Ring assembly method and manufacturing method

A process of setting a front end-side retaining ring at a small diameter part of a ring temporary holding jig. A process of causing the ring temporary holding jig to temporarily hold the front end-side retaining ring by using a first ring press member. A process of attaching the ring temporary holding jig to a shaft. A process of transferring the front end-side retaining ring from a large diameter part of the ring temporary holding jig to a first outer peripheral surface of the shaft by using a second ring press member including a dimension shorter than a dimension of the first ring press member. A process of sliding the front end-side retaining ring on the first outer peripheral surface of the shaft to assemble the front end-side retaining ring in the ring groove by using the second ring press member.

TECHNICAL FIELD

The present disclosure relates to a ring assembly method and a manufacturing method.

BACKGROUND ART

Patent Literature 1 discloses a method for mounting a seal ring to a groove part formed on an outer peripheral surface of a shaft. Specifically, a ring mounting jig having a tapered outer peripheral surface is mounted on a leading end of the shaft, and the seal ring is gradually deformed to expand its diameter by being slid on the tapered outer peripheral surface. The deformed seal ring with the expanded diameter is moved on the outer peripheral surface of the shaft, and when the seal ring eventually reaches the groove part, the diameter of the seal ring is reduced due to deformation and the seal ring is mounted in the groove part.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

However, since the jig for sliding the seal ring on the tapered outer peripheral surface is long, it is not possible to assemble the seal ring in the groove part of the shaft if a sufficient working space cannot be ensured to use the jig.

An object of the present disclosure is to provide a technique for assembling a ring in a ring groove of a cylindrical member even without a sufficient working space.

Solution to Problem

A first example aspect of the present disclosure provides a ring assembly method for assembling a ring in a ring groove formed on an outer peripheral surface of a cylindrical member. The ring assembly method includes: setting the ring at a small diameter part of a ring temporary holding jig, the ring temporary holding jig including the small diameter part, a tapered part, and a large diameter part in this order, an outer diameter of the small diameter part being smaller than an outer diameter of the large diameter part, an outer peripheral surface of the tapered part being formed to connect an outer peripheral surface of the small diameter part to an outer peripheral surface of the large diameter part, and the outer diameter of the large diameter part being larger than an outer diameter of the cylindrical member; moving the ring to the large diameter part from the small diameter part through the tapered part by using a first ring press member including a cylindrical shape with a leading end part elastically deformable in a radial direction and including a first length in an axial direction, so that the ring temporary holding jig temporarily holds the ring; attaching the ring temporary holding jig for temporarily holding the ring to the cylindrical member; transferring the ring from the large diameter part of the ring temporary holding jig to the outer peripheral surface of the cylindrical member by using a second ring press member, the second ring press member including a cylindrical shape and a second length shorter than the first length in the axial direction; and sliding the ring on the outer peripheral surface of the cylindrical member and then assembling the ring in the ring groove by using the second ring press member. According to the above method, the ring can be assembled in the ring groove of the cylindrical member even without a sufficient working space.

The first ring press member may include a cylindrical part and a plurality of elastic pieces extending from the cylindrical part. According to the above method, the first ring press member can be implemented with a simple configuration.

When the ring is moved relative to the ring temporary holding jig in order to have the ring temporary holding jig to temporarily hold the ring, a ring movement control member including an outer diameter larger than the outer diameter of the large diameter part may be made adjacent to the large diameter part of the ring temporary holding jig. According to the above method, when the ring is moved relative to the ring temporary holding jig in order to have the ring temporary holding jig temporarily hold the ring, the ring does not climb over the large diameter part.

The ring temporary holding jig may include a temporary holding insertion part inserted into an internal space of the cylindrical member when the ring temporary holding jig is attached to the cylindrical member, a temporary holding-side lock hole may be formed in an outer peripheral surface of the temporary holding insertion part, the cylindrical member may include a cylindrical member-side lock hole penetrating therethrough in a radial direction, and when the ring temporary holding jig for temporarily holding the ring is attached to the cylindrical member, the temporary holding insertion part of the ring temporary holding jig may be inserted into the internal space of the cylindrical member, the cylindrical member-side lock hole and the temporary holding-side lock hole may be aligned with each other, and a lock pin may be inserted into the cylindrical member-side lock hole and the temporary holding-side lock hole. According to the above method, the ring temporary holding jig for temporarily holding the ring can be surely attached to the cylindrical member.

The ring temporary holding jig may include a permanent magnet magnetically coupled to the lock pin inserted into the temporary holding-side lock hole. According to the above method, the state in which the lock pin is inserted into the temporary holding-side lock hole can be maintained with a simple configuration, and the lock pin can be easily pulled out from the temporary holding-side lock hole by using a magnet stronger than the permanent magnet.

The second ring press member may include a cylindrical part, a lid part for closing an end part of the cylindrical part, and a bolt, the bolt may include a bolt body with at least a thread part and a head part, a bolt through-hole may be formed in the lid part, the bolt body of the bolt may be inserted into the bolt through-hole, a thread hole corresponding to the bolt through-hole may be formed in the ring temporary holding jig, and when the ring is slid on the outer peripheral surface of the cylindrical member and then assembled in the ring groove, the ring temporary holding jig may be pulled into the second ring press member by fastening the thread part of the bolt to the thread hole of the ring temporary holding jig. According to the above method, the ring can be slid with a strong force on the outer peripheral surface of the cylindrical member.

A second example aspect of the present disclosure provides a method for manufacturing a shaft assembly including: a cylindrical member including a ring groove formed on an outer peripheral surface; and a ring assembled in the ring groove. The method includes: setting the ring at a small diameter part of a ring temporary holding jig, the ring temporary holding jig including the small diameter part, a tapered part, and a large diameter part in this order, an outer diameter of the small diameter part being smaller than an outer diameter of the large diameter part, an outer peripheral surface of the tapered part being formed to connect an outer peripheral surface of the small diameter part to an outer peripheral surface of the large diameter part, and the outer diameter of the large diameter part being larger than an outer diameter of the cylindrical member; moving the ring to the large diameter part from the small diameter part through the tapered part by using a first ring press member including a cylindrical shape with a leading end part elastically deformable in a radial direction and including a first length in an axial direction, so that the ring temporary holding jig temporarily holds the ring; attaching the ring temporary holding jig for temporarily holding the ring to the cylindrical member; transferring the ring from the large diameter part of the ring temporary holding jig to the outer peripheral surface of the cylindrical member by using a second ring press member, the second ring press member including a cylindrical shape and a second length shorter than the first length in the axial direction; and sliding the ring on the outer peripheral surface of the cylindrical member and then assembling the ring in the ring groove by using the second ring press member. According to the above method, the ring can be assembled in the ring groove of the cylindrical member even without the sufficient working space.

The first ring press member may include a cylindrical part and a plurality of elastic pieces extending from the cylindrical part. According to the above method, the first ring press member can be implemented with a simple configuration.

When the ring is moved relative to the ring temporary holding jig in order to have the ring temporary holding jig to temporarily hold the ring, a ring movement control member including an outer diameter larger than the outer diameter of the large diameter part may be made adjacent to the large diameter part of the ring temporary holding jig. According to the above method, when the ring is moved relative to the ring temporary holding jig in order to have the ring temporary holding jig temporarily hold the ring, the ring does not climb over the large diameter part.

The ring temporary holding jig may include a temporary holding insertion part inserted into an internal space of the cylindrical member when the ring temporary holding jig is attached to the cylindrical member, a temporary holding-side lock hole may be formed in an outer peripheral surface of the temporary holding insertion part, the cylindrical member may include a cylindrical member-side lock hole penetrating therethrough in a radial direction, and when the ring temporary holding jig for temporarily holding the ring is attached to the cylindrical member, the temporary holding insertion part of the ring temporary holding jig may be inserted into the internal space of the cylindrical member, the cylindrical member-side lock hole and the temporary holding-side lock hole may be aligned with each other, and a lock pin may be inserted into the cylindrical member-side lock hole and the temporary holding-side lock hole. According to the above method, the ring temporary holding jig for temporarily holding the ring can be surely attached to the cylindrical member.

The ring temporary holding jig may include a permanent magnet magnetically coupled to the lock pin inserted into the temporary holding-side lock hole. According to the above method, the state in which the lock pin is inserted into the temporary holding-side lock hole can be maintained with a simple configuration, and the lock pin can be easily pulled out from the temporary holding-side lock hole by using a magnet stronger than the permanent magnet.

The second ring press member may include a cylindrical part, a lid part for closing an end part of the cylindrical part, and a bolt, the bolt may include a bolt body with at least a thread part and a head part, a bolt through-hole may be formed in the lid part, the bolt body of the bolt may be inserted into the bolt through-hole, a thread hole corresponding to the bolt through-hole may be formed in the ring temporary holding jig, and when the ring is slid on the outer peripheral surface of the cylindrical member and then assembled in the ring groove, the ring temporary holding jig may be pulled into the second ring press member by fastening the thread part of the bolt to the thread hole of the ring temporary holding jig. According to the above method, the ring can be slid with a strong force on the outer peripheral surface of the cylindrical member.

Advantageous Effects of Invention

According to the present disclosure, a ring can be assembled in a ring groove of a cylindrical member even without a sufficient working space.

DESCRIPTION OF EMBODIMENTS

FIGS.1and2show a shaft assembly1. As shown inFIGS.1and2, the shaft assembly1includes a shaft2(cylindrical member), a taper roller bearing3, an inner housing4, a front end-side retaining ring5, a ball bearing6, a preload mechanism7, and a rear end-side retaining ring8. In this embodiment, the shaft assembly1is composed of at least the shaft2and the front end-side retaining ring5. As shown inFIG.2, the shaft assembly1is housed in a cylindrical frame10.

The shaft2is one specific example of a hollow cylindrical member, typically made of stainless steel. The shaft2includes a first peripheral surface2awhere the taper roller bearing3is disposed, a second outer peripheral surface2bwhere the ball bearing6is disposed, and a third peripheral surface2cdisposed between the first peripheral surface2aand the second outer peripheral surface2b. In this embodiment, outer diameters of the first outer peripheral surface2aand the second outer peripheral surface2bare equal, and an outer diameter of the third outer peripheral surface2cis smaller than the outer diameters of the first outer peripheral surface2aand the second outer peripheral surface2b.

A front end-side ring groove2d(ring groove) is formed on the first outer peripheral surface2aof the shaft2. Similarly, a rear end-side ring groove2eis formed on the second outer peripheral surface2bof the shaft2.

Here, the terms “forward” and “rearward” are defined with reference toFIG.2. An axial direction of the shaft2includes “forward” and “rearward”. The term “forward” is defined as a direction in which the front end-side ring groove2dis viewed from the rear end-side ring groove2e. The “rearward” is a direction in which the rear end-side ring groove2eis viewed from the front end-side ring groove2d. The shaft2has a front end part11and a rear end part12.

Returning toFIG.1, a plurality of shaft-side lock holes2f(cylindrical member-side lock holes) are formed in the front end part11of the shaft2. Each shaft-side lock hole2fis a through-hole that penetrates the front end part11in a radial direction.

The shaft2shown inFIG.2is, for example, a part of a propeller that rotates at a high speed, and a rearward axial load is applied thereto. The taper roller bearing3is disposed with an orientation suitable for receiving this axial load. The taper roller bearing3has an inner race3a, an outer race3b, and a plurality of conical rollers (not shown). The outer race3bis fixed to the frame10by press-fitting.

The inner housing4is made of, for example, stainless steel, and is positioned radially inward of the taper roller bearing3. The inner housing4includes a cylindrical housing body4adisposed between the inner race3aof the taper roller bearing3and the first outer peripheral surface2aof the shaft2, and an annular flange4bprojecting radially outward from a front end of the housing body4a. The flange4bfaces the inner race3aof the taper roller bearing3in the axial direction. A ring housing recessed part4dis formed radially inwardly of a front face4cof the flange4b.

FIG.3shows a cross-sectional view of the shaft assembly before the front end-side retaining ring5is assembled in the front end-side ring groove2dof the shaft2.

FIG.4shows a perspective view of the front end-side retaining ring5. As shown inFIG.4, the front end-side retaining ring5is typically made of stainless steel and is a C-shaped ring. The front end-side retaining ring5generally has a rectangular cross section.

Returning toFIG.2, the ball bearing6mainly receives a radial load.

The preload mechanism7generates a rearward preload required for the inner race3aof the taper roller bearing3and includes, for example, a disc spring7a.

The rear end-side retaining ring8is made of, for example, stainless steel and is assembled in the rear end-side ring groove2eof the shaft2. The rear end-side retaining ring8applies the preload generated by the preload mechanism7to the shaft2.

In this configuration, the outer race3bof the taper roller bearing3and the ball bearing6are axially fixed to each other with the frame10interposed therebetween. The preload generated by the preload mechanism7is applied to the inner race3athrough the rear end-side retaining ring8and shaft2, the front end-side retaining ring5, and the inner housing4in this order. As a result, the preload generated by the preload mechanism7is applied between the inner race3aand the outer race3bof the taper roller bearing3, and the inner race3aand the outer race3bare normally pressed against each other in the axial direction.

As shown inFIG.3, before the front end-side retaining ring5is assembled, the preload generated by the preload mechanism7causes the shaft2to move rearward with respect to the taper roller bearing3, and as a result, the front end-side ring groove2dof the shaft2is positioned radially inward of the housing body4aof the inner housing4.

Next, a ring assembly method for assembling the front end-side retaining ring5in the front end-side ring groove2dformed on the first outer peripheral surface2aof the shaft2is described with reference toFIG.5and subsequent drawings. In other words, the method of manufacturing the shaft assembly1is described with reference toFIG.5and subsequent drawings.

However, prior to the explanation of the ring assembly method and the method for manufacturing the shaft assembly1, it is assumed, for example, that all the components except the front end-side retaining ring5have already been assembled as shown inFIG.3.

As shown inFIG.5, the ring assembly method and the method for manufacturing the shaft assembly1include a ring setting process (S1), a temporary holding process (S2), an attaching process (S3), a ring transferring process (S4), and a ring moving process (S5) in the order described.

FIGS.6and7show a ring temporary holding jig20used in the ring setting process and a ring movement control member21used in the temporary holding process.FIG.8shows a state in which the ring temporary holding jig20is mounted on a ring movement control member21.

As shown inFIGS.6and7, the ring temporary holding jig20is made of, for example, stainless steel and includes a holder body22and a temporary holding insertion part23.

As shown inFIG.7, the holder body22includes a small diameter part24, a tapered part25, and a large diameter part26in the order described. An outer peripheral surface24aof the small diameter part24extends parallel to the axial direction. An outer peripheral surface25aof the tapered part25is inclined with respect to the axial direction. The outer peripheral surface25aof the tapered part25is inclined in such a way that a diameter thereof is expanded toward an outer peripheral surface26aof the large diameter part26. The outer peripheral surface26aof the large diameter part26extends parallel to the axial direction. An outer diameter of the small diameter part24is smaller than an outer diameter of the large diameter part26. The outer diameter of the small diameter part24is smaller than an inner diameter of the front end-side retaining ring5when no load is applied thereto. The outer diameter of the large diameter part26is equal to the outer diameter of the first outer peripheral surface2aof the shaft2shown inFIG.2or slightly larger than the outer diameter of the first outer peripheral surface2aof the shaft2. Returning toFIG.7, the outer peripheral surface25aof the tapered part25is inclined with respect to the axial direction so as to connect the outer peripheral surface24aof the small diameter part24to the outer peripheral surface26aof the large diameter part26. Returning toFIG.6, a thread hole27is formed in the front face22aof the holder body22.

The temporary holding insertion part23is configured to be insertable into an internal space of the shaft2shown inFIG.2. An outer diameter of the temporary holding insertion part23is smaller than the outer diameter of the large diameter part26. A plurality of temporary holding-side lock holes28are formed in the outer peripheral surface23aof the temporary holding insertion part23. Each temporary holding-side lock hole28extends in the radial direction. Each temporary holding-side lock hole28houses a permanent magnet29.

The ring movement control member21is, for example, a stainless steel ring with a rectangular cross section, and is configured in such a way that the temporary holding insertion part23of the ring temporary holding jig20can be inserted into the ring movement control member21. The ring movement control member21includes an inner peripheral surface21aand an outer peripheral surface21b, and two end surfaces21c. An inner diameter of the inner peripheral surface21ais substantially equal to the outer diameter of the temporary holding insertion part23of the ring temporary holding jig20. An outer diameter of the outer peripheral surface21bis larger than the outer diameter of the large diameter part26of the holder body22of the ring temporary holding jig20. Therefore, when the temporary holding insertion part23of the ring temporary holding jig20is inserted into the ring movement control member21, the large diameter part26of the holder body22of the ring temporary holding jig20sits on one end surface21cof the ring movement control member21. As a result, the large diameter part26of the holder body22of the ring temporary holding jig20is axially adjacent to the ring movement control member21. In a state in which the large diameter part26sits on the end surface21c, the end surface21con which the large diameter part26sits is exposed radially outward of the large diameter part26.

In this state, as shown inFIG.8, the front end-side retaining ring5is set radially outward of the small diameter part24of the holder body22of the ring temporary holding jig20. At this time, the front end-side retaining ring5falls and sits on the outer peripheral surface25aof the tapered part25or is inclined, so that the front end-side retaining ring5is caught by the outer peripheral surface24aof the small diameter part24and then stays.

Next, the front end-side retaining ring5is moved from the small diameter part24to the large diameter part26through the tapered part25so that the ring temporary holding jig20temporarily holds the front end-side retaining ring5. In this temporary holding process, the first ring press member30shown inFIG.9is used.

As shown inFIG.9, the first ring press member30is made of, for example, resin and includes a cylindrical part31and a plurality of elastic pieces32extending from the cylindrical part31in the axial direction of the cylindrical part31. Each elastic piece32is a cantilever that is elastic and deformable in the radial direction. The first ring press member30has a dimension30D in the axial direction of the first ring press member30.

Then, as shown inFIG.10, a leading end part32aof each elastic piece32is pushed against the front end-side retaining ring5, and the front end-side retaining ring5is pushed toward the ring movement control member21. Then, the front end-side retaining ring5slides down the outer peripheral surface25aof the tapered part25while the front end-side retaining ring5is deformed and the diameter thereof is expanded, and eventually reaches the outer peripheral surface26aof the large diameter part26and also reaches the end surface21cof the ring movement control member21. The front end-side retaining ring5is pressed against the outer peripheral surface26aof the large diameter part26by a spring elastic restoring force, so that, as shown inFIG.11, the front end-side retaining ring5is temporarily held by the large diameter part26of the holder body22of the ring temporary holding jig20. Since the ring movement control member21is no longer used after the above temporary holding is completed, the ring movement control member21is removed from the ring temporary holding jig20and recovered.

Next, as shown inFIGS.12and13, the ring temporary holding jig20for temporarily holding the front end-side retaining ring5is attached to the front end part11of the shaft2. Specifically, as shown inFIG.13, the temporary holding insertion part23of the ring temporary holding jig20is inserted into an internal space of the front end part11of the shaft2, and the large diameter part26of the holder body22of the ring temporary holding jig20is axially abut against the front end part11of the shaft2. In this embodiment, the outer diameter of the outer peripheral surface26aof the large diameter part26is set to be equal to the outer diameter of the front end part11of the shaft2. Therefore, by the above abutment, the outer peripheral surface26aof the large diameter part26and the first outer peripheral surface2aof the shaft2become the same plane, so that the front end-side retaining ring5can move from the outer peripheral surface26aof the large diameter part26to the first outer peripheral surface2aof the shaft2.

At this time, the plurality of temporary holding-side lock holes28formed in the outer peripheral surface23aof the temporary holding insertion part23of the ring temporary holding jig20shown inFIG.7are aligned with the plurality of shaft-side lock holes2fformed in the front end part11of the shaft2shown inFIG.1, respectively, and lock pins33are inserted into the respective shaft-side lock holes2fand corresponding temporary holding-side lock holes28as shown inFIG.12. Each inserted lock pin33is magnetically coupled to the permanent magnet29shown inFIG.7, so that each lock pin33does not fall out of the corresponding shaft-side lock hole2f. When the lock pin33is simultaneously accommodated in each shaft-side lock hole2fand the corresponding temporary holding-side lock hole28, removal of the ring temporary holding jig20from the shaft2is prohibited.

Next, inFIG.13, the front end-side retaining ring5temporarily held by the ring temporary holding jig20is transferred to the first outer peripheral surface2aof the shaft2. In this transfer, a second ring press member40shown inFIGS.14and15is used.

As shown inFIG.14, the second ring press member40has a dimension40D in the axial direction. The dimension40D of the second ring press member40is smaller than the dimension30D of the first ring press member30shown inFIG.9. That is, the second ring press member40is shorter than the first ring press member30. Returning toFIG.14, the second ring press member40includes a press member body41and a bolt42.

As shown inFIG.15, the press member body41is made of, for example, stainless steel and includes a cylindrical body43and a lid part44that closes a forward end part of the cylindrical body43.

An inner diameter of the cylindrical body43is set slightly larger than the outer diameter of the front end part11of the shaft2. The inner diameter of the cylindrical body43is set slightly larger than the outer diameter of the large diameter part26of the ring temporary holding jig20. An annular flange45projecting radially outward and a housing press part46projecting radially outward from a radially outward end part of the flange45are formed at an end part on the rear side of the cylindrical body43. An inner diameter of the housing press part46is set larger than an outer diameter of the front end-side retaining ring5. Therefore, the front end-side retaining ring5can be accommodated radially inward of the housing press part46. A dimension46dof the housing press part46in the axial direction is set larger than a dimension5T of the front end-side retaining ring5in the axial direction.

The bolt42includes a bolt body50and a head part51. The bolt body50includes a thread part52and a torso part53.

A bolt through-hole54is formed in the center of the lid part44, through which the bolt body50of the bolt42can be inserted.

Next, as shown inFIG.15, the flange45of the second ring press member40faces the front end-side retaining ring5in the axial direction. In this state, by pushing the second ring press member40rearward, the front end-side retaining ring5is transferred from the outer peripheral surface26aof the large diameter part26of the ring temporary holding jig20to the first outer peripheral surface2aof the shaft2.

Note that as shown inFIG.14, a plurality of holes41ainto which detent bars (not shown) can be inserted are formed in an outer peripheral surface of the press member body41.

Returning toFIG.15, when the second ring press member40is continuously pushed rearward, the front end-side retaining ring5slides rearward on the first outer peripheral surface2aof the shaft2. Then, as shown inFIG.16, the housing press part46of the second ring press member40abuts against the front face4cof the flange4bof the inner housing4. At this time, since the taper roller bearing3is axially fixed to the frame10, the second ring press member40can no longer be pushed rearward.

In this state, the bolt42is rotated and the thread part52of the bolt42is fastened to the thread hole27of the holder body22of the ring temporary holding jig20. At this time, since the head part51of the bolt42is formed larger than the bolt through-hole54, a rearward movement is prohibited. Therefore, as the above fastening proceeds, the shaft2is pulled forward through the ring temporary holding jig20and further pulled into the internal space of the press member body41of the second ring press member40as shown inFIG.17.

When the bolt42is rotated, a detent bar may be inserted into one of the plurality of holes41ashown inFIG.14. By doing so, co-rotation of the press member body41can be easily prevented.

Then, as shown inFIG.17, when the front end-side ring groove2dof the shaft2moves forward relative to the second ring press member40, it reaches the radially inward of the front end-side retaining ring5, and then the front end-side retaining ring5is assembled in the front end-side ring groove2dwhile the front end-side retaining ring5is deformed and the diameter thereof is reduced by the spring elastic restoring force.

When the above assembly is completed, the bolt42is pulled out from the thread hole27of the ring temporary holding jig20to recover the second ring press member40from the shaft2. Then, the shaft2is moved rearward relative to the taper roller bearing3due to the preload generated by the preload mechanism7, resulting in the state shown inFIG.2.

The plurality of lock pins33shown inFIG.12are pulled out from the corresponding shaft-side lock holes2fto recover the ring temporary holding jig20from the shaft2. In order to pull out the plurality of lock pins33from the corresponding shaft-side lock holes2f, magnets stronger than the permanent magnets29magnetically coupled to the respective lock pins33(seeFIG.7) may be magnetically coupled to the lock pins33. Thus, by pulling the magnets radially outward, the lock pins33can be easily pulled out from the shaft-side lock holes2f.

Although the preferred embodiment of the present disclosure has been described above, the above embodiment has the following features.

For example, as shown inFIG.2, the ring assembly method for assembling the front end-side retaining ring5(ring) in the front end-side ring groove2d(ring groove) formed on the first outer peripheral surface2a(outer peripheral surface) of the shaft2(cylindrical member) includes the following processes.As shown inFIG.8, a process of setting the front end-side retaining ring5at the small diameter part24of the ring temporary holding jig20, the ring temporary holding jig20including the small diameter part24, the tapered part25, and the large diameter part26in this order, the outer diameter of the small diameter part24being smaller than the outer diameter of the large diameter part26, the outer peripheral surface25aof the tapered part25being formed to connect the outer peripheral surface24aof the small diameter part24to the outer peripheral surface26aof the large diameter part26, and the outer diameter of the large diameter part26being larger than the outer diameter of the shaft2(S1).As shown inFIGS.9and10, a process of moving the front end-side retaining ring5to the large diameter part26from the small diameter part24through the tapered part25by using the first ring press member30including the cylindrical shape with the leading end part32aelastically deformable in the radial direction and including the dimension30D (first length) in the axial direction, so that the ring temporary holding jig20temporarily holds the front end-side retaining ring5(S2).As shown inFIGS.12and13, a process of attaching the ring temporary holding jig20for temporarily holding the front end-side retaining ring5to the shaft2(S3).As shown inFIGS.14and15, a process of transferring the front end-side retaining ring5from the large diameter part26of the ring temporary holding jig20to the first outer peripheral surface2aof the shaft2by using the second ring press member40including the cylindrical shape and the length40D (second length) that is shorter than the dimension30D in the axial direction (S4).As shown inFIGS.16and17, a process of sliding the front end-side retaining ring5on the first outer peripheral surface2aof the shaft2to assemble the front end-side retaining ring5in the ring groove2dby using the second ring press member40(S5).

According to the above method, the front end-side retaining ring5can be assembled in the front end-side ring groove2dof the shaft2even without a sufficient working space.

Also, as shown inFIG.9, the first ring press member30has the cylindrical part31and the plurality of elastic pieces32extending from the cylindrical part31. According to the above method, the first ring press member30can be implemented with a simple configuration.

In addition, as shown inFIG.10, when the front end-side retaining ring5is moved relative to the ring temporary holding jig20in order to have the ring temporary holding jig20temporarily hold the front end-side retaining ring5, the ring movement control member21having the outer diameter larger than the outer diameter of the large diameter part26is made adjacent to the large diameter part26of the ring temporary holding jig20. According to the above method, when the front end-side retaining ring5is moved relative to the ring temporary holding jig20in order to have the ring temporary holding jig20temporarily hold the front end-side retaining ring5, the front end-side retaining ring5does not climb over the large diameter part26.

Also, as shown inFIG.13, the ring temporary holding jig20includes the temporary holding insertion part23that is inserted into the internal space of the shaft2when the ring temporary holding jig20is attached to the shaft2. As shown inFIG.7, the plurality of temporary holding-side lock holes28are formed in the outer peripheral surface23aof the temporary holding insertion part23. As shown inFIG.1, the shaft2has the shaft-side lock holes2f(cylindrical member-side lock holes) that penetrate in the radial direction. As shown inFIGS.12and13, when the ring temporary holding jig20for temporarily holding the front end-side retaining ring5is attached to the shaft2, the temporary holding insertion part23of the ring temporary holding jig20is inserted into the internal space of the shaft2, the plurality of shaft-side lock holes2fare aligned with the plurality of temporary holding-side lock holes28, and the plurality of lock pins33are inserted into the plurality of shaft-side lock holes2fand the plurality of temporary holding-side lock holes28, respectively. According to the above method, the ring temporary holding jig20for temporarily holding the front end-side retaining ring5can be surely attached to the shaft2.

As shown inFIG.7, one temporary holding-side lock hole28may be formed in the outer peripheral surface23aof the temporary holding insertion part23in place of the plurality of temporary holding-side lock holes28formed in the outer peripheral surface23aof the temporary holding insertion part23. The same applies to the shaft-side lock holes2f.

Also, as shown inFIG.7, the ring temporary holding jig20has the permanent magnets29magnetically coupled to the lock pins33inserted into the respective temporary holding-side lock holes28. According to the above method, the state in which the lock pins33are inserted into the temporary holding-side lock holes28can be maintained with a simple configuration, and the lock pins33can be easily pulled out from the temporary holding-side lock holes28by using magnets stronger than the permanent magnets29.

Moreover, as shown inFIGS.14and15, the second ring press member40includes the cylindrical body43(cylindrical part), the lid part44that closes the end part of the cylindrical body43, and the bolt42. The bolt42includes the bolt body50with at least the thread part52and the head part51. The bolt through-hole54is formed in the lid part44. The bolt body50of the bolt42is inserted into the bolt through-hole54. As shown inFIG.16, the thread hole27corresponding to the bolt through-hole54is formed in the ring temporary holding jig20. When the front end-side retaining ring5is slid on the first outer peripheral surface2aof the shaft2and assembled in the front end-side ring groove2d, the ring temporary holding jig20is pulled into the second ring press member40by fastening the thread part52of the bolt42to the thread hole27of the ring temporary holding jig20. According to the above method, the front end-side retaining ring5can be slid with a strong force on the first outer peripheral surface2aof the shaft2.

This application claims priority on the basis of Japanese Patent Application No. 2020-139784, filed Aug. 21, 2020, the entire disclosure of which is incorporated herein by reference.

REFERENCE SIGNS LIST