JP2017160962A - Manufacturing method of bearing for pivot, manufacturing method of pivot and manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a plurality of bearings for a pivot capable of reducing variation in occurrence of outgassing in a short time.SOLUTION: A manufacturing method of a bearing for a pivot includes: a bearing assembly step S1 of arranging rolling bodies with intervals in a circumferential direction in an annular space between an inner ring and an outer ring arranged coaxially, and injecting grease into the annular space, thereby assembling a bearing assembly; a heating step S2 of heating an aggregation of a plurality of bearing assemblies assembled in the bearing assembly step S1, at a temperature higher than a predetermined target temperature in a vacuum state; and a cooling step S3 of cooling the aggregation heated in the heating step S2 by gas convection.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pivot bearing manufacturing method, a pivot manufacturing method, and a manufacturing apparatus.

  Conventionally, there is a problem that data read / write becomes difficult or crashes because outgas generated in a pivot adheres to a magnetic head or a disk. In particular, with the recent increase in the recording density of hard disks, the pivots are required to be further outgassed. A pivot bearing manufacturing method and a pivot that reduce the occurrence of outgas to such a demand are known (for example, refer to Patent Document 1).

  The pivot bearing manufacturing method described in Patent Document 1 is a method of manufacturing a hard disk drive (HDD) by heating a bearing (bearing) in a vacuum state in a vacuum oven to volatilize components that generate outgas contained in grease. Before installing the pivot in the drive), the excess outgas in the pivot is removed.

Japanese Patent Laying-Open No. 2015-169316

  However, since heat is transmitted by radiation in a vacuum state, when multiple samples such as bearings are placed in a vacuum oven and heated in a vacuum state, the sample near the heater tends to rise in temperature but is far from the heater. There is a tendency that the temperature does not rise easily. Further, the higher the sample temperature, the more efficiently the outgas can be removed. When the sample temperature is low, the outgas cannot be sufficiently removed.

  For this reason, the pivot bearing manufacturing method described in Patent Document 1 has a problem that a sample having a high temperature and a sample having a low temperature are mixed, resulting in variations in the amount of outgas removed between the samples. In particular, when heating is performed with a larger power in order to shorten the heating time, the temperature difference between the samples increases according to the distance from the heater to the sample, and the variation in the outgas removal amount becomes even greater.

  The present invention has been made in view of the above-described circumstances, and a plurality of pivot bearings or a pivot bearing manufacturing method capable of manufacturing a plurality of pivots, in which outgas generation is reduced in a short time without variation. An object of the present invention is to provide a manufacturing method and a manufacturing apparatus.

In order to achieve the above object, the present invention provides the following means.
The present invention assembles a bearing assembly by arranging rolling elements in an annular space between an inner ring and an outer ring arranged coaxially at intervals in the circumferential direction and injecting grease into the annular space. A bearing assembly step, a heating step of heating the assembly of the plurality of bearing assemblies assembled in the bearing assembly step at a temperature higher than a predetermined target temperature in a vacuum state, and the heating in the heating step And a cooling process for cooling the assembly by gas convection.

  According to the present invention, the assembly of the plurality of bearing assemblies assembled in the bearing assembly process is heated in the heating process, thereby volatilizing the component that generates outgas contained in the grease of each bearing assembly. Thus, components that generate outgas can be released.

  In this case, by heating the assembly at a temperature higher than the predetermined target temperature in a vacuum state in the heating process, the exposed outer bearing assembly in the assembly mainly exceeds the predetermined target temperature by radiant heat. To be heated. Next, by convection of gas in the cooling process, the temperature of the outer bearing assembly heated in the assembly is lowered, and the temperature of the inner bearing assembly is increased by heat transfer from the outer bearing assembly. To do.

As a result, the temperature of the entire assembly of the plurality of bearing assemblies can be raised to the vicinity of the target temperature on average, and variation in the amount of outgas removal between the plurality of bearing assemblies can be reduced.
In addition, compared to raising the temperature of all the bearing assemblies to a predetermined target temperature in the heating process, it is better to overshoot the temperature of the outer bearing assembly and bring it closer to the target temperature by lowering it. The solid can be brought close to the target temperature in a short time.
Therefore, it is possible to manufacture a plurality of pivot bearings in which outgas generation is reduced without variation in a short time.

In the above invention, the heating step and the cooling step may be alternately repeated a plurality of times.
With this configuration, in the heating process and the cooling process each time, the temperature difference between the bearing assembly having a high temperature in the assembly and the bearing assembly having a low temperature does not fall within a predetermined temperature range. Even if it exists, the temperature difference of these bearing assemblies can be reduced by the amount that the heating step and the cooling step are alternately repeated a plurality of times. Thereby, the dispersion | variation in the removal amount of the outgas of the whole aggregate | assembly can be reduced more.

In the said invention, the said cooling process is good also as convection of nitrogen gas, helium gas, or argon gas.
By comprising in this way, it can prevent that a grease oxidizes and can prevent the lubrication performance of grease from deteriorating.

In the said invention, it is good also as including the leaving process which leaves the said assembly cooled by the said cooling process at predetermined temperature over predetermined time.
With such a configuration, the heat transfer from the outer bearing assembly to the inner bearing assembly can be advanced by the leaving step, and the temperature variation of the entire assembly can be further reduced. Further, by leaving the assembly in a vacuum state for a predetermined time, further outgas can be removed without variation. The predetermined temperature is lower than the temperature in the heating step and higher than the temperature in the cooling step.

In the said invention, it is good also as including the obstruction | occlusion member arrangement | positioning process which obstruct | occludes the said annular space of the said bearing assembly with an obstruction | occlusion member after the said leaving process.
With this configuration, in the leaving step, the component that generates outgas contained in the grease in the annular space is volatilized in a state where the annular space of the bearing assembly is opened. Can be efficiently released. After the leaving step, the annular space of the bearing assembly is closed by the closing member in the closing member arranging step, so that the mist-like grease is discharged from the pivot when the pivot is operated in the hard disk. It is possible to manufacture a bearing that suppresses this.

  The present invention assembles a bearing assembly by arranging rolling elements in an annular space between an inner ring and an outer ring arranged coaxially at intervals in the circumferential direction and injecting grease into the annular space. A bearing assembly process, a pivot assembly process for assembling a pivot assembly by fitting a shaft to the inner ring of the bearing assembly, and a plurality of the bearing assemblies assembled by the bearing assembly or the pivot assembly A heating step of heating the assembly of the plurality of pivot assemblies assembled in the process at a temperature higher than a predetermined target temperature in a vacuum state, and cooling the assembly heated in the heating step by gas convection And a cooling method for manufacturing the pivot.

  According to the present invention, each bearing assembly is heated by heating the assembly of the plurality of bearing assemblies assembled by the bearing assembly process or the assembly of the plurality of pivot assemblies assembled by the pivot assembly process. The components generating outgas contained in the grease can be volatilized and released.

  In this case, in the heating process, the exposed outer bearing assembly or pivot assembly, which is mainly exposed in the assembly, is heated to a predetermined target temperature or more by radiant heat, and in the cooling process, the heated outside in the assembly is heated. The temperature of the inner bearing assembly or the pivot assembly is increased by the heat transfer from the outer bearing assembly or the pivot assembly while the temperature of the bearing assembly or the pivot assembly is decreased.

  As a result, the temperature of the entire assembly can be raised to the vicinity of the target temperature on average in a short time, and variation in the amount of outgas removal among the plurality of pivot assemblies can be reduced. Therefore, it is possible to manufacture a plurality of pivots in which outgas generation is reduced without variation in a short time.

In the above invention, the heating step and the cooling step may be alternately repeated a plurality of times.
With this configuration, the temperature difference between the pivot assembly having a high temperature inside the assembly and the pivot assembly having a low temperature can be reduced, and variation in the outgas removal amount of the entire assembly can be further reduced. .

In the said invention, the said cooling process is good also as convection of nitrogen gas, helium gas, or argon gas.
By comprising in this way, it can prevent that a grease oxidizes and can prevent the lubrication performance of grease from deteriorating.

In the said invention, it is good also as including the leaving process which leaves the said assembly cooled by the said cooling process at predetermined temperature over predetermined time.
By configuring in this way, the heat transfer from the outer pivot assembly to the inner pivot assembly is progressed by the leaving step, thereby further reducing the variation in the temperature of the entire assembly and the variation in the amount of outgas removal. Can be further reduced. The predetermined temperature is lower than the temperature in the heating step and higher than the temperature in the cooling step.

In the said invention, it is good also as including the obstruction | occlusion member arrangement | positioning process which obstruct | occludes the said annular space of the said bearing assembly with an obstruction | occlusion member after the said leaving process.
With this configuration, in the leaving step, it is possible to efficiently release components that generate outgas in a state where the annular space of the pivot assembly is opened. Further, in the subsequent closing member arrangement step, the annular space is closed by the closing member, thereby manufacturing a pivot that suppresses the release of mist-like grease from the pivot when operating in the hard disk. be able to.

  The present invention relates to a plurality of bearing assemblies in which grease is injected into an annular space between an inner ring and an outer ring in which a plurality of rolling elements are arranged at intervals in the circumferential direction, or the bearing assembly described above. A housing capable of accommodating a plurality of pivot assemblies each having a shaft fitted to an inner ring, a vacuum generation unit that evacuates the housing, a heating unit that heats the housing by heat radiation, and a housing A temperature detecting unit for detecting a temperature of the accommodated bearing assembly or the pivot assembly; a gas injection unit capable of injecting gas into the housing; and the plurality of bearing assemblies or the plurality of pivot assemblies. The housing is heated by the heating unit in a state where the housing is evacuated by the vacuum generation unit, and the temperature of the bearing assembly or the pivot assembly detected by the temperature detection unit is predetermined. Reached the target temperature Case, to provide a manufacturing apparatus and a control unit for convective the housing to by injecting the predetermined low temperature of the gas than the target temperature by the gas injection section in the housing.

  According to the present invention, a plurality of bearing assemblies or a plurality of pivot assemblies are accommodated in the casing, and the inside of the casing is evacuated by the vacuum generation section and heated in the casing by heat radiation. The radiant heat heats the outer bearing assembly or pivot assembly that is mainly exposed in the assembly of bearing assemblies or the assembly of pivot assemblies. By heating the bearing assembly or the pivot assembly, the component that generates outgas contained in the grease of each bearing assembly or pivot assembly is volatilized and the component that generates outgas is released. it can.

In this case, when the temperature of the bearing assembly or the pivot assembly detected by the temperature detection unit by the control unit reaches a predetermined target temperature, the temperature in the casing is lower than the predetermined target temperature by the gas injection unit. As a result, the temperature of the heated outer bearing assembly or pivot assembly is lowered while the gas is convected in the housing, and the radiant heat from the outer bearing assembly or pivot assembly The temperature of the inner bearing assembly or pivot assembly increases.
As a result, the temperature of the plurality of bearing assemblies or pivot assemblies is increased to the vicinity of a predetermined target temperature on average to reduce variation in the amount of outgas removal between the plurality of bearing assemblies or between the pivot assemblies. be able to.

Also, compared to raising the temperature of all bearing assemblies or pivot assemblies to a predetermined target temperature by heat radiation from the heating section, the temperature of the outer bearing assembly or pivot assembly is once overshooted and lowered. All the bearing assemblies or pivot assemblies can be brought closer to the target temperature in a shorter time by approaching the target temperature.
Therefore, it is possible to automatically manufacture a plurality of pivot bearings or pivots in which generation of outgas is reduced without variation in a short time.

  According to the pivot bearing manufacturing method, the pivot manufacturing method, and the manufacturing apparatus according to the present invention, it is possible to manufacture a plurality of pivot bearings or a plurality of pivots in which outgas generation is reduced without variation in a short time. Play.

It is the longitudinal cross-sectional view which fractured | ruptured a part of pivot which concerns on 1st Embodiment of this invention to the axial direction. It is a flowchart explaining the manufacturing method of the bearing which concerns on 1st Embodiment of this invention, and the manufacturing method of a pivot. It is a longitudinal cross-sectional view which shows a mode that the aggregate | assembly of a some bearing assembly is heated with a vacuum oven by a heating process. It is a longitudinal cross-sectional view which shows a mode that the aggregate | assembly of the several bearing assembly heated by the cooling process is cooled by the convection of air. It is a graph which shows an example of the relationship between the temperature of the aggregate | assembly of a bearing assembly, and time in the case of manufacturing a bearing and a pivot by the manufacturing method of the bearing which concerns on 1st Embodiment of this invention, and the manufacturing method of a pivot. As a comparative example of the present invention, it is a graph showing an example of the relationship between the temperature and time of an assembly of bearing assemblies when a bearing and a pivot are manufactured by a conventional bearing manufacturing method and a pivot manufacturing method. It is a flowchart explaining the manufacturing method of the pivot which concerns on 2nd Embodiment of this invention. It is the longitudinal cross-sectional view which fractured | ruptured a part of pivot which concerns on the 3rd modification of each embodiment of this invention to the axial direction.

[First Embodiment]
Hereinafter, a pivot bearing manufacturing method (hereinafter simply referred to as a bearing), a pivot manufacturing method, and a pivot according to a first embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the pivot 1 according to this embodiment includes two bearings 3, a shaft 5 fitted to these bearings 3, and a spacer member 7 sandwiched between the two bearings 3 in the axial direction. It has.

  The two bearings 3 are spaced circumferentially in an annular inner ring 9 and an outer ring 11 that are coaxially disposed adjacent to each other in the radial direction, and an annular space 13 between the inner ring 9 and the outer ring 11. And a plurality of rolling elements 15 to be arranged. Further, the annular space 13 is filled with grease 17 as a lubricant. A state where the grease 17 is sealed in the bearing 3 in the manufacturing process is a bearing assembly 3 ′, and a state where the shaft 5 is fitted to the two bearing assemblies 3 ′ is a pivot assembly 1 ′.

  The inner ring 9 has a raceway (inner ring raceway) formed on the outer peripheral surface, and the outer ring 11 has a raceway (outer ring raceway) formed on the inner peripheral surface. When the rolling elements 15 roll between the raceway of the inner ring 9 and the raceway of the outer ring 11, the inner ring 9 and the outer ring 11 are rotated relative to each other.

The rolling elements 15 are rotatably held in the annular space 13 in a state where they are arranged at equal intervals by a retainer (not shown).
The retainer includes a plurality of protrusions provided to protrude in the axial direction along the circumferential direction of the annular base portion, a recess formed by connecting the protrusions, and a pocket for holding the rolling element 15, and the rolling element 15. And a grease pocket for holding the grease 17 therebetween.

  The grease 17 includes a viscous base oil (for example, mineral oil, ester synthetic oil, synthetic hydrocarbon oil (poly α-olefin (PAO)), etc.) and a urea compound (for example, an aliphatic urea compound, an alicyclic ring). A thickener composed of a formula urea compound, an aromatic urea compound, etc.), an antioxidant, a rust inhibitor, and an extreme pressure agent.

  Further, the grease 17 adheres to the raceway of the inner ring 9, the raceway of the outer ring 11, and the surfaces of the rolling elements 15, so that the pivot 1 maintains good torque characteristics and fluidity. The content of the thickener in the grease 17 is preferably 10 to 20% by mass.

The spacer member 7 is formed in a hollow ring shape. The spacer member 7 has an inner diameter that is larger than the outer diameter of the inner ring 9, and an outer diameter that is substantially the same as the outer ring 11. The spacer member 7 is sandwiched between the outer rings 11 of the two bearings 3 in the axial direction, whereby a gap is formed between the inner rings 9 of the two bearings 3.
The shaft 5 is provided with a flange-like flange portion 5a extending radially outward over the entire circumference at one end in the axial direction.

  In the state where the spacer member 7 is sandwiched between the outer rings 11 of the two bearings 3, the shaft 5 is fitted in the inner ring 9, and one inner ring 9 is abutted against the flange portion 5 a of the shaft 5, the inner rings 9 are pivoted. By applying an external force that approaches in the direction, the two bearings 3 can be brought into a preloaded state.

Next, a method for manufacturing the bearing and the pivot according to the present embodiment will be described below.
As shown in the flowchart of FIG. 2, the bearing manufacturing method according to the present embodiment assembles a bearing assembly 3 ′ in which grease 17 is sealed in an annular space 13 between the inner ring 9 and the outer ring 11. Step S1, a heating step S2 for heating the assembled plurality of bearing assemblies 3 ′ in a vacuum state, and a cooling step S3 for cooling the heated plurality of bearing assemblies 3 ′ by gas convection (see FIG. 4) And a leaving step S4 in which the plurality of bearing assemblies 3 ′ cooled in the cooling step S3 are left at a predetermined temperature (predetermined target temperature).

  In addition, the pivot manufacturing method according to the present embodiment includes the inner rings 9 of the two bearing assemblies 3 ′ left in the leaving step S4 in addition to the bearing assembling step S1, the heating step S2, the cooling step S3, and the leaving step S4. A pivot assembly step S5 for assembling the pivot assembly 1 'by fitting the shaft 5 to the shaft 5 is included.

  In the bearing assembling step S1, the inner ring 9 and the corresponding outer ring 11 are arranged coaxially, and a plurality of rolling elements 15 are provided in an annular space 13 between the inner ring 9 and the outer ring 11 with a space in the circumferential direction. Is supposed to be placed. Then, the grease 17 generated by selecting and mixing the components necessary for achieving the desired lubrication performance is injected into the grease pocket of the retainer disposed in the annular space 13, as shown in FIG. A bearing assembly 3 'as shown is assembled.

  In the heating step S 2, as shown in FIG. 3, a plurality of bearing assemblies 3 ′ assembled in the bearing assembly step S 1 are collected to form an assembly, and the assembly P of these bearing assemblies 3 ′ is vacuumed by a vacuum oven 21. In this state, heating is performed at a temperature higher than a predetermined target temperature.

  Specifically, in the heating step S2, the assembly P of the bearing assemblies 3 ′ is arranged in the vicinity of the center of the inside of the housing 22 of the vacuum oven 21 with the bearing assemblies 3 ′ spaced apart from each other. ing. And while making the inside of the housing | casing 22 into a vacuum with the vacuum generator (illustration omitted) of the vacuum oven 21, the several heater 23 provided in each wall part of the housing | casing 22 is operated, The heat | fever of each heater 23 is carried out. Is transmitted to the assembly P by radiation through the wall surface of the vacuum oven 21. As a result, heat is sequentially transferred from the outer bearing assembly 3 ′ to the inner bearing assembly 3 ′ by radiation within the assembly P, and the inner side thereof is radiated from the outer bearing assembly 3 ′. The bearing assembly 3 'is warmed, and the inner bearing assembly 3' is warmed by the radiant heat from the bearing assembly 3 '. In addition, the heating step S2 is performed, for example, until the average temperature of the entire assembly P reaches a predetermined target temperature.

  The predetermined target temperature (Target) of the assembly P is set to 60 ° C., for example. In the heating step S2, the heater 23 is operated so that the temperature of the wall surface of the vacuum oven 21 is, for example, 130 ° C. or lower, more preferably 120 ° C. or lower. By doing in this way, it can prevent that additives, such as an extreme pressure agent, contained in the grease 17 react and deteriorate by a temperature rise, and can prevent the lubrication performance of the grease 17 from deteriorating. . In the present embodiment, for example, the temperature of the heater 23 is set so that the temperature of the wall surface of the vacuum oven 21 is 100 ° C.

  In the cooling step S3, as shown in FIG. 4, normal temperature air is injected into the vacuum oven 21, and the assembly P of the bearing assembly 3 ′ heated in the heating step S2 is cooled by air convection. It has become.

  For example, in the cooling step S <b> 3, normal temperature air is injected into the vacuum oven 21 from the suction port 21 a provided in one wall portion of the housing 22 of the vacuum oven 21, and the tank is filled with air. The inside is cooled. The air whose temperature has increased in the vacuum oven 21 is then discharged, and the inside of the tank is again in a vacuum state. In the cooling step S3, for example, the temperature difference between the bearing assembly 3 ′ having a high temperature of the assembly P of the bearing assembly 3 ′ and the bearing assembly 3 ′ having a low temperature is ± 5 with respect to the target temperature of 60 ° C. This is done until it approaches the temperature range of ° C.

In the leaving step S4, the bearing assemblies 3 ′ are arranged at a distance from each other in the vacuum oven 21, and the vacuum oven 21 is evacuated to a predetermined target temperature (60 ° C. in this embodiment). The assembly P is held for a predetermined time (for example, three and a half hours).
In the pivot assembly step S5, the inner rings 9 of the two bearing assemblies 3 ′ and the shaft 5 are fixed by press-fitting or adhesive.

  According to the bearing manufacturing method and the pivot manufacturing method configured as described above, the assembly P of the plurality of bearing assemblies 3 ′ assembled in the bearing assembly step S1 is heated in the heating step S2. A component that generates outgas contained in the grease 17 of the bearing assembly 3 ′ (hereinafter referred to as “outgas component”) is volatilized and the outgas component is released.

  In this case, in the heating step S2, as shown in FIG. 3, the assembly P of the plurality of bearing assemblies 3 ′ is heated in a vacuum state at 100 ° C. in the vacuum oven 21, as shown in FIG. In addition, the temperature (Max) of the exposed outer bearing assembly 3 ′ in the assembly P is mainly heated to a target temperature of 60 ° C. or more by radiant heat.

  The heating step S2 is performed until the average temperature (Ave) of the entire assembly P of the bearing assembly 3 'reaches the target temperature of 60 ° C. Heat is hardly transmitted, and when the average temperature of the entire assembly P reaches the target temperature of 60 ° C., the inner bearing assembly 3 ′ does not reach the target temperature of 60 ° C.

  Next, as shown in FIG. 4, the cooling step S <b> 3 fills the vacuum oven 21 with air at room temperature, and the temperature of the outer bearing assembly 3 ′ heated in the assembly P decreases, while the outer bearings thereof are lowered. The temperature of the inner bearing assembly 3 ′ increases due to the radiant heat from the assembly 3 ′. Thereby, as shown in FIG. 5, the temperature difference between the temperature (Max) of the outer bearing assembly 3 ′ of the assembly P and the temperature (Min) of the inner bearing assembly 3 ′ is reduced.

  Next, in the leaving step S4, the assembly P of the bearing assembly 3 ′ is left at 60 ° C. for 3 and a half hours in the vacuum oven 21, whereby the average temperature of the entire assembly P is maintained at the target temperature of 60 ° C. Thus, heat transfer from the outer bearing assembly 3 ′ to the inner bearing assembly 3 ′ proceeds while the outgas component of the grease 17 is released. As a result, the temperature difference between the outer bearing assembly 3 ′ and the inner bearing assembly 3 ′ becomes smaller, and variations in the temperature of the entire assembly P are reduced, so that the plurality of bearing assemblies 3 ′ of the assembly P are reduced. Variation in the amount of outgas component removed between the two is reduced.

  Next, in the pivot assembly step S5, the shaft 5 is fitted to the inner rings 9 of the two bearings 3 left in the leaving step S4, and the pivot assembly 1 'is assembled. Specifically, the shaft 5 is fitted to the inner ring 9 of one bearing 3 whose adhesive is applied to the inner surface, and one end surface of the inner ring 9 is abutted against the flange portion 5 a of the shaft 5. Then, in a state where the spacer member 7 is disposed so as to be sandwiched between the outer rings 11, the shaft 5 is fitted to the inner ring 9 of the other bearing 3 having an inner surface coated with an adhesive. And the adhesive agent of each inner ring | wheel 9 is hardened in the state which applied the external force in the direction which the inner rings 9 of the two bearings 3 adjoin, and provided the appropriate preload. Thereby, the pivot 1 is completed. Each inner ring 9 and shaft 5 may be fixed by press-fitting or fixed by welding in addition to being fixed by an adhesive.

  As described above, according to the bearing manufacturing method and the pivot manufacturing method according to the present embodiment, it is contained in the grease 17 of each bearing assembly 3 ′ through the heating step S2, the cooling step S3, and the leaving step S4. By removing the outgas component, the plurality of bearings 3 and the pivot 1 in which the grease 17 in which the concentration of the outgas component is sufficiently reduced without variation are finally enclosed can be manufactured.

  Further, as compared with the conventional case where the temperature of all the bearing assemblies 3 ′ is raised to a predetermined target temperature by the heating step S 2, the temperature of the outer bearing assembly 3 ′ is once overshooted and then lowered. By approaching the target temperature, all the bearing assemblies 3 'can be brought close to the target temperature in a short time.

  For example, as a comparison of the bearing manufacturing method and the pivot manufacturing method according to the present embodiment, the assembly P of the plurality of bearing assemblies 3 ′ is vacuumed until the temperature of the entire assembly reaches an average around the target temperature on average. An example in the case of continuing to heat at 60 degreeC in a state is shown in FIG. In the example of the graph of FIG. 6, it takes 4 hours or more for the temperature of the entire assembly P to reach the vicinity of the target temperature on average after the start of heating.

On the other hand, according to the bearing manufacturing method and the pivot manufacturing method according to the present embodiment, as shown in the graph of FIG. 5, the entire assembly P of the plurality of bearing assemblies 3 ′ is started after heating is started. It is possible to significantly reduce the time required until the temperature reaches the vicinity of the target temperature on average. Furthermore, in this embodiment, the assembly P of the bearing assemblies 3 ′ cooled in the cooling step S3 is left at a predetermined target temperature (60 ° C.) for a predetermined time, so that the bearing assemblies 3 ′ between the assemblies P are separated. The temperature difference can be further reduced to further reduce variation in outgas and variation in the amount of removed outgas.
Therefore, according to the present embodiment, it is possible to manufacture a plurality of bearings 3 and pivots 1 in which generation of outgas is reduced without variation in a short time.

  In addition, according to the pivot 1 according to the present embodiment, since the bearing 3 in which the grease 17 in which the concentration of the outgas component is sufficiently reduced is used, the generation of outgas during use can be reduced.

[Second Embodiment]
Next, a pivot manufacturing method according to a second embodiment of the present invention will be described.
In the pivot manufacturing method according to the present embodiment, instead of performing the heating step S2, the cooling step S3, and the leaving step S4 on the assembly P of the plurality of bearing assemblies 3 ′, the assembly of the plurality of pivot assemblies 1 ′ is performed. It differs from the first embodiment in that the body is subjected to a heating step S2, a cooling step S3 and a leaving step S4.
In the following, parts having the same configuration as those of the bearing manufacturing method, the pivot manufacturing method, and the pivot 1 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in the flowchart of FIG. 7, in the pivot manufacturing method according to the present embodiment, the heating step S2, the cooling step S3, and the leaving step S4 are performed on the plurality of bearing assemblies 3 ′ assembled in the bearing assembling step S1. The pivot assembly process S5 is performed before the process. The assembly of a plurality of pivot assemblies 1 ′ assembled in the pivot assembly step S5 is subjected to a heating step S2, a cooling step S3, and a leaving step S4.

  According to the pivot manufacturing method of the present embodiment, in the heating step S2, the exposed outer pivot assembly 1 ′ in the assembly of the pivot assemblies 1 ′ is mainly heated to a predetermined target temperature or higher by radiant heat. Is done. Then, in the cooling step S3, the temperature of the heated outer pivot assembly 1 ′ in the assembly of the pivot assemblies 1 ′ decreases, and the inner pivot assembly is radiated by the radiant heat from the outer pivot assembly 1 ′. The 1 'temperature rises.

  Accordingly, the temperature of the entire assembly of the pivot assemblies 1 ′ can be raised to the vicinity of the target temperature on average in a short time, and variation in the amount of outgas removal among the plurality of pivot assemblies 1 ′ can be reduced. it can. Accordingly, it is possible to manufacture a plurality of pivots 1 in which the generation of outgas is reduced without variation in a short time.

Each of the above embodiments can be modified as follows.
In each of the above embodiments, the heating step S2 and the cooling step S3 are each performed only once. However, as a first modification, the heating step S2 and the cooling step S3 may be alternately repeated a plurality of times. Good. In this case, for example, the temperature difference between the outer bearing assembly 3 ′ or pivot assembly 1 ′ of the assembly and the inner bearing assembly 3 ′ or pivot assembly 1 ′ is ± 5 with respect to the target temperature of 60 ° C. The heating step S2 and the cooling step S3 may be alternately repeated until the temperature falls within the temperature range of ° C.

  In this way, in each heating step S2 and cooling step S3, the outer bearing assembly 3 ′ or the pivot assembly 1 ′ having a high temperature of the aggregate and the inner bearing assembly 3 ′ having a low temperature are used. Alternatively, even if the temperature difference from the pivot assembly 1 ′ does not fall within the predetermined temperature range, these bearing assemblies can be made in a shorter time by repeating the heating step S 2 and the cooling step S 3 a plurality of times alternately. The temperature difference of 3 'or pivot assembly 1' can be reduced. Thereby, the dispersion | variation in the removal amount of the outgas of the whole assembly of bearing assembly 3 'or pivot assembly 1' can be reduced more.

In the above embodiments, air is convected in the cooling step S3. However, as a second modification, for example, nitrogen gas, helium gas, argon gas, or the like may be convected.
By doing in this way, it can prevent that a grease oxidizes and can prevent the lubrication performance of the grease 17 from deteriorating. In the pivot manufacturing method according to the second embodiment, the adhesive that fixes the inner ring 9 and the shaft 5 can be provided by convection of nitrogen gas instead of air around the pivot assembly 1 ′ in the cooling step S <b> 3. There is an advantage that curing of the resin can be accelerated.

  As a third modified example, as shown in FIG. 8, the shield 1 and the hub cap 27 (where the pivot 1 is disposed at a position closing one end of the annular space 13 in the axial direction of one bearing assembly 3 ′). Any of them may include a closing member.

  The shield 25 is, for example, an annular plate-shaped member made of metal or plastic, and has an inner diameter larger than the outer diameter of the inner ring 9. The outer diameter is larger than the inner diameter of the outer ring 11. It is formed with large dimensions. The shield 25 is arranged so that the outer edge portion is fixed to the inner wall surface of the outer ring 11 in the one bearing 3 so as to close the space between the inner and outer rings.

  The hub cap 27 is, for example, an annular plate-shaped member made of metal or plastic, and has an inner diameter that is substantially the same as the outer diameter of the shaft 5. The outer diameter is the same as the outer diameter of the outer ring 11. It is formed with approximately equal dimensions. The hub cap 27 is disposed in a fitted state at the end of the shaft 5 opposite to the flange portion 5a, and closes the annular space 13 of the bearing 3 far from the flange portion 5a.

  In the pivot assembly 1 ′, the shaft 5 is inserted in the order of the bearing assembly 3 ′ without the shield 25, the spacer member 7, and the bearing assembly 3 ′ with the shield 25. That is, the bearing assembly 3 ′ having the shield 25 is arranged on the side far from the flange portion 5 a of the shaft 5. Further, the bearing assembly 3 ′ including the shield 25 is configured to fit the shaft 5 in a direction in which the shield 25 is arranged farther from the other bearing assembly 3 ′. A hub cap 27 is disposed adjacent to the shield 25 side of the bearing assembly 3 ′ including the shield 25 in the axial direction.

  In this modification, the manufacturing method of the bearing and the pivot is a shield arranging step (blocking member arranging step) in which an annular shield 25 is arranged along the radial direction on the outer ring 11 of the bearing assembly 3 ′ after the leaving step S4. And a hub cap arranging step (occluding member arranging step) for arranging the hub cap 27 at the axial end of the pivot assembly 1 ′.

  In this manner, in the leaving step S4, the outgas component contained in the grease 17 in the annular space 13 is volatilized while the annular space 13 of the bearing assembly 3 ′ is open. The outgas component can be released efficiently. After the leaving step S4, the annular space 13 of the bearing assembly 3 ′ is closed with the shield 25 and the hub cap 27 by the shield arrangement step and the hub cap arrangement step, thereby preventing the grease 17 from leaking to the outside. The bearing 3 and the pivot 1 can be manufactured.

  This modification is different from the bearing manufacturing method and the pivot manufacturing method according to the first embodiment in that one bearing assembly is used after the leaving step S4 and before the pivot assembly 1 ′ is assembled by the pivot assembly step S5. It is preferable that a shield arrangement process is performed on the three-dimensional body 3 ′, and a hub cap arrangement process is performed on the pivot assembly 1 ′ after assembling the pivot assembly 1 ′ in the pivot assembly process S5. On the other hand, in the pivot manufacturing method according to the second embodiment, after the leaving step S4, one of the bearing assemblies 3 ′ in the pivot assembly 1 ′ is subjected to a shield arrangement step and a hub cap arrangement step. That's fine.

[Third Embodiment]
Next, a vacuum oven (manufacturing apparatus) according to a third embodiment of the present invention will be described.
In addition to the configuration of the vacuum oven 21 of the first embodiment and the second embodiment, the vacuum oven according to the present embodiment controls the temperature of the bearing assembly 3 ′ or the pivot assembly 1 ′ accommodated in the housing 22. PC (Personal) having a program for controlling a temperature sensor (temperature detection unit, not shown) to be detected, a vacuum generator (vacuum generation unit), a heater (heating unit) 23, a temperature sensor and a suction port (gas injection unit) 21a And a control device (not shown) such as a computer.
In the following, parts having the same configurations as those of the bearing manufacturing method, the pivot manufacturing method, and the pivot 1 according to the first embodiment or the second embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The control device operates the vacuum generator by executing the program to evacuate the housing 22 in which the plurality of bearing assemblies 3 ′ or the plurality of pivot assemblies 1 ′ are spaced apart from each other, The heater 23 is operated to heat the inside of the housing 22 to, for example, 100 ° C. by heat radiation. As a result, heat is transferred in sequence from the outer bearing assembly 3 ′ to the inner bearing assembly 3 ′ or from the outer pivot assembly 1 ′ to the inner pivot assembly 1 ′ by radiant heat. The bearing assembly 3 'or the pivot assembly 1' is heated to a predetermined target temperature or higher.

  When the average temperature of the assembly P of the bearing assembly 3 ′ or the assembly of the pivot assembly 1 detected by the temperature sensor reaches a predetermined target temperature (for example, 60 ° C.), the control device executes the program. Thus, the suction port 21 a is opened, normal temperature air is injected into the housing 22, and air is convected in the housing 22. As a result, the temperature of the heated outer bearing assembly 3 ′ or pivot assembly 1 ′ is lowered, while the inner bearing assembly 3 is radiated from the outer bearing assembly 3 ′ or pivot assembly 1 ′. 'Or the temperature of the pivot assembly 1' rises, and the temperature difference between the plurality of bearing assemblies 3 'or between the plurality of pivot assemblies 1' decreases.

  According to this modification, the temperature of the plurality of bearing assemblies 3 ′ or the plurality of pivot assemblies 1 ′ is increased to an average vicinity of a predetermined target temperature in a short time by the control of the control device, and the plurality of bearings Variations in the amount of outgas removal between the assemblies 3 ′ or between the pivot assemblies 1 ′ can be reduced. Therefore, a plurality of pivot bearings 3 or pivots 2 in which the generation of outgas is reduced without variation can be automatically manufactured in a short time.

  In this modification, a predetermined time elapses after the normal temperature air is injected into the casing 22 or the bearing set detected by the temperature sensor after the normal temperature air is injected into the casing 22. The temperature difference between the bearing assembly 3 ′ having a high temperature in the three-dimensional assembly 3 ′ and the bearing assembly 3 ′ having a low temperature or the temperature of the pivot assembly 1 ′ having a high temperature in the assembly of the pivot assembly 1 ′ When the temperature difference from the lower pivot assembly 1 ′ approaches the temperature range of ± 5 ° C. with respect to the target temperature of 60 ° C., the control device closes the suction port 21a by the execution of the program, and vacuums by the vacuum generator. The oven 21 may be evacuated again and the inside of the housing 22 may be maintained at a predetermined target temperature (for example, 60 ° C.) by the heater 23.

  In this state, if the assembly P of the bearing assembly 3 ′ or the assembly of the pivot assembly 1 ′ is left, for example, for a predetermined time (for example, three and a half hours), the outer bearing assembly 3 ′ and the inner bearing assembly 3 Heat transfer by radiant heat to ′ or heat transfer by radiant heat from the outer pivot solid 1 ′ to the inner pivot solid 1 ′ proceeds. Accordingly, the temperature variation of the entire assembly of the bearing assemblies 3 ′ or the entire assembly of the pivot assemblies 1 ′ is reduced, and the outgas between the plurality of bearing assemblies 3 ′ or between the plurality of pivot assemblies 1 ′ is reduced. Variations in the amount of component removal can be further reduced.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included. For example, the present invention is not limited to those applied to the above-described embodiments and modifications, and may be applied to embodiments that appropriately combine these embodiments and modifications, and is not particularly limited. .

1 Pivot 1 ′ Pivot Assembly 3 Bearing (Pivot Bearing)
3 'bearing assembly 5 shaft 9 inner ring 11 outer ring 13 annular space 15 rolling element 17 grease 21 vacuum oven (manufacturing apparatus)
21a Suction port (gas injection part)
22 Housing 25 Shield (blocking member)
27 Hub cap (blocking member)
S1 Bearing assembly process S2 Heating process S3 Cooling process S4 Standing process S5 Pivot assembly process

Claims (11)

A bearing assembly step of assembling a bearing assembly by disposing rolling elements in an annular space between an inner ring and an outer ring arranged coaxially at a circumferential interval and injecting grease into the annular space; ,
A heating step of heating the assembly of the plurality of bearing assemblies assembled in the bearing assembly step at a temperature higher than a predetermined target temperature in a vacuum state;
And a cooling step of cooling the aggregate heated in the heating step by gas convection.   The method for manufacturing a pivot bearing according to claim 1, wherein the heating step and the cooling step are alternately repeated a plurality of times.   The pivot bearing manufacturing method according to claim 1, wherein the cooling step convects nitrogen gas, helium gas, or argon gas.   The method for manufacturing a pivot bearing according to any one of claims 1 to 3, further comprising a leaving step of leaving the aggregate cooled in the cooling step at a predetermined temperature for a predetermined time.   The pivot bearing manufacturing method according to claim 4, further comprising: a closing member arranging step of closing the annular space of the bearing assembly with a closing member after the leaving step. A bearing assembly step of assembling a bearing assembly by disposing rolling elements in an annular space between an inner ring and an outer ring arranged coaxially at a circumferential interval and injecting grease into the annular space; ,
A pivot assembly step of assembling a pivot assembly by fitting a shaft to the inner ring of the bearing assembly;
The assembly of the plurality of bearing assemblies assembled by the bearing assembly or the assembly of the plurality of pivot assemblies assembled by the pivot assembly process is heated at a temperature higher than a predetermined target temperature in a vacuum state. Heating process to
And a cooling step of cooling the aggregate heated in the heating step by gas convection.   The pivot manufacturing method according to claim 6, wherein the heating step and the cooling step are alternately repeated a plurality of times.   The pivot manufacturing method according to claim 6 or 7, wherein the cooling step convects nitrogen gas, helium gas, or argon gas.   The pivot manufacturing method according to any one of claims 6 to 8, further comprising a leaving step in which the aggregate cooled in the cooling step is left at a predetermined temperature for a predetermined time.   The pivot manufacturing method according to claim 9, further comprising a closing member arranging step of closing the annular space of the bearing assembly with a closing member after the leaving step. A plurality of rolling elements are arranged at intervals in the circumferential direction. A plurality of bearing assemblies in which grease is injected into an annular space between an inner ring and an outer ring, or a shaft is disposed on the inner ring of the bearing assembly. A housing capable of storing a plurality of fitted pivot assemblies;
A vacuum generator for evacuating the housing;
A heating unit for heating the inside of the housing by thermal radiation;
A temperature detector for detecting the temperature of the bearing assembly or the pivot assembly housed in the housing;
A gas injection part capable of injecting gas into the housing;
In the state where the housing containing the plurality of bearing assemblies or the plurality of pivot assemblies is evacuated by the vacuum generating unit, the inside of the housing is heated by the heating unit and detected by the temperature detecting unit. When the temperature of the bearing assembly or the pivot assembly reaches a predetermined target temperature, a gas having a temperature lower than the predetermined target temperature is injected into the casing by the gas injection section. And a control device for causing convection.

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