pressed and matched with the inner bearing rings of the two support bearings of the support bearing group respectively.

[0016] Further, a positioning ring groove is provided on the outer wall of the inner rotating ring, and the positioning ring groove is in concave-convex fit with the outer bearing ring of the support bearing.

[0017] Further, the sum of the cross-sectional areas of at least three of the positioning shafts is greater than the cross-sectional area of the inner hole of the inner rotating ring.

[0018] Beneficial effects: In the prior art, in order to increase the rotational speed and load capacity, multiple bearings are usually installed in series. This is better than a single bearing, but when the number is too large, the effect weakens, and uneven stress occurs. Because when the main shaft is overly lengthened, the diameter of the main shaft also needs to be increased. Otherwise, a slender shaft is not conducive to high-speed rotation and is prone to resonance and breakage. If the diameter of the main shaft is increased, the size of the bearing also needs to be increased. By checking the bearing parameters, it can be known that the load capacity increases, but the rotational speed decreases. To solve this problem, the present solution adopts increasing the number of support bearings radially, and the size of the added support bearings is not much different from the original bearings. Through the uniform force of multiple support bearings together, while not overly increasing the length of the main shaft, the number of support bearings is increased to make the force uniform, and the size of the added support bearings is not restricted within a reasonable range.

[0019] The improved solution can not only make the added bearings bear force simultaneously, but also cancel out the centrifugal force generated by the added bearings and the load generated by the bearing positioning shaft, thereby further increasing the rotational speed. Since the outer ring of the support bearing in this solution is tangent to the inner groove of the rotating inner ring, and the diameter of the rotating inner ring is much smaller than the outer ring diameter of the bearing in the prior art, the linear velocity of the outer ring of the support bearing and the inner groove of the rotating inner ring is equal. And the position of the rotating body of the support bearing is inside the outer ring of the support bearing. Therefore, when the bearing sizes are the same, the linear velocity of the rotating body is less than the linear velocity of the rotating body of the bearing in the prior art, indirectly increasing the maximum rotational speed that the entire bearing can withstand.

[0020] The high-speed bearing group structure adopts the design form of an outer shell, a rotating inner ring, support bearings, and a rotating outer ring. When the rotating inner ring rotates at high speed, it drives the support bearings to follow. Since the outer shell is connected to the bearing inner rings of each support bearing by positioning shafts, that is, the support bearings themselves remain in place in the annular space, and the bearing outer rings and rotating bodies of the support bearings move with the high-speed rotation of the rotating inner ring. The rotation of the bearing outer rings and rotating bodies of the support bearings will generate centrifugal force, transforming the rotation of the rollers (self-rotation plus revolution) in the original bearing structure into the rotation of the bearing outer rings of the support bearings, introducing a new centrifugal force, which cancels out the centrifugal force of the rotating inner ring itself, avoiding excessive pressure on the rollers in the existing bearing structure.

[0021] Since there is lubricating fluid in the gap between the rotating outer ring and the outer shell, the rotation of the main shaft drives the rotating inner ring of the bearing group structure to rotate. The rotating inner ring drives the bearing outer rings of the support bearings to rotate, and the bearing outer rings drive the rotating outer ring to rotate. The rotating outer ring transmits part of the force directly to the outer shell through the lubricating fluid in the gap. This part of the force does not pass through the rotating bodies of the support bearings, reducing the load on the rotating bodies and being conducive to the high-speed rotation of the bearing group structure.

[0022] In addition, when the outer ring of the support bearing moves, it will drive the rotating outer ring to rotate at the same linear velocity. According to the centripetal force formula, when the linear velocities are equal, the larger the rotation radius of the particle, the smaller its centripetal force. The magnitude of the centrifugal force is also related to the mass. By setting the volume and material of the rotating outer ring (materials with high density can be selected), the magnitude of the centrifugal force generated outside can be set, so that most or all of the centrifugal force of the outer ring cancels out the centrifugal force under the additional load of the inner ring, and has little impact on the rotational speed. Because as the rotational speed increases, the rotational speed of the inner ring under load increases, and the centrifugal force also increases, while the outer ring also increases the centrifugal force with the increase of the rotational speed. And the support bearing is tightly installed in the annular space between the rotating inner ring and the rotating outer ring. The rotating outer ring always forms a radially inward tightening force on the outer ring of the support bearing, further canceling out the centrifugal force generated by the rotating inner ring, and improving the integrity and reliability of the bearing structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 FIG. 1 is a front view schematic diagram of the high-speed bearing group structure in the specific embodiment 1 of the high-speed bearing group structure of the present invention;

[0024] Figure 2 is Figure 1 a cross-sectional view of the high-speed bearing group structure at A-A;

[0025] Figure 3 FIG. 2 is a radial cross-sectional view of the high-speed bearing group structure in the specific embodiment 1 of the high-speed bearing group structure of the present invention.

[0026] In the figure: 1 - outer housing, 10 - central through hole, 11 - first half shell, 110 - front shell plate, 111 - outer peripheral edge of the first half shell, 112 - convex shaft of the first half shell, 12 - second half shell, 120 - rear shell plate, 121 - outer peripheral edge of the second half shell, 122 - convex shaft of the second half shell, 13 - stop ring, 2 - rotating inner ring, 20 - positioning ring groove, 21 - sealing strip, 3 - rotating outer ring, 30 - positioning inner edge, 4 - support bearing, 41 - bearing inner ring, 42 - bearing outer ring, 43 - rotating body, 45 - cage. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following combines the drawings and embodiments to further describe in detail the specific embodiments of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0028] Specific embodiment 1 of the high-speed bearing group structure of the present invention, as Figures 1 to 3As shown in the figure, the high-speed bearing group structure includes a housing 1, a rotating inner ring 2, a rotating outer ring 3 and a support bearing 4 installed in the housing 1. A central through hole 10 is provided on the housing 1. The rotating inner ring 2 is arranged at the central through hole 10. The support bearings 4 are circumferentially and spacedly arranged on the outer periphery of the rotating inner ring 2. The support bearing 4 includes an inner bearing ring 41, an outer bearing ring 42, a rotating body 43 and a cage 45. A positioning shaft is connected between the housing 1 and the inner bearing ring 41 of each support bearing 4. The support bearing 4 is tightly installed in the annular space between the rotating inner ring 2 and the rotating outer ring 3.

[0029] The high-speed bearing group structure adopts the design form of the housing 1, the rotating inner ring 2, the support bearing 4 and the rotating outer ring 3. When the rotating inner ring 2 rotates at a high speed, it drives the support bearing 4 to follow. Since a positioning shaft is connected between the housing 1 and the inner bearing ring 41 of each support bearing 4, that is, the support bearing 4 itself will keep its position unchanged in the annular space, and the outer bearing ring 42 and the rotating body 43 of the support bearing 4 move with the high-speed rotation of the rotating inner ring 2. The operation of the outer bearing ring 42 and the rotating body 43 of the support bearing 4 will generate centrifugal force, which changes the rotation of the roller including self-rotation and revolution in the original bearing structure into the self-rotation movement of the outer bearing ring 42 of the support bearing 4, introducing a new centrifugal force. This centrifugal force cancels out the centrifugal force of the rotating inner ring 2 itself, avoiding the excessive pressure on the roller in the existing bearing structure.

[0030] In addition, when the outer bearing ring 42 of the support bearing 4 moves, it will drive the rotating outer ring 3 to rotate at the same speed. According to the centripetal force formula, when the linear velocity is equal, the larger the rotation radius of the particle, the smaller its centripetal force, and the magnitude of the centrifugal force is also related to the mass. The magnitude of the centrifugal force generated outside can be set by setting the volume and material of the rotating outer ring (materials with high density can be selected), so that the centrifugal force of the outer ring cancels out most or all of the centrifugal force of the inner ring under the applied load, and has little impact on the rotation speed. Because as the rotation speed increases, the centrifugal force also increases under the load state of the inner ring, and the outer ring also increases the centrifugal force with the increase of the rotation speed; and the support bearing 4 is tightly installed in the annular space between the rotating inner ring 2 and the rotating outer ring 3, and the rotating outer ring 3 always forms a radially inward tightening force on the outer bearing ring 42 of the support bearing 4, further canceling out the centrifugal force generated by the rotating inner ring 2, improving the integrity and reliability of the bearing structure.

[0031] In this embodiment, the positioning shaft is fixedly connected to the outer housing 1. Specifically, the outer housing 1 includes a first half-shell 11 and a second half-shell 12 that are snap-fitted. The first half-shell 11 includes a front shell plate 110, an outer peripheral edge, and a convex shaft. The second half-shell 12 is symmetrically arranged with the first half-shell 11 in structure; the second half-shell 12 includes a rear shell plate 120, an outer peripheral edge, and a convex shaft. The convex shaft 112 of the first half-shell and the convex shaft 122 of the second half-shell are butted to form the positioning shaft. Designing the outer housing 1 into the first half-shell 11 and the second half-shell 12 that are snap-fitted facilitates subsequent assembly operations and improves the production and manufacturing efficiency.

[0032] To improve the support performance of the support bearing 4 for the rotating inner ring 2, there are four groups of support bearings 4 (four groups in this embodiment, and three groups or more than four groups in other embodiments). The four groups of support bearing groups are circumferentially and evenly distributed on the outer periphery of the rotating inner ring 2. And, there are a total of eight support bearings 4. Two support bearings 4 among the eight support bearings 4 form a support bearing group, and the two support bearings 4 of each support bearing group are respectively installed on the convex shaft 112 of the first half-shell and the convex shaft 122 of the second half-shell. The two support bearings 4 of each support bearing group are respectively installed on the convex shaft 112 of the first half-shell and the convex shaft 122 of the second half-shell. That is to say, the two support bearings 4 of each support bearing group are installed on the same positioning shaft, increasing the contact area between the support bearing 4 and the rotating inner ring 2 and the rotating outer ring 3, and improving the pressure resistance of the entire bearing structure during high-speed operation.

[0033] Among them, a positioning inner edge 30 is provided in the middle of the inner wall of the rotating outer ring 3. The two support bearings 4 of each support bearing group are respectively arranged on both sides of the positioning inner edge 30. The positioning inner edge 30 of the rotating outer ring 3 serves to separate the two support bearings 4 in each support bearing group, ensuring that the operation of each support bearing 4 does not interfere with each other. The inner ring of the rotating outer ring 3 is tangent to the bearing outer ring of the support bearing 4 and is closely matched. The outer peripheral edge 111 of the first half-shell and the outer peripheral edge 121 of the second half-shell are butted to form the annular outer wall of the outer housing 1. The rotating outer ring 3 is installed in the annular outer wall of the outer housing 1 with a gap, and a lubricating fluid is filled between the rotating outer ring 3 and the annular outer wall of the outer housing 1. The lubricating fluid is used to further reduce the frictional resistance during the operation of the support bearing 4 and the rotating outer ring. A sealing strip 21 is also provided between the rotating inner ring 2 and the central through hole 10 of the outer housing 1 to prevent the lubricating fluid from leaking out. In other embodiments, in order to meet different usage requirements, the sealing strip can also be directly omitted.

[0034] Moreover, a positioning ring groove 20 is provided on the outer wall of the rotating inner ring 2, and the positioning ring groove 20 is in concave-convex fit with the outer ring 42 of the support bearing 4. A stop ring 13 is also sleeved on the positioning shaft, and the stop ring 13 is axially pressed against the inner rings 41 of the two support bearings 4 of each support bearing group. Specifically, the stop ring 13 is sleeved at the butt joint position of the convex shaft 112 of the first half shell and the convex shaft 122 of the second half shell. By axially pressing the inner rings 41 of the two support bearings 4 with the stop ring 13, it is ensured that the inner rings 41 of the support bearings 4 will not move axially. The rotation accuracy of the outer ring 42 of the support bearing 4 is ensured by using the positioning inner edge 30 of the rotating outer ring 3 and the positioning ring groove 20 of the rotating inner ring 2. In addition, the radial dimension of the outer ring 42 of the support bearing 4 can be larger than the radial dimension of the rotating inner ring 2, which reduces the operating angular velocity of the outer ring 42 of the support bearing 4 during follow-up movement and avoids the situation of bearing structure damage caused by excessive centrifugal force generated by the outer ring 42 of the support bearing 4.

[0035] The support bearing 4 adopted in this solution can be a metal bearing, a ceramic bearing, etc. commonly used in the prior art. In order to save manufacturing costs, the rollers can be made solid instead of hollow, increasing the centrifugal force effect, which cancels out the interaction force with the rotating outer ring 3 with a load, playing a balancing role. The higher the rotation speed, the greater the centrifugal force, and the greater the force to be cancelled out; if it is necessary to reduce the centrifugal force of the rotating body, a smaller support bearing 4 can be selected to achieve the purpose of reducing the centrifugal force of the rotating body. Usually, in the prior art, in order to increase the rotation speed and the load capacity, multiple bearings are installed in series, which is better than a single bearing, but when the number is too large, the effect weakens, because when the main shaft is lengthened, the diameter of the main shaft also needs to be increased, otherwise a slender shaft is not conducive to high-speed rotation and is prone to resonance and breakage; if the diameter of the main shaft is increased alone, the size of the bearing also needs to be increased. By checking the bearing parameters, it can be known that the load capacity is increased, but the rotation speed is decreased.

[0036] In order to solve this problem, this solution adopts the method of increasing the number of support bearings 4 in the radial direction, and the size of the added support bearings 4 is not much different from the size of the original bearings, and can be the same size, smaller or larger than the original bearings. Through the common force of multiple support bearings 4, the number of support bearings 4 is increased without increasing the length of the main shaft too much, and the size of the added support bearings 4 is within a reasonable range and is not restricted. The reason is: if the bearing is increased, the speed capacity of the bearing is reduced. Since this solution connects the outer ring of the support bearing 4 to the main shaft, the speed of the main shaft is equal, and the speed of the support bearing 4 (in revolutions per minute) is inversely proportional to the diameter of the support bearing 4. The larger the support bearing 4, the smaller the required speed. This does not conflict with increasing the size of the support bearing 4; if the size of the added support bearing 4 is smaller than the original bearing, there is more installation space, and the number of support bearings 4 can be increased. The advantage in quantity can make up for the problem of low load-bearing capacity of small bearings.

[0037] Since the number of support bearings 4 is increased, the load borne by each support bearing 4 is reduced, which is beneficial to the high-speed rotation of the bearing group structure. Since the centrifugal force generated by the bearing outer ring 42 and the centrifugal force of the main shaft offset each other, the load on the rotating body 43 is reduced. Reducing the load is beneficial to the high-speed rotation of the bearing outer ring 42.

[0038] In this solution, a rotating outer ring 3 is provided outside the bearing outer ring 42, and its force-bearing position forms an angle of 180 degrees with the rotating inner ring installed on the main shaft. Because the rotating outer ring 3 will be affected by the rotating inner ring 2 during operation and there is an unbalanced load, the centrifugal force of the rotating outer ring 3 is transmitted to the bearing at a point of application that is 180 degrees from the point of application of the rotating inner ring through the center of the circle, and their forces offset each other. The magnitude of the offset force increases with the increase of the rotation speed. The offset of the centrifugal force reduces the load on the rotating body 43, which is beneficial to the high-speed rotation of the bearing group structure.

[0039] Since there is lubricating fluid in the gap between the rotating outer ring 3 and the outer shell, the rotation of the main shaft drives the rotating inner ring 2 of the bearing group structure to rotate, and the rotating inner ring 2 drives the bearing outer ring 42 of the support bearing 4 to rotate, and the bearing outer ring 42 drives the rotating outer ring 3 to rotate. The rotating outer ring 3 transmits part of the force directly to the outer shell 1 through the lubricating fluid in the gap. This part of the force does not pass through the rotating body 43 of the support bearing 4, reducing the load of the rotating body 43, which is conducive to the high-speed rotation of the bearing group structure.

[0040] For other specific embodiments of the high-speed bearing group structure of the present invention, in order to meet different usage requirements, the number of support bearings can be designed to be three or more than four, and the three or more than four support bearings are arranged centrosymmetrically about the rotating inner ring. Alternatively, the support bearing group can be designed into three groups, and the three groups of support bearings are arranged centrosymmetrically about the rotating inner ring, and each group of support bearing groups includes three coaxially installed support bearings, which can also increase the contact area between the support bearings and the rotating inner ring and the rotating outer ring, and achieve the purpose of improving the pressure resistance of the entire bearing structure during high-speed operation. Or, the number of groups of the support bearing group can also be set to be more than four groups.

[0041] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and replacements can be made, and these improvements and replacements should also be regarded as the protection scope of the present invention.

Claims

1. A high-speed bearing set structure, characterized in that, It includes an outer housing, a rotating inner ring, a rotating outer ring and a support bearing installed in the outer housing. A central through hole is provided on the outer housing. The rotating inner ring is arranged at the central through hole. The support bearings are circumferentially and spacedly arranged on the outer periphery of the rotating inner ring. The support bearing includes an inner bearing ring, an outer bearing ring and a rotating body. A positioning shaft is connected between the outer housing and the inner bearing ring of each support bearing. The support bearing is tightly installed in the annular space between the rotating inner ring and the rotating outer ring. The rotating outer ring is used to always form a radially inward tightening force on the outer bearing ring of the support bearing to offset the centrifugal force generated by the rotating inner ring. The outer housing includes a first half shell and a second half shell that are snap-fitted and matched. The first half shell includes a front shell plate, an outer peripheral edge and a convex shaft. The structure of the second half shell is symmetrically arranged with that of the first half shell. The second half shell includes a rear shell plate, an outer peripheral edge and a convex shaft. The convex shafts of the first half shell and the second half shell are butted to form the positioning shaft. The outer peripheral edges of the first half shell and the second half shell are butted to form the annular outer wall of the outer housing. The rotating outer ring is installed in the annular outer wall with a gap, and a lubricating fluid is filled between the rotating outer ring and the annular outer wall.

2. The structure of the high-speed bearing set according to claim 1, characterized in that The positioning shaft is fixedly connected to the outer housing.

3. The high-speed bearing set structure according to claim 1, characterized in that, There are at least three groups of the support bearings, and at least three groups of support bearing groups are circumferentially and evenly distributed on the outer periphery of the rotating inner ring.

4. The high-speed bearing set structure according to claim 3, characterized in that There are at least six support bearings in total. Two support bearings among at least six support bearings form a support bearing group, and the two support bearings of each support bearing group are respectively installed on the same positioning shaft.

5. The structure of the high-speed bearing set according to claim 4, wherein, A positioning inner edge is provided in the middle of the inner wall of the rotating outer ring. The two support bearings of each support bearing group are respectively arranged on both sides of the positioning inner edge.

6. The structure of the high-speed bearing set according to claim 5, wherein, A stop ring is also sleeved on the positioning shaft, and the stop ring is axially pressed and matched with the inner bearing rings of the two support bearings of the support bearing group respectively.

7. The structure of the high-speed bearing set according to claim 1, characterized in that, A positioning ring groove is provided on the outer wall of the rotating inner ring, and the positioning ring groove is in concave-convex fit with the outer bearing ring of the support bearing.

8. The structure of the high-speed bearing set according to claim 4, characterized in that, The sum of the cross-sectional areas of at least three positioning shafts is greater than the cross-sectional area of the inner hole of the rotating inner ring.

Images