A main bearing of a CT machine

Abstract

The present invention provides a main bearing for a CT machine, belonging to the technical field of bearing manufacturing. The main bearing for a CT machine includes 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 in contact with the two rows of balls, and the other includes a first split ring and a second split ring. The first split ring is provided with a boss for temporarily supporting the first row of balls when installing the first row of balls. Gaskets are respectively fixed on the two split rings through retaining rings. Both retaining rings are integral annular rings and are provided with raceways in contact with the balls. Both split rings have an inner diameter or an outer diameter adapted to the corresponding retaining ring for the corresponding retaining ring to be directly installed on the split ring along the axial direction. A support ring for temporarily supporting the second row of balls when installing the second row of balls is clamped between the two split rings. Compared with the existing steel wire with a notch, the integral annular ring has higher structural strength, eliminating the problem of abnormal noise of the bearing. At the same time, the use of the support ring ensures the smooth assembly of the bearing.

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 the common knowledge in the field, the settings of the first boss 1.1 and the second boss 1.2 also have reasons. When assembling the bearing, first, a upper gasket and an upper outer wire are installed in the outer upper ring, and a lower gasket and a lower outer wire are installed in the outer lower ring. Then, the outer upper ring is inverted, and the first row of steel balls and the cage are loaded into the outer upper ring together. Since the cage used in the bearing is not a complete ring and also has a cut, the raceway of the upper outer wire alone cannot effectively support the first row of steel balls. Due to the existence of the cut, the cage will sag downward. At this time, the first boss 1.1 can be used to temporarily support the first row of steel balls until the inner ring is installed. After that, the upper raceway of the inner ring and the raceway on the upper outer 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 effectively support the second row of steel balls. At this time, the second boss 1.2 can be used to temporarily support the second row of steel balls until the outer lower ring is installed. After that, the raceway on the lower outer wire and the lower raceway of the inner ring can be used to limit the second row of steel balls.

[0006] However, for the upper outer wire and the lower outer wire, due to the existence of the cut, the structural strength of the wire is lower than that of an integral ring, and it is very difficult to align the cut positions. There is a certain probability of misalignment or gap, so that the steel balls will collide and vibrate every time they run to the cut position, causing abnormal noise in the bearing. Summary of the Invention

[0007] The purpose of the present invention is to provide a main bearing for a CT machine to solve the problems that the wire of the existing main bearing for a CT machine has low structural strength due to the existence of the cut and misalignment or gap will occur at the cut position, resulting in abnormal noise in the bearing.

[0008] To achieve the above object, the main bearing for a CT machine in the present invention adopts the following technical solutions:

[0009] A main bearing for a CT machine includes 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 includes 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 installing the first row of balls and the cage. Gaskets are respectively fixed on the two split rings through rings. The rings on the two split rings are both integral annular rings and are both provided with raceways contacting the balls. The two split rings both have an inner diameter or an outer diameter adapted to the corresponding ring for the corresponding ring to be directly installed on the split ring along the axial direction. A support ring for temporarily supporting the second row of balls when installing the second row of balls and the cage is clamped between the two split rings.

[0010] The beneficial effects of the above technical solution are as follows: The present invention belongs to an improved invention. It 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 compared with the wire with a notch in the prior art, eliminating the problem of misalignment or gap at the notch causing abnormal noise in the bearing. At the same time, both of the two split rings have an inner diameter or an outer diameter adapted to the corresponding ring for the corresponding ring to be directly axially mounted on the split ring. Compared with the prior art, it is equivalent to removing a boss structure, ensuring that the integral ring can be inserted into the corresponding split ring. A support ring is clamped between the two split rings for temporarily supporting the second row of balls when installing the second row of balls and the cage. The support ring compensates for the temporary support function of the removed boss structure, ensuring the smooth assembly of the bearing.

[0011] Further, the first split ring and the second split ring have mating end faces in contact with each other. An installation step for sleeving and installing the support ring is provided on the mating end face of the first split ring, and the mating end face of the second split ring presses against the support ring.

[0012] Further, the support ring is provided with an inclined surface for contacting the second row of balls.

[0013] Further, the gaskets on the two split rings both include a cylindrical part pre-compressed by the circumferential surface of the corresponding ring and a plate-like part pre-compressed by the end face of the corresponding ring. The cylindrical part and the plate-like part are connected and the longitudinal section is in an L shape.

[0014] Further, installation grooves for installing the corresponding gaskets are provided on both of the two split rings. The installation groove includes 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 communicated, and the ring is fixed on the corresponding split ring by hot fitting or press fitting.

[0015] Further, the pre-compression deformation amount of the cylindrical part is 0.1 - 0.6 mm, and the pre-compression deformation amount of the plate-like part is 0.1 - 0.5 mm.

[0016] Further, the two split rings are fixedly connected by threaded fasteners.

[0017] Further, a stop structure for positioning the positions of the two split rings before installing the threaded fasteners is provided on the two split rings.

[0018] Further, the support ring is a plastic ring.

[0019] Further, the support ring is a nylon ring. Description of the Drawings

[0020] Figure 1 It is a structural diagram of the outer upper ring of the CT machine bearing in the prior art;

[0021] Figure 2 This is a cross-sectional view of the main bearing of the CT machine according to Embodiment 1 of the present invention;

[0022] Figure 3 This is a partial cross-sectional view of the integral ring in the main bearing of the CT machine according to Embodiment 1 of the present invention;

[0023] Figure 4 This is a partial cross-sectional view of the first split ring in the main bearing of the CT machine according to Embodiment 1 of the present invention;

[0024] Figure 5 This is a partial cross-sectional view of the second split ring in the main bearing of the CT machine according to Embodiment 1 of the present invention;

[0025] Figure 6 This is a cross-sectional view of the main bearing of the CT machine according to Embodiment 2 of the present invention;

[0026] Figure 1 Wherein: 1.1, the first boss; 1.2, the second boss; 1.3, the recessed mating part;

[0027] Figures 2 to 6 Wherein: 1, the first split ring; 1-1, the boss; 1-2, the first mounting groove; 1-2-1, the first end face groove; 1-2-2, the first circumferential face groove; 1-3, the first mating circumferential face; 1-4, the first mating end face; 1-5, the mounting step; 2, the second split ring; 2-1, the second mounting groove; 2-1-1, the second end face groove; 2-1-2, the second circumferential face groove; 2-2, the second mating end face; 2-3, the second mating circumferential face; 3, the integral ring; 3-1, the first raceway; 3-2, the second raceway; 4, the first ball; 5, the first cage; 6, the second ball; 7, the second cage; 8, the first gasket; 9, the first ring; 10, the second gasket; 11, the second ring; 12, the support ring; 13, the screw. Detailed implementation manners

[0028] Aiming at the technical problems existing in the prior art, the basic concept of the present invention is to use an integral ring to realize the fixed installation of the gasket. The integral ring has no cut, high structural strength, and will not cause abnormal noise in the bearing. At the same time, in order to realize the installation of the integral ring, the present invention designs that both split rings have an inner diameter or an outer diameter adapted to the corresponding ring, so that the corresponding ring can be directly installed on the split ring along the axial direction, and a support ring is clamped between the two split rings to temporarily support the second row of balls when installing the second row of balls and cages, ensuring the smooth assembly of the bearing.

[0029] The features and performance of the present invention will be further described in detail below in conjunction with embodiments.

[0030] Embodiment 1 of the main bearing of the CT machine in the present invention:

[0031] As Figure 2 shown, the main bearing of the CT machine includes an inner ring, an outer ring, and two rows of balls each equipped with a cage. The balls in the two rows are the first balls 4 and the second balls 6 respectively. The first balls 4 in one row are equipped with a first cage 5, and the second balls 6 in one row are equipped with a second cage 7. Neither the first cage 5 nor the second cage 7 is a complete ring, but has a notch.

[0032] In this embodiment, the outer ring is an integral ring 3. The integral ring 3 is provided with raceways that respectively contact the two rows of balls. Combining Figure 2 and Figure 3 shown, they are the first raceway 3-1 that contacts the first balls 4 and the second raceway 3-2 that contacts the second balls 6 respectively.

[0033] 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 a threaded fastener. The threaded fastener is specifically a screw 13. This connection method has higher reliability and avoids the phenomenon of thread skipping and threading disorder when bearing impact during transportation due to using non-standard large-diameter fine-threaded screws for connection, thereby avoiding the situation where the bearing loses accuracy and fails. At the same time, for the convenience of assembly operation, the two split rings are provided with a stop structure for positioning the positions of the two split rings before installing the screw 13, and the two split rings have mating end faces that are in contact. Among them, the first split ring 1 has a first mating end face 1-4 ( Figure 4 shown), and the second split ring 2 has a second mating end face 2-2 ( Figure 5 shown).

[0034] Gaskets are respectively fixed on the two split rings through rings. As Figure 2 shown, a first gasket 8 is fixed on the first split ring 1 through a first ring 9, and a second gasket 10 is fixed on the second split ring 2 through a second ring 11. Both the first gasket 8 and the second gasket 10 are rubber gaskets, and specifically can be made of nitrile rubber material or hydrogenated nitrile rubber material. Both the first ring 9 and the second ring 11 are integral annular rings. The first ring 9 is provided with a raceway that contacts the first balls 4, and the second ring 11 is provided with a raceway that contacts the second balls 6. Both rings are thin-walled steel rings, and are integrally hardened with bearing steel. Because the rings are provided with raceways, they can also be called thin-walled raceway steel rings. Compared with the existing wire with a notch, the integral annular ring has higher structural strength and eliminates the problem of abnormal noise generated by the bearing due to misalignment or gap at the notch.

[0035] Both split rings have an outer diameter adapted to the corresponding raceway ring for the corresponding raceway ring to be directly axially mounted onto the split ring. At the same time, both split rings are provided with mounting grooves for mounting the corresponding gasket. Since the function of the raceway ring is to compress the gasket and provide a raceway for the balls, the meaning of "adapted" is that the raceway ring can be mounted onto the split ring and can also compress the gasket. The split ring has an adapted part, and the outer diameter of the adapted part is slightly smaller than the inner diameter of the corresponding raceway ring, so as to use the gap between the two to guide the raceway ring to move smoothly axially, facilitating the installation of the raceway ring through the adapted part of the split ring.

[0036] Combined with Figure 2 and Figure 4 As shown, the first split ring 1 is provided with a first mounting groove 1-2 for mounting the first gasket 8. The first gasket 8 includes a cylindrical part pre-compressed by the inner peripheral surface of the first raceway ring 9 and a plate-like part pre-compressed by the end face of the first raceway ring 9. The cylindrical part and the plate-like part are connected and the longitudinal section is L-shaped. Therefore, the first mounting groove 1-2 includes a first peripheral surface groove 1-2-2 for accommodating the cylindrical part of the first gasket 8 and a first end face groove 1-2-1 for accommodating the plate-like part of the first gasket 8. The first peripheral surface groove 1-2-2 and the first end face groove 1-2-1 are connected. The first split ring 1 has a first adapted peripheral surface 1-3, and the first adapted peripheral surface 1-3 is located between the first peripheral surface groove 1-2-2 and the first mating end face 1-4. The outer diameter of the first adapted peripheral surface 1-3 is slightly smaller than the inner diameter of the first raceway ring 9. The first adapted peripheral surface 1-3 is the adapted part on the first split ring 1, that is, the first raceway ring 9 needs to axially cross the first adapted peripheral surface 1-3 to be installed in place. Since the first raceway ring 9 needs to compress the cylindrical part of the first gasket 8 after crossing the first adapted peripheral surface 1-3, the original outer diameter of the cylindrical part is larger than the outer diameter of the first adapted peripheral surface 1-3, and the first raceway ring 9 needs to be installed by hot fitting or press fitting to pre-compress the cylindrical part of the first gasket 8.

[0037] During manufacturing, control the inner diameter dimension of the first raceway ring 9 and the bottom diameter dimension of the first peripheral surface groove 1-2-2, so that the cylindrical part of the first gasket 8 has a pre-compression deformation of 0.1 - 0.6 mm on one side in the radial direction after installation; at the same time, control the distance between the bottom of the first end face groove 1-2-1 and the first mating end face 1-4, so that the plate-like part of the first gasket 8 has a pre-compression deformation of 0.1 - 0.5 mm on one side in the axial direction after installation to ensure the use effect of the first gasket 8.

[0038] Combined with Figure 2 and Figure 5As shown in the figure, a second mounting groove 2-1 for mounting the second gasket 10 is provided on the second split ring 2. The second gasket 10 includes a cylindrical part pre-compressed by the inner peripheral surface of the second collar 11 and a plate-like part pre-compressed by the end face of the second collar 11. The cylindrical part and the plate-like part are connected and the longitudinal section is L-shaped. Therefore, the second mounting groove 2-1 includes a second circumferential groove 2-1-2 for accommodating the cylindrical part of the second gasket 10 and a second end face groove 2-1-1 for accommodating the plate-like part of the second gasket 10. The second circumferential groove 2-1-2 and the second end face groove 2-1-1 are communicated. The second split ring 2 has a second mating circumferential surface 2-3. The outer diameter of the second mating circumferential surface 2-3 is slightly smaller than the inner diameter of the second collar 11. The second mating circumferential surface 2-3 is the mating part on the second split ring 2, that is, the second collar 11 needs to cross the second mating circumferential surface 2-3 axially to be installed in place. Since the second collar 11 needs to compress the cylindrical part of the second gasket 10 after crossing the second mating circumferential surface 2-3, the original outer diameter of the cylindrical part is larger than the outer diameter of the second mating circumferential surface 2-3. The second collar 11 needs to be installed by hot fitting or press fitting to pre-compress the cylindrical part of the second gasket 10.

[0039] During manufacturing, control the inner diameter dimension of the second collar 11 and the bottom diameter dimension of the second circumferential groove 2-1-2, so that the cylindrical part of the second gasket 10 has a pre-compression deformation of 0.1-0.6 mm on one side in the radial direction after installation; at the same time, control the distance between the bottom of the second end face groove 2-1-1 and the second mating end face 2-2, so that the plate-like part of the second gasket 10 has a pre-compression deformation of 0.1-0.5 mm on one side in the axial direction after installation to ensure the use effect of the second gasket 10.

[0040] In addition, as shown in Figure 2 and Figure 4 the figure, a boss 1-1 for temporarily supporting each first ball 4 when installing the first ball 4 and the first cage 5 is provided on the first split ring 1, which is convenient for the installation of the first row of balls and the cage. At the same time, a support ring 12 for temporarily supporting the second row of balls when installing the second row of balls and the cage is clamped between the two split rings. Since the first collar 9 in the present invention is an integral ring and is directly installed, the setting of the first mating circumferential 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 collar 9, and canceling the boss structure means the loss of the temporary support function for the second row of balls, while the support ring 12 just makes up for this function to ensure the smooth assembly of the bearing.

[0041] Meanwhile, an installation step 1-5 for sleeving and installing the support ring 12 is provided at the edge of the first mating end face 1-4, facilitating the positioning of the support ring 12. The second mating end face 2-2 of the second split ring 2 presses against the support ring 12 to fix the support ring 12 and prevent it from moving.

[0042] In addition, an inclined surface for contacting each second ball 6 when installing the second row of balls and the cage is provided on the support ring 12, 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 from nylon material, has good processability and low cost, and the nylon material has good damping property, so that the vibration during the operation of the bearing will not cause noise on the support ring 12.

[0043] When assembling the main bearing of the CT machine of the present invention, first, the first gasket 8 is installed in the first installation groove 1-2 of the first split ring 1, and then the first ring 9 is installed by a hot-fitting or press-fitting method, ensuring that the cylindrical part of the first gasket 8 has a set pre-compression deformation amount. At the same time, the second gasket 10 is installed in the second installation groove 2-1 of the second split ring 2, and then the second ring 11 is installed by a hot-fitting or press-fitting method, ensuring that the cylindrical part of the second gasket 10 has a set pre-compression deformation amount.

[0044] The remaining assembly process of the main bearing of the CT machine is as follows:

[0045] First, place the first split ring 1 horizontally on a platform or a fulcrum with the plane where the screw head is located facing downwards, that is, Figure 2 viewed in combination, the first split ring 1 is placed upside down on the platform or the fulcrum, and then the first row of balls and the cage are installed together from top to bottom. At this time, the raceway on the first ring 9 can support each first ball 4. However, since the first cage 5 has a cut, it will sag downwards. At this time, the boss 1-1 can form a temporary support for each first ball 4 to maintain the basic shape of the first row of balls and the cage. Then, the integral ring 3 is installed from top to bottom. When the first raceway 3-1 on the integral ring 3 contacts each first ball 4, the first ball 4 disengages from the boss 1-1, forms a gap with the boss 1-1, and is limited between the first raceway 3-1 and the raceway of the first ring 9.

[0046] Then, the support ring 12 is sleeved on the mounting step 1-5 of the first split ring 1 with the inclined surface of the support ring 12 facing upward. Then, the second row of balls and the cage are installed together from top to bottom. At this time, the second raceway 3-2 on the integral ring 3 can support each second ball 6. However, since the second cage 7 has a notch and will sag downward, the support ring 12 can form a temporary support for each second ball 6 to maintain the basic shape of the second row of balls and the cage. 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 disengages from the support ring 12, forming a gap with the support ring 12, and is limited between the second raceway 3-2 and the raceway of the second ring 11. Finally, each screw 13 is installed from bottom to top and pre-tightened symmetrically and crosswise in a circumferential manner. Under the pre-tightening force of the screw 13, the mating end faces of the first split ring 1 and the second split ring 2 come into contact. The end face of the first ring 9 axially pre-compresses the plate-like part of the first gasket 8, and the end face of the second ring 11 axially pre-compresses 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.

[0047] When the main bearing of the CT machine is in use, the bearing is in a vertical state. The combined ring composed of the first split ring 1 and the second split ring 2 is fixed to the CT machine frame through 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 integral ring 3 through screws. The integral ring 3 is driven to rotate by a driving device through a synchronous toothed belt or a multi-wedge belt. When the integral ring 3 with a mass of hundreds of kilograms rotates at a high speed, the axial load, radial load, overturning moment, vibration, and impact energy generated are transmitted to the CT machine frame through the two raceways of the integral ring 3, the first balls 4 and the second balls 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. During this transmission process, due to the inlay of the gaskets, the high damping performance of the gaskets is utilized to isolate and consume the vibration and impact energy generated during the rotation of the integral ring 3, greatly reducing the vibration and noise during the operation of the bearing.

[0048] Embodiment 2 of the main bearing of the CT machine in the present invention:

[0049] As Figure 6As shown, the main difference from Embodiment 1 is that the combined ring composed of the first split ring 1 and the second split ring 2 is the outer ring, while the integral ring 3 is the inner ring. At this time, the integral ring 3 is still the rotating race, fixedly connected to the rotating scanning part of the CT machine. The combined ring composed of the first split ring 1 and the second split ring 2 is still the fixed ring, fixedly connected to the CT machine frame. At this time, the first gasket 8 and the first race 9 are still installed on the first split ring 1, the second gasket 10 and the second race 11 are still installed on the second split ring 2, and the support ring 12 is still clamped between the first split ring 1 and the second split ring 2. The effect is the same as that of Embodiment 1 and will not be repeated here. Additionally, it should be noted that in this embodiment, both split rings have an inner diameter adapted to the corresponding race, and the outer diameters of both races are slightly smaller than the inner diameter of the corresponding adapted part of the split ring. Therefore, both races can still be smoothly installed through the guidance of the corresponding adapted part of the split ring.

[0050] In other embodiments of the main bearing of the CT machine: The support ring can also be made of other engineering plastics such as polyethylene or polypropylene. Of course, the support ring can also be a steel ring.

[0051] In other embodiments of the main bearing of the CT machine: The two split rings can no longer be provided with a rabbet structure and can be directly fixed with screws.

[0052] In other embodiments of the main bearing of the CT machine: The threaded fasteners used to fix the two split rings can also be a combination of bolts and nuts.

[0053] In other embodiments of the main bearing of the CT machine: The two split rings can also be directly thread - connected instead of being fixedly connected by threaded fasteners, that is, one is provided with an internal thread and the other is provided with an external thread.

[0054] In other embodiments of the main bearing of the CT machine: The pre - compression deformation amount of the cylindrical parts of the two gaskets may not be within the range of 0.1 - 0.6 mm. According to the specific dimensions of the gasket and the bearing, the pre - compression deformation amount of the cylindrical part can also be greater than 0.6 mm, such as 0.7 mm, 0.8 mm or even larger. Of course, the pre - compression deformation amount of the plate - shaped parts of the two gaskets may not be within the range of 0.1 - 0.5 mm. According to the specific dimensions of the gasket and the bearing, the pre - compression deformation amount of the plate - shaped part can also be greater than 0.5 mm, such as 0.6 mm, 0.7 mm or even larger.

[0055] In other embodiments of the main bearing of the CT machine: The installation grooves including the circumferential groove and the end - face groove may not be provided on the two split rings. At this time, the gasket is directly installed on the corresponding split ring, and the race still needs to be installed by hot - fitting or press - fitting to make the cylindrical part of the gasket reach the required pre - compression deformation amount.

[0056] In other embodiments of the main bearing of the CT machine: The longitudinal section of the gasket may not be L-shaped. In addition to having a peripheral surface and an end surface in contact with the corresponding split ring, the part in contact with the corresponding race is an arc surface. At this time, a matching arc surface is provided on the race, that is, there are two arc surfaces on the race at this time, one is in contact with the gasket, and the other is in contact with the ball.

[0057] In other embodiments of the main bearing of the CT machine: The inclined surface in contact with the second row of balls may no longer be provided on the support ring, and the edge of the support ring is directly used to support the second row of balls.

[0058] In other embodiments of the main bearing of the CT machine: Mounting steps may also be provided on the second split ring, and the mounting steps on the two split rings are buckled to realize the pressing and fixing of the support ring; in other embodiments, no mounting steps are provided on any one of the split rings, and at this time the support ring is directly clamped between the end surfaces of the two split rings.

[0059] The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. The patent protection scope of the present invention is subject to the claims. Any equivalent structural changes made by using the description and drawings of the present invention shall be included in the protection scope of the present invention by the same token.

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 rings and balls are arranged in a one-to-one correspondence. The two split rings have an inner diameter or outer diameter that matches the corresponding ring so that the corresponding ring can be directly installed on the split ring along the axial direction. 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 first split ring has a first mating end face that is in contact with the second split ring, and the edge of the first mating end face is provided with an installation step for the support ring to be installed.

2. The CT machine main bearing according to claim 1 is characterized in that: The second split ring has a second mating end face that is in mating contact with the first split ring, and the second 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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