JP5570268B2 - Method for manufacturing rolling bearing device - Google Patents

Description

  The present invention relates to a method for manufacturing a rolling bearing device.

  Generally, a rolling bearing device is composed of a rolling bearing having an inner ring and an outer ring arranged coaxially, an inner cylinder fitted to the inner ring of the rolling bearing, and an outer cylinder fitting the outer ring of the rolling bearing. The cylinder and the outer cylinder are supported by a rolling bearing so as to be relatively rotatable (see, for example, Patent Document 1 and Patent Document 2). In the rolling bearing device described in Patent Document 1, a shaft (inner cylinder), an inner ring, a housing (outer cylinder), and an outer ring are joined by an adhesive, respectively. In the rolling bearing device described in Patent Document 2, the shaft and the inner ring are anaerobic. It is joined by a sex adhesive.

Japanese Patent Laid-Open No. 11-182543 JP 2000-346085 A

  However, anaerobic adhesives have many outgas components, and if outgas adheres to a magnetic disk of a hard disk drive (HDD) in which a rolling bearing device is used, it may affect recording and reproduction. In addition, anaerobic adhesives have a disadvantage of low productivity because of a long curing time. In addition, when the shaft and inner ring and the housing and outer ring are joined with an adhesive as in the conventional rolling bearing device, the rigidity of the adhesive fluctuates due to temperature changes, which changes the preload and fluctuates the resonance frequency and torque. There is an inconvenience.

  The present invention has been made in view of the above-described circumstances, and provides a method of manufacturing a rolling bearing device that has sufficient bonding strength, reduces outgas generation, and prevents occurrence of resonance frequency fluctuation and torque fluctuation. The purpose is to do.

In order to achieve the above object, the present invention provides the following means.
According to the present invention, at least one of the fitting portions between the inner rings of the two rolling bearings arranged coaxially with an interval in the axial direction and the first member fitted to the inner rings is provided on the inner ring. A first welding process in which laser welding is performed with a laser power that does not cause thermal deformation of the metal, and the fitting portion joined in the first welding process is laser-welded with a laser power higher than that in the first welding process. A rolling bearing device manufacturing method including a second welding step , wherein the second welding step is a position that is different in the circumferential direction from a welding location at the first welding step in the same fitting portion. A method for manufacturing a rolling bearing device is provided.

  According to the present invention, a rolling bearing device capable of relatively rotatably supporting the first member and the swing arm is manufactured by directly attaching a swing arm used for a magnetic recording device (HDD) or the like to the outer ring. .

  In this case, the first member and the inner ring can be fixed by the first welding process while maintaining the shape of the inner ring substantially. Therefore, in the second welding process, even when a force that relatively changes the material to be welded acts when the melted welded part is cured and contracted, the welding part is fixed by the first welding process. The fitting portion can be joined with high joining strength while suppressing displacement of the welded material by force.

  Further, when the fitting portions are joined by laser welding, generation of outgas as in the case of joining with an anaerobic adhesive can be prevented, and productivity can be improved by shortening the joining time. Further, according to laser welding, it is possible to avoid a change in preload due to a change in the rigidity of the adhesive due to a temperature change as in the case of joining with an adhesive, and to stabilize the resonance frequency and torque. Therefore, it is possible to manufacture a rolling bearing device that reduces the occurrence of outgas and prevents the occurrence of resonance frequency fluctuations and torque fluctuations while ensuring sufficient bonding strength.

  In the above invention, the inner ring and the first that are pressed in a state where the spacer portion is sandwiched in the axial direction between the outer rings of the two rolling bearings and the inner rings are pressed in a direction relatively close to the axial direction. Laser welding by the first welding process and laser welding by the second welding process may be performed on the fitting portion with the member.

  By comprising in this way, the spacer part is pinched | interposed between the outer rings of two rolling bearings, and the clearance gap according to the length of the spacer part is formed between inner rings. Therefore, it is possible to apply preload to the two rolling bearings by pressing the inner rings in a direction in which the inner rings are relatively close to each other. Then, by applying the first welding process and the second joining process to the fitted portion of the inner ring that has been pressed, the rolling bearing device in which the preloaded state is maintained can be easily manufactured in a short time.

  Moreover, in the said invention, said 1st laser welding process is carrying out laser welding of the proximity | contact place which brought each said inner ring | wheel and said 1st member close to each other in one radial direction relatively. Also good.

  By configuring in this way, even when there is a gap in the fitting portion between each inner ring and the first member, it is possible to reliably close the adjacent portions in the circumferential direction in the fitting portion by laser welding. Can be fixed to. Moreover, the proximity | contact location with a small clearance gap in a fitting part can be easily specified by making a part of fitting part approach closely.

  Further, the axial centers of the two rolling bearings can be made to coincide with each other by bringing each inner ring and the first member relatively in one radial direction. Thereby, for example, it is possible to manufacture a rolling bearing device in which the first member and the swing arm can relatively rotate with high accuracy around the axes of these two rolling bearings.

According to the present invention, at least one of the fitting portions of the outer rings of the two rolling bearings arranged coaxially with an interval in the axial direction and the second member for fitting the outer rings to the outer ring. A first welding step in which laser welding is performed with a laser power that does not cause thermal deformation, and a laser welding is performed on the fitting portion in a state joined by the first welding step with a laser power higher than that in the first welding step. A rolling bearing device manufacturing method including two welding steps , wherein the second welding step is located at a position that is different in the circumferential direction from the welding portion in the first welding step in the same fitting portion. Provided is a method of manufacturing a rolling bearing device characterized by laser welding .

  According to the present invention, a rolling bearing device capable of relatively rotatably supporting the swing arm and the second member is manufactured by directly attaching the swing arm used for the HDD or the like to the inner ring.

  In this case, the second member and the outer ring can be fixed by the first welding process while substantially maintaining the shape of the outer ring. Therefore, in the second welding step, the fitting portion can be joined with high joining strength while suppressing the displacement of the welded material by the fixing force of the welded portion in the first welding step. As a result, it is possible to manufacture a rolling bearing device in which generation of outgas is reduced and generation of resonance frequency fluctuation and torque fluctuation is prevented while ensuring sufficient bonding strength.

  In the above invention, the outer ring and the second that are pressed in a state where the spacer portion is sandwiched in the axial direction between the inner rings of the two rolling bearings and the outer rings are pressed in a direction relatively close to the axial direction. Laser welding by the first welding process and laser welding by the second welding process may be performed on the fitting portion with the member.

  By configuring in this way, a gap according to the length of the spacer portion is formed between the outer rings, so by applying the first welding step and the second joining step to the fitted portion of the pressed outer ring, A rolling bearing device in which the preloaded state is maintained can be easily manufactured in a short time.

  In the above invention, the first laser welding step may perform laser welding at adjacent locations where the outer rings and the second member are moved closer to each other in the radial direction to be close to each other. .

  By comprising in this way, even if it is a case where a clearance gap exists in the fitting part of each outer ring | wheel and the 2nd member, a proximity | contact part can be reliably fixed by laser welding. Further, it is possible to easily identify the proximity location.

  Further, by bringing each outer ring and the second member relatively in one radial direction, the axial centers of the two rolling bearings can be made to coincide, for example, a swing arm around the axis of the two rolling bearings. A rolling bearing device in which the second member can be relatively rotated with high accuracy can be manufactured.

  In the above invention, the first welding step may further perform laser welding at a position that is different in the circumferential direction with respect to the adjacent location by increasing the diameter of the welding range from the adjacent location.

  By configuring in this way, the diameter dimension (spot diameter) of the welding range for laser welding is individually set according to the size of the gap of the fitting portion, and stable welding is performed at a plurality of circumferential positions in the fitting portion. Can be applied. Therefore, it is possible to more reliably suppress the displacement of the material to be welded due to the laser welding in the second welding process.

The present invention relates to each fitting portion between each inner ring of two rolling bearings arranged coaxially with an interval in the axial direction and a first member fitted to these inner rings, and the two rolling bearings. A first welding step in which at least one of the fitting portions of the outer rings and the second member for fitting the outer rings is laser-welded with laser power that does not cause thermal deformation of the inner ring or the outer ring; A method of manufacturing a rolling bearing device including a second welding step of laser welding the fitting portions joined in the first welding step with a laser power higher than that of the first welding step , Provided is a method of manufacturing a rolling bearing device, wherein the second welding step performs laser welding at a position that is different in the circumferential direction from a welding spot in the first fitting step in the same fitting portion. .

  According to the present invention, the outer rings of the two rolling bearings each having the first member fitted to each inner ring are fitted to the second member, respectively, and the first welding process is performed at least at one place of each fitting portion. The first member and the second member are joined by the laser welding by the laser welding and the laser welding by the second welding process, and the first and second members and the two rolling bearings are joined to each other. A rolling bearing device that is relatively rotatably supported is manufactured.

  In this case, the first member and the inner ring or the first ring are maintained while maintaining the shape of the inner ring or the outer ring by laser welding the fitting portion with laser power that does not cause thermal deformation of the inner ring or the outer ring in the first welding step. The two members and the outer ring can be fixed. In this state, by performing laser welding with a higher laser power than in the first welding process in the second welding process, the force to relatively change the material to be welded when the melted welded part is cured and contracted. Even in the case of acting, the fitting portion can be joined with high joining strength while suppressing the displacement of the welded material by the fixing force of the welded part in the first welding process.

  Further, when the fitting portions are joined by laser welding, generation of outgas as in the case of joining with an anaerobic adhesive can be prevented, and productivity can be improved by shortening the joining time. Further, according to laser welding, it is possible to avoid a change in preload due to a change in the rigidity of the adhesive due to a temperature change as in the case of joining with an adhesive, and to stabilize the resonance frequency and torque. Therefore, by joining at least one part of the fitting portion by the first welding process and the subsequent second welding process, generation of outgas is reduced while ensuring sufficient joining strength, and resonance frequency fluctuations and torque are reduced. It is possible to manufacture a rolling bearing device that prevents occurrence of fluctuations.

  In the above invention, the inner ring of one of the rolling bearings is abutted against the flange portion protruding radially outward of the first member, and the two rolling bearings are sandwiched with the spacer portion in the axial direction between the outer rings. In the state where the inner ring of the other rolling bearing is pressed in a direction to bring it closer to the inner ring of the one rolling bearing, the fitting portion between the first member and the inner ring of the other rolling bearing is Laser welding by the first welding process and laser welding by the second welding process may be performed.

  With this configuration, the spacer portion is sandwiched between the outer rings of the two rolling bearings, whereby a gap corresponding to the length of the spacer portion is formed between the inner rings of the two rolling bearings. Accordingly, it is possible to apply preload to the two rolling bearings simply by pressing the inner ring of the other rolling bearing toward the inner ring of one rolling bearing that is abutted against the flange of the first member. And the state which applied the pre-load is maintained by giving a 1st welding process and a 2nd joining process to the fitting part with the inner ring of the 1st member and the other rolling bearing in the state pressed in this way. The rolling bearing device can be easily manufactured in a short time.

  In the first aspect of the invention, the first laser welding step may move the inner ring and the first member and / or the outer ring and the second member toward each other in a relatively radial direction. It is good also as carrying out laser welding of the proximity | contact place made close to.

  By comprising in this way, even if there is a gap in the fitting part between each inner ring and the first member and the fitting part between each outer ring and the second member, the fitting part is formed by laser welding. It is possible to reliably fix the adjacent portions that are close to each other in the circumferential direction. Moreover, the proximity | contact location with a small clearance gap in a fitting part can be easily specified by making a part of fitting part approach closely.

  Further, by bringing at least one of each inner ring and the first member and / or each outer ring and the second member relatively in one radial direction, the axes of the two rolling bearings can be made to coincide. Thereby, it is possible to manufacture a rolling bearing device in which the first member and the second member can relatively rotate with high accuracy around the axes of these two rolling bearings.

  Further, in the above invention, the first welding step may further perform laser welding at a position different in the circumferential direction with respect to the adjacent portion by increasing the diameter dimension of the welding range from the adjacent portion.

  By configuring in this way, the diameter dimension (spot diameter) of the welding range for laser welding is individually set according to the size of the gap of the fitting portion, and stable welding is performed at a plurality of circumferential positions in the fitting portion. Can be applied. Therefore, it is possible to more reliably suppress the displacement of the material to be welded due to the laser welding in the second welding process.

  Moreover, in the said invention, the said 1st welding process performs the laser welding in which the 1st welding trace of a diameter dimension of 100 micrometers or less is formed in the welding time of 5 msec or less, and the said 2nd welding process is the said Laser welding may be performed in which a second weld trace having a larger diameter than the first weld trace is formed.

Moreover, in the said invention, the said 1st welding process is good also as performing the said laser welding in the same said fitting part to at least 3 or more places at intervals in the circumferential direction.
By comprising in this way, a fitting part can be balanced and fixed to the circumferential direction by a 1st welding process, and joining by a 2nd welding process can be performed with sufficient precision in the whole circumferential direction. In addition, it is preferable to perform laser welding at equal intervals in the circumferential direction of the fitting portion.

Moreover, in the said invention, the said 2nd welding process is good also as performing the said laser welding in the said same fitting part in multiple times, overlapping a part of welding location.
By comprising in this way, the fixing force of a welding location improves compared with the case where it joins by one laser welding, and a fitting part can be joined by higher joining strength.

Moreover, in the said invention, the said 2nd welding process is good also as performing the said laser welding in the same said fitting part in multiple places at equal intervals in the circumferential direction.
By comprising in this way, a fitting part can be balanced and joined to the circumferential direction by a 2nd welding process.

In the above invention, the second welding process includes a melting process in which a predetermined laser power is melted in a melting time of 5 msec or less, and a laser that is lower than that in the melting process at the welding spot melted by the melting process. It is good also as including the cooling process cooled while irradiating power.
By configuring in this way, the welded part melted by the melting process is gradually cooled and solidified by the cooling process, thereby preventing the occurrence of cracks due to rapid cooling and manufacturing a rolling bearing device with higher joint strength. can do.

  According to the present invention, there is an effect that it is possible to manufacture a rolling bearing device that has sufficient joint strength, reduces outgas generation, and prevents occurrence of resonance frequency fluctuation and torque fluctuation.

It is a longitudinal cross-sectional view of the rolling bearing apparatus which concerns on one Embodiment of this invention. It is a longitudinal cross-sectional view which expands and shows the fitting location of the inner ring | wheel and shaft of the rolling bearing of FIG. It is a figure which shows the relationship between the intensity | strength of the 1st laser power and irradiation time in a 1st welding process. It is a cross-sectional view which shows the welding location by the 1st welding process of the inner ring | wheel and shaft of FIG. It is a cross-sectional view which shows the welding location by the 2nd welding process of the inner ring | wheel and shaft of FIG. It is a flowchart which shows the manufacturing method of the rolling bearing apparatus which concerns on one Embodiment of this invention. It is a cross-sectional view which shows the welding location by the 1st welding process of the outer ring | wheel and sleeve of FIG. It is a cross-sectional view which shows the welding location by the 2nd welding process of the outer ring | wheel and sleeve of FIG. It is a cross-sectional view which shows the welding location by the 1st welding process of the inner ring | wheel and shaft which concern on the modification of one Embodiment of this invention, and a 2nd welding process. It is a cross-sectional view which shows the welding location by the 1st welding process of the outer ring | wheel and sleeve which concerns on the modification of one Embodiment of this invention, and a 2nd welding process. It is a cross-sectional view which shows the welding location by the 1st welding process of the inner ring | wheel and shaft which concerns on another modification of one Embodiment of this invention, and a 2nd welding process. It is a cross-sectional view which shows the welding location by the 1st welding process of the inner ring | wheel and shaft which concerns on another modification of one Embodiment of this invention, and a 2nd welding process. It is a figure which shows the relationship between the intensity | strength of 2nd laser power and irradiation time in the 2nd welding process which concerns on the modification of one Embodiment of this invention. It is a figure which shows the relationship between the intensity | strength of 2nd laser power and irradiation time in the 2nd welding process which concerns on another modification of one Embodiment of this invention. It is a longitudinal cross-sectional view of the rolling bearing apparatus of the structure which is not provided with the sleeve which concerns on another modification of one Embodiment of this invention. It is the figure which looked at the rolling bearing apparatus which concerns on another modification of one Embodiment of this invention to the axial direction. It is a flowchart which shows the manufacturing method of the rolling bearing apparatus which concerns on another modification of one Embodiment of this invention.

Hereinafter, a manufacturing method of a rolling bearing device concerning one embodiment of the present invention is explained with reference to drawings.
A method for manufacturing a rolling bearing device according to the present embodiment includes, for example, a rolling bearing device 10 for swinging a swing arm used in a magnetic recording device (HDD), an optical recording device, or the like, as shown in FIG. To manufacture. As the rolling bearing device 10, for example, a shaft (first member) 13 and a sleeve (second member) are constituted by a first rolling bearing 1A and a second rolling bearing 1B (hereinafter referred to as “rolling bearings 1A and 1B”). ) 23 is supported so as to be relatively rotatable. The two rolling bearings 1A and 1B roll a plurality of rolling elements 7 at predetermined intervals in the circumferential direction in an annular space between the inner rings 3a and 3b and the outer rings 5a and 5b arranged coaxially. It is possible to hold.

  In this manufacturing method, two rolling bearings 1A and 1B are coaxially arranged with an interval in the axial direction, and each fitting portion between each inner ring 3a and 3b and the shaft 13 fitted to these inner rings 3a and 3b. And the 1st welding process of laser-welding each fitting part of each outer ring 5a, 5b and fitting hole 25 of sleeve 23 which fits these outer rings 5a, 5b, and the 1st in each fitting part This includes a second welding process in which laser welding is performed at a position different from the welding location 33 in the circumferential direction.

  The first welding step and the second welding step are performed at portions where the end surfaces of the inner rings 3a and 3b and the outer peripheral surface of the shaft 13 shown in FIG. 2 intersect, and fitting holes between the end surfaces of the outer rings 5a and 5b and the sleeve 23. Laser welding is performed on each of the portions where the inner peripheral surface of 25 intersects. Further, in the first welding step and the second welding step, laser welding is performed at least at three or more locations at intervals in the circumferential direction in the same fitting portion (FIGS. 4 and 5). reference). In the present embodiment, laser welding is performed at three locations at equal intervals in the circumferential direction.

  The first welding process is a laser power that does not cause thermal deformation of the inner rings 3a, 3b and the outer rings 5a, 5b, for example, as shown in FIG. 3, with a welding time of 5 msec or less, as shown in FIGS. Laser welding is performed by a laser power (hereinafter referred to as “first laser power”) 33F on which a welding trace (hereinafter referred to as “first welding trace”) 33F having a diameter of 100 μm or less is formed. In FIG. 3, the vertical axis indicates the intensity of the laser power, and the horizontal axis indicates the irradiation time (the same applies to FIGS. 13 and 14).

  In the second welding process, a laser power higher than the first laser power in the first welding process, for example, a laser power that provides a bonding strength that does not cause displacement when the shaft 13 and the sleeve 23 rotate relative to each other ( Hereinafter, laser welding is performed according to “second laser power”. Further, in the second welding process, laser welding is performed at a position shifted in the circumferential direction so as not to overlap the welding location 33 in the first welding process. According to the second laser power, as shown in FIG. 5, a welding mark (hereinafter referred to as “second welding mark”) 33S having a diameter larger than that of the first welding mark 33F is formed. Yes.

Hereinafter, a method for manufacturing the rolling bearing device 10 will be described with reference to the flowchart of FIG.
First, the shaft 13 is fitted to the inner ring 3a of the first rolling bearing 1A (hereinafter, this fitting portion is referred to as “fitting portion 29A”), and the entire circumference provided at one end of the shaft 13 in the axial direction. The end face of the inner ring 3a is abutted against the flange 15 that protrudes radially outward.

  Then, as shown in FIG. 3, three portions of the fitting portion 29 </ b> A where the end surface opposite to the end surface abutted against the flange portion 15 of the inner ring 3 a and the outer peripheral surface of the shaft 13 intersect are first. Laser welding is performed with laser power to fix the inner ring 3a and the shaft 13 (first welding step S1 of the inner ring 3a). In this case, laser welding is performed with a first laser power that does not cause thermal deformation of the inner ring 3a, thereby maintaining the shape of the inner ring 3a and causing a displacement in the material to be welded (here, the inner ring 3a and the shaft 13). The fitting portion 29A can be fixed without any problems.

  Subsequently, as shown in FIG. 5, the positions shifted in the circumferential direction with respect to the three first welding traces 33 </ b> F in the fitting portion 29 </ b> A are respectively laser-welded by the second laser power, and the inner ring 3 a and the shaft 13. Are joined (second welding step S2 of the inner ring 3a). In this case, when laser welding is performed with a second laser power that is higher in intensity than the first laser power, a force that relatively changes the material to be welded acts when the molten welded portion 33 is cured and contracted. Even so, it is possible to join with a high joining strength while suppressing the displacement of the material to be welded by the fixing force of the welding location 33 in the first welding step S1.

  Next, the outer ring 5b of the second rolling bearing 1B is fitted into a sleeve 23 having a convex portion (hereinafter referred to as a “spacer portion”) 27 protruding inward in the radial direction substantially at the center of the fitting hole 25 in the axial direction. (The fitting portion is hereinafter referred to as “fitting portion 29D”), and the end surface of the outer ring 5b is abutted against the spacer portion 27. Then, as shown in FIG. 7, the first laser power is applied to three portions where the end surface opposite to the end surface abutted against the spacer portion 27 of the outer ring 5 b and the inner peripheral surface of the fitting hole 25 intersect. Laser welding is performed to fix the outer ring 5b and the fitting hole 25 of the sleeve 23 (first welding step S3 of the outer ring 5b).

  Subsequently, as shown in FIG. 8, the positions shifted in the circumferential direction with respect to the three first welding traces 33 </ b> F in the fitting portion 29 </ b> D are laser-welded by the second laser power, and the outer ring 5 b, the sleeve 23, and the like. Are joined (second welding step S4 of the outer ring 5b). Also in this case, similarly to the fitting portion 29A, the first welding step S3 and the second welding step S4 can be joined with high joining strength while suppressing the positional deviation between the outer ring 5b and the sleeve 23.

  Next, in a state where the flange portion 15 of the shaft 13 is fixed vertically downward, the sleeve 23 is assembled to the shaft 13 from the opposite side of the fitting portion 29D in the axial direction. The outer ring 5a of the first rolling bearing 1A joined to the shaft 13 is fitted into the fitting hole 25 of the sleeve 23 (hereinafter, this fitting part is referred to as “fitting part 29C”), and the end surface of the outer ring 5a is engaged. And the shaft 13 is fitted to the inner ring 3b of the second rolling bearing 1B joined to the sleeve 23 (hereinafter, this fitting portion is referred to as “fitting portion 29B”). An assembly of the rolling bearing device 10 is formed.

  In this state, as shown in FIG. 7, first, in the fitting portion 29 </ b> C, the end surface opposite to the end surface abutted against the spacer portion 27 of the outer ring 5 a intersects the inner peripheral surface of the fitting hole 25. The three portions of the portion to be welded are laser welded by the first laser power, and the outer ring 5a and the fitting hole 25 of the sleeve 23 are fixed (first welding step S5 of the outer ring 5a).

  Subsequently, as shown in FIG. 8, the positions shifted in the circumferential direction with respect to the three first welding traces 33 </ b> F in the fitting portion 29 </ b> C are laser-welded by the second laser power, and the outer ring 5 a and the sleeve 23. Are joined (second welding step S6 of the outer ring 5a). Also in this case, similarly to the fitting portion 29A and the fitting portion 29D, the first welding step S5 and the second welding step S6 are joined with high joining strength while suppressing the positional deviation between the outer ring 5a and the sleeve 23. be able to.

Next, the fitting portion 29B is joined by laser welding.
Here, a gap corresponding to the length of the spacer portion 27 is formed between the inner rings 3a and 3b by the spacer portion 27 sandwiched between the outer rings 5a and 5b of the rolling bearings 1A and 1B. Therefore, the inner ring 3a and the inner ring 3b are pressed in a direction in which they are close to each other, and a preload is applied to the rolling bearings 1A and 1B.

  In this case, since the inner ring 3a of the first rolling bearing 1A is abutted against the flange portion 15 of the shaft 13, the inner ring of the second rolling bearing 1B disposed on the opposite side in the axial direction with respect to the inner ring 3a. Preload can be applied to both of the rolling bearings 1A and 1B simply by pressing 3b in the axial direction.

  Therefore, first, the inner ring 3b of the second rolling bearing 1B is pressed in the axial direction, and in this state, three portions where the end surface of the inner ring 3b and the outer peripheral surface of the shaft 13 intersect are laser-welded with the first laser power. The inner ring 3b and the shaft 13 are fixed (first welding step S7 of the inner ring 3b). Subsequently, the positions shifted in the circumferential direction with respect to the three first welding traces 33F in the fitting portion 29B are laser-welded by the second laser power, and the inner ring 3b and the shaft 13 are joined (the inner ring 3b). Second welding step S8).

  As a result, like the other fitting portions 29A, 29C, and 29D, the fitting portion 29B is joined with high joining strength while suppressing the positional deviation between the inner ring 3b and the shaft 13, so that the rolling bearings 1A and 1B are joined. The rolling bearing device 10 in which the preloaded state is maintained is completed.

  In this rolling bearing device 10, since the fitting portions 29A, 29B, 29C, and 29D are joined by laser welding, it is possible to prevent the occurrence of outgas as in the case of joining with an anaerobic adhesive and to shorten the joining time. This can improve productivity. Further, according to laser welding, it is possible to avoid a change in preload caused by a change in the rigidity of the adhesive due to a temperature change as in the case of joining with an adhesive, and to stabilize the resonance frequency and torque.

As described above, according to the method for manufacturing the rolling bearing device 10 according to the present embodiment, the fitting portions 29A, 29B, 29C, and 29D are made to have low strength by the first welding process and the second welding process. The rolling bearing device 10 is manufactured by reducing the outgas generation and preventing the occurrence of resonance frequency fluctuation and torque fluctuation while securing sufficient bonding strength by joining the power and high laser power in two times. can do.
In the present embodiment, laser welding is performed at a position different from the first welding mark 33F in the circumferential direction in the second welding process. For example, in the second welding process, the first welding mark 33F and The same position may be laser welded.

  In the present embodiment, the first welding process and the second welding process are performed on all the fitting parts 29A, 29B, 29C, and 29D, but at least the fitting parts 29A, 29B, 29C, and 29D are used. It is good also as giving a 1st welding process and a 2nd welding process to one fitting part. For example, the fitting portions 29A and 29B between the inner rings 3a and 3b and the shaft 13 are joined by laser welding, and the fitting portions 29C and 29D between the outer rings 5a and 5b and the fitting hole 25 of the sleeve 23 are joined by an adhesive. It is good as well.

  Further, in the present embodiment, the second welding step is to perform laser welding at three locations at equal intervals in the circumferential direction, but instead, for example, as shown in FIGS. 9 and 10, Laser welding in the same fitting portion 29A (29B, 29C, 29D) may be performed a plurality of times (for example, twice) with a part of the welded portion 33 overlapped. As the overlapping range, for example, it is preferable that the overlap rate is 10% or more of the area of the second welding trace 33. By doing in this way, the fixing force of the welding location 33 improves compared with the case where it joins by 1 time of laser welding, and higher joint strength can be ensured.

  Further, in the same fitting portion 29A (29B, 29C, 29D), for example, laser welding by the first welding process and laser welding by the second welding process are performed as shown in FIGS. Alternatively, it may be applied to a plurality of locations (three locations in the figure) at equal intervals alternately in the direction. By doing in this way, 29 A of fitting parts can be balanced and joined to the circumferential direction by the 1st welding process and the 2nd welding process.

  In the present embodiment, the second welding process is simply laser welding with the second laser power. For example, as shown in FIG. 13 or FIG. 14, the second welding process has a predetermined laser power. For example, a melting process in which the second laser power is melted in a melting time of 5 msec or less, and a laser power lower in intensity than the second laser power is irradiated for a certain time (for example, 10 msec or more) to the welded portion 33 melted by the melting process. It is good also as including the cooling process cooled while doing. By doing so, the welded portion 33 melted by the second laser power in the melting step is gradually cooled and solidified by the laser power having a low strength by the cooling step, so that generation of cracks due to rapid cooling is prevented. Thus, it is possible to manufacture the rolling bearing device 10 having higher bonding strength. In this case, in the cooling step, as shown in FIG. 13, the irradiation may be continued for a certain time without changing the intensity of the laser power, or the intensity of the laser power is gradually increased as shown in FIG. It is good also as irradiating, reducing.

  In the present embodiment, the sleeve 23 provided with the spacer portion 27 on the inner surface of the fitting hole 25 has been described as an example of the second member. Instead, for example, a sleeve without the spacer portion 27 is described. The ring-shaped spacer may be sandwiched between the inner rings 3a and 3b of the rolling bearings 1A and 1B. In this case, since a gap corresponding to the length of the spacer is formed in the outer rings 5a and 5b, the outer rings 5a and 5b may be pressed in a direction in which they approach each other.

  In the present embodiment, the rolling bearing device 10 includes the sleeve 23. For example, unlike the rolling bearing device 110 illustrated in FIG. 15, the sleeve 23 is not provided, and the outer rings 5a of the rolling bearings 1A and 1B are provided. It is good also as a structure which pinches | interposes the ring-shaped spacer part 127 between 5b. In this case, since a gap corresponding to the length of the spacer portion 127 is formed in the inner rings 3a and 3b, the inner rings 3a and 3b may be pressed in a direction in which they approach each other.

Further, the present embodiment can be modified as follows.
For example, as a modification of the present embodiment, as shown in FIG. 16, the first welding process is performed in such a manner that the inner rings 3 a and 3 b and the shaft 13 and the outer rings 5 a and 5 b and the sleeve 23 are relatively arranged in one radial direction. It is good also as laser welding the location (proximity location) where each member contacted or approached each other. Alternatively, laser welding may be performed by increasing the diameter size (spot diameter) of the welding range at a position different in the circumferential direction (for example, two different positions) with respect to the contacted or adjacent part, and making the diameter size (spot diameter) of the welding range larger than that of the adjacent part. .

  Specifically, as shown in the flowchart of FIG. 17, first, fitting portions 29A, 29B between the inner rings 3a, 3b and the shaft 13 and fitting portions 29C, 29D between the outer rings 5a, 5b and the sleeve 23 are respectively provided. Adhesive is applied (step Sm1), the assembly of the rolling bearing device 10 is assembled (step Sm2), and the inner ring 3a and the inner ring 3b are pressed in a direction approaching each other to pre-load the rolling bearings 1A and 1B ( Step Sm3).

  Subsequently, in the first welding step, the outer circumferential surface of the sleeve 23 is pressed in one direction from the radially outer side to the radially inner side (center of the shaft 13), and the inner rings 3a and 3b and the shaft 13 and The outer rings 5a and 5b and the sleeve 23 are moved in one radial direction (step Sm4). As a result, the inner rings 3a and 3b and the shaft 13 and the outer rings 5a and 5b and the sleeve 23 can be partially brought into contact with each other or brought into close proximity with each other, so that the axes of the two rolling bearings 1A and 1B can be aligned. It is desirable that the strength of pressing the outer peripheral surface of the sleeve 23 is weaker than the strength of pressing the inner ring 3a and the inner ring 3b when preloading the rolling bearings 1A and 1B. By doing in this way, the state which applied the preload to rolling bearing 1A, 1B can be maintained, and it can prevent that a distortion arises in the assembly of rolling bearing apparatus 10. FIG.

  Next, the portion where the inner ring 3b and the shaft 13 are in contact with or close to each other in the fitting portion 29B is first laser welded with the first laser power (this portion is referred to as the first welding portion 33F1). The first welding location 33F1 has a spot diameter of about 100 μm. Subsequently, laser welding is performed at positions shifted by about 120 ° in the circumferential direction with respect to the first welding point 33F1 with the first laser power (these points are the second welding point 33F2 and the third welding point 33F3. Step Sm5). The spot diameter of each of the second welded spot 33F2 and the third welded spot 33F3 is about 150 μm.

  Since the second welded spot 33F2 and the third welded spot 33F3 have a larger gap than the first welded spot 33F1, by setting the spot diameter individually according to the size of the gap of the fitted part, the fitted part Stable welding can be performed at a plurality of locations in the circumferential direction. Therefore, it is possible to more reliably suppress the displacement of the material to be welded (here, the inner ring 3b and the shaft 13) by the laser welding in the second welding process. Laser welding may be performed while the outer peripheral surface of the sleeve 23 is pressed, or laser welding may be performed without pressing the inner ring 3b and the shaft 13 as long as the state can be maintained in contact or close proximity.

  Next, in the second welding process, the positions shifted in the circumferential direction with respect to the first welding location 33F1, the second welding location 33F2 and the third welding location 33F3 are laser-welded with the second laser power, respectively. 3b and the shaft 13 are joined (step Sm6). Thereby, the assembly of the rolling bearing device 10 is completed, and the rolling bearing device 10 is taken out from the production line (step Sm7).

  Thereafter, the other fitting portions 29A, 29C, and 29D are joined by an adhesive, whereby the rolling bearing device 10 is completed. For example, when an anaerobic adhesive is used as the adhesive, the adhesive is cured by allowing it to stand for a predetermined time, and the fitting portions 29A, 29C, and 29D are joined. When a thermosetting adhesive is used as the adhesive, the adhesive is cured by applying predetermined heat, and the fitting portions 29A, 29C, and 29D are joined.

  As described above, according to the present modification, even when there is a gap between the fitting portions 29A, 29B, 29C, and 29D, a part of the fitting portions 29A, 29B, 29C, and 29D is brought into contact with or close to each other. Thus, it is possible to identify the location where the gap has become small and to fix this location reliably by laser welding. Further, it is possible to manufacture the rolling bearing device 10 in which the shaft centers of the two rolling bearings 1A and 1B coincide with each other so that the shaft 13 and the sleeve 23 can relatively rotate with high accuracy.

  In this modification, the case where only the inner ring 3b and the shaft 13 are laser-welded after the assembly of the rolling bearing device 10 has been assembled has been described as an example. However, for example, the fitting of the outer rings 5a and 5b and the sleeve 25 is performed. Laser welding may be performed in a state where the joint portions 29C and 29D are moved in one direction in the same manner. Moreover, it is good also as not using an adhesive agent. When a ring-shaped spacer is disposed between the inner rings 3a and 3b using a sleeve that does not include the spacer portion 27, each of the fitting portions 29A and 29B between the inner rings 3a and 3b and the shaft 13, Laser welding may be performed in a state where the fitting portions 29C and 29D of the outer rings 5a and 5b and the sleeve 25 are moved in one radial direction by the first welding process.

  Further, in this modification, the laser welding is first performed on the contact or the close part in the fitting portion, but for example, the position different in the circumferential direction with respect to the contact or the close part is first laser welded. It is good. In this case, the spot diameter may be individually set according to the size of the gap in the fitting portion. Moreover, in this modification, it decided to laser-weld three places of the circumferential direction in a fitting part, For example, as laser welding of two places or less of the circumferential direction, or four places or more of the circumferential direction Good.

  In the present embodiment and its modification, the rolling bearing device 10 includes the shaft 13 and the sleeve 23. Instead, for example, the rolling bearing device 10 does not include the sleeve 23, and the HDD or the like. The outer rings 5a and 5b may be directly fitted into the bearing fitting holes of the swing arm used. Further, for example, the rolling bearing device 10 may be configured not to include the shaft 13 but to fit the swing arm directly to the inner rings 3a and 3b.

DESCRIPTION OF SYMBOLS 1A 1st rolling bearing 1B 2nd rolling bearing 3a, 3b Inner ring 5a, 5b Outer ring 7 Rolling element 10, 110 Rolling bearing apparatus 13 Shaft (1st member)
23 Sleeve (second member)
25 Fitting hole 27, 127 Spacer part S1, S3, S5, S7 First welding step S2, S4, S6, S8 Second welding step

Claims (16)

At least one of the fitting portions of the inner rings of the two rolling bearings arranged coaxially with an interval in the axial direction and the first member fitted to the inner rings is subjected to thermal deformation on the inner ring. A first welding process in which laser welding is performed with laser power that does not occur;
A method of manufacturing a rolling bearing device including a second welding step of laser welding the fitting portions in a state of being joined by the first welding step with a laser power higher than that of the first welding step ,
The method for manufacturing a rolling bearing device, wherein the second welding step performs laser welding at a position that is different in the circumferential direction from a welding location in the same fitting portion at the time of the first welding step.   Fitting between the pressed inner ring and the first member in a state where the spacer portion is sandwiched in the axial direction between the outer rings of the two rolling bearings and the inner rings are pressed in a direction relatively close to the axial direction. The method for manufacturing a rolling bearing device according to claim 1, wherein laser welding by the first welding process and laser welding by the second welding process are performed on a joint portion.   3. The first laser welding process according to claim 1 or 2, wherein the first laser welding step performs laser welding of adjacent portions where the inner rings and the first member are relatively moved toward one direction in the radial direction to be close to each other. Method of rolling bearing device of the present invention. At least one of the fitting portions of the outer rings of the two rolling bearings arranged coaxially with an interval in the axial direction and the second member for fitting the outer rings is subjected to thermal deformation in the outer ring. A first welding process in which laser welding is performed with laser power that is not allowed;
A method of manufacturing a rolling bearing device including a second welding step of laser welding the fitting portions in a state of being joined by the first welding step with a laser power higher than that of the first welding step ,
The method for manufacturing a rolling bearing device, wherein the second welding step performs laser welding at a position that is different in the circumferential direction from a welding location in the same fitting portion at the time of the first welding step.   Fitting between the pressed outer ring and the second member in a state where the spacer portion is sandwiched in the axial direction between the inner rings of the two rolling bearings and the outer rings are pressed in a direction relatively close to the axial direction. The method for manufacturing a rolling bearing device according to claim 4, wherein laser welding by the first welding process and laser welding by the second welding process are performed on a joint portion.   6. The first laser welding process according to claim 4 or 5, wherein the first laser welding step performs laser welding of adjacent portions where the outer rings and the second member are relatively moved toward one direction in the radial direction to be close to each other. Method of rolling bearing device of the present invention.   The rolling bearing device according to claim 3 or 6, wherein the first welding step further performs laser welding at a position that is different in the circumferential direction with respect to the adjacent portion by increasing a diameter size of a welding range from the adjacent portion. Manufacturing method. Each fitting part of each inner ring of two rolling bearings arranged coaxially at intervals in the axial direction and a first member fitted to these inner rings, and each outer ring of said two rolling bearings A first welding step of laser welding at least one portion of each fitting portion with the second member for fitting these outer rings by laser power that does not cause thermal deformation of the inner ring or the outer ring;
A method of manufacturing a rolling bearing device including a second welding step of laser welding the fitting portions in a state of being joined by the first welding step with a laser power higher than that of the first welding step ,
The method for manufacturing a rolling bearing device, wherein the second welding step performs laser welding at a position that is different in the circumferential direction from a welding location in the same fitting portion at the time of the first welding step.   The inner ring of one of the rolling bearings is abutted against a flange portion protruding radially outward of the first member, and the two rolling bearings are arranged with a spacer portion sandwiched between the outer rings in the axial direction. In the state where the inner ring of the other rolling bearing is pressed in the direction of approaching the inner ring of the one rolling bearing, the first weld is applied to the fitting portion between the first member and the inner ring of the other rolling bearing. The method of manufacturing a rolling bearing device according to claim 8, wherein laser welding according to a process and laser welding according to the second welding process are performed.   In the first laser welding step, the inner ring and the first member and / or the outer ring and the second member are moved closer to one direction in the radial direction to approach each other. The method for manufacturing a rolling bearing device according to claim 8 or 9, wherein laser welding is performed.   The manufacturing method of the rolling bearing device according to claim 10, wherein the first welding step further performs laser welding at a position different in the circumferential direction with respect to the adjacent portion by increasing a diameter size of a welding range from the adjacent portion.   The first welding process performs laser welding in which a first welding trace having a diameter of 100 μm or less is formed in a welding time of 5 msec or less, and the second welding process is larger than the first welding trace. The method for manufacturing a rolling bearing device according to any one of claims 1 to 11, wherein laser welding is performed to form a second welding mark having a radial dimension.   The manufacturing of the rolling bearing device according to any one of claims 1 to 12, wherein in the first welding step, the laser welding in the same fitting portion is performed at least at three or more locations in the circumferential direction. Method.   The method for manufacturing a rolling bearing device according to any one of claims 1 to 13, wherein in the second welding step, the laser welding in the same fitting portion is performed a plurality of times by overlapping a part of the welding portion. .   The method for manufacturing a rolling bearing device according to any one of claims 1 to 14, wherein the second welding step performs the laser welding in the same fitting portion at a plurality of locations at equal intervals in the circumferential direction.   The second welding step is a melting step that melts with a predetermined laser power in a melting time of 5 msec or less, and cooling while irradiating the welding spot melted by the melting step with a laser power lower than that in the melting step. The manufacturing method of the rolling bearing apparatus in any one of Claims 1-15 including a cooling process.

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