JP2006029590A - Lubricant-contained polymer-filled tapered roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low torque lubricant-contained polymer-filled tapered roller bearing. <P>SOLUTION: The tapered roller bearing 1 is provided with an outer ring 3; an inner ring 2, a plurality of taper roller 4 situated between the outer and inner rings 3 and 2; a holder 5 to hold the tapered roller 4; and a lubricant-contained polymer 6 filled in a space formed by the outer ring 3, the inner ring 2, the tapered roller 4, and the holder 5. The inner ring 2 has a recessed part containing the tapered roller 4 on its outer peripheral side. The recessed part is provided with the surface on the large collar part side and the surface on the small collar part side of the inner ring 2. The lubricant contained polymer tapered roller bearing 1 is constituted such that slide contact is carried out without interposing the lubricant-contained polymer 6 between the surface on the large collar part side and the end face of the tapered roller 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tapered roller bearing filled with a lubricant-containing polymer.

  In general, 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 that can be scattered or fluidized while the bearing is rotating. To prevent this, taper roller bearings are sealed with a seal plate or the like. In general, this method is difficult to apply to a small special purpose bearing.

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. The filling method of the lubricant-containing polymer is generally a full pack in which the end face of the bearing and the lubricant-containing polymer coincide with each other, and the manufacturing method is a heat molding method in which the material is sandwiched by an appropriate jig and molded by heat treatment. Is known (see, for example, Patent Document 1).
Japanese Patent Publication No. 63-23239

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

  In the manufacturing process of the lubricant-containing polymer-filled tapered roller bearing, if the molten lubricant-containing polymer is filled, this enters between the end surface of the tapered roller and the surface of the inner ring recess on the large collar side. During operation, when an axial load or radial load is applied to the outer ring, the load is transmitted from the outer ring to the tapered roller, and this load is transmitted from the tapered roller to the inner ring. In this state, the end surface of the tapered roller Since the lubricant-containing polymer has entered between the inner ring recess and the surface on the side of the large collar, there has been a problem that the movement of the tapered roller is hindered and the torque accompanying the rotation of the bearing is increased.

  Therefore, the present invention aims to solve the above-described problems, and the lubricant-containing polymer does not enter between the surface of the concave portion of the inner ring and the end surface of the tapered roller so that both are in sliding contact with each other. The object of the present invention is to provide a low-torque lubricant-containing polymer tapered roller bearing.

  A lubricant-containing polymer-filled tapered roller bearing according to the present invention includes an outer ring, an inner ring, a plurality of tapered rollers interposed between the outer ring and the inner ring, a cage for holding the tapered roller, the outer ring, A lubricant-containing polymer-filled tapered roller bearing comprising a lubricant-containing polymer filled in a space formed by an inner ring, a tapered roller and a cage, wherein the inner ring has the tapered roller on an outer peripheral side thereof. A recess for accommodating the recess, and the recess includes a surface on the large collar portion side and a surface on the small collar portion side of the inner ring, and the lubricant-containing polymer is interposed between the surface on the large collar portion side and the end surface of the tapered roller. It is characterized by being in sliding contact with no intervening.

  As the lubricant-containing polymer that can be used in the present invention, a synthetic resin selected from the group of polyolefin resins such as polyethylene, polypropylene, polybutylene, and polymethylpentene, paraffin hydrocarbon oils such as poly α-olefin oil, Add a lubricant prepared by mixing any of naphthenic hydrocarbon oil, mineral oil, ether oil such as dialkyldiphenyl ether oil, ester oil such as phthalate ester, etc. alone or in combination, and heat it above the melting point of the resin. And then solidified by cooling and then cooling. An additive such as an antioxidant, a rust inhibitor, an antiwear agent, a foam remover, or an extreme pressure agent may be added to the lubricant in advance.

  The composition ratio of the lubricant-containing polymer is 10 to 50% by weight of polyolefin resin and 90 to 50% by weight of lubricant with respect to the total weight. By setting the polyolefin resin to 10% by weight or more, desired hardness and strength can be obtained, and it becomes easier to maintain the initial shape when a load is applied due to rotation of the bearing, etc., and it can be detached from the inner space of the bearing. It becomes easy to do. Further, by increasing the amount of lubricant by setting the polyolefin resin to 50% by weight or less, the amount of lubricant supplied 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 in combination. A combination of a relatively low molecular weight and a lubricant provides a lubricant-containing polymer having a certain level of mechanical strength, lubricant supply capability, and oil retention. Replacing some of the relatively low molecular weight materials with those classified as waxes, the difference in molecular weight between those classified as waxes and lubricating oils is small, so the affinity with lubricating oils is increased. As a result, the oil retaining property of the lubricant-containing polymer is improved, and the lubricant can be supplied over a long period of time. On the other hand, the mechanical strength decreases. Also, if 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 the affinity with the lubricating oil is lowered, resulting in a decrease in oil retention and a lubricant-containing polymer. Lubricant oozes out quickly. 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, in addition to a polyolefin-based resin such as polyethylene wax, a hydrocarbon-based one such as paraffin-based synthetic wax can be used.

  Considering the balance of moldability, mechanical strength, oil retention, and lubricant supply amount, the composition ratio of the lubricant-containing polymer is 0 to 5% by weight classified as wax, and 8 is relatively low molecular weight. The weight is preferably 48% by weight, 2 to 20% by weight of ultra-high molecular weight, and 10 to 50% by weight of the total of the three resins (the remainder being 90 to 50% by weight of lubricant).

As one of the mechanical strengths, the hardness “HD _A ” of the lubricant-containing polymer of the present invention 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, damage due to rotation of the bearing can be further prevented. In addition, by setting the hardness “HD _A ” to 95 or less, the force that restrains the tapered roller is suppressed, and the bearing torque increases or the heat generated by the rotation of the bearing increases and the temperature of the bearing increases. More can be prevented.

  In order to improve the mechanical strength of the lubricant-containing polymer of the present invention, a product obtained by adding the following thermoplastic resin and thermosetting resin to the polyolefin resin may be used.

  As the thermoplastic resin, 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, each resin such as unsaturated polyester resin, urea resin, melamine resin, phenol resin, polyimide resin, and epoxy resin can be used.

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

  Moreover, in order to improve mechanical strength, you may add a filler. As this filler, for example, inorganic whiskers such as calcium carbonate, magnesium carbonate, potassium titanate whisker and aluminum borate whisker, or inorganic fibers such as glass fiber and metal fiber and those braided into a cloth shape, In the case of an organic compound, carbon black, graphite powder, carbon fiber, aramid fiber, polyester fiber, or the like may be added.

  Furthermore, for the purpose of preventing deterioration of polyolefin resin due to heat, anti-aging agents such as N, N′-diphenyl-p-phenyldiamine, 2,2′-methylenebis (4-ethyl-6-t-butylphenol), In addition, 2-hydroxy-4-n-octoxybenzophenone, 2- (2'-hydroxy-3'-t-butyl-5'-methyl-phenyl) -5-chlorobenzo for the purpose of preventing deterioration by light You may add ultraviolet absorbers, such as a triazole.

  The addition amount of all the above additives (other than polyolefin resin and lubricant) is preferably 20% by weight or less of the total amount of the molding raw material as a whole, in order to maintain the supply capability of the lubricant. .

  As the polymer material that can be used in the present invention, any thermoplastic resin that can be injection-molded can be used in addition to those based on the polyolefin resin as described above, and the oil content can be increased. Examples of the material include a polyester-based elastomer.

  Further, the mold for producing the 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, and the upper mold The mold and the lower mold are brought into close contact with each other to form an outer ring, an inner ring, a plurality of tapered rollers interposed between the inner ring and the outer ring, and a gap for storing a retainer for holding the tapered roller. An elastic member is provided on at least one of the upper mold side and the lower mold side, and the upper mold 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. It is also possible to use the mold and the lower mold that are configured to press the outer ring and the inner ring from the axial direction of the tapered roller through the elastic member. By using such a manufacturing die, it becomes possible to manufacture a low-torque lubricant-containing polymer tapered roller bearing.

  In addition, such a manufacturing mold is such that the upper mold and the lower mold are brought into close contact with each other so that the joints of both molds come into contact with each other and an elastic member is provided. In addition, the injection pressure into the gap of the molten polymer can be relieved, and the indentation of the tapered roller can be prevented from being attached to the inner ring outer peripheral part and the outer ring inner peripheral part.

  Since the lubricant-containing polymer-filled tapered roller bearing of the present invention has the above-described configuration, there is no lubricant-containing polymer between the tapered roller end surface and the surface of the inner ring recess on the large flange portion side. Rotates smoothly and shows good lubricity.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a 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 view showing a manufacturing die for 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 manufacturing die for a lubricant-containing polymer-filled tapered roller bearing according to a third embodiment of the present invention. FIG. 4 is a plan view of the upper mold according to the 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 the lubricant-containing polymer of the present invention will be described with reference to FIG.

  As shown in the sectional view of FIG. 1, a lubricant-containing polymer-filled tapered roller bearing 1 according to the present embodiment is a tapered roller which is an outer ring 3, an inner ring 2, and a rolling element interposed between the outer ring and the inner ring. 4, a cage 5 for holding the tapered roller 4, and a lubricant polymer 6. The outer ring 3 and the inner ring 2 form a hollow rotating body having a locus in which the cross-sectional shape shown in FIG. 1 is rotated about the rotation axis II ′. The inner ring 2 has a concave portion that accommodates the tapered roller 4 obliquely on the outer peripheral side, and a portion that accommodates the tapered roller 4 includes 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 collar portion side and a surface 22 on the small collar portion side. On the other hand, the outer ring 3 also has a thick part and a thin part in the radial direction. The cage 5 has a bent portion.

  When the outer ring 3 of the bearing 1 receives a radial load (arrow A in FIG. 1) or a thrust load (arrow B in FIG. 1), the force is transmitted from the outer ring 3 to the tapered roller 4, and from the tapered roller 4 It is transmitted to the inner ring 2. Here, since the end surface of the tapered roller 4 and the surface 21 on the large collar portion side are in sliding contact, it is desirable to make the friction coefficient as small as possible. On the other hand, since the thrust load or the radial load is not applied in the direction from the end face of the tapered roller 4 to the face 22 on the small collar portion side of the inner ring 2, the 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 collar portion side of the recess of the inner ring 2 are in sliding contact with no lubricant-containing polymer interposed therebetween, so that the cone due to the presence of the lubricant-containing polymer is present. There is no problem that the movement of the rollers is obstructed, and the lubricating oil oozes out from the lubricant-containing polymer and is supplied to the sliding contact portion, so that the torque accompanying the rotation of the bearing can be reduced.

(Second Embodiment)
Next, a method for manufacturing a tapered roller bearing filled with the lubricant-containing polymer of 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 12 </ b> A closer to the shaft than the portion that houses the bearing and the portion that houses the bearing. The lower mold 11 has a surface 11A and a surface 11B that face 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 storing the outer ring 3, the inner ring 2, the tapered roller 4, and the cage 5, respectively, when they are in close contact with each other. Yes. The upper mold 12 has a gap for providing an elastic member, and an elastic member 15 is provided in the gap, and the thick part of the outer ring is pressed through the elastic member 15. Yes. In order to inject a molten lubricant-containing polymer (hereinafter referred to as a molten polymer) positioned above the bent portion of the cage 5 and conducted from above to 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.

  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, and a molten polymer is formed on the end portion of the runner portion 18 by an outer ring, an inner ring, a tapered roller, and a cage. An injection gate 13 is provided for injection into the space. At the center of the injection gate 13, a pin gate for injecting a molten polymer is provided. In addition to the example shown in FIG. 4, the runner portion 18 can be circular, but by making it radial rather than circular, the volume of the portion through which the molten polymer is conducted is reduced, thus saving material. In addition, there is an advantage that the injection pressure received by the internal bearing can be reduced.

  As shown in FIG. 5, 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, so that the gas in the gap is driven out of the production mold. It is possible to completely fill the gap with molten polymer.

  Next, a manufacturing method of a lubricant-containing 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 roller 4 and the cage 5 are stored in the lower mold recess. The inner ring 2 is stored so that the thin part is on the upper side of the figure and the thick part is on the lower side of the figure. For the outer ring 3, the thick part is on the upper side of the figure and the thin part is on the lower side of the figure. Store it to the side.

  After storing, the upper mold 12 is brought into close contact with the lower mold 11 so that the upper mold face 12A and the face 12B are brought into close contact with the lower mold face 11A and the face 11B, respectively. In this state, the upper mold 12 and the lower mold 11 are fixed by tightening the screws 16. At this time, the upper mold 12 is brought into contact with the thick portion of the outer ring 3 via the elastic member 15. Thereby, a force is applied from the upper mold 12 to the elastic member 15, 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, Further, transmission from the inner ring 2 to the lower mold 11 causes the lower mold 11 and the thick part of the inner ring 2 to be pressed, whereby the end surface of the tapered roller 4 is brought into contact with the surface 21 on the large collar portion side of the inner ring 2. Pressed. Along with this, a gap of about 0.1 to 0.5 mm is formed between the upper mold 12 and the thin part of the inner ring 2, and between the lower mold 11 and the thin part of the outer ring 3 is 0. A gap of about 1 to 0.5 mm is formed. There is a gap of about 0.5 to 2 mm between the tip of the cage 5 and the upper mold 12 or the lower mold 11.

  When the upper die 12 and the lower die 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 so that the molten polymer enters without gaps. In addition, it has an effect of reducing the injection pressure of the molten polymer into the gap and preventing the outer ring portion of the inner ring 2 and the inner ring portion of the outer ring 3 from being indented by the tapered roller 4. Yes. 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 hits the bent portion of the cage 5, and then is divided between the cage 5 and the inner ring 2 and between the cage 5 and the outer ring 3. To fill the gap.

  By positioning the injection gate 13 above the bent portion of the cage 5, the injected molten polymer flows through the cage 5 to the surface 22 on the small collar side of the inner ring, and the surface on the small collar portion side. A force is applied in a direction in which the upper surface of the tapered roller 4 near 22 is pushed downward. By transmitting this force, a force is applied in a direction in which the end face of the tapered roller 4 is pressed against the face 21 on the large collar portion side, and the contact between the end face of the tapered roller 4 and the face 21 on the large collar portion is more closely adhered. There is an effect to become. This can be achieved by making the mold for attaching the elastic member 15 pressing the thick part of the outer ring and the mold for providing the injection gate 13 both the same upper mold.

  The injection of the molten polymer is preferably a vertical injection molding machine in which production dies are arranged vertically. Compared to the horizontal injection molding machine, the vertical injection molding machine is filled with the molten polymer with the cage biased in the production mold when the outer ring, inner ring, tapered roller and cage are filled and then the molten polymer is filled. In addition, there is an advantage that there is little risk of being solidified and the occupied floor area is small. As the vertical injection molding machine, for example, an injection molding machine described in Japanese Patent Application Laid-Open No. 8-309793 is used, in which a hopper is improved and a mold is arranged in a vertical type.

  On the other hand, FIG. 6 is a comparative example, and the manufacturing mold 30 is different from the second embodiment in that the inner ring 2, the outer ring 3, the tapered roller 4 and the elastic member 152 are stored upside down. Is different. That is, the thick part of the inner ring 2 is above the figure (the face 212 on the large collar part side is upward), the thin part is below the figure (the face 222 on the small collar part side is below), and the thin part of the outer ring 3 is thin. The upper part is thicker and the tapered part of the tapered roller 4 is arranged on the upper side. An injection gate 132 for injecting the molten polymer into the upper mold 122 is provided. An elastic member 152 is attached to the mold 112. That is, the mold for providing the injection gate 132 and the mold for attaching the elastic member 152 are different.

  In this comparative example, when the flow pressure of the injected molten polymer, that is, the injection molding pressure becomes larger than the force with which the elastic member 152 pushes the thick portion of the outer ring 3, the end surface of the tapered roller 4 and the surface on the large collar side A gap is formed between the gap and the lubricant-containing polymer 62.

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

(Third embodiment)
Different manufacturing methods of the 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 part of the outer ring 3, and the lower mold 111 is interposed between the thick part of the inner ring 2 and the elastic member 151. Is different from the second embodiment. That is, the mold for attaching the elastic member 151 that presses the thick part of the inner ring 2 and the mold for providing the injection gate 131 are separately provided in the lower mold 111 and the upper mold 121 on the opposite side.

  Also in the case of the present embodiment, as in the second embodiment, both the force pressed by the elastic member 151 and the pressure caused by the flow of the molten polymer are such that the end surface of the tapered roller 4 is on the large collar side of the inner ring. It works in the direction of pressing against the surface 211 of the. Thus, when the upper mold 121 and the lower mold 111 are fixed, the elastic member 151 presses the surface 211 on the large collar portion side of the inner ring against the end surface of the tapered roller 4 to eliminate the gap between the two. It has the effect of preventing the molten polymer from entering, and further reduces the injection pressure of the molten polymer into the gap to prevent the outer ring of the inner ring 2 and the inner ring of the outer ring 3 from being indented by the tapered roller 4. It also has the effect of

Example 1
In this example, a lubricant-containing polymer having the following composition was used.
Composition (1) High density polyethylene (classified as relatively low molecular weight): 10% by weight
(2) Ultra high molecular weight polyethylene (classified as ultra high molecular weight): 12.5% by weight
(3) Polyethylene wax (classified as wax): 2.5% by weight
(4) Mineral oil: 75% by weight

  First, a tapered roller bearing was assembled by a normal method, and this was degreased and cleaned. Next, spray a fluorine-based mold release agent (Daikin Industries, Ltd., Daifree GA-6010) 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 release agent coating was formed. In this tapered roller bearing, as shown in FIG. 2, the thin part of the inner ring 2 is on the upper side, the thick part is on the lower side, the thick part of the outer ring 3 is on the upper side, and the thin part is on the lower side. The upper mold 12 was brought into close contact therewith and the screw 16 was tightened.

  Next, the lubricant-containing polymer is pumped to a hopper of an injection molding machine (not shown in FIG. 2), and the molten and heated polymer is pressed with a screw from the injection gate 13 formed on the upper mold 12. A molten polymer was injected into the gap. At this time, since gaps are formed between the upper mold 12 and the thin part of the inner ring 2 and between the lower mold 11 and the thin part of the outer ring 3, the molten polymer is also injected into this gap. Is done. The injected molten polymer is cooled and solidified in the production mold 10 so as to approach the mold temperature. Thereafter, the product was taken out from the production mold 10 to obtain a tapered roller bearing for filling a lubricant-containing polymer (inner diameter 120 mm, outer diameter 180 mm, width 38 mm).

  When the obtained tapered roller bearing for filling the polymer containing the lubricant was disassembled and investigated, it was found that the lubricant containing polymer was not filled between the end surface of the tapered roller 4 and the surface 21 on the side of the large collar portion of the inner ring 2. On the other hand, it was observed that the lubricant-containing polymer 6 entered between the end surface of the tapered roller 4 and the surface 22 on the small collar portion side of the inner ring 2. Further, when the inner peripheral surface of the outer ring 3 was observed, there was almost no indentation due to injection, and even if it was slightly observed, it was extremely mild.

(Comparative example)
In the comparative example, as shown in FIG. 6, the tapered roller bearing has a thin portion of the inner ring 2 on the lower side and a thick portion on the upper side, and a thick portion of the outer ring 3 on the lower side and a thin portion on the upper side. A tapered roller bearing for filling a lubricant-containing polymer was obtained in the same manner as in Example 1 except that it was stored in the manufacturing die 30 so as to come to the center.

  When the obtained tapered roller bearing for filling the polymer containing the lubricant was disassembled and investigated, the polymer containing the lubricant was filled between the end surface of the tapered roller 4 and the surface 212 on the large collar portion side of the inner ring 2. 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 on the small collar side of the inner ring 2.

  This is because the end surface of the tapered roller 4 in the vicinity of the surface 212 on the large collar portion side of the inner ring is pushed downward in the figure by the flow pressure of the injected molten polymer, so that the surface 212 on the large collar portion side and the tapered roller 4 A gap is formed between the end face and the lubricant-containing polymer 62 is filled in the gap.

(Starting torque comparison test)
For the bearings obtained in Example 1 and Comparative Example, the starting torque was measured while changing the preload. FIG. 7 is a graph plotting the starting torque of Example 1 when the starting torque of the comparative example at each preload is 100%.

  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 decreased with an increase in the preload.

  As a general rule, tapered roller bearings filled with a lubricant-containing polymer are filled with a lubricant-containing polymer, so that the movement of the tapered roller is hindered and compared to a bearing that is not filled with a lubricant-containing polymer. However, as the preload increases, the contact resistance between the end faces of the tapered rollers and the inner and outer rings increases, and the inhibition 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 of the outer peripheral portion of the inner ring, the friction between the end surface of the tapered roller and the outer peripheral portion of the inner ring is large during rotation. Thus, the starting torque is prevented from approaching the starting torque in the non-filling state as the preload is increased. Therefore, as the relative value of the starting torque, the difference between the first embodiment and the comparative example increases as the preload increases.

It is sectional drawing which shows a part of lubricant containing polymer filling tapered roller bearing based on the 1st Embodiment of this invention. It is a schematic diagram which shows the manufacture metal mold | die of the lubricant containing polymer filling tapered roller bearing based on the 2nd Embodiment of this invention. It is a schematic diagram which shows the manufacture metal mold | die of the lubricant containing polymer filling tapered roller bearing based on the 3rd Embodiment of this invention. It is the top view which looked at the upper metal mold | die based on the 2nd Embodiment of this invention from the upper direction of FIG. It is the bottom view which looked at the lower metal mold | die based on the 2nd Embodiment of this invention from the downward direction of FIG. It is a schematic diagram which shows the manufacture metal mold | die of the lubricant containing polymer filling tapered roller bearing which concerns on a comparative example. It is the figure which showed the change of the relative value of the starting torque accompanying the change of a preload.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lubricant containing polymer filling 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 Lubricant containing 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 portion 21, 211, 212 Large cage Surface 22, 221, 222 on the part side

Claims (2)

An outer ring, an inner ring, a plurality of tapered rollers interposed between the outer ring and the inner ring, a cage that holds the tapered roller, and a space formed by the outer ring, the inner ring, the tapered roller, and the cage. And a lubricant-containing polymer-filled tapered roller bearing comprising:
The inner ring has a concave portion for accommodating the tapered roller on the outer peripheral side thereof, and the concave portion includes a surface on the large collar portion side and a surface on the small collar portion side of the inner ring, and the surface on the large collar portion side. And a tapered roller bearing filled with a lubricant, wherein the end faces of the tapered roller are in sliding contact with no lubricant-containing polymer interposed therebetween. 2. The lubricant-containing polymer-filled tapered roller bearing according to claim 1, wherein the lubricant-containing polymer has a hardness (HD _A ) of 65 or more and 95 or less as measured on a dirometer A scale.

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