JPH0235221A - Bearing fitting method - Google Patents

Abstract

PURPOSE:To automate fitting of a roller by heating the bearing outer ring to be hot fitted up to a temp. within a specified extent precisely by means of induction heating, then demagnetizing by damping waves due to a resonance circuit, and at the same time performing hot fitting of rolling element. CONSTITUTION:The outer ring 2 of a bearing is placed on an outer ring seat mount 14 on an index table 10. This table 10 rotates in the direction of arrow to move the mount 14 to positions 14c and 14d, and the mount 14 is elevated into an induction coil 8. Then the mount 14 and outer ring 2 are rotated through a mount drive shaft 12a, and current is supplied to the coil 8, and thus an induction current is generated in the outer ring 2 to cause rise of the temp. to a specified level. Then the rollers 3 in a roller holding tool 13a are fitted in the heated outer ring 2 one by one from the lowermost one 3 at every turns of an eccentric rotary disc 12. When current supply to the coil 8 is shut off after the outer ring 2 is heated to specified temp., damping waves are generated in the coil 8, and the residual magnetism in the outer ring 2 is erased.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a hair ring fitting method for shrink-fitting a rolling element, and particularly to a hair ring fitting method using an induction heating device equipped with an induction heating coil constituting a resonant circuit. This invention relates to a method for fitting a bearing that is heated.

B. Summary of the Invention The present invention aims to provide a fitting method that uses induction heating to heat the outer ring of a bearing to raise its temperature and shrink-fit a rolling element, as well as eliminate residual magnetism in the bearing, thereby forming a resonant circuit. The outer ring of the bearing is heated to a predetermined temperature using an induction heating coil, and then the residual magnetism of the bearing is demagnetized by the damping waveform of the resonant circuit. This method simultaneously demagnetizes the bearing and shrink-fits the rolling elements, and makes temperature control easy and automation possible.

C. PRIOR TECHNOLOGY Conventionally, various types of bearings have been provided in response to various types of loads, such as the magnitude of the load to be borne and the number of revolutions per rotation in the direction. Bear links can be roughly divided into radial bearings and thrust bearings, depending on the direction of the load they bear.
The keystone bear link is a type of bear link that bears the radial load. Figures 1 (a) and (b) show its external appearance. The keystone bearing link I is a radial bearing used for heavy loads, and its irregular structure is inscribed in the hair ring outer ring 2 and is a rolling element. Cylindrical lump (
3 (hereinafter referred to as 1-A) are arranged continuously over the entire circumference.

The keystone bearing link 1 eliminates the need for a retainer to prevent the roller 3 from falling off.In order to prevent the hoop from falling out during operation, the inner diameter of the portion of the outer ring 2 that accommodates the roller is the minimum diameter at which the roller 3 falls off toward the inner diameter. It is configured smaller.

In the manufacture of the keystone bearing I described in 2 above, a method of shrink-fitting the outer ring 2 was used as a fitting method in which the roller 3 was inscribed in the outer ring 2 of the bearing and continuously installed over the entire circumference. That is, a method has been used in which a 711] bath heated to a predetermined temperature is used as a heating means, the outer ring of the bearing is immersed in the oil bath, the temperature is raised, and when the predetermined temperature is reached, the roller is inserted.

D Problems that the invention sought to solve In this heating method of raising the temperature of the hair ring outer ring by heating it to a predetermined temperature and immersing it in an oil tank, problems that should be improved have been pointed out and countermeasures have been required. .

Firstly, it takes several hours to heat up the oil tank for startup, and furthermore, it takes a long time to immerse the bearing outer ring in the oil tank that has reached a specified temperature and raise the temperature to the specified temperature, which leads to low productivity and production lines. It becomes a bottleneck. Secondly, there is a lot of energy loss, and it is necessary to heat the oil tank itself in order to heat the oil as the heating medium, which, together with the heat dissipation of the oil housed in the large volume container, results in poor thermal efficiency. Thirdly, it is difficult to accurately control the temperature of the heating medium housed in a large-volume container, and the response is slow and vulnerable to external disturbances, making numerical and routine management difficult. This is the problem. Fourthly, due to the various problems mentioned above, it is difficult to incorporate the shrinking process into an automatic production line, and when it is carried out by manual operation, it becomes difficult to shrink fit the outer ring after a few seconds after it is removed from the oil tank. Since the fitting conditions are not constant, there is a large variation in product quality, which is a quality problem. Fifth, there is a process for demagnetization in addition to the tempering process. This is a problem in the rationalization of the production line due to the need for such equipment.

The present invention was created in view of the problem described in 1 above, and aims to automate roller fitting by easily and highly precisely controlling the heating of the outer ring of a bearing, and also demagnetizes it during shrink fitting. The purpose of this is to provide a fitting method that

93 Means and Functions for Solving the Problems The present invention heats the outer ring of a bearing to be heated to a predetermined temperature range with high precision by induction heating, and then demagnetizes it using a damping wave generated by a resonant circuit. In this system, the outer ring is heated to a predetermined temperature using an induction heating device equipped with induction heating coils that constitute several resonant circuits, and the inside of the outer ring is heated using a device called "A". It is characterized by heating the rolling elements to the peripheral surface and gradually reducing the magnetizing force of the outer ring by turning off the power with the resonant circuit connected. By using a fitting jig to forcibly press-fit the rolling elements as long as the firing temperature is below the temperature at which fitting and unfitting is possible, it is possible to suppress the temperature rise of the outer ring to a low level, and to prevent hair loss. By demagnetizing the ring, the residual magnetism that has been applied to the outer ring during the previous process is removed, eliminating the possibility of attracting foreign objects or metal powder that may occur during the subsequent process or when using the hair link. be removed.

F. Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIGS. 5(a) and 5(b) are diagrams showing the arrangement positional relationship of the main parts of the hair ring assembly device used in the embodiment of the present invention, and FIG. 5(a) is a front view of the main parts. Figure 5 (b
) shows a plan view. 6(a) and 6(b) show the assembly mechanism of the bearing assembly device, FIG. 6(a) shows a plan view, and FIG. 6(b) shows a B-B A cross-sectional view of the line is shown.

The configuration of the heating section 4 of the induction heating device used in this example is as follows.
The configuration of the assembly mechanism of the bearing assembly (=I device) will be explained with reference to FIGS. 6(a) and 6(b).

The first feature of the present invention is to heat and raise the temperature of the bearing outer ring of the object to be heated using an induction heating device, and as shown in FIGS. 5(a) and 5(b), the bearing assembly device is It is installed close to the heating coil of the induction heating device. The heating unit 4 of the induction heating device includes an inverter 5 that converts the three-phase AC power supplied to the heating unit of the induction heating device into a variable voltage variable frequency AC power, and an inverter 5 that transforms the output of the inverter 5. A lance 6 that separates the circuit configuration from the heating coil section, a matching section 7 that achieves impedance matching necessary for the resonant circuit of the heating coil section for the demagnetization effect described later, and an outer ring 2 of the bearing that is the workpiece. It generally consists of an induction coil 8 for heating.

The configuration of a resonant circuit that performs magnetic erasure of the outer ring of the bear link, which is a main part of the present invention, will be explained with reference to FIGS. 4(a) and 4(b). FIG. 4(b) shows the electric circuit of the induction heating coil section of this embodiment, and shows the matching section 7 and the matching section 7.
and an induction coil 8 coupled by a transformer 6. FIG. 4(a) shows an equivalent circuit of FIG. 4(b), which constitutes a parallel resonant circuit using the inverter 5 as a power source. In Fig. 4 (2L), the critical conditions for generating the resonant vibration waveform shown in Fig. 4 (a) are the frequency of the vibration waveform, the value of the circuit resistance inductance, and the value of the matching capacitor. By selecting the load matching circuit constants of Furusato et al., this is realized in a loaded state where the bare link outer ring 2 is present in the induction coil 8 as described in .

Next, a set of bearings τj that can carry out the firing method of the present invention
Regarding the configuration of the device, Fig. 5(a), (b) and Fig. 6(
This will be explained with reference to a) and (b). In this embodiment, as shown in FIG. 5(1)), the induction coil 8 is composed of coils 8a and 8b connected in series so as to simultaneously heat two hairlink outer rings at once. An index table 10 that rotates below the induction coil 8 is provided with an outer ring seating base 14 on which the hair link outer ring 2 is placed at each of the positions I4a to +4.h divided into 38 equal parts.Outer ring seating base As shown in FIG. 6 (1), I4 has a hole in the center that allows the disk drive shaft +2b to be loosely inserted therein, and a convex hole that fits with the inner diameter of the edge of the outer ring 2 of the seat 4. It also forms a recessed part that rotatably fits into the hair link outer ring 2 and the coater 13 that is fitted into the outer ring 2 of the hair link. Furthermore, a rotary eccentric disk I2 is provided at the center of the outer ring seat I4, and the rotary eccentric disk I2 is rotated by a disk drive ++l+I2b, and the roller 3 is connected to a hair link by this rotary eccentric disk 12. It is fitted into the outer ring 2.

The roller coater 13 has one outer ring seating base for each outer ring seating base 14.
4, holding a predetermined number of rollers 3, and rotating the bearing outer ring 2 into the hair link outer ring 2 when it is heated by induction to a predetermined temperature. The rollers 3 are sequentially supplied as the eccentric disk 12 rotates.

The method of fitting the hair ring of this embodiment in the apparatus configured as described above will be explained in detail.

The hair link outer ring 2 and [J-RA 3 are respectively transported from the previous process to a transfer means (not shown)], and the hair link outer ring 2 is placed on the outer ring seating base 14 placed on the index table 10. Ru. The bearing outer ring 2 is fixed by fitting the convex portion of the outer ring seating base 14 located at positions 14a and I 4 b to the inner diameter of the edge, and
A number of rollers are supplied to fit into the roller coater 13 mounted above. index table 1
0 rotates in the direction shown in FIG. 5(1)) and moves the outer ring seating base 14 to positions 14c and 14c]. Figure 5 (a
) is F of the index table 10.
The outer ring seating bases 14 at positions 14c and 14d are moved up 1" into the induction coil 8, and each hair link outer ring 2 is positioned at the center of the induction coil 8 and stopped. .

Next, the outer ring seat 14 and the outer ring 2 are rotated by a driving source (not shown) via the seating part moving shaft 12a (at this time, the roller roller 13 is held by a holding mechanism (not shown) and does not rotate), and The induction coil 8 is energized to generate an induced current in the bearing outer ring 2 (ioI
, heat to the specified temperature. Next, the hair ring assembling device fits the roller 3 onto the heated hair link outer ring 2, and rotates with the roller 3 installed in a cylindrical shape in the roller coater 13, with the lowermost end opening toward the bare link outer ring. The number of rollers 3 housed in the roller holder 13a that allows rotation of the eccentric disk ( ) is one of the rotating eccentric disks 12.
Hair link outer ring 2 from the roller located at the lowest end every rotation
The roller holders 13a are supplied to the inner circumferential surface of the roller holder 13a, and are sequentially waited at the end of the roller holder 13a by natural falling.

The method of "Roller assembly 1" will be explained with reference to FIGS. 2 and 3. As shown in Fig. 3, when the outer diameter of the rollers 3 is DR, the center diameter (pidge circle: I) to the center of the rollers 3 when the rollers 3 are in close contact with each other to form a circle (l-) is I) As p, the outer circumferential diameter formed by the roller 3 is 1]12, and [! - The diameter of the contact point of La 3 is 1). It is shown closed. Further, the inner diameter of the roller housing portion of the bear link outer ring 2 is indicated by Dl. moshi roller 3
In order to transfer I) 1 is configured as Dl, slightly more dog. In order to fit and connect the C-nola 3 to the inner circumferential surface of the roller housing portion of the hair ring outer ring 2, the last one roller must be inserted as shown by the two-dot chain line in FIG. 3, the distance between the center G1 of roller 3 and 07 is 1 piece 7.
It is necessary that 7 ≧ 2 In order to prevent the hair link from rolling and falling off, it is necessary to hold the inner diameter of the roller housing portion of the hair link outer ring 2 smaller than I) above. Therefore, in order to freely fit the roller 3 into the hair link outer ring 2, the hair ring outer ring 2 is thermally expanded and the inner diameter of the roller storage portion is changed from Di to I)o'.
It is necessary to expand the scope further. Next, calculate the fitting at that time.

That is, the center of the roller to be inserted last is G, 1. The centers of the rollers on both sides that contact this roller are GG, and the centers when the hair link outer ring 2 is heated and expanded and the rollers are fitted are G.

G + G 2 ' Then, the fitting of the straight line -h for fitting the roller (minimum dimensional difference that allows free fitting) EL is: EL=G,'G,''-G,G,=20 .G, -G,G.

It is.

From FIGS. 2 and 3, the method for calculating the fitting of the roller 3 is as follows: 1. 2π El, =20+Go G+G2-2Dn Dpsi
n7 = 21) nDps+n- (where n is the number of fitted rollers 3).

Note that the clearance for the rotation of the roller 3 is extremely small, so Di (inner diameter of the roller housing portion of the outer ring) is taken. (Outer circumference diameter of roller 3) and clearance I) 1. = I).

D n ”; D i D n to E L-2D R
−(D i−D n)sin γ.

Next, the shrink-fitting allowance is calculated from the elongation of the circumference due to thermal expansion of the outer ring of the hair ring, and is calculated as E L 4-πXDpXOXα (the right side is the elongation of the circumference). From now on, the shrink-fitting allowance due to thermal expansion that allows the hair ring outer ring 2 to be freely fitted with [1-RA 3] is approximately as follows: πX(D i D n)XθXα≧2D R-(D
In the case of i-DR) sin7, the baking surface temperature is as follows. Conversely, the conditions for forcibly fitting using an external force, that is, a pressing force, are approximately as follows: π(Di DR)θ・α<2DR−(Di−Dn)s
in7, and the grilling surface temperature is as follows (The symbols used in the above calculation formula are: Di is the inner diameter of the outer ring of the bearing, DR is the outer diameter of the roller, θ is the heating temperature, and α is the coefficient of thermal expansion).

Furthermore, since the hair ring outer ring 2 has been heat treated in the previous step, it is generally desirable that the heating temperature during shrink fitting be low. Using the shrink-fitting method described above, in which the roller is forcibly press-fitted while keeping the heat-hardened surface temperature below the roller's free surface fitting temperature, prevents changes in the metal structure of the bearing outer ring and decreases in strength, hardness, etc. It is effective in improving the quality of products, and 6 is preferable from the point of view of energy saving. Then, as described in item 1, after the bearing link outer ring 2 is heated by induction to a predetermined temperature, the rollers are automatically installed without any delay.This makes it easier to carry out shrink-fitting with such low-temperature heating. be.

Under the above assembly conditions, the roller 3iJ that has fallen to the lower end of the roller holder 13a in the Rollan coater 13 and the rotating eccentric disk I2 are rotationally driven by the disk drive shaft +2b, and the outer ring seating base 14 is seated. By being rotationally driven by the base moving shaft 12a, the hair ring outer ring 2 of the outer ring seating base 14' also rotates, so that the bearing outer ring 2 is The rollers 3 are fitted into the inner circular surface one by one, and the roller 3 that is fitted last is pushed by the rotating eccentric disk 12 under the temperature conditions of θ and is in a free surface fitting state. Or it is forcibly pressed into place.

On the other hand, the power supply to the induction coil 8 was turned off after the hair ring outer ring 2 was heated to a predetermined temperature. At this time, a damped vibration wave is generated in the induction coil 8 due to resonance, an example of which is shown in FIG. .

Calculating an example of the load matching circuit constant that generates the above-mentioned resonant vibration wave, the resonant frequency f = 100001 (z.

cos9 = 0.4, inductance r, = 4
″+1, 253.3 (μH, μF), coil paste actance X=2πfI7, X=0.251Ω″−Z1
Therefore, R=0. It is calculated that I01Ω, C=63.3μF.

When comparing the calculated value with the vibration conditions, it is clear that R2<Therefore, the vibration conditions are satisfied.

Figure 8 (λ) is a graph showing the distribution of residual magnetism applied to the bearing outer ring 2 up to the previous process, and Figure 8 (b)
is the club whose residual magnetism was measured after applying the damped vibration wave of this example, and is the same object to be measured. In the figure, the vertical axis shows the magnetic flux density (GAUSS), and the horizontal axis shows the measurement position in the circumferential direction of the hair ring outer ring 2. As shown in the figure,
The magnetism imparted to the hair ring outer ring 2 is reduced to almost zero, and there is no risk of adsorption of iron powder or metal foreign matter during subsequent processing steps or use of the bearing.

The cylinder 15 that supported the outer ring seat I71 in the induction coil 8 is lowered to return the outer ring seat I4 to its home position on the index table 10. Subsequently, the index table 10 rotates to move the outer ring seat 14 to the positions 14e and 4. f, the assembled bearing I is left to cool, and is carried out by a transfer means (not shown).

By repeating the above steps, the bearing I is continuously fired in a fully automatic manner.

In implementing the present invention, the present invention is not limited to the above-mentioned embodiments. For example, the position 14 of the index table IO
c and I 4 d, only the temperature is raised by induction heating of the hair ring outer ring 2 and the residual magnetism is demagnetized, and then the index table 10 is quickly rotated to position 14.
e and 14. The rolling elements (rollers) 3 may be assembled onto the circumferential surface of the hair ring outer ring 2 at step f. Alternatively, to inductively heat the bearing outer ring 2 to a predetermined temperature, perform the first stage of heating to an intermediate temperature at position 14c of the index table IO, then rotate to position 14d and perform the second stage of heating. A heating method may be used in which the temperature difference between the outer circumference and the inner circumference of the outer hair ring 2 is reduced by setting the temperature to a predetermined temperature by transferring heat therebetween. It goes without saying that the workpiece is not limited to keystone bearings, but can be applied to other bearings.

G9 Effects of the Invention - As explained, the present invention is equipped with an induction heating device to heat the bearing outer ring to a predetermined temperature, and then turn off the power with the resonant circuit connected to gradually reduce the magnetizing force of the hair ring outer ring. Since this method first demagnetizes and then shrink-fits the rolling elements onto the inner peripheral surface of the outer ring of the hair ring, firstly, the temperature monitoring and control of the shrink-fitting temperature is electrically controlled, which improves the accuracy of temperature control. It becomes possible to automate the work, and automation stabilizes the working conditions during assembly.Furthermore, it becomes easier to shrink-fit at a low heating temperature where material changes are less likely to occur, achieving uniform quality and increasing productivity. This will solve the bottlenecks of traditional production lines.

Second, since the residual magnetism imparted to the outer ring of the bearing is demagnetized during the shrink-fitting process, the residual magnetism is removed, increasing the lifespan and durability of the product, and reducing variations in characteristics. Furthermore, there is no need to provide a separate demagnetization process.

Thirdly, unlike conventional oil bath immersion, heating energy is saved and energy savings are achieved.

Fourth, since an oil tank is not used for heating, problems such as deterioration of the working environment due to steam from the pool, risk of fire, and preheating of the oil tank before starting work are all improved.

With the above-mentioned great effects, the economic effects are enormous.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are external views of the keystone bearing used in the embodiment of the present invention, Figures 2 and 3 are diagrams for explaining the calculation of shrink-fitting in this embodiment, and Figure 4 (a) and (b) are circuit diagrams of the resonant circuit used in this example;
) is a diagram showing the arrangement positional relationship of the main parts of the bear link assembly device,
Figures 6 (3) and (b) are diagrams showing the configuration of the assembly mechanism part of the bearing assembly device, Figure 7 is a diagram showing the damped vibration waveform of the resonant circuit, and Figures 8 (a, ), ( b) is a diagram illustrating the demagnetizing effect due to the damped oscillation wave of the resonant circuit. 1 ・Keystone bearing, 2 Bearing outer ring, 3
... Roller (rolling element), 4. Induction heating section (induction heating device), 5. Inverter, 6. Transformer, 7. Alignment section,
8...Induction coil, 10... Index table,
12 Rotating eccentric disk, 14 Outer ring seating. To the ward! Kuniguchi Figure 8 (a) Circumferential measurement position Circumferential measurement position

Claims (2)

[Claims] (1) In a bearing fitting method in which the outer ring is heated and shrink-fitted to the fitting of rolling elements connected to the inner periphery of the outer ring, a resonant circuit with a load matching circuit constant of R^2<(4L/C) is used. The outer ring is heated to a predetermined temperature by an induction heating device equipped with an induction heating coil, and the power is turned off with the resonant circuit connected to gradually reduce the magnetizing force of the outer ring. A bearing fitting method characterized by shrink fitting rolling elements. (2) The bearing according to claim 1, wherein the rolling element is forcibly press-fitted with a fitting jig at a shrink-fitting temperature at which the temperature of the outer ring is raised to a temperature below which the rolling element can be freely fitted and removed. Fitting method. (However, in the loaded state of the induction heating resonant circuit, R: resistance value, L: inductance value, C: capacitance value)