JP2001330029A - Lubricant-containing polymer-filled tapered roller bearing and metal mold for manufacturing the tapered roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low torque lubricant-containing polymer-filled tapered roller bearing and a metal mold for manufacturing the tapered bearing. SOLUTION: This lubricant-containing polymer-filled tapered roller bearing comprises an outer ring, an inner ring, a plurality of tapered rollers installed between the outer ring and the inner ring, a retainer for holding the tapered rollers, and lubricant-containing polymer filled in a space formed by the outer ring, inner ring, tapered rollers, and retainer. The inner ring comprises a recessed part for storing the tapered rollers on the outer peripheral side thereof, and the recessed part comprises the face of the inner ring on a large flange part side and the face on a small flange part side. The surface on the large flange part side is brought in slidable contact with the end faces of the tapered rollers without providing the lubricant-containing polymer therebetween.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a tapered roller bearing filled with a lubricant-containing polymer and a mold for manufacturing the same.

2. Description of the Related Art Generally, a gap formed by an outer ring, an inner ring, and a tapered roller of a tapered roller bearing is filled with lubricating oil or grease in order to impart lubricity. These lubricating oils and greases are liquid or semi-solid substances, and have the problem of scattering or fluidizing during rotation of the bearing. To prevent this, seal the tapered roller bearing with a seal plate, etc. However, this method has been difficult to apply to small special-purpose bearings.

In order to solve this problem, in recent years, a method has been proposed in which a lubricant-containing polymer composed of grease and polyethylene is filled in a gap formed by an outer ring, an inner ring and a tapered roller of a bearing. As a method of filling the lubricant-containing polymer, a full-pack in which the end surface of the bearing and the lubricant-containing polymer match is generally used. As a manufacturing method, a heat molding method of sandwiching with an appropriate jig and molding by heat treatment is used. Is known (see Japanese Patent Publication No. 63-23239).

However, tapered roller bearings filled with a lubricant-containing polymer molded by heat treatment, sandwiched between appropriate jigs, have the following specific problems.

In a manufacturing process of a lubricant-containing polymer-filled tapered roller bearing, when a molten lubricant-containing polymer is filled, the polymer enters between the end face of the tapered roller and the surface of the inner ring recessed side on the large flange portion. In operation,
When an axial load or a radial load is applied to the outer ring, the load is transmitted from the outer ring to the tapered rollers, and further, this load is transmitted from the tapered rollers to the inner ring,
In this state, since the lubricant-containing polymer has entered between the end face of the tapered roller and the surface of the inner ring recess on the large flange portion, the movement of the tapered roller is hindered, and the torque associated with the rotation of the bearing increases. There was a problem.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems, and to prevent the lubricant-containing polymer from entering between the surface of the concave portion of the inner ring on the side of the large flange portion and the end surface of the tapered roller. It is an object of the present invention to provide a lubricant-containing polymer tapered roller bearing which is in sliding contact and has a low torque, and a mold for manufacturing the same.

SUMMARY OF THE INVENTION A lubricant-filled polymer-filled tapered roller bearing according to the present invention comprises an outer ring, an inner ring, a plurality of tapered rollers interposed between the outer ring and the inner ring; A lubricant-containing polymer-filled tapered roller bearing, comprising: a retainer to retain; and an outer ring, an inner ring, a lubricant-containing polymer filled in a space formed by the tapered rollers and the retainer. A concave portion for accommodating the tapered roller on an outer peripheral side thereof, the concave portion includes a surface on the large flange portion side and a surface on the small flange portion side of the inner ring, and the surface on the large flange portion and the tapered roller. Are in sliding contact with each other without a lubricant-containing polymer interposed therebetween.

[0005] A mold for producing a lubricant-containing polymer-filled tapered roller bearing according to the present invention is a mold for producing a lubricant-containing polymer-filled tapered roller bearing comprising an upper mold and a lower mold. The mold and the lower mold are in close contact with each other, and an outer ring, an inner ring, a gap for accommodating a plurality of tapered rollers interposed between the inner ring and the outer ring and a retainer for holding the tapered rollers are formed, An elastic member is provided on at least one of the upper mold side and the lower mold side in the gap, and the upper portion is configured so that the tapered roller is pressed in the axial direction by the outer ring and the inner ring in the retracted state. The mold and the lower mold are configured to press the outer ring and the inner ring from the axial direction of the tapered rollers via the elastic member.

The lubricant-containing polymers usable in the present invention include polyethylene, polypropylene, polybutylene,
Synthetic resins selected from the group of polyolefin resins such as polymethylpentene, paraffinic hydrocarbon oils such as poly-α-olefin oils, naphthenic hydrocarbon oils, mineral oils, ether oils such as dialkyldiphenyl ether oils, and phthalate esters And a lubricant prepared by mixing any one of the above ester oils or the like, or by mixing them, is heated at a temperature equal to or higher than the melting point of the resin, plasticized, and then cooled to be solidified. Additives such as an antioxidant, a rust inhibitor, an antiwear agent, a defoamer, and an extreme pressure agent may be added to the lubricant in advance.

The composition ratio of the lubricant-containing polymer is such that the polyolefin resin is 10 to 50% by weight based on the total weight,
The lubricant is 90 to 50% by weight. By making the polyolefin resin 10% by weight or more, more desired hardness and strength can be obtained, the initial shape can be more easily maintained when a load is applied due to rotation of the bearing, and desorption from the inner space of the bearing. Easier to do. By increasing the amount of the lubricant to 50% by weight or less of the polyolefin-based resin, the supply amount of the lubricant to the bearing is increased, and the life of the bearing can be further extended.

The average molecular weight of the polyolefin resin group is preferably in the range of 700 to 5 × 10 ⁶ . And those classified into wax an average molecular weight from 700 to 1 × 10 ^4, and a relatively low molecular weight an average molecular weight ^{1 × 10 4 ~1 × 10 6} , an average molecular weight 1 × ^{10 6} ~5 × ¹⁰ 6 Super High molecular weight compounds are used alone or as a mixture.
The combination of a relatively low molecular weight lubricant with a lubricant provides a lubricant-containing polymer with some mechanical strength, lubricant supply capacity, and oil retention. Replacing some of the relatively low molecular weight ones among those classified as wax, the affinity between the wax classified and the lubricating oil increases because the difference in molecular weight between the lubricating oil and the lubricating oil increases. As a result, the oil retaining property of the lubricant-containing polymer is improved, and the lubricant can be supplied for a long period of time. On the other hand, on the other hand, the mechanical strength decreases. In addition, if the polymer is replaced with an ultra-high molecular weight one, the difference in molecular weight between the ultra-high molecular weight one and the lubricating oil is large, so that the affinity with the lubricating oil is lowered. Oozes out lubricant from the surface. This shortens the time to reach the amount of lubricant that can be supplied from the lubricant-containing polymer, and shortens the life of the bearing. On the other hand, the mechanical strength is improved.

As the wax, besides polyolefin resins such as polyethylene wax, hydrocarbon waxes such as paraffin synthetic wax can be used.

In consideration of the balance of moldability, mechanical strength, oil retention, and lubricant supply, the composition ratio of the lubricant-containing polymer is 0 to 5% by weight for waxes and relatively low molecular weight. 8 to 48% by weight, ultrahigh molecular weight 2 to 20% by weight, and a total of three resin components of 10 to 50% by weight (the remainder is 90 to 50% by weight of a lubricant).

[0011] One of the mechanical strength, hardness of the lubricant-containing polymer of the present invention "HD _A" is preferably in the range of 65 to 95, more preferably in the range of 70 to 90. By setting the hardness “HD _A ” to 65 or more,
Breakage due to rotation of the bearing can be further prevented. Further, by setting the hardness “HD _A ” to 95 or less, the force for restraining the tapered rollers is suppressed, and the torque of the bearing is increased, and the heat generated by the rotation of the bearing is increased to increase the temperature of the bearing. It can be prevented more.

In order to improve the mechanical strength of the lubricant-containing polymer of the present invention, a thermoplastic resin and a thermosetting resin as described below may be added to the polyolefin resin.

As the thermoplastic resin, various resins such as polyamide, polycarbonate, polybutylene terephthalate, polyphenylene sulfide, polyether sulfone, polyether ether ketone, polyamide imide, polystyrene and ABS resin can be used.

As the thermosetting resin, resins such as unsaturated polyester resin, urea resin, melamine resin, phenol resin, polyimide resin, epoxy resin and the like can be used.

These resins may be used alone or in combination. When these resins are added, an appropriate compatibilizer may be added as necessary to disperse the polyolefin-based resin and other resins in a more uniform state.

In order to improve the mechanical strength, a filler may be added. As the filler, for example,
Calcium carbonate, magnesium carbonate, inorganic whiskers such as potassium titanate whiskers and aluminum borate whiskers, or inorganic fibers such as glass fibers and metal fibers and those woven into a cloth, and organic compounds such as carbon black, Graphite powder, carbon fiber,
Aramid fiber or polyester fiber may be added.

Further, in order to prevent deterioration of the polyolefin resin due to heat, aging of N, N'-diphenyl-p-phenyldiamine, 2,2'-methylenebis (4-ethyl-6-t-butylphenol) and the like. Inhibitors and 2-hydroxy-4-n-octoxybenzophenone, 2- (2'-hydroxy-3'-t-butyl-5'-methyl
An ultraviolet absorber such as -phenyl) -5-chlorobenzotriazole may be added.

The additive amount of all of the above additives (other than the polyolefin resin and the lubricant) should be not more than 20% by weight of the total amount of the molding raw material as a whole, so that the lubricant supply capacity is maintained. Above.

As the polymer material which can be used in the present invention, in addition to those based on the above-mentioned polyolefin resin, any thermoplastic resin which can be injection-molded can be used, and among them, the oil content is increased. What can be used is, for example, a polyester elastomer.

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a cross-sectional view showing a part of a lubricant-containing polymer-filled tapered roller bearing according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing a mold for manufacturing a lubricant-containing polymer-filled tapered roller bearing according to a second embodiment of the present invention. FIG. 3 is a schematic view showing a mold for manufacturing a lubricant-containing polymer-filled tapered roller bearing according to a third embodiment of the present invention. FIG. 4 is a plan view of an upper mold according to a second embodiment of the present invention, as viewed from above in FIG. FIG. 5 is a bottom view of the lower mold according to the second embodiment of the present invention as viewed from below in FIG.

(First Embodiment) A tapered roller bearing filled with a lubricant-containing polymer according to the present invention will be described with reference to FIG.

As shown in the sectional view of FIG. 1, a tapered roller bearing 1 filled with a lubricant-containing polymer according to the present embodiment comprises an outer ring 3, an inner ring 2, and a rolling element interposed between the outer ring and the inner ring. A tapered roller 4, a retainer 5 for holding the tapered roller 4, and a lubricant polymer 6 are provided. Outer ring 3 and inner ring 2
Is a hollow rotating body having a locus whose cross-sectional shape shown in FIG. 1 is rotated about a rotation axis II ′.
The inner ring 2 has a concave portion on the outer peripheral side for accommodating the tapered roller 4 at an angle. The portion accommodating the tapered roller 4 has a thick portion and a thin portion in the radial direction of the inner ring 2. The concave portion of the inner ring 2 has a surface 21 on the large flange portion side and a surface 22 on the small flange portion side. On the other hand, the outer ring 3 also has a thick portion and a thin portion in the radial direction. The retainer 5 has a bent portion.

The outer ring 3 of the bearing 1 has a radial load (FIG. 1).
When a middle or an arrow A) or a thrust load (an arrow B in FIG. 1) is received, the force is transmitted from the outer ring 3 to the tapered roller 4 and transmitted from the tapered roller 4 to the inner ring 2. Here, since the end surface of the tapered roller 4 and the surface 21 on the large flange portion are in sliding contact, it is desirable that the friction coefficient be as small as possible. On the other hand, since no component of thrust load or radial load is applied in the direction from the end face of the tapered roller 4 to the face 22 on the small flange portion side of the inner ring 2, friction is small in this portion.

In the present embodiment, the end surface of the tapered roller 4 and the surface 21 on the large flange portion side of the concave portion of the inner ring 2 are in sliding contact with no lubricant-containing polymer therebetween, so that the lubricant-containing polymer There is no problem that the movement of the tapered rollers is hindered due to the presence, and since the lubricating oil exudes from the lubricant-containing polymer and is supplied to the sliding contact portion, the torque associated with the rotation of the bearing can be reduced. .

(Second Embodiment) Next, a method of manufacturing a tapered roller bearing filled with a lubricant-containing polymer according to the present invention will be described with reference to FIG.

As shown in FIG. 2, the manufacturing mold 10 includes an upper mold 12 and a lower mold 11, and the upper mold 12 has a surface 12A on the axial side of a portion for housing the bearing and a housing for the bearing. The lower mold 11 has a surface 11A and a surface 11B opposed to the surface 12A and the surface 12B, respectively. The upper mold 12 and the lower mold 11 have an upper mold recess and a lower mold recess for accommodating the outer ring 3, the inner ring 2, the tapered rollers 4, and the retainer 5, respectively, when both are brought into close contact with each other. I have.
The upper mold 12 has a gap for providing an elastic member,
An elastic member 15 is provided in the gap, and a thick portion of the outer race is pressed through the elastic member 15. The upper mold 12 is for injecting a molten lubricant-containing polymer (hereinafter, referred to as a molten polymer) that is located above the bent portion of the retainer 5 and that is conducted from above toward the upper mold recess. The injection gate 13 is provided. The lower mold 11 has a gas escape hole 8 in the lower mold recess.

FIG. 4 is a plan view of the upper mold 12 as viewed from above in FIG. 2, and FIG. 5 is a bottom view of the lower mold 11 as viewed from below in FIG.

As shown in FIG. 4, the upper mold 12 has a runner portion 18 formed radially.
An injection gate 13 for injecting the molten polymer into a space formed by the outer ring, the inner ring, the tapered rollers, and the retainer is provided at a terminal portion of the injection roller 8. Injection gate 1
At the center of 3 is provided a pin gate for injecting molten polymer into it. In addition to the example shown in FIG. 4, the runner portion may be formed in a circular shape. However, by making the runner portion more radial than in the circular shape, the volume of a portion where the molten polymer is conducted becomes smaller, so that material can be saved. This has the advantage that the injection pressure applied to the internal bearing can be reduced.

As shown in FIG. 5, since the lower mold 11 has the gas escape holes 8 on the same vertical line corresponding to the intermediate position of the injection gate 13, the gas in the gap moves out of the production mold. It has been expelled and the gap has been completely filled with molten polymer.

Next, a method of manufacturing a lubricant-filled polymer-filled tapered roller bearing using a manufacturing die will be described with reference to FIG.

First, the outer ring 3, the inner ring 2, the tapered rollers 4, and the retainer 5 are stored in the lower mold recess. The inner ring 2 is stored such that a thin portion is located on the upper side of the figure and a thicker part is located on the lower side of the figure. For the outer ring 3, the thicker part is located on the upper side of the figure and is located on the lower side of the figure. Store so that it comes to the side.

After storage, the upper mold 12 is moved to the lower mold 11
So that the upper mold surface 12A and the lower mold surface 12B are in close contact with the lower mold surface 11A and the lower surface 11B, respectively. In this state, the upper mold 12 and the lower mold 11 are fixed by tightening the screw 16. At this time, the upper mold 12 is provided with the thick portion of the outer race 3 and the elastic member 1.
5 is contacted. Thereby, a force is applied from the upper mold 12 to the elastic member 15, and this force is transmitted from the elastic member 15 to the outer ring 3, transmitted from the outer ring 3 to the tapered roller 4, and transmitted from the tapered roller 4 to the inner ring 2, Furthermore, inner ring 2
The lower mold 11 and the thick portion of the inner ring 2 are pressed by the lower mold 11, whereby the end surface of the tapered roller 4 is pressed against the surface 21 of the inner ring 2 on the side of the large flange. Accordingly, the distance between the upper mold 12 and the thin portion of the inner ring 2 is set to 0.1 mm.
A gap of about 1 to 0.5 mm is formed, and a gap of about 0.1 to 0.5 mm is formed between the lower mold 11 and the thin portion of the outer ring 3. Each of the distance between the tip of the retainer 5 and the upper mold 12 or the lower mold 11 is 0.5 to 0.5.
It has a gap of about 2 mm.

When the upper mold 12 and the lower mold 11 are fixed, the elastic member 15 presses the end surface of the tapered roller 4 against the surface 21 on the side of the large collar portion of the inner ring to eliminate the gap, and the molten polymer is formed. This has the effect of preventing the molten polymer from entering the gap, and also has the effect of reducing the injection pressure of the molten polymer into the gap and preventing the impression of the tapered rollers 4 from being formed on the outer peripheral portion of the inner ring 2 and the inner peripheral portion of the outer ring 3. Have. As the elastic member 15, an elastic member such as a coil spring, a leaf spring, or a shape memory alloy is used.

Next, the molten lubricant-containing polymer is injected into the gap through the injection gate 13 to fill the gap. The molten lubricant-containing polymer is conducted into the gap through the injection gate 13 and the cage 5
After being hit by the bent portion, the space between the retainer 5 and the inner ring 2 and between the retainer 5 and the outer ring 3 is filled in the gap.

Since the injection gate 13 is positioned above the bent portion of the retainer 5, the injected molten polymer flows through the retainer 5 to the surface 22 of the inner ring on the side of the small flange, and the small flange is formed. A force is applied in a direction to push the upper surface of the tapered roller 4 near the side surface 22 downward. By transmitting this force,
A force is applied in the direction of pressing the end surface of the tapered roller 4 against the surface 21 on the large flange portion, and the end surface of the tapered roller 4 and the surface 2 on the large flange portion are pressed.
This has the effect of making the contact with No. 1 more closely contact. This can be achieved by using the same upper mold as the mold for attaching the elastic member 15 for pressing the thick part of the outer ring and the mold for providing the injection gate 13.

The injection of the molten polymer is preferably performed by a vertical injection molding machine in which production dies are arranged vertically. Compared to the horizontal injection molding machine, the vertical injection molding machine fills the molten polymer after filling the molten polymer after storing the outer ring, inner ring, tapered roller, and cage, with the cage in the manufacturing mold biased. There is an advantage that the occupied floor area can be reduced, in addition to a small possibility of being solidified. As the vertical injection molding machine, for example, an injection molding machine described in JP-A-8-309793 in which a hopper is improved and a mold is arranged in a vertical mold is used.

On the other hand, FIG. 6 is a comparative example, and the manufacturing die 30 is different from the second embodiment in that the inner ring 2, the outer ring 3, the tapered rollers 4, and the elastic members 152 are stored upside down. The form is different. That is, the thick portion of the inner ring 2 is located above in the figure (the surface 212 on the large flange portion is upward), and the thin portion is located below (the surface 222 on the small flange portion is downward) in the diagram, and the thin portion of the outer ring 3 is small. Tapered rollers 4 with the upper part and the thicker part below
The wide part of the taper is disposed above, and the upper mold 1
Injection gate 13 for injecting molten polymer into 22
2 are provided, and the elastic member 152 is attached to the lower mold 112. That is, a mold for providing the injection gate 132 and a mold for attaching the elastic member 152 are different.

In this comparative example, the flow pressure of the injected molten polymer, that is, the injection molding pressure,
If the force is greater than the force pushing the thick part of the outer ring 3, a gap is formed between the end face of the tapered roller 4 and the face 212 on the large flange portion side, and the gap is filled with the lubricant-containing polymer 62. Would.

When the upper mold 122 and the lower mold 112 are fixed by increasing the spring force of the elastic member 152, the surface 212 on the large flange portion side of the inner ring is fixed to the end face of the tapered roller 4. The gap between the two can be pressed to prevent the molten polymer from entering, but it is not practical because the spring needs to be large, the mold becomes large, and the injection molding conditions are limited.

(Third Embodiment) A different method of manufacturing a lubricant-containing polymer-filled tapered roller bearing of the present invention will be described with reference to FIG.

As shown in FIG. 3, in the manufacturing mold 20, the upper mold 121 is in contact with the thick portion of the outer ring 3, and the lower mold 111 is formed by the thick portion of the inner ring 2 and the elastic member. The second embodiment differs from the second embodiment in that they are in contact with each other via the center 151. That is, a mold for mounting the elastic member 151 for pressing the thick part of the inner race 2 and the injection gate 13
1 are separately provided in the lower mold 111 and the upper mold 121 on the opposite sides.

Also in the case of the present embodiment, the second
In the same manner as in the first embodiment, the pressing force of the elastic member 151 and the pressure due to the flow of the molten polymer are both tapered rollers 4
Work in the direction of pressing the end surface of the inner ring against the surface 211 on the side of the large collar portion of the inner ring. Thereby, the elastic member 151 is connected to the upper mold 1.
When the lower mold 111 and the lower mold 111 are fixed, the surface 211 on the side of the large collar portion of the inner ring is pressed against the end surface of the tapered roller 4 to eliminate the gap between them and prevent the molten polymer from entering. Has the effect of relaxing the injection pressure of the molten polymer into the gap and preventing the outer peripheral portion of the inner ring 2 and the inner peripheral portion of the outer ring 3 from being indented by the tapered rollers 4.

EXAMPLES (Example 1) In this example, a polymer having the following composition was used as a lubricant-containing polymer. Composition High density polyethylene (classified as relatively low molecular weight): 10% by weight Ultra high molecular weight polyethylene (classified as ultra high molecular weight): 12.5% by weight Polyethylene wax (classified as wax): 2.5% by weight Mineral oil: 75% by weight % First, a tapered roller bearing was assembled by a usual method, and this was degreased and washed. Next, a fluorine-based release agent (Daikin Industries, Ltd., DAIFREE GA-6010) is spray-coated on the outer peripheral surface of the inner ring of the tapered roller bearing, the inner peripheral surface of the outer ring, the outer edge of the tapered roller, and the surface of the cage. A coating of the release agent was formed. As shown in FIG. 2, the tapered roller bearing has a thin portion of the inner ring 2 on the upper side and a thick portion on the lower side.
The thick portion of the outer race 3 is stored in the recess of the lower mold 11 such that the thin portion is on the upper side and the thin portion is on the lower side.
And the screw 16 was tightened.

Next, the lubricant-containing polymer is pressure-fed to a hopper of an injection molding machine (not shown in FIG. 2), heated to a temperature higher than its melting point, and pressed by a screw to form an injection mold formed on the upper mold 12. The molten polymer was injected from the gate 13 into the gap. At this time, since gaps are formed between the upper mold 12 and the thin portion of the inner ring 2 and between the lower mold 11 and the thin portion of the outer ring 3, the molten polymer is injected into the gaps. Is done. The injected molten polymer is cooled and solidified in the production mold 10 so as to approach the mold temperature.
Then, it is taken out from the production mold 10 and tapered roller bearings (inner diameter 120 mm, outer diameter 180
mm, width 38 mm).

When the obtained tapered roller bearing for filling a lubricant-containing polymer was disassembled and examined, the lubricant-containing polymer was filled between the end face of the tapered roller 4 and the face 21 on the large flange portion side of the inner ring 2. However, the lubricant-containing polymer 6 was observed to enter between the end face of the tapered roller 4 and the face 22 of the inner ring 2 on the side of the small flange. Further, when the inner peripheral surface of the outer ring 3 was observed, almost no indentation due to injection was observed, and even if it was slightly observed, it was extremely light.

(Comparative Example) In a comparative example, as shown in FIG. 6, a tapered roller bearing is constructed such that the thin portion of the inner ring 2 is located on the lower side, the thick portion is located on the upper side, and the thick portion of the outer ring 3 is located on the lower side. Other than storing the thin part on the side in the manufacturing mold 30 so that it comes to the upper side,
A tapered roller bearing for filling a lubricant-containing polymer was obtained in the same manner as in Example 1.

When the obtained tapered roller bearing for filling a lubricant-containing polymer was disassembled and examined, the lubricant-containing polymer was filled between the end face of the tapered roller 4 and the face 212 of the inner ring 2 on the side of the large flange. On the other hand, it was observed that the lubricant-containing polymer 62 was not filled between the end face of the tapered roller 4 and the face 222 of the inner ring 2 on the small flange portion side.

This is because the end face of the tapered roller 4 near the surface 212 on the side of the large flange of the inner ring is pushed downward in the drawing by the flow pressure of the injected molten polymer, so that the surface 212 on the side of the large flange is conical. A gap was formed between the roller 4 and the end face thereof, and the gap was filled with the lubricant-containing polymer 62.

(Starting torque comparison test) The starting torque of the bearings obtained in Example 1 and Comparative Example was measured while changing the preload. FIG. 7 is a diagram plotting the starting torque of the first embodiment when the starting torque of the comparative example is set to 100% under each preload.

Referring to FIG. 7, in Example 1, the relative value of the starting torque was lower than that of the comparative example, and the relative value of the starting torque was reduced as the preload increased.

Considering that a tapered roller bearing filled with a lubricant-containing polymer is generally filled with a lubricant-containing polymer, the movement of the tapered rollers is hindered, so that the tapered roller bearing is less than a bearing not filled with a lubricant-containing polymer. However, the starting torque tends to be higher, but as the preload increases, the contact resistance between the end face of the tapered roller and the inner and outer rings increases,
It is believed that the inhibitory resistance of the lubricant-containing polymer tends to be negligible. In the comparative example, since the lubricant-containing polymer is filled between the end surface of the tapered roller and the surface on the large collar portion side of the outer periphery of the inner ring, the friction between the end surface of the tapered roller and the outer periphery of the inner ring during rotation is large. That is, the starting torque is prevented from approaching the starting torque in the unfilled state as the preload increases. Therefore, as the relative value of the starting torque, the difference between Example 1 and the comparative example increases as the preload increases.

According to the present invention, the lubricant-containing polymer-filled tapered roller bearing of the present invention has no lubricant-containing polymer between the end surface of the tapered roller and the surface of the inner ring at the side of the large flange. Therefore, it rotates smoothly with low torque and shows good lubricity.

Further, by using the production mold of the present invention, it is possible to produce a low-torque lubricant-containing polymer tapered roller bearing.

Further, the production mold is configured such that the upper mold and the lower mold are brought into close contact with each other, so that the joint of the two molds is securely brought into contact with each other, and is provided with an elastic member. In addition, the injection pressure of the molten polymer into the gap is alleviated, and it is possible to prevent tapered roller impressions from being formed on the outer peripheral portion of the inner ring and the inner peripheral portion of the outer ring.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a part of a lubricant-containing polymer-filled tapered roller bearing according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a mold for manufacturing a lubricant-containing polymer-filled tapered roller bearing according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram showing a mold for manufacturing a lubricant-containing polymer-filled tapered roller bearing according to a third embodiment of the present invention.

FIG. 4 is a plan view of an upper mold according to a second embodiment of the present invention, as viewed from above in FIG. 2;

FIG. 5 is a bottom view of the lower mold according to the second embodiment of the present invention as viewed from below in FIG. 2;

FIG. 6 is a schematic diagram showing a mold for manufacturing a lubricant-containing polymer-filled tapered roller bearing according to a comparative example.

FIG. 7 is a diagram showing a change in a relative value of a starting torque according to a change in a preload.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Lubricant-containing polymer-filled tapered roller bearing 2 Inner ring 3 Outer ring 4 Tapered roller 5 Cage 6, 61, 62 Lubricant-containing polymer 8, 81, 82 Gas escape hole 10, 20, 30 For lubricant-filled polymer-filled tapered roller bearing Manufacturing mold 11, 111, 112 Lower mold 12, 121, 122 Upper mold 13, 131, 132 Injection gate 15, 151, 152 Elastic member 16, 161, 162 Screw 18 Runner 21, 21, 211, 212 Part side surface 22, 221, 222 Surface of small collar part side

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat 参考 (Reference) B29L 31:04 B29L 31:04 (72) Inventor Yasushi Amano 1-5-150 Kugenuma Jinmei, Fujisawa-shi, Kanagawa F-term (reference) in NSK Ltd. JN26 JQ81

Claims (2)

[Claims] 1. An outer ring, an inner ring, a plurality of tapered rollers interposed between the outer ring and the inner ring, a retainer for holding the tapered rollers, and the outer ring, the inner ring, the tapered rollers, and the retainer. A lubricant-containing polymer-filled tapered roller bearing comprising: a lubricant-containing polymer filled in a space to be formed; wherein the inner ring has a concave portion for accommodating the tapered roller on an outer peripheral side thereof. The concave portion includes a surface on the large flange portion side and a surface on the small flange portion side of the inner ring, and the surface on the large flange portion and the end surface of the tapered roller are in sliding contact with no lubricant-containing polymer interposed therebetween. A polymer-filled tapered roller bearing containing a lubricant. 2. A mold for manufacturing a lubricant-filled polymer-filled tapered roller bearing comprising an upper mold and a lower mold, wherein the upper mold and the lower mold are in close contact with each other to form an outer ring, an inner ring, and the like. A gap for accommodating a plurality of tapered rollers interposed between the inner ring and the outer ring and a retainer for holding the tapered rollers is formed, and at least one of the upper mold side and the lower mold side in the gap has elasticity. The upper die and the lower die are provided with the outer ring and the inner ring via the elastic member so that the tapered roller is pressed in the axial direction by the outer ring and the inner ring in the storage state. A lubricant-containing polymer-filled tapered roller bearing, which is adapted to be pressed in the axial direction of the tapered rollers.