Main bearing of CT machine

Abstract

The invention provides a main bearing of a CT machine, and belongs to the technical field of bearing manufacturing. The CT machine main bearing comprises an inner ring, an outer ring and two rows of balls provided with retainers, one of the inner ring and the outer ring is provided with a raceway in contact with the two rows of balls, the other of the inner ring and the outer ring comprises a first split ring and a second split ring, the first split ring is provided with a boss used for temporarily supporting the first row of balls when the first row of balls are installed, and the second split ring is provided with a boss used for temporarily supporting the second row of balls when the second row of balls are installed. Gaskets are fixed on the two split rings through ferrules respectively, the two ferrules are integrated annular rings and are provided with raceways in contact with the balls, and the two split rings are provided with inner diameters or outer diameters matched with the corresponding ferrules so that the corresponding ferrules can be directly installed on the split rings in the axial direction. A supporting ring used for temporarily supporting the second row of balls when the second row of balls are installed is arranged between the two split rings in a clamped mode. Compared with an existing steel wire with a notch, the integrated annular ring is higher in structural strength, the problem of abnormal sound of the bearing is completely eradicated, and meanwhile it is guaranteed that the bearing can be smoothly assembled through the supporting ring.

Description

Technical Field

[0001] The invention relates to a main bearing of a CT machine and belongs to the technical field of bearing manufacturing. Background Art

[0002] The main bearing of the CT machine is used in the connection between the fixed CT frame and the rotating scanning part. It is a key component of the rotating scanning part of the CT machine. It is used to transmit and withstand the axial load, radial load and overturning moment generated by devices such as X-ray tubes, collimators, detectors, slip rings, etc. It must meet the CT machine's high speed, low noise, high precision, low vibration and long life requirements.

[0003] The Chinese utility model patent with the authorization announcement number CN217977029U discloses a new type of combined steel wire raceway CT machine bearing, which is a double-row angular contact ball bearing, including an inner ring, an outer ring group is arranged outside the inner ring, two rows of steel balls are arranged between the inner ring and the outer ring group, and each row of steel balls is equipped with a retainer. The outer ring group includes an outer upper ring and an outer lower ring, and the outer upper ring and the outer lower ring are respectively provided with a recessed matching part recessed inward, and the two recessed matching parts are respectively installed with rubber gaskets through outer steel wires, and the two outer steel wires are respectively provided with a raceway matching with the steel ball, and the inner ring is also provided with a raceway matching with the steel ball.

[0004] The above-mentioned CT machine bearing has a rubber liner between the outer steel wire and the outer ring, which can reduce the vibration and noise generated by the bearing when running at high speed. However, those skilled in the art know that the outer steel wire has a cutout and is not an integrated ring-shaped steel wire. For example, the Chinese utility model patent with the authorization announcement number CN221569207U discloses a steel wire structure for a steel wire roller CT machine bearing, which discloses that the two ends of the steel wire are provided with cutouts, and the cutouts have a certain inclination. After installation, the cutouts at both ends are in contact so that the steel wire can be enclosed into a circle. This structure is actually convenient for the installation of the steel wire. Figure 1 The figure shows the structure of the outer upper ring in patent CN217977029U, on which the first boss 1.1 and the second boss 1.2 are arranged. Since the inner diameter of the recessed fitting portion 1.3 is large and the inner diameter of the second boss 1.2 is small, the steel wire cannot pass over the second boss 1.2 and be installed in the recessed fitting portion 1.3 when it is in a circular shape. By using the incision, the two ends of the steel wire can be overlapped first to reduce its outer diameter so that it can pass through the second boss 1.2 and then be opened into a circle after installation.

[0005] According to common sense in this field, the setting of the first boss 1.1 and the second boss 1.2 is also for a reason. When the bearing is assembled, the upper gasket and the upper outer steel wire are first installed in the outer upper ring, and the lower gasket and the lower outer steel wire are installed in the outer lower ring. Then the outer upper ring is inverted, and the first row of steel balls and the retaining cage are installed into the outer upper ring together. Since the retaining cage used in the bearing is not a complete ring and also has a cutout, the raceway of the upper outer steel wire alone cannot form effective support for the first row of steel balls. The retaining cage will droop downward due to the presence of the cutout. At this time, the first boss 1.1 can be used to form temporary support for the first row of steel balls until the inner ring is installed. Then the upper raceway of the inner ring and the raceway on the upper outer steel wire can be used to limit the first row of steel balls. Similarly, before installing the outer lower ring, the lower raceway of the inner ring alone cannot provide effective support for the second row of steel balls. At this time, the second boss 1.2 can be used to provide temporary support for the second row of steel balls until the outer lower ring is installed. Then, the raceway on the lower outer steel wire and the lower raceway of the inner ring can be used to limit the position of the second row of steel balls.

[0006] However, for the upper outer steel wire and the lower outer steel wire, due to the existence of the cut, the structural strength of the steel wire is not as good as that of the one-piece ring, and the cut is difficult to align. There is a certain probability of misalignment or gap, causing the steel ball to collide and vibrate every time it runs to the position of the cut, causing abnormal noise in the bearing. Summary of the invention

[0007] The object of the present invention is to provide a CT machine main bearing to solve the problem that the steel wire of the existing CT machine main bearing has low structural strength due to the presence of a cutout and that the cutout may cause misalignment or gaps, thereby causing abnormal noise in the bearing.

[0008] To achieve the above purpose, the main bearing of the CT machine in the present invention adopts the following technical solution: A CT machine main bearing comprises an inner ring, an outer ring and two rows of balls each equipped with a cage, one of the inner ring and the outer ring is provided with raceways respectively contacting the two rows of balls, and the other comprises a first split ring and a second split ring which are fixedly connected, the first split ring is provided with a boss for temporarily supporting the first row of balls when the first row of balls and the cage are installed, the two split rings are respectively fixed with a gasket through a ferrule, the ferrules on the two split rings are both integral annular rings and are both provided with raceways contacting the balls, the two split rings have an inner diameter or an outer diameter adapted to the corresponding ferrule so that the corresponding ferrule can be directly mounted on the split ring along the axial direction, and a support ring for temporarily supporting the second row of balls when the second row of balls and the cage are installed is sandwiched between the two split rings.

[0009] The beneficial effects of the above technical solution are as follows: the present invention is an improved invention, which further defines that the rings on the two split rings are both integral annular rings and are both provided with raceways in contact with the balls. The integral annular ring has higher structural strength than the steel wire with incisions in the prior art, and eliminates the problem of abnormal noise in the bearing caused by misalignment or gaps at the incisions; at the same time, the two split rings have inner diameters or outer diameters that match the corresponding rings so that the corresponding rings can be directly axially mounted on the split rings. Compared with the prior art, it is equivalent to removing a boss structure to ensure that the integral ring can be installed in the corresponding split ring; a support ring is sandwiched between the two split rings for temporarily supporting the second row of balls when installing the second row of balls and the retaining frame. The support ring makes up for the temporary support function of the removed boss structure to ensure that the bearing assembly can proceed smoothly.

[0010] Furthermore, the first split ring and the second split ring have mating end faces in contact with each other, the mating end face of the first split ring is provided with an installation step for the support ring to be installed, and the mating end face of the second split ring presses the support ring.

[0011] Furthermore, the support ring is provided with an inclined surface for contacting with the second row of balls.

[0012] Furthermore, the gaskets on the two split rings each include a cylindrical portion pre-compressed by the circumferential surface of the corresponding ring and a plate portion pre-compressed by the end surface of the corresponding ring. The cylindrical portion and the plate portion are connected and have an L-shaped longitudinal section.

[0013] Furthermore, both split rings are provided with mounting grooves for installing corresponding gaskets, and the mounting grooves include a circumferential groove for accommodating the cylindrical part of the corresponding gasket and an end face groove for accommodating the plate-like part of the corresponding gasket. The circumferential groove and the end face groove are connected, and the ring is fixed to the corresponding split ring by heat fitting or press fitting.

[0014] Furthermore, the pre-compression deformation amount of the cylindrical part is 0.1 to 0.6 mm, and the pre-compression deformation amount of the plate-shaped part is 0.1 to 0.5 mm.

[0015] Furthermore, the two split rings are fixedly connected by threaded fasteners.

[0016] Furthermore, the two split rings are provided with stop structures for positioning the two split rings before installing the threaded fasteners.

[0017] Furthermore, the supporting ring is a plastic ring.

[0018] Furthermore, the supporting ring is a nylon ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the outer upper ring of a CT machine bearing in the prior art; Figure 2 It is a cross-sectional view of Embodiment 1 of the main bearing of a CT machine of the present invention; Figure 3 It is a partial cross-sectional view of the integrated ring in Embodiment 1 of the CT machine main bearing of the present invention; Figure 4 It is a partial cross-sectional view of the first split ring in Embodiment 1 of the CT machine main bearing of the present invention; Figure 5 It is a partial cross-sectional view of the second split ring in Embodiment 1 of the CT machine main bearing of the present invention; Figure 6 It is a cross-sectional view of Embodiment 2 of the main bearing of a CT machine of the present invention; Figure 1 Middle: 1.1, first boss; 1.2, second boss; 1.3, recessed mating portion; Figure 2~Figure 6 In: 1. first split ring; 1-1. boss; 1-2. first mounting groove; 1-2-1. first end face groove; 1-2-2. first circumferential groove; 1-3. first matching circumferential surface; 1-4. first mating end face; 1-5. mounting step; 2. second split ring; 2-1. second mounting groove; 2-1-1. second end face groove; 2-1-2. second circumferential groove; 2-2. second mating end face; 2-3. second matching circumferential surface; 3. integrated ring; 3-1. first raceway; 3-2. second raceway; 4. first ball; 5. first retaining frame; 6. second ball; 7. second retaining frame; 8. first gasket; 9. first ferrule; 10. second gasket; 11. second ferrule; 12. support ring; 13. screw. DETAILED DESCRIPTION

[0020] In view of the technical problems existing in the prior art, the basic concept of the present invention is to use an integrated ring to achieve the fixed installation of the gasket. The integrated ring has no incisions, has high structural strength, and will not cause abnormal noise in the bearing. At the same time, in order to achieve the installation of the integrated ring, the present invention designs two split rings with inner diameters or outer diameters that match the corresponding rings, so that the corresponding rings can be directly installed on the split rings along the axial direction, and a support ring is sandwiched between the two split rings to temporarily support the second row of balls when installing the second row of balls and retaining cages, thereby ensuring the smooth assembly of the bearing.

[0021] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0022] Embodiment 1 of the main bearing of a CT machine in the present invention: like Figure 2As shown, the main bearing of the CT machine includes an inner ring, an outer ring and two rows of balls each equipped with a retainer. The balls in the two rows are respectively the first balls 4 and the second balls 6. One row of first balls 4 is equipped with a first retainer 5, and one row of second balls 6 is equipped with a second retainer 7. Both the first retainer 5 and the second retainer 7 are not complete rings, but have cutouts.

[0023] The outer ring in this embodiment is an integral ring 3, on which raceways are provided that contact the two rows of balls respectively. Figure 2 and Figure 3 As shown, there is a first raceway 3-1 in contact with the first ball 4 and a second raceway 3-2 in contact with the second ball 6 respectively.

[0024] The inner ring in this embodiment is a combined ring, including a first split ring 1 and a second split ring 2 that are fixedly connected. The two split rings are fixedly connected by threaded fasteners, which are specifically screws 13. This connection method has higher reliability and avoids the use of non-standard large-diameter fine-pitch threads for connection, which may cause thread jump and random threading when subjected to impact during transportation, thereby avoiding the loss of precision and failure of the bearing. At the same time, to facilitate assembly operations, the two split rings are provided with a stop structure for locating the positions of the two split rings before installing the screws 13, and the two split rings have mating end faces that are in contact with each other, wherein the first split ring 1 is the first mating end face 1-4 ( Figure 4 As shown), the second split ring 2 is the second mating end face 2-2 ( Figure 5 as shown).

[0025] The two split rings are respectively fixed with gaskets through ferrules, such as Figure 2 As shown, the first split ring 1 is fixed with a first gasket 8 through a first ring 9, and the second split ring 2 is fixed with a second gasket 10 through a second ring 11. Both the first gasket 8 and the second gasket 10 are rubber gaskets, which can be made of nitrile rubber material or hydrogenated nitrile rubber material. The first ring 9 and the second ring 11 are both one-piece annular rings. The first ring 9 is provided with a raceway in contact with the first ball 4, and the second ring 11 is provided with a raceway in contact with the second ball 6. Both rings are thin-walled steel rings, which are integrally hardened with bearing steel. Since the steel rings are provided with raceways, they can also be called thin-walled raceway steel rings. Compared with the steel wire with cutouts in the prior art, the one-piece annular ring has a higher structural strength, and eliminates the problem of abnormal noise in the bearing caused by misalignment or gaps at the cutouts.

[0026] Both split rings have an outer diameter that matches the corresponding ring so that the corresponding ring can be directly installed on the split ring along the axial direction. At the same time, both split rings are provided with installation grooves for installing corresponding gaskets. Since the function of the ring is to compress the gasket and provide a raceway for the ball, the meaning of "matching" is that the ring can be installed on the split ring and compress the gasket at the same time. The split ring has an adapting part, and the outer diameter of the adapting part is slightly smaller than the inner diameter of the corresponding ring, so that the gap between the two is used to guide the ring to move smoothly along the axial direction, which is convenient for the ring to be installed through the adapting part of the split ring.

[0027] Combination Figure 2 and Figure 4 As shown, the first split ring 1 is provided with a first installation groove 1-2 for installing the first gasket 8. The first gasket 8 includes a cylindrical portion pre-pressed by the inner circumference of the first ring 9 and a plate portion pre-pressed by the end face of the first ring 9. The cylindrical portion and the plate portion are connected and have an L-shaped longitudinal section. Therefore, the first installation groove 1-2 includes a first circumferential groove 1-2-2 for accommodating the cylindrical portion of the first gasket 8 and a first end face groove 1-2-1 for accommodating the plate portion of the first gasket 8. The first circumferential groove 1-2-2 and the first end face groove 1-2-1 are connected. The first split ring 1 has a first adapting circumferential surface 1-3, which is located between the first circumferential groove 1-2-2 and the first mating end surface 1-4. The outer diameter of the first adapting circumferential surface 1-3 is slightly smaller than the inner diameter of the first ferrule 9. The first adapting circumferential surface 1-3 is the adapting part on the first split ring 1, that is, the first ferrule 9 needs to cross the first adapting circumferential surface 1-3 along the axial direction to be installed in place. Since the first ferrule 9 needs to press the cylindrical part of the first gasket 8 after crossing the first adapting circumferential surface 1-3, the original outer diameter of the cylindrical part is larger than the outer diameter of the first adapting circumferential surface 1-3, and the first ferrule 9 needs to be installed by heat-fitting or press-fitting to pre-tighten the cylindrical part of the first gasket 8.

[0028] During processing and manufacturing, the inner diameter of the first ring 9 and the bottom diameter of the first circumferential groove 1-2-2 are controlled so that the cylindrical part of the first liner 8 has a pre-compression deformation of 0.1 to 0.6 mm on one side in the radial direction after installation; at the same time, the distance from the bottom of the first end face groove 1-2-1 to the first mating end face 1-4 is controlled so that the plate-like part of the first liner 8 has a pre-compression deformation of 0.1 to 0.5 mm on one side in the axial direction after installation, so as to ensure the use effect of the first liner 8.

[0029] Combination Figure 2 and Figure 5As shown, the second split ring 2 is provided with a second installation groove 2-1 for installing the second gasket 10. The second gasket 10 includes a cylindrical portion pre-pressed by the inner circumference of the second ring 11 and a plate portion pre-pressed by the end face of the second ring 11. The cylindrical portion and the plate portion are connected and the longitudinal section is L-shaped. Therefore, the second installation groove 2-1 includes a second circumferential groove 2-1-2 for accommodating the cylindrical portion of the second gasket 10 and a second end face groove 2-1-1 for accommodating the plate portion of the second gasket 10. The second circumferential groove 2-1-2 is connected to the second end face groove 2-1-1. The second split ring 2 has a second matching circumferential surface 2-3. The outer diameter of the second matching circumferential surface 2-3 is slightly smaller than the inner diameter of the second ring 11. The second matching circumferential surface 2-3 is the matching part on the second split ring 2, that is, the second ring 11 needs to cross the second matching circumferential surface 2-3 along the axial direction to be installed in place. Since the second ring 11 needs to compress the cylindrical part of the second liner 10 after crossing the second matching surface 2-3, the original outer diameter of the cylindrical part is larger than the outer diameter of the second matching surface 2-3. The second ring 11 needs to be installed by heat fitting or press fitting to pre-tighten the cylindrical part of the second liner 10.

[0030] During processing and manufacturing, the inner diameter of the second ring 11 and the bottom diameter of the second circumferential groove 2-1-2 are controlled so that the cylindrical part of the second liner 10 has a pre-compression deformation of 0.1 to 0.6 mm on one side in the radial direction after installation; at the same time, the distance from the bottom of the second end face groove 2-1-1 to the second mating end face 2-2 is controlled so that the plate-like part of the second liner 10 has a pre-compression deformation of 0.1 to 0.5 mm on one side in the axial direction after installation, so as to ensure the use effect of the second liner 10.

[0031] In addition, combined Figure 2 and Figure 4 As shown, the first split ring 1 is provided with a boss 1-1 for temporarily supporting each first ball 4 when installing the first ball 4 and the first retainer 5, which facilitates the installation of the first row of balls and the retainer. At the same time, a support ring 12 is sandwiched between the two split rings for temporarily supporting the second row of balls when installing the second row of balls and the retainer. Since the first ring 9 in the present invention is an integrated annular ring and is directly installed, the setting of the first adapting peripheral surface 1-3 on the first split ring 1 is equivalent to canceling a boss structure in the prior art, otherwise the boss structure will interfere with the first ring 9, and canceling the boss structure means the loss of the temporary support function for the second row of balls, and the support ring 12 just makes up for this function, ensuring that the assembly of the bearing can proceed smoothly.

[0032] At the same time, the edge of the first mating end face 1-4 is provided with an installation step 1-5 for the support ring 12 to be installed, so as to facilitate the positioning of the support ring 12. The second mating end face 2-2 of the second split ring 2 presses the support ring 12 to fix the support ring 12 and prevent it from moving.

[0033] In addition, the support ring 12 is provided with an inclined surface for contacting each second ball 6 when installing the second row of balls and the cage, so that the support effect is better. At the same time, the support ring 12 is a plastic ring, preferably a nylon ring, which is injection molded with nylon material, has good processability and low cost, and the nylon material has good damping performance, so the vibration of the bearing during operation will not cause the support ring 12 to generate noise.

[0034] When assembling the main bearing of the CT machine of the present invention, firstly, the first liner 8 is installed in the first installation groove 1-2 of the first split ring 1, and then the first ferrule 9 is installed by heat-fitting or press-fitting method, so as to ensure that the cylindrical part of the first liner 8 has a set pre-compression deformation amount. At the same time, the second liner 10 is installed in the second installation groove 2-1 of the second split ring 2, and then the second ferrule 11 is installed by heat-fitting or press-fitting method, so as to ensure that the cylindrical part of the second liner 10 has a set pre-compression deformation amount.

[0035] The remaining assembly process of the CT machine main bearing is as follows: First, place the first split ring 1 with the screw head plane at the bottom and horizontally on a platform or fulcrum, that is, Figure 2 From the perspective of the embodiment, the first split ring 1 is placed upside down on a platform or a fulcrum, and then the first row of balls and the retaining frame are installed from top to bottom. At this time, the raceway on the first ring 9 can support each first ball 4, but since the first retaining frame 5 has a cutout, it will droop downward. At this time, the boss 1-1 can be used to form a temporary support for each first ball 4 to maintain the basic shape of the first row of balls and the retaining frame. Then the integrated ring 3 is installed from top to bottom. When the first raceway 3-1 on the integrated ring 3 contacts each first ball 4, the first ball 4 is separated from the boss 1-1, a gap is formed between the boss 1-1, and is limited between the first raceway 3-1 and the raceway of the first ring 9.

[0036] Then, the support ring 12 is mounted on the installation step 1-5 of the first split ring 1, with the inclined surface of the support ring 12 facing upwards, and then the second row of balls and the retaining frame are installed from top to bottom. At this time, the second raceway 3-2 on the integral ring 3 can support each second ball 6, but since the second retaining frame 7 has a cutout and will droop downwards, the support ring 12 can be used to form a temporary support for each second ball 6 to maintain the basic shape of the second row of balls and the retaining frame. Then, the second split ring 2 is installed from top to bottom. When the raceway of the second ring 11 on the second split ring 2 contacts each second ball 6, the second ball 6 is separated from the support ring 12, a gap is formed between the support ring 12, and the second ball 6 is limited between the second raceway 3-2 and the raceway of the second ring 11. Finally, install each screw 13 from bottom to top and pre-tighten them crosswise and symmetrically around the circumference. Under the pre-tightening force of the screws 13, the mating end faces of the first split ring 1 and the second split ring 2 are in contact, the end face of the first ring 9 performs axial pre-tightening on the plate-like part of the first gasket 8, and the end face of the second ring 11 performs axial pre-tightening on the plate-like part of the second gasket 10. At the same time, the first split ring 1 and the second split ring 2 are fixed.

[0037] When the main bearing of the CT machine is in use, the bearing is in a vertical state, and the combined ring composed of the first split ring 1 and the second split ring 2 is fixed to the CT frame by mounting bolts; the rotating scanning part of the CT machine, such as the X-ray tube, collimator, detector, slip ring, etc., is installed on the end face of the integrated ring 3 by screws; the integrated ring 3 is driven to rotate by the driving device through a synchronous toothed belt or a multi-V belt; when the integrated ring 3 with a mass of hundreds of kilograms rotates at high speed, the axial load, radial load, overturning moment, vibration and impact energy generated are transmitted to the CT frame through the two raceways of the integrated ring 3, the first ball 4 and the second ball 6, the first ring 9 and the second ring 11, the first gasket 8 and the second gasket 10, the first split ring 1 and the second split ring 2. In this transmission process, due to the inlay of the gasket, the high damping performance of the gasket is utilized to isolate and consume the vibration and impact energy generated by the rotation of the integrated ring 3, thereby greatly reducing the vibration and noise of the bearing during operation.

[0038] Embodiment 2 of the main bearing of a CT machine in the present invention: like Figure 6As shown, the main difference from Example 1 is that the combined ring composed of the first split ring 1 and the second split ring 2 is an outer ring, and the integrated ring 3 is an inner ring. At this time, the integrated ring 3 is still a rotating ring, fixedly connected to the rotating scanning part of the CT machine, and the combined ring composed of the first split ring 1 and the second split ring 2 is still a fixed ring, fixedly connected to the CT frame. At this time, the first gasket 8 and the first ring 9 are still installed on the first split ring 1, the second gasket 10 and the second ring 11 are still installed on the second split ring 2, and the support ring 12 is still sandwiched between the first split ring 1 and the second split ring 2. The effect is the same as in Example 1 and will not be repeated here. It should also be noted that in this embodiment, both of the two split rings have an inner diameter that matches the corresponding ring, and the outer diameters of the two rings are slightly smaller than the inner diameter of the corresponding split ring matching part, so the two rings can still be smoothly installed through the guidance of the corresponding split ring matching part.

[0039] In other embodiments of the main bearing of a CT machine: the support ring can also be made of other engineering plastics such as polyethylene or polypropylene, and of course the support ring can also be a steel ring.

[0040] In other embodiments of the main bearing of a CT machine: the two split rings may no longer be provided with a stop structure and may be directly fixed with screws.

[0041] In other embodiments of the CT machine main bearing: the threaded fasteners used to fix the two split rings can also be a combination of bolts and nuts.

[0042] In other embodiments of the CT machine main bearing: the two split rings may be directly threadedly connected instead of being fixedly connected by threaded fasteners, that is, one of them is provided with an internal thread and the other is provided with an external thread.

[0043] In other embodiments of the main bearing of a CT machine: the pre-tightening deformation of the two cylindrical parts of the gaskets may not be in the range of 0.1 to 0.6 mm. Depending on the specific dimensions of the gasket and the bearing, the pre-tightening deformation of the cylindrical parts may be greater than 0.6 mm, such as 0.7 mm, 0.8 mm or even greater; of course, the pre-tightening deformation of the two plate-like parts of the gaskets may not be in the range of 0.1 to 0.5 mm. Depending on the specific dimensions of the gasket and the bearing, the pre-tightening deformation of the plate-like parts may be greater than 0.5 mm, such as 0.6 mm, 0.7 mm or even greater.

[0044] In other embodiments of the main bearing of a CT machine: the two split rings may no longer be provided with mounting grooves including circumferential grooves and end grooves. In this case, the gasket is directly installed on the corresponding split ring. In this case, the ring still needs to be installed by heat fitting or press fitting so that the cylindrical part of the gasket can achieve the required pre-tightening deformation.

[0045] In other embodiments of the main bearing of a CT machine: the longitudinal section of the liner may not be L-shaped. In addition to having a circumferential surface and an end surface in contact with the corresponding split ring, the portion in contact with the corresponding ferrule is an arc surface. In this case, a matching arc surface is provided on the ferrule, that is, there are two arc surfaces on the ferrule, one is in contact with the liner, and the other is in contact with the ball.

[0046] In other embodiments of the main bearing of a CT machine: the support ring may no longer be provided with an inclined surface in contact with the second row of balls, and the second row of balls can be directly supported by the edges of the support ring.

[0047] In other embodiments of the main bearing of the CT machine: a mounting step can also be set on the second split ring, and the mounting steps on the two split rings are interlocked to achieve compression and fixation of the support ring; in other embodiments, no mounting step is set on any of the split rings, and the support ring is directly clamped between the end faces of the two split rings.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. A CT machine main bearing, comprising an inner ring, an outer ring and two rows of balls each equipped with a cage, one of the inner ring and the outer ring is provided with a raceway respectively contacting the two rows of balls, the other comprises a first split ring and a second split ring fixedly connected, the first split ring is provided with a boss for temporarily supporting the first row of balls when the first row of balls and the cage are installed, and the two split rings are respectively fixed with a liner through a ring, wherein: The rings on the two split rings are both integral annular rings and are both provided with raceways that contact the balls. The two split rings have inner diameters or outer diameters that match the corresponding rings so that the corresponding rings can be directly installed axially onto the split rings. A support ring is sandwiched between the two split rings for temporarily supporting the second row of balls when installing the second row of balls and retaining cages.

2. The CT machine main bearing according to claim 1 is characterized in that: The first split ring and the second split ring have mating end faces in mating contact. The mating end face of the first split ring is provided with an installation step for the support ring to be installed. The mating end face of the second split ring presses the support ring.

3. The CT machine main bearing according to claim 1 or 2, characterized in that: The support ring is provided with an inclined surface for contacting the second row of balls.

4. The CT machine main bearing according to claim 1 or 2, characterized in that: The gaskets on the two split rings each include a cylindrical portion pre-pressed by the circumferential surface of the corresponding ring and a plate portion pre-pressed by the end surface of the corresponding ring. The cylindrical portion and the plate portion are connected and have an L-shaped longitudinal section.

5. The CT machine main bearing according to claim 4 is characterized in that: Both split rings are provided with mounting grooves for installing corresponding gaskets. The mounting grooves include a circumferential groove for accommodating the cylindrical part of the corresponding gasket and an end groove for accommodating the plate-like part of the corresponding gasket. The circumferential groove and the end groove are connected, and the ring is fixed to the corresponding split ring by heat fitting or press fitting.

6. The CT machine main bearing according to claim 4 is characterized in that: The pre-compression deformation of the cylindrical part is 0.1 to 0.6 mm, and the pre-compression deformation of the plate-shaped part is 0.1 to 0.5 mm.

7. The CT machine main bearing according to claim 1 or 2, characterized in that: The two split rings are fixedly connected by threaded fasteners.

8. The CT machine main bearing according to claim 7 is characterized in that: The two split rings are provided with stop structures for positioning the positions of the two split rings before installing the threaded fasteners.

9. The CT machine main bearing according to claim 1 or 2, characterized in that: The support ring is a plastic ring.

10. The CT machine main bearing according to claim 9, characterized in that: The support ring is a nylon ring.

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