RU49904U1 - ROTATION NODE - Google Patents

Abstract

The rotation unit belongs to the field of mechanical engineering and can be used in drives, in particular, in drives of vibrational motion scanners. The purpose of the development of the proposed utility model is: 2. Reduction of friction on the shaft of rotation of the drive, which is very important with the oscillatory movement of the drive shaft of the scanner. 2. An increase in the range of unloading of axial forces by increasing the axial displacement of a spring-loaded bearing installed with the possibility of movement, which provides an extension of the temperature range of the scanner, 3. Ensuring reliable operation of the device for unloading rolling bearings from axial forces, in particular, by eliminating the possibility of mashing the movable parts of the rolling bearing with a spring element. This goal is achieved by the fact that in the rotation unit containing the housing, the drive rotation shaft installed in the housing is mounted on bearings distributed at its ends, which also contains a bearing unloading device from axial forces, including a spring element, one of the bearings distributed at the ends of the rotation shaft is fixed in the relief of the housing, and the other is mounted with the possibility of axial movement by springing the aforementioned discharge device, the bearings being made as rolling bearings, and an intermediate part is introduced into the unloading device, made in the form of a cylinder with a diameter equal to the diameter of the outer (fixed) cage of the spring-loaded bearing and consisting of a platform and a cylindrical support formed by a concentric selection also in the form of a cylinder with a diameter more internal, but less external diameter of the outer race of the bearing, by means of a cylindrical support the intermediate part is mounted on the outer race of the bearing, while the spring element is mounted directly It is directly on the platform of the intermediate part on one side and fixed in the relief cavity of the body on the other. In the intermediate part, a through concentric hole can be additionally made with a diameter greater than the diameter of the journal of the rotation shaft protruding from the rolling bearing, but less than the installation diameter of the spring element. The height of the walls of the relief cavity of the housing is sufficient to accommodate the spring element, the intermediate part, and the spring-loaded bearing with a margin of axial movement of the said bearing. In other words, in the claimed rotation unit, the sliding friction is replaced by rolling friction, which is significantly (not less than an order of magnitude) less, which is very important for the oscillatory movement of the scanner drive shaft, because especially when the shaft stops when changing the direction of rotation (the moment when the drive shaft must be moved in the opposite direction), it is necessary to have minimal friction. The increase in stroke installed with the possibility of moving the spring-loaded bearing compared to the prototype became possible when

the same ball sizes in the prototype and in the inventive device also due to the replacement of the rotary plain bearing in the prototype with the design of the rolling bearing and the absence of axial motion limiters, in contrast to the prototype, in the inventive device. In the prototype, the possible stroke of the bearing is less than 1/2 of the diameter of the ball, otherwise the ball will fall out of the enclosure space (husking), in the inventive device, the bearing stroke is not less than the thickness of the bearing race (see Fig. 1, a) and b) t. e. more than the diameter of the ball. This increase in the axial stroke (movement) of the spring-loaded bearing is ensured by the design of the rolling bearing, and in contrast to the prototype, the absence of additional limiters for the axial movement of the bearing. In addition, an intermediate part is introduced into the device for unloading bearings from axial forces of the inventive “Rotation Unit” in this utility model, which protects the movable part of the bearing from mechanical action of the spring element, as well as from contamination on the bearing. At the same time, in the claimed rotation unit, in addition to solving the tasks, an additional positive effect is possible, consisting in the possibility of manufacturing the body and shaft - from materials with different linear expansion coefficients, i.e. from various materials justified by the developers. When the scanner operates in a wide temperature range, the drive shaft and housing are subject to different linear expansion, this leads to a significant increase in the axial load on the bearings holding the shaft, in the claimed node of rotation, the problem of unloading from the axial force is solved by increasing the stroke of the spring bearing provided by the design of the rolling bearing and lack of traffic limits.

Description

The rotation unit belongs to the field of mechanical engineering and can be used in drives, in particular, in drives of vibrational motion scanners.

Known node rotation of a screw compressor according to Copyright certificate No. 730977, F 01 C 21/00, "Device for unloading bearings of a screw compressor from axial forces". In the said rotation unit, the unloading elements interacting with the ends of the bearings on which the rotation shaft is mounted are made in the form of annular chambers with elastic walls in communication with the compressor forcing and provided with a travel stop on the side opposite to the bearing. The operation of this device is related to the specific operation of the compressor, namely, air injection. To use the device for Copyright St. No. 730977 in our drive would require air supply and discharge, which is not justified difficult and not economical, and would lead to an increase in size.

Known "Rolling bearing" patent No. 2052680. which contains a shaft pin, two angular contact rolling bearings installed according to the tandem scheme, the support is equipped with a stepped sleeve. The axial load distribution device in the support is made in the form of a closed chamber filled with hydroplast formed by the surfaces of the annular grooves of the corresponding bearing rings of the same name, the end face of the step sleeve and the axial groove. This device does not solve our problem, it aligns - redistributes the axial load between the two bearings, but does not reduce the axial load. The device is difficult to perform, it is necessary to isolate the bearings from the hydroplast, for this form a closed chamber by making annular grooves and axial grooves on the bearing rings and installing a stepped sleeve.

The well-known "bearing assembly for rotation drives" A. St. No. 1059298 F 16 C 17/18, containing two floating sleeves located in the housing and covering the journal of the shaft of the main drive, which rotate in the journal

different sides by an autonomous drive, one always in one direction, the other in the other, regardless of the direction of rotation of the main shaft. In this case, the direction of rotation of one of the bushings (either one or the other, depending on the direction of rotation of the axle of the main shaft) coincides with the direction of rotation of the main shaft, and the other is directed in the opposite direction. When the direction of rotation of the main shaft changes, the pattern repeats. In this way, the friction moment is maintained constant by stabilizing its variable component when the direction of rotation of the main drive changes. This invention relates to drives requiring high stability and uniformity of rotation at very low speeds, the drives of antennas, locators, radiators, in such devices there is no problem of reducing the friction moment when changing the direction of rotation, but only the task of stabilizing it is constancy.

The closest selected as a prototype is the rotation unit, made in patent No. 2137217 "slewing bearing". The device contains (see Fig. 2 - patent No. 2137217), a housing (base and cover) with two fixed non-rotating supports (220, 222) placed in it, and a rotation shaft (225) of the drive of the drive disk, at the ends of which bearings are formed glide in the form of single balls (201, 202), each of which is located in the so-called ball enclosure space, actually in conical recesses made on one side at the ends of the aforementioned shaft and on the other in each of the non-rotating bearings. Moreover, the speed of rotation of the balls, depending on the angle of inclination of the surface of the attachment to the axis of rotation of the shaft can be from zero to the speed of the shaft. It should be noted that the "Swivel bearing" according to patent No. 2137217 is a sliding bearing, since during operation of the bearing the ball does not contact the investment surfaces at one point, but along the sliding circumference (cm / 1 /, p. 529). One of the non-rotating supports is fixed in the housing motionless (222), and the other (220) is attached to a compressing spring (224) to provide a controlled axial preload on the rotation unit. Lubrication is provided in the nesting space of the balls, the space is isolated by a circular ring, non-rotating supports are made with movement limiters (226, 227). The invention relates to the field of bearings used to support the rotating nodes of computer storage devices, in particular, magnetic disk drives, more specifically to bearings used in drives and spindles

disk drive. One of the main objectives of the invention is to increase the durability of drives in the presence of mechanical shocks and other influences. Also, the main purpose of the prototype is to miniaturize the drive device by miniaturizing in particular the rotation unit.

The device operates as follows: the rotation shaft (225) of the drive (105) rotates on a pair of spherical balls (201, 202) sliding along it with its conical recesses (221 and 223). Balls are held by fixed non-rotating supports (220 and 222). The support 220 is attached to a compressible spring (224), which is located inside the relief in the inner surface of the cover (115). The support (222) is rigidly attached to the base (104). Supports contain movement restraints (226 and 227). A pair of steep rings (228 and 229) isolates the cavities in which the balls are located. The preload of the bearings is ensured by the application of axial force to the support (220) using a compressible preload spring (224) and further transmission of this force to the ball (201), through the shaft to the ball (202) and the support (222).

According to the authors of the prototype, the issue of increased impact resistance is solved by increasing the size of the ball compared to smaller ball bearings of rolling bearings and by increasing the contact area of the axial holding force created by the spring element (if in the rolling bearings these are separate contact points) balls and the shaft, then in the prototype it is a circle whose length depends on the angle of inclination of the surface of the space for enclosing the ball).

However, it should be noted that winning in shock resistance, a rotary bearing (prototype) undoubtedly loses in terms of the magnitude of the friction of motion and friction of friction. When rotating, and changing the direction of rotation of the shaft, in the case of the use of a sliding bearing in drives, in particular in drives of vibrational motion scanners, the friction of friction increases compared to the use of a rolling bearing. This is understandable, because, as the authors explain, the contact area of the axial holding force applied to the ball is increased in the sliding bearing proposed by the prototype as compared to the rolling bearings, in the prototype the contact area is a circle whose diameter depends on the inclination of the surface of the insert to the axis of rotation, and in rolling bearings - this is the point. To prove the claim of reduced friction and friction when using rolling bearings compared with

prototype, where a sliding bearing is used, we will calculate the moments of rolling friction and sliding friction.

We turn to the source / 1 /, p. 490, the friction moment of ball bearings: M _Tr = 1.4 F _{r_} k (D ₂ / D _w +1), where.

M _Tr - the moment of friction of rolling;

F _{r_} is the radial load;

k is the coefficient of rolling friction;

D ₂ - the diameter of the inner ring;

D _W - the diameter of the balls.

Let us assume that the radial load when evaluating the friction moments is the same for the case of a rolling bearing and then a sliding bearing and is equal to F _r = 1, with a known coefficient of rolling friction equal to k = 0.0005 (see / 1 / M p. 490, 8th line from the bottom ) and with the ratio of the diameter of the inner ring to the diameter of the ball equal to 6/1 (real rolling bearing), we have the following:

M _Tr = 1.4 × 1 × 0.0005 × (6/1 + 1) = 0.0049

Further, to calculate the moment of sliding friction (prototype), we also turn to the source / 1 /, p. 544 - the friction moment of the spherical support (slip) from the axial force is expressed as follows:

M _tp = μ (A / Sin α) (d _p / 2) = μA / Sinα × Dcos α / 2)

Where (see Figure 1, a)):

μ is the coefficient of friction, μ = 0.16, (see / 1 / Table 9.31 on p. 53);

A is the axial force, as specified above. take A = 1;

α is the angle of inclination of the surfaces of the enclosure of the ball to the axis of rotation, the preferred angle, as noted in the description of the prototype α = 45 degrees;

d _p - the diameter of the circumference of the bearing;

d _p = (2D) / 2 × Cos α = Dcos α, (see construction Figa);

D is the diameter of the ball; let D = 4.

Then M _Tr = 0.16 × 1 / Sin45 ° × (4Cos45 °) / 2 = 0.32

As you can see, the sliding friction moment is more than two orders of magnitude higher than the rolling friction moment. Those. the question of reducing the moment of friction of movement and starting when changing the direction of movement is not resolved in the prototype.

Drive drives on disks due to the compact design of the drives themselves are not burdened by the large dimensions of the rotation shaft, and since,

One of the goals of the prototype is to miniaturize the product as a whole, rather, on the contrary, the drives and their rotation shafts are designed to be minimally possible, in addition, the issue of miniaturization of the rotation unit in the prototype is solved by reducing the dimensions and the bearing itself. Linear changes in the drive shaft due to a wide range of operating temperatures are not so noticeable due to the small dimensions of the shaft itself. Therefore, the authors of the prototype did not have the task of unloading the rotary bearing from axial forces arising from linear changes in the shaft and drive housing due to the wide range of operating temperatures and dimensions of the shaft itself (the shorter the shaft, the less the problem of an increase in axial loads). In the prototype, it was not necessary to provide significant axial displacement of the unloading bearing, therefore, in the prototype, limiters for bearing movement (226, 227) were introduced to protect the ball from falling out of the enclosure space. Those. the problem of ensuring the unloading of bearings from axial forces in a wide range of operating temperatures did not stand before the developers of the prototype.

To the drives of scanners, and especially scanners of vibrational motion, in which the direction of rotation of the shaft is constantly changing to the opposite, stringent requirements have been made to reduce friction of movement and especially friction, moving, which occurs when the direction of rotation changes. The reduction in friction provides, as the calculation proves, the use of rolling bearings in the rotation assembly.

Oscillatory motion scanners are used in various fields of science and technology, for example, to read texts, to create video effects in show business, on vehicles for night and thermal imaging, in technological food installations, in targeting devices for aircraft and ground mobile vehicles, therefore, the operating temperature range is wide (from -50 degrees Celsius to +50 degrees Celsius), depending on the area of use. The requirements regarding the unloading of rotary bearings from axial forces arising during the operation of the scanner in such a wide temperature range are themselves quite stringent. Moreover, these requirements are exacerbated by increasing the length of the drive shaft, because often, as in our case, with a certain volume of the scanner allocated for it in the cockpit of the aircraft, or ground means, the cross section of the hull is limited in area, i.e. to accommodate all working units in the housing, it, and therefore the drive shaft, must be elongated. Consequently,

for unloading bearings from axial forces should be provided with a greater absolute value of the axial movement of the installed with the possibility of moving the spring-loaded bearing in comparison with the prototype.

Due to the specificity of the design of the rolling bearing, when the axial force unloading device is in direct contact with the end face and mounted with the possibility of axial movement of the bearing, the moving part of the bearing is rubbed by the spring element and, as a result, the device is unreliable, and even the bearing is damaged.

The purpose of developing the proposed utility model is;

1. Friction reduction on the rotation shaft of the drive, which is very important for the oscillatory movement of the scanner drive shaft.

2. The increase in the range of unloading of axial forces due to the increase in axial displacement installed with the possibility of movement of a spring-loaded bearing, which provides an extension of the temperature range of the scanner

3. Ensuring reliable operation of the device for unloading rolling bearings from axial forces, in particular, by eliminating the possibility of mashing the movable part of the rolling bearing with a spring element.

This goal is achieved by the fact that in the rotation unit containing the housing, the drive rotation shaft installed in the housing is mounted on bearings distributed at its ends, which also contains a bearing unloading device from axial forces, including a spring element, one of the bearings distributed at the ends of the rotation shaft is fixed in the relief of the housing, and the other is mounted with the possibility of axial movement by springing the aforementioned discharge device, the bearings being made as rolling bearings, and an intermediate part is introduced into the unloading device, made in the form of a cylinder with a diameter equal to the diameter of the outer (fixed) cage of the spring-loaded bearing and consisting of a platform and a cylindrical support formed by a concentric selection also in the form of a cylinder with a diameter more internal, but less external the diameter of the outer race of the bearing, by means of a cylindrical support the intermediate part is mounted on the outer race of the bearing, while the spring element is installed

directly on the platform of the intermediate part on the one hand and fixed in the relief cavity of the body on the other.

In the intermediate part, a through concentric hole can be additionally made with a diameter greater than the diameter of the journal of the rotation shaft protruding from the rolling bearing, but less than the installation diameter of the spring element.

The height of the walls of the relief cavity of the housing is sufficient to accommodate the spring element, the intermediate part, and the bearing with a margin of axial displacement of the spring-loaded bearing.

In other words, by replacing the sliding bearing with a rolling bearing containing an external (in our case, a stationary) cage, an internal (movable) cage, and balls with a separator located between the cages, the sliding friction in the inventive rotation unit is replaced by rolling friction, which is significantly (not less than an order of magnitude) less, which is very important for the oscillatory movement of the scanner drive shaft, because especially when the shaft stops when changing the direction of rotation (the moment when the drive shaft must be moved in the opposite direction), it is necessary to have minimal friction. The increase in the stroke of the spring-loaded bearing installed with the possibility of moving in comparison with the prototype became possible with the same ball sizes in the prototype and in the inventive device due to the replacement of the rotary sliding bearing in the prototype with a rolling bearing and the absence of axial movement limiters in the inventive device. In the prototype, the possible stroke of the bearing is less than 1/2 of the diameter of the ball, otherwise the ball will fall out of the enclosure space (husking), in the inventive device, the bearing stroke is not less than the thickness of the bearing race (see Fig. 1, a) and b) t. e. more than the diameter of the ball. This is ensured by the design of the rolling bearing, and in contrast to the prototype, the absence of additional limiters of axial movement of the bearing.

In addition, an intermediate part is introduced into the device for unloading bearings from axial forces of the inventive rotation unit in this utility model, which protects the movable part of the bearing from mechanical action of the spring element, as well as from contaminants entering the bearing.

Moreover, in the inventive rotation unit, in addition to solving the tasks, an additional positive effect is possible, consisting in the possibility of manufacturing a housing and a shaft - from materials with different coefficients

linear expansion i.e. from various materials justified by the developers. When the scanner operates in a wide temperature range, the drive shaft and housing are subject to different linear expansion, this leads to a significant increase in the axial load on the bearings holding the shaft, in the inventive rotation unit, the problem of unloading from the axial force is solved by increasing the stroke of the spring-loaded bearing.

The inventive device is represented by the following drawings,

Figure 1. a) Section of a plain bearing, b) Section of a rolling bearing.

Figure 2. Assembly drawing of the device.

Figure 3. Design options for the intermediate part.

The device of the inventive "Node rotation" is presented in Figure 2. Like the prototype, the device contains a housing (1), a drive rotation shaft (2) located in it, mounted, as in the prototype, on two bearings. As in the prototype, one of the bearings (3) is fixed motionless relative to the housing in the relief of the housing (4), and the other bearing (5) is spring-loaded by a spring element (6). Unlike the prototype, the rotation shaft of the drive is mounted on rolling bearings (the so-called ball bearings), and not sliding, this is very important for the drive of oscillatory motion from the point of view of overcoming lower friction forces at the moment of changing the direction of rotation of the drive shaft. In contrast to the prototype, an intermediate part (7) is introduced into the unloading element, in which two zones (see also FIG. 3) can be distinguished from the platform (8) and the cylindrical support (9). The intermediate part provides unimpeded springing, protecting the moving part of the bearing from being rubbed by the spring element, and, in addition, protects the bearing from dust and foreign objects. If necessary, in the case of a drive shaft design with a pin protruding from the bearing (10), an intermediate part with a through hole (11) can be made. The unloading device and the bearing mounted with the ability to move are located in the relief cavity (12) of the housing.

The device operates as follows: in the initial position, before the drive starts, the spring element (6) provides preliminary axial load, unlike the prototype, through the intermediate part (7) to the bearing (5), then through the drive shaft (2) to the bearing (3) . When power is applied, the rotation shaft (2) of the drive rotates on a pair of plain bearings (3 and 5), in

one and the other side (oscillatory motion). The reduction of friction at the moment (stragging) of the change in the direction of rotation of the shaft is ensured by the fact that the sliding friction used in the "Rotary Bearing" is replaced in the claimed "Rotation Bearing" by significantly less rolling friction, which is very important when the scanner drive is oscillating.

The bearing (5) through the intermediate part (7) introduced for effective and unhindered contact of the spring element with the end face of the bearing (or rather, the end face of its outer stationary cage) interacts with the spring element (6). In this case, the intermediate part (7) protects the moving part of the bearing from rubbing and dust, and when the axial load changes to a smaller or larger side, the spring element either expands (with a decrease in axial load) or contracts (with an increase in axial load), thereby adjusting and leaving constant axial load of bearings and without interfering with their rotation. Moreover, the limits of regulation of the axial load significantly exceed the ability to control the axial load in the prototype, because in the proposed device, the axial stroke of the spring-loaded bearing (5) is determined by the size of the height of the outer cage - N (see Fig. 1b)), the spring-loaded bearing can move by this value in the relief cavity of the housing (12), because the claimed device does not provide axial displacement limiters (unlike the prototype). It should be noted that in the event of a temperature reduction in the size of the rotation shaft (2), the height of the walls of the relief cavity of the housing is made with the estimated margin for the stroke of the spring-loaded bearing, determined by the type of selected shaft and housing materials, as well as the operating temperature range.

The device can be implemented industrially, by means of mastered technologies used in precision engineering, such as turning, pressure processing (stamping, upsetting).

Utility Model "Rotation Node"

Sources taken into account.

/ 1 / - "Reference Designer Precision Instrumentation", under the general editorship of Dr. Tech. Sciences of K.N. Yavlensky, B.P. Timofeev, and Ph.D. tech. sciences EE Chaadaevoy, Leningrad "engineering", 1989

/ 2 / - Copyright sv. No. 730977, F 01 C 21/00 “Device for unloading bearings of a screw compressor from axial forces” - analogue-1.

/ 3 / - Copyright sv. No. 2052680, "Rolling support" - analogue-2.

/ 4 / - Copyright St. No. 1059298 “Bearing assembly for rotation drives”, F 16 C 17/18 - analogue-3.

/ 5 / - Patent No. 2137217 "slewing bearing", F 16 C 19/50 - prototype.

Claims (3)

1. A rotation assembly comprising a housing, a drive rotation shaft located in the housing mounted on bearings distributed at its ends, a bearing unloading device from axial forces, comprising a spring element, one of the bearings distributed at the ends of the rotation shaft of the bearings being fixed motionless in the relief of the housing, and the other - installed with the possibility of axial movement by springing the above-mentioned unloading device, characterized in that the bearings are made in the form of rolling bearings, in a device for for loading, an intermediate part is introduced, made in the form of a cylinder with a diameter equal to the diameter of the outer (fixed) cage of the spring-loaded bearing and consisting of a platform and a cylindrical support formed by a concentric selection also in the form of a cylinder with a diameter more than the inner but less than the outer diameter of the outer cage of the bearing, by means of a cylindrical support the intermediate part is mounted on the outer race of the bearing, while the spring element is mounted directly on the platform of the intermediate waist on one side and fixed in the relief cavity of the body on the other. 2. The device according to claim 1, characterized in that the intermediate part is additionally provided with a through concentric hole with a diameter greater than the diameter of the journal of the rotation shaft protruding from the rolling bearing, but less than the installation diameter of the spring element. 3. The device according to claim 1, characterized in that the height of the walls of the relief cavity of the housing is sufficient to accommodate a spring element, an intermediate part, and a spring-loaded bearing with a margin of travel of the aforementioned bearing.