CN213744478U

CN213744478U - Spindle bearing for economical CT machine

Info

Publication number: CN213744478U
Application number: CN202022073427.8U
Authority: CN
Inventors: 孙建修; 王黎峰; 郑晓生; 杜云飞; 汤向伟
Original assignee: Luoyang Luozhou Precision Bearing Co ltd
Current assignee: Luoyang Luozhou Precision Bearing Co ltd
Priority date: 2020-09-21
Filing date: 2020-09-21
Publication date: 2021-07-20
Anticipated expiration: 2030-09-21

Abstract

A main shaft bearing for an economical CT machine is formed by back-to-back pairing of two thin-wall angular contact ball bearings; the retainer of the thin-wall angular contact ball bearing is in a flexible long belt shape before assembly, is in an unsealed annular belt shape after assembly, and a certain gap is reserved between belt heads. The utility model discloses owing to adopt angular contact ball bearing structure, the steel ball number can increase, and the contact angle can reduce, and its machining precision, start-up friction performance, bearing capacity etc. can obtain very big promotion to improve the operating speed, the noise reduction of bearing, increase of service life. The utility model discloses a holder adopts flexible nylon belt as the preparation material, and the holder can be according to the arbitrary intercepting of service length, need not drop into extra mould, and manufacturing cost is lower. The nylon retainer reduces the running noise of the bearing and the weight of the bearing. The utility model discloses occupation to installation space is little, has reduced material consumption, has reduced manufacturing cost.

Description

Spindle bearing for economical CT machine

Technical Field

The utility model belongs to the technical field of the bearing technique and specifically relates to an economical main shaft bearing for CT machine is related to.

Background

CT machines are one of the indispensable devices in medical diagnosis today and have been rapidly developed in recent years. The bearing of the CT machine is a key part of a rotary scanning part of the CT machine, is used for transmitting and bearing radial load, axial load and overturning moment generated by devices such as an X-ray tube, a collimator, a detector, a slip ring and the like, and needs to meet the use requirements of the CT machine on high rotating speed, low noise, high precision, low vibration and long service life.

The development of the main shaft bearing for the medical CT machine in China has been for 20 years, the main shaft bearing adopts a four-point contact ball turntable bearing all the time, adopts a segmented nylon retainer structure, can bear certain radial load, axial load, overturning moment and the like, and has the advantages of high rotating speed, low noise, high precision and low vibration.

With the development of medical equipment technology, the requirements on the main shaft bearing of the CT machine are gradually improved, the rotating speed is improved from the initial 60r/min to the current 180r/min, the noise value is reduced from 70dB to 60dB, and the original four-point contact ball turntable bearing structure cannot meet the requirements of the existing high rotating speed and low noise value. Therefore, not only the manufacturing process, performance, and economy of the main shaft bearing need to be improved, but also the structure of the main shaft bearing needs to be further improved.

SUMMERY OF THE UTILITY MODEL

In order to overcome not enough in the background art, the utility model discloses an economical CT machine main shaft bearing adopts following technical scheme:

a main shaft bearing for an economical CT machine is formed by back-to-back pairing of two thin-wall angular contact ball bearings; the retainer of the thin-wall angular contact ball bearing is in a flexible long belt shape before assembly.

As a further improvement, the utility model discloses a circle and be equipped with the interior keyway with CT main shaft connection in each thin wall angular contact ball bearing, circle the outer keyway that is equipped with and CT casing body coupling on the outer.

As a further improvement of the utility model, the cross section of the inner key groove and the outer key groove is semicircular.

As the utility model discloses a further improvement, circle, be close to pairing terminal surface department on each thin wall angular contact ball bearing's inner ring, be equipped with semi-circular oil groove along radial direction, semi-circular oil groove and the interior keyway of circle on set up relatively.

As a further improvement of the utility model, the thickness of the middle part of the section of the retainer is larger than the thickness of the two sides of the section of the retainer.

As a further improvement of the utility model, the retainer is made of a nylon material with high strength.

As a further improvement of the utility model, the retainer is in the shape of an unsealed annular band after being assembled, and a certain gap is reserved between the band heads.

As a further improvement of the utility model, the contact angle alpha of the thin-wall angular contact ball bearing is less than or equal to 15 degrees.

Due to the adoption of the technical scheme, the utility model discloses following beneficial effect has:

the utility model provides a main shaft bearing for CT machine is different from conventional four point contact ball carousel bearing, and it is paird the use through the back to back by two the same thin wall angular contact ball bearings. Compared with a four-point contact ball turntable bearing, the four-point contact ball turntable bearing has the advantages that the number of steel balls can be increased, the contact angle can be reduced, the machining precision, the starting friction performance, the bearing capacity and the like can be greatly improved, the working speed of the bearing is improved, the noise is reduced, and the service life is prolonged.

The utility model discloses a holder adopts flexible nylon belt as the preparation material, and the holder can be according to the arbitrary intercepting of service length, need not drop into expensive mould expense, and manufacturing cost is extremely low. The nylon retainer reduces the running noise of the bearing and the weight of the bearing.

The utility model discloses occupation to installation space is little, has reduced material consumption, has reduced manufacturing cost.

Drawings

Fig. 1 is a schematic structural view of a conventional angular contact ball bearing.

Fig. 2 is a schematic structural diagram of the present invention.

Fig. 3 is a partial structural view of the cage.

Fig. 4 is a sectional view a-a in fig. 3.

In the figure: 1. an outer ring; 2. an inner ring; 3. a steel ball; 4. a holder; 5. an outer keyway; 6. an inner keyway; 7. and a circular oil groove.

Detailed Description

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only for explaining the technical principle of the present invention, and are not intended to limit the scope of the present invention.

The key for improving the service life and the economical efficiency of the main shaft bearing of the CT machine is that the angular contact ball bearing structure is adopted, the number of steel balls can be increased, the contact angle can be reduced, the processing precision, the starting friction performance, the bearing capacity and the like can be greatly improved, so that the working speed of the bearing is improved, the noise is reduced, and the service life is prolonged.

In a conventional angular contact ball bearing, as shown in fig. 1, a metal solid retainer 4 is adopted, the wall thicknesses of an inner ring 2 and an outer ring 1 are also large, and the inner ring 2 and the outer ring 1 are also easy to realize the matching installation with a main shaft and a shell. However, for the CT machine, the conventional angular contact ball bearing cannot be directly used, because firstly, the limited installation space of the CT machine is not suitable for the installation of the conventional angular contact ball bearing; secondly, the diameter of the bearing of the main shaft of the CT machine is larger than 1 m, and the problem of insufficient strength exists due to the adoption of the bakelite retainer 4; the retainer 4 stamped by steel has the problems of insufficient rigidity, large deformation and large noise; the holder 4 made of brass has the disadvantages of heavy weight and serious friction, and is not suitable for the use requirements of high rotating speed and low noise.

Therefore, a new structure of the main shaft bearing for CT machine is needed.

An economical spindle bearing for a CT machine is composed of two thin-wall angular contact ball bearings which are paired back to back as shown in figure 2, wherein the two thin-wall angular contact ball bearings meet the installation space requirement of the CT machine in size. Because two thin-wall angular contact ball bearings are installed in a back-to-back matching mode and are equivalent to two rows of ball bearings with a widening distance, the anti-overturning moment is greatly increased. Because the medical CT machine bearing mainly bears radial force and the axial force is small, the contact angle alpha of the thin-wall angular contact ball bearing is 15 degrees, so that the requirements on axial load and radial load are met, and the working rotating speed of the bearing is improved.

In addition, the inner ring 2 and the outer ring 1 of the two thin-wall angular contact ball bearings are independent, and the inner ring 2 and the outer ring 1 bear unidirectional load and do not bear alternating load every time the main shaft rotates for one circle, so that the fatigue damage of the alternating load to the inner ring 2 and the outer ring 1 can be avoided, and the service life of the bearing is greatly prolonged.

In order to ensure the use requirement of the retainer 4 and improve the economy of the retainer 4, the retainer 4 of the thin-wall angular contact ball bearing is a flexible long-strip-shaped retainer 4 before assembly. Specifically, as shown in fig. 3, the holder 4 is in a long strip shape with equal pitch (pitch t), and the length is determined by the circumference of the center circle where the steel ball 3 is located. After steel balls 3 are arranged in the pocket holes, the steel balls are arranged in the raceways of the outer ring 1 and the inner ring 2, and the retainer 4 naturally encloses a circular belt. In order to avoid interference friction, the belt head is not butted with the belt tail, and a certain gap is reserved between the belt head and the belt tail. A plurality of pockets are arranged at equal intervals on the holder 4, and the pockets are spherical pockets having a shape close to the contour of the steel ball 3, and are guided by the steel ball 3.

In order to prevent the steel ball 3 from coming out of the spherical pocket, as shown in fig. 4, the thickness of the middle portion of the cross section of the cage 4 is greater than the thickness of both sides thereof. The thickness of the middle part is larger, so that the spherical pocket has a certain locking amount for the steel ball 3, the smooth pressing-in of the steel ball 3 can be ensured, and the steel ball 3 is not separated. Because the retainer 4 can be cut according to the using length, the expensive mould cost is not needed to be invested, and the production and manufacturing cost is low.

The retainer 4 is made of nylon 11, nylon 12 or nylon EM740 nylon material with high strength, the methylene chain in the nylon 11 molecular chain is longer, the density of the amido is low, and the nylon is provided with the properties of nylon 66 and polyolefin, thus being engineering plastic with excellent comprehensive performance. The nylon 11 has excellent mechanical property, higher impact strength, good stress cracking resistance and dynamic fatigue performance, can still maintain the toughness at a very low temperature, and has good flexibility and low bending modulus. Nylon 11 has excellent chemical stability and good corrosion resistance to alkali, alcohol, ketone, aromatic hydrocarbon, salt solution and grease. The nylon 12 has the performance similar to that of nylon 11, and has excellent flexibility, stable size and easy processing. The nylon 12 has excellent shock resistance, low abrasion, low friction and self-lubricating performance, so that the friction noise of the nylon 12 product is low. Nylon EM740 has excellent creep and fatigue resistance, high impact resistance, excellent elasticity at low temperature, strong chemical resistance, resistance to oils and various solvents, high strength, good flexibility and dynamic mechanical properties.

In order to prevent the creep between the inner ring 2 and the main shaft, the technical scheme is further improved, the inner ring 2 of each thin-wall angular contact ball bearing is provided with an inner key groove 6 with a semicircular cross section, correspondingly, the main shaft of the CT machine is provided with a semicircular key groove, when in connection, the inner key groove 6 on the inner ring 2 is aligned with the semicircular key groove on the main shaft to form a circular hole, and a cylindrical pin is inserted into the circular hole to complete the connection between the inner ring 2 and the main shaft. Similarly, in order to prevent the outer ring 1 and the shell from creeping, an outer keyway 5 with a semicircular cross section is arranged on the outer ring 1 of each thin-wall angular contact ball bearing, a semicircular keyway is arranged on the shell of the CT machine, the outer keyway 5 on the outer ring 1 is aligned with the semicircular keyway on the shell to form a round hole during connection, and a cylindrical pin is inserted into the round hole to complete the connection between the outer ring 1 and the shell.

In order to improve the lubricating environment inside the main shaft bearing, the technical scheme is further improved, a semicircular oil groove is arranged on the inner ring 2 of each thin-wall angular contact ball bearing and close to the matched end face in the radial direction, and the semicircular oil groove is arranged opposite to the inner key groove 6 on the inner ring 2. After the inner rings 2 of the two thin-wall angular contact ball bearings are positioned and connected with the main shaft, the semicircular oil grooves on the two inner rings 2 form a complete circular oil groove 7, and the circular oil groove 7 is convenient for injecting lubricating grease or lubricating oil.

The part of the utility model not detailed is prior art. Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides an economic CT machine main shaft bearing which characterized by: the device is formed by back-to-back matching of two thin-wall angular contact ball bearings; the retainer of the thin-wall angular contact ball bearing is in a flexible long belt shape before assembly; an inner key groove connected with a main shaft of the CT machine is arranged on an inner ring of each thin-wall angular contact ball bearing, and an outer key groove connected with a shell of the CT machine is arranged on an outer ring.

2. The main shaft bearing for the economical CT machine as claimed in claim 1, wherein: the cross sections of the inner key groove and the outer key groove are semicircular.

3. The main shaft bearing for the economical CT machine as claimed in claim 1, wherein: and semicircular oil grooves are arranged on the inner ring of each thin-wall angular contact ball bearing and close to the matched end surface along the radial direction, and the semicircular oil grooves are arranged opposite to the inner key grooves on the inner ring.

4. The main shaft bearing for the economical CT machine as claimed in claim 1, wherein: the thickness of the middle part of the cross section of the retainer is larger than the thickness of the two sides of the cross section of the retainer.

5. The main shaft bearing for the economical CT machine as claimed in claim 1 or 4, wherein: the retainer is made of a nylon material with high strength.

6. The main shaft bearing for the economical CT machine as claimed in claim 5, wherein: the retainer is in an unsealed annular band shape after being assembled, and a certain gap is reserved between band heads.

7. The main shaft bearing for the economical CT machine as claimed in claim 1, wherein: the contact angle alpha of the thin-wall angular contact ball bearing is less than or equal to 15 degrees.