JPS62148087A - Production of bearing - Google Patents

Abstract

PURPOSE:To improve the bearing characteristics by forming a bearing metal layer as well as performing a chamfering on the corner part of a bearing base metal, then, by building up the bearing metal by welding with low heat input to the corner part after building up the bearing metal on the peripheral face. CONSTITUTION:A white metal bearing alloy layer 9a is formed via a torch 5 on the chamfering part A, which is worked in advance at the corner part at acute angle of a segment type bearing base metal 2. The white metal is then subjected to a build-up welding on the inner peripheral face 2b of the base metal 2. In this case, a flat welding is performed by using a positioner, etc. In succession, the bearing alloy is subjected to a build-up welding once again on the baring alloy layer 9a of the chamfering part and a new bearing alloy layer 9c is formed under the low heat input welding conditions. In this way, the metal flow drop at the corner part and the excessive dilution of the alloy can be prevented. Consequently the bearing characteristic can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a bearing, and more particularly to a method for manufacturing a bearing by overlay welding flash metal on a bearing.

[Conventional technology]

With the recent increase in the capacity of electric power generators and motors,
The thrust bearings and main bearings used in these systems are also desired to be capable of withstanding high speeds and high loads.

Conventionally, methods for manufacturing such flat bearings include the pouring method and centrifugal casting method, in which bearing metal such as white metal is poured onto the base metal of the bearing and then lined with it. Primarily targeting bearings with a flat lining surface, such as thrust bearings, instead of the pouring method or centrifugal casting method, the bearing metal is lined using a welding method using a TIG arc as a heat source. Methods of manufacturing have also been implemented. Compared to casting methods, this method does not require plating or heating of the alloy, and it is easy to weld as it can be welded directly onto the alloy.It also allows for automatic welding by robots, etc., so there is no need for hot wires for the worker. It has features such as no need for it, stable quality, and excellent adhesion strength. Here, a method for manufacturing a bearing by this conventional welding overlay method will be explained with reference to FIGS. 3 and 4. Figures 3(a) and (b) K show,
When applying the overlay welding method to a full bearing with a curved lining surface 3, such as a cylindrical bearing base metal 1 or a segment type bearing base metal 2, when using a low melting point material such as white metal, overlay welding In order to prevent the layer from sagging or running down, lining is performed while always keeping the lining surface 3 facing downward and always keeping the lining surface 3 on which it is built up horizontally. For example, when manufacturing a cylindrical bearing, as shown in FIG. A device is used that includes a manipulator 6 having a disposed and axially movable welding torch 5 attached to its tip, and a controller 7 for interlocking these. With this device, the bearing base metal 1 is attached to the positioner 4.
The manipulator 6 is run so as to perform overlay welding in the axial direction 8 of the bearing base metal 1 fixed to the positioner 4 at the same time.
The manipulator 6 was rotated by the amount of overlay for each passing pass of the manipulator 6, and the υ bearing metal was lined with the bearing base metal 1 by overlay welding in the same manner as for planar bearings to manufacture the bearing.

[Problem that the invention seeks to solve]

However, when performing overlay welding on a segment type bearing base metal 2 etc. as shown in FIG. Because of the presence of the acute angle part 2C, even if the welding posture and welding conditions are changed, the metal layer at this acute angle part 2c will sag or run down, and furthermore, the Fe content in the alloy will flow into the metal layer due to welding heat input. There is a problem that dilution increases. Conventionally, in order to solve this problem, a patch plate such as a copper plate was provided at the acute corner 2c to allow the metal layer to flow down and to alleviate the heat concentration at the acute corner. However, this method has the problem that the quality of the lined metal depends on the material and size of the backing plate and the shape of the acute angle portion 2c. For this reason, it was not necessarily a good idea from the point of view of obtaining metal of stable quality. Especially when the bearing inner diameter is extremely small (
For example, in a water turbine generator (segment type bearing base metal with a diameter of 1 m or less), the acute angle part 2C is extremely sharp, so in some cases, the acute angle part 2C burns through due to welding heat input, gets mixed into the metal layer, and the inner circumferential surface After machining, metal sliding surfaces were sometimes deposited in different patterns.

Therefore, in order to solve the above-mentioned problems, the present invention prevents excessive dilution of Fe in the alloy caused by flowing down of the bearing metal at the corners of the bearing base metal and heat concentration at the corners, and An object of the present invention is to provide a method for manufacturing a bearing having a high adhesion strength.

[Means for solving problems]

In order to achieve the above object, the present invention provides a method for manufacturing a bearing by welding and overlaying a bearing metal on a bearing base metal having an inner circumferential surface, in which the corners of the bearing base metal are machined to form a surface. A chamfered portion 9 is formed, and the bearing metal is welded overlay on the chamfered portion to form a bearing metal layer having a predetermined thickness necessary for adhesion between the bearing metal and the chamfered portion, and then the A method for manufacturing a bearing, characterized in that bearing metal is bath-welded overlay on the inner circumferential surface of a bearing base metal, and then the bearing metal is welded overlay again on the bearing metal layer under predetermined low heat input conditions. provide.

[Effect]

By chamfering the corners of the bearing base metal, heat concentration during welding in the subsequent process can be alleviated. After forming this chamfered part, a bearing metal layer with a predetermined thickness necessary for adhesion between the bearing metal and the chamfered part is formed on this chamfered part, and then on the inner circumferential surface of the bearing base metal. Since the bearing metal is welded overlay, the absolute amount of melting of the bearing metal layer is small, so the bearing metal I- will not flow down when welding near the chamfered portion in the weld overlay on the inner circumferential surface. Furthermore, when welding overlay on this bearing metal layer again, it is done under low heat input conditions, so it is possible to manufacture the bearing without diluting new Fe from the chamfered part of the bearing base metal. Become.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1(a) to (d). 2 is a segment type bearing base metal 6C1
First of all, the inner circumference 1fi of this segment type bearing base metal 2 is
2b and the axial base metal side surface 2a.
cj9 chamfer processing is applied. This chamfer is processed approximately parallel to the bottom surface 2d of the bearing base metal 2 by machining, grinding, etc. so that the width B is 5 arms to 8 arms, and by this processing, a flat chamfered part A is formed. do. (See Fig. 1(a)) Next, as shown in Fig. 1(b), the welding torch 5 facing the surface of the chamfered part A with a predetermined distance is used to cut the chamfered part A. Bearing base metal 2 while weaving on A
For example, under certain welding conditions shown in Table 1, a white metal bearing alloy layer 9a is formed by one-layer overlay on the chamfer 9 A by arc heat of TIG welding to ensure close contact with the alloy. . In addition, if the white metal bearing alloy 719a becomes 2n to 3 thick after welding one layer, this alloy layer can be machined or grinded to a predetermined thickness C (to the extent that an adhesive layer remains). Processed to about 0.5 mrx ~ 1 fight).

In this case, the minimum metal thickness C of the chamfered portion A is set to 0.5 to 1.
If it is possible to build up the metal to about 0.0 mm, it is possible to omit mechanically removing the metal to a predetermined thickness.

Table 1 Welding conditions: Wire diameter: 4.01 L In the above welding, a white metal (JISWJ2 equivalent) wire 10 is supplied by a wire supply device 11 installed near the welding torch 5. Further, during welding, the bottom surface portion 2d of the bearing base metal 2 is cooled with water to prevent deformation of the bearing base metal due to welding heat input.

After forming the white metal bearing alloy layer 9a of a predetermined thickness C on the chamfered portion as described above, as shown in FIG. Weld overlay of white metal. In this case, the bearing base metal 2 is fixed horizontally to the positioner 4 so that the built-up part of the bearing inner peripheral surface 2b is always in a downward welding position, and the manipulator 6 with the welding torch 5 attached to the tip is mounted on the bearing base. The manipulator 6 is moved in the direction of the metal axis (direction perpendicular to the figure in FIG. 1(C)) under the constant welding conditions shown in Table 1, for example.
For each pass of travel, the bearing base metal 2t is rotated by the amount corresponding to the overlay using the positioner 4. In this manner, welding overlay in the axial direction of the bearing base metal 2 is repeated to form the white metal bearing alloy /d9b on the inner circumferential surface 2b. Note that during welding, the bottom surface portion 2d of the bearing base metal 2 is cooled with water.

Finally, white metal is welded overlay again on the white metal bearing alloy layer 9a formed on the chamfered portion to form a new white metal bearing alloy layer 9C to obtain a predetermined metal thickness. The weld build-up in this case is performed only for the purpose of melting the white metal, and is carried out under certain low heat input welding conditions shown in Table 2, for example. (See Figure 1(d)) Below is Table 2 in the margin Welding conditions Next, the effects will be explained. In the step shown in FIG. 1(b), after performing one-stroke welding under the constant welding conditions shown in Table 1, the bearing base metal 2 and the white metal bearing alloy layer 9a in the recovered part were assembled. When the adhesion was confirmed by an ultrasonic flaw detection test, no waveform indicating poor adhesion was observed. Further, by chamfering the acute angle portion 2C, the concentration of arc heat is alleviated, and the bearing base metal 2 does not melt or drop. Furthermore, as shown in Table 3, the dilution of Fe from the bearing base metal 2 is significantly greater in the white metal bearing alloy layer 9a than in the case where white metal is directly overlaid on the chamfered portion and the acute angle portion 2C. becomes a low value.

Margin Table 3 below: Fe analysis value of white metal layer (corner position) When overlay welding of the white metal bearing alloy layer 9a on the inner circumferential surface 2b-\ with a predetermined thickness C or more is performed, the area near the chamfered portion When welding, a part of the TIG arc may melt the white metal bearing alloy layer 9a that has already been formed, or the amount of melting of this white metal bearing alloy layer 9a may be large, and the low viscosity white metal may adhere in some cases. Although the white metal bearing alloy layer 9a may flow down with the layer, in the above embodiment, the white metal bearing alloy layer 9a is coated with a predetermined thickness C for the purpose of adhesion.
tζ, when overlay welding is performed on the inner circumferential surface 2b, even if a part of the TIG arc melts the white metal alloy layer 9a during welding near the chamfered part A, the absolute amount of melting is small, so that close contact cannot be achieved. It does not flow down with the layers.

In addition, the white metal bearing alloy layer 9a shown in FIG. 1(d)
In the process of bath welding again on top of the metal to make up the shortfall for the predetermined metal thickness, welding is carried out under low heat input welding conditions as shown in Table 2, so welding arc heat is directly applied to the bearing base metal. 2, and is spent only on melting the redundant white metal wire 10 for forming the new white metal bearing alloy layer 9C. Therefore, Sn and F formed on the contact surface between the white metal bearing alloy layer 9a and the bearing base metal 2
The alloy layer with e is not destroyed either, and this dense layer is ensured. Furthermore, no new dilution of Fe from the bearing base metal 2 occurs.

Furthermore, when the manufactured bearing was subjected to an ultrasonic flaw detection test after being machined to a predetermined metal thickness after completing the last process, no waveforms indicating insufficient adhesion were observed on the chamfered portion.

Further, in the visual inspection of this machined surface, no foreign pattern of Fe was observed on the machined surface due to excessive dilution of the bearing base metal 2 near the chamfer. Next, Table 4 shows the analysis results of the amount of Fe in the white metal bearing alloy layer on the inner circumferential surface 2b of the recovered part and the bearing base metal 2.

Table 4 Re analysis values of white metal layer As is clear from Table 4, the dilution of Fe in the chamfered portion A and the inner circumferential surface 2b of the bearing base metal 2 is approximately the same. In comparison, it is possible to manufacture a high-quality bearing with very small alloy penetration at the corners.

Next, regarding other embodiments of the present invention, FIGS. 2(a) and (1)
)) for explanation. 1 is a cylindrical bearing base metal;
An oil ring groove portion 12 is formed on the inner circumferential surface 1b of this cylindrical bearing base metal 1. When lining this oil ring groove 12 with white metal, first
A chamfered portion A is formed by processing the corner IC formed by the groove portion side face 1a. Next, the positioner 4 is rotated so that the chamfer is horizontal, and welding is performed, and a predetermined thickness of 0.5 mm is applied to the chamfer to form only a dense layer.
~1) white metal bearing alloy layer 9a is formed.

Thereafter, the positioner 4 is rotated so that the inner circumferential surface 1b and the groove side surface 1a are horizontal, and bath welding is performed to form the white metal bearing alloy layer 9b.

Finally, the portion lacking in the predetermined metal thickness of the chamfered portion is overlay-welded onto the white metal bearing alloy layer 9a under low heat input conditions to manufacture the bearing. In this embodiment as well, the same functions and effects as in the above-mentioned embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, the corners of the bearing base metal are machined to form the chamfered 9 portions, and bearing metal is overlaid on the chamfered portions to form a metal layer for the purpose of dense yM, and then, Bearing metal is overlay-welded to the inner peripheral surface of the bearing base metal to a predetermined thickness, and finally overlay-welded is again applied to the metal layer at the corners under low heat input conditions, so there is no chance of metal running down or corners. Excessive dilution of the alloy due to heat concentration in the parts can be prevented, and a tg bearing having stable and good bearing characteristics can be manufactured.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a method for manufacturing a bearing according to an embodiment of the present invention, FIG. 2 is a perspective view showing an alloy for an alant type bearing according to another embodiment of the present invention, and FIG. 1 is a weld overlay. FIG. 2 is a front view showing the device. l・Cylindrical bearing base metal, 1b...inner peripheral surface, IC/corner,
2... Segment type bearing base metal, 2b... Inner peripheral surface, 2C
...Acute corner, 9a...White metal bearing alloy layer, 1
0...White metal wire, A. Chamfered part, C...
Predetermined thickness. Agent Patent Attorney Nori Ken Yudo Chika Hiroshi Mitsumata Collection of works 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A method for manufacturing a bearing by lining a bearing base metal having an inner circumferential surface with a bearing metal by welding overlay, comprising: processing a corner of the bearing base metal to form a chamfered portion; The bearing metal is welded over the chamfered portion to form a bearing metal layer with a predetermined thickness necessary for adhesion between the bearing metal and the chamfered portion, and then the bearing metal is welded onto the inner peripheral surface of the bearing base metal. and then welding the bearing metal onto the bearing metal layer again under predetermined low heat input conditions.