JPH08303466A - Rolling bearing - Google Patents

Abstract

PURPOSE: To well perform holding of lubricant between a spacers and rollers, so as to enable the smooth rotation to be maintained for a long period. CONSTITUTION: Rolling elements 3 consisting of cylindrical rollers are interposed between an inner ring 1 and an outer ring 2. Spacers 4 for keeping the distance between all the rolling elements 3 are interposed between all the rolling elements 3 arranged in the circumferential direction. Lubricant holding recessed parts 5 are provided on recessed cylindrical surface-shaped roller contact surfaces 4a of respective spacers 4. Each recessed part 5 may be formed into a single groove, a plurality of grooves or an unperforated hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing generally used for various industrial machines, construction machines and other equipment, and more particularly to a cylindrical roller bearing of a type in which a spacer is interposed between rolling elements instead of a cage. Etc. related to rolling bearings.

[0002]

2. Description of the Related Art In a cylindrical roller bearing, as shown in FIG. 6, as a means for maintaining the distance between the rollers 73 between the inner and outer races 71, 72, there is a spacer 74 instead of a cage. The spacer 74 is formed in a substantially prismatic shape as shown in FIG. 7B, and the rolling element contact surface 74a that contacts the roller 73 is a concave cylindrical surface. The radius of curvature of the rolling element contact surface 74a is
It is usually larger than the radius of curvature of 3, and a lubricant such as grease is retained in the space of the difference in curvature.

[0003]

Due to the sliding of the rollers 73 and the force in the circumferential direction, the rolling element contact surface 74a of the spacer 74 is worn or deformed. If the lubricant is insufficient in this state, the contact surface 74a is greatly worn. As a result, the gap in the circumferential direction increases, and the guide of the roller 73 becomes insufficient, which hinders smooth rotation of the bearing.

An object of the present invention is to provide a rolling bearing capable of favorably retaining a lubricant between a spacer and a rolling element and maintaining smooth rotation for a long period of time.

[0005]

A bearing according to the present invention is a rolling bearing in which a spacer is interposed between rolling elements that are circumferentially adjacent to each other, and a lubricant retaining recess is provided on a rolling element contact surface of the spacer. It is a thing. The rolling bearing may be a cylindrical roller bearing, and in this case, the spacer has concave cylindrical surface contact surfaces on both sides. Further, the rolling element may be spherical, and the spacer may have concave spherical contact surfaces on both sides.

[0006]

[Function] Even if the lubricant is retained in the lubricant retaining concave portion of the spacer and the amount of the peripheral lubricant is reduced, the lubricant of the concave portion is supplied to the contact surface by sliding of the rolling element and the spacer. Be done.
Therefore, the frictional resistance between the spacer and the rolling elements is kept small.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG. In this rolling bearing, a rolling element 3 composed of a cylindrical roller is interposed between an inner ring 1 and an outer ring 2, and a spacer 4 is interposed between rolling elements 3 arranged in the circumferential direction so that the distance between the rolling elements 3 is increased. In the cylindrical roller bearing to be kept, a lubricant retaining recess 5 is provided on the rolling element contact surface 4a of each spacer 4. The outer ring 2 has both flanges, and the inner ring 1 is a single flange and has a flange ring 1A attached. In addition, the inner ring 1 may have both flanges, and the outer ring 2 may have one side flange to which side wheels are attached.

As shown in FIG. 1 (C), the spacer 4 has a substantially prismatic shape, and both side surfaces thereof are formed as rolling element contact surfaces 4a having a concave cylindrical surface shape. The material of the spacer 4 may be metal or resin, and a suitable material example will be described in detail later. In this example, the lubricant retaining recess 5 is a plurality of grooves extending in the cylindrical axis direction, but it may be a non-through hole. Further, the number of grooves and holes is not limited to two, and may be one or three or more.

2A to 2F show a lubricant holding recess 5
It is a perspective view of the spacer 4 which shows each modification of. In the example of FIG. 2 (A), the rolling element contact surface 4a is provided with a pair of grooves that are inclined with respect to the cylindrical axis in a V-shape to form the lubricant retaining recess 5. In the example of FIG. 2B, a plurality of grooves inclined in the same direction with respect to the cylinder axis are used as the lubricant retaining recess 5. In the example of FIG. 2C, a pair of grooves intersecting with each other is used as the lubricant retaining recess 5. In the example of FIG. 2D, a plurality of grooves extending in the circumferential direction of the cylindrical surface are used as the lubricant retaining recess 5. In the example of FIG. 2E, the rolling element contact surfaces 4a, 4 on both sides are
The round hole-shaped recessed portion provided in a is used as the lubricant retaining recess 5. In the example of FIG. 2 (F), the fine grooves parallel to the cylindrical axis direction are densely arranged on the entire surface of the rolling element contact surface 4a, and the lubricant retaining recess 5 is formed.
There is. It is presumed that the pair of groove shapes intersecting with each other as shown in FIG. 2C can uniformly supply the lubricant evenly to the sliding surface between the spacer 4 and the rolling elements with a small number of grooves. Further, since the number of grooves is small, it may be possible to reduce the contact surface pressure of the sliding surface.

The cross-sectional shape of the groove to be the lubricant holding recess 5 is
For example, as shown in FIGS. 3A to 3I, various cross-sectional shapes can be used. That is, it can be a V-shaped section (A), a rectangular section (B), a trapezoidal section (C), an arcuate section (D), a vertical elliptical arc section (E), a lateral elliptical arc section (F), and the like. The cross-sectional shapes (G) to (I) having chamfered portions at the groove opening edges of these cross-sectional shapes can be used. Since the groove to be the lubricant holding concave portion 5 is formed by the ridge on the molding surface of the mold, it may have a cross-sectional shape that makes it easy to process the ridge of the mold. The groove width B and the depth H are preferably dimensioned so that they can be molded by injection molding, and the groove width B is about 0. A range of about 001 to 0.1 times is preferable, and about 0.0
It is estimated that the range of about 1 to 0.05 times is most preferable. Further, it is estimated that the depth H is most preferably in the same range as the groove width B. When the grooves to be the lubricant holding recesses 5 are densely arranged as shown in FIG. 2 (F), it is preferable that the distance between the adjacent grooves is about the same as the groove width B. If the groove width and groove depth are too large, the contact surface pressure at the sliding part between the spacer and the rolling element will be high, which may cause wear and lead to a decrease in strength. It is considered that the lubricating effect of grease, lubricant, etc. cannot be expected.

According to this structure, the lubricant such as grease is held in the lubricant holding concave portion 5 of the spacer 4, and even if the amount of the surrounding lubricant decreases, the lubricant in the concave portion 5 and the rolling element 3 and the spacer By sliding with 4, it is supplied to the contact surface. Therefore, the frictional resistance between the spacer 4 and the rolling elements 3 is maintained small. Further, since the frictional resistance is small, abrasion is unlikely to occur and the increase in the gap can be suppressed to a low level. Therefore, the spacer 4
The proper guide of the rolling element 3 by the rolling element contact surface 4a is maintained for a long period of time.

FIG. 4 shows another embodiment of the present invention. This embodiment is an example applied to a thrust spherical roller bearing. A rolling element 23 composed of barrel-shaped rollers is interposed between the inner ring 21 and the outer ring 22, and a spacer 24 is interposed between the rolling elements 23 arranged in the circumferential direction. The spacer 24 has substantially the same shape as that of the cylindrical roller bearing of FIG. 1, but the rolling element contact surfaces 24a on both sides of the spacer 24 are spherical according to the outer diameter surface of the barrel-shaped rolling element 23. It is formed on. This rolling element contact surface 2
A lubricant holding recess 5 is formed in 4a. The lubricant retaining recess 5 may have the various configurations described above with reference to FIGS. Note that θ indicates the centering angle. Also in this configuration, the lubricant retained in the lubricant retaining recess 5 of the spacer 24 can provide a good lubricating function for a long period of time.

FIG. 5 shows still another embodiment of the present invention. This example is an example applied to a swivel bearing. Inner ring 41
A large number of rolling elements 43 made of steel balls are arranged between the outer ring 42 and the outer ring 42, and a spacer 44 is interposed between the adjacent rolling elements 43, 43. The outer ring 42 is formed with a bolt hole 50 for attachment to a pedestal, and the inner ring 41 is integrally formed with an internal gear 47 which meshes with a pinion 46 for turning drive. The inner race 41 and the outer race 42 have rolling elements 4
The annular raceway grooves 48 and 49 for rolling the 3 are formed so as to face each other, and the rolling elements 43 and the spacers 44 are arranged in the raceway grooves 48 and 49. The spacer 44 is formed in a cylindrical shape, and the rolling element contact surfaces 44a having a concave spherical surface are formed on both surfaces.
The lubricant retaining recess 5 is formed on these rolling element contact surfaces 44a. The lubricant holding concave portion 5 can have various shapes described above with reference to FIGS. Also in this configuration, the lubricant held in the lubricant holding recess 5 of the spacer 44
A good lubricating function can be obtained over a long period of time.

Next, an example of a preferable material when the spacer 4 in each of the embodiments is made of metal will be described. When the spacer 4 is made of metal, a copper alloy is preferable, and in addition to this, carbon steel for mechanical structure such as S30C can also be used. Copper-based metals such as brass are preferable because they have relatively better sliding characteristics than general steel, are soft, and can be easily forged or pressed.
The method of forming the lubricant retaining recess 5 formed of a groove in the copper alloy is not particularly limited, such as cutting, cold forging, and hot forging.
Recesses that do not require relatively high precision, such as the groove width B or the groove depth H, are about 0.01 to 0.1 times the diameter of the rolling element, or about 0.01 to 0.05 of the diameter of the rolling element. If it is more than twice, form a part corresponding to the groove in the mold of the spacer,
As a mold, when molding a spacer, the groove can be efficiently formed at the same time when the spacer is molded. If precision is not particularly required, post-processing or the like for increasing the precision of the groove may be omitted. However, if the rolling element has a relatively small diameter, and if the above-mentioned groove requires a certain degree of accuracy, it is estimated that the groove can be relatively easily and efficiently formed by forging. To be done. In this case, spacer 4
Can be formed, for example, by casting in a shape having no lubricant retaining recess 5, or by casting or the like in such a shape that a post-processing is possible, for example, a shallow recess smaller than a multiple of the above numerical value is formed. For example, the material having this shape may be annealed, and then a groove serving as the lubricant retaining recess 5 may be formed by forging or pressing. This groove forming method is particularly effective for the following high strength brass castings. The above-mentioned annealing process is carried out to eliminate distortion when accuracy is required, but this process may be omitted. As the copper-based metal used for the spacer 4, brass is preferable, and among these, 64 brass and high strength brass are preferable. The high-strength brass is made by adding 0.1 to 5.0% of manganese (Mn) to hex brass and, if necessary, slightly adding components such as Al, Fe, Sn, and Ni. It becomes stronger due to solid solution in the α phase and β phase, and the corrosion resistance and wear resistance are also increased.

High-strength brass castings are classified as JIS Class 1 (H
B _S C1), 1 type C (HB _S C1C), 2 types (HB _S C
2) 2 types C (HB _S C2C), 3 types (HB _S C3),
3 types C (HB _S C3C), 4 types (HB _S C4), 4 types C
(HB _S C4C) are classified into eight types. Its chemical composition is shown in Table 1. Besides this, Sn, Ni, Pb,
In some cases, a small amount of components such as Si may be included. In addition, 1 kind C is 1 kind, 2 kinds C is 2 kinds, 3 kinds C is 3 kinds, and 4 kinds C is 4 kinds.
It has the same ingredients as the seeds.

[0016]

[Table 1]

Of these, Type 1 and Type C have high strength and hardness, good corrosion resistance, and are also used in bearing cages. Class 2 and Class C have high strength and good wear resistance, and are also used in bearing cages. 3 types and 3 types C
Has particularly high hardness and good wear resistance, and is used for low-speed, high-load sliding parts and the like. Type 4 and Type 4 C have higher strength and hardness than Type 3, have good wear resistance, and are used for low-speed, high-load sliding parts and the like. Brinell hardness (H
In terms of hardness in B), Type 1 and Type C are 90 or more, 2
100 or more for species and 2 species C, 16 for 3 and 3 species C
5 or more, 4 types and 4 types C are 200 or more. When the compression strength is expressed in Kgf / mm ² , 1 type is 19.0 and 1 type is 1
9.5, 2 types 25.0, 3 types 39.0, 4 types 4
It is 7.0.

The high-strength brass casting used for the spacer 4 in the present invention and the examples may be any of the above-mentioned ones, and any one of the above-mentioned appropriate components may be selected depending on the size of the bearing and the operating conditions. To do. That is, as components, 55 to 65% of copper (Cu) and 22 to 42 of zinc (Zn) are included.
%, Manganese (Mn) may be contained in an amount of 0.1 to 5.0%. Of these, the Brinell hardness (HB) is approximately 90-
Brass and high strength brass castings of about 130 are very soft compared to about HB200 of S45C and about 130 of S30C which are carbon steel for machine structural use before quenching. Therefore, it is considered that it is easy to form the groove to be the lubricant retaining recess 5 by cold or hot forging, particularly hot forging or press working. The relationship between the mechanical properties and the temperature of the high strength brass casting is such that one of the above-mentioned ones has a Brinell hardness (HB) of about 97 at 0 ° C. to room temperature and about 94 at 100 ° C. It becomes soft at about 85 ° C and about 80 at 210 ° C. Hot forging is a forging performed by heating a material in a temperature range of a recrystallization temperature or more and a solidus temperature or less, but because of the relationship between the temperature and the altitude as described above, it is not a hot forging,
It is considered that the groove serving as the lubricant retaining recess 5 can be easily formed by forging or pressing while heating to some extent. Since high-strength brass castings have a narrow solidification temperature range, it is essentially difficult to generate finely dispersed shrinkage cavities like bronze castings. A sound casting can be obtained if sufficient consideration is given to temperature and the like. High strength brass castings are much less sensitive to wall thickness than bronze castings.

An example of the material when the spacer 4 of each of the above-mentioned embodiments is made of resin will be described. The resin used for the spacer 4 is preferably a resin that can be injection-molded, and even if fibers and other fillers are mixed, a composition that allows injection-molding is sufficient. Generally, the resin material is considered to be preferable because the resin material has more or less lubricating properties in itself. Examples of the resin material suitable for the spacer include the following materials. That is, as the fluororesin, polytetrafluoroethylene (PTFE), tetrafluoroethylene-
Perfluoroalkyl vinyl ether copolymer (PF
A), tetrafluoroethylene-ethylene copolymer (ETFE) or the like is used, and polyamide (Nanron 66, nylon 6), cloth-containing phenol resin or the like can also be used. In addition, a composition obtained by adding an organopolysiloxane elastomer and a fibrous reinforcing material to a polyphenylene sulfide resin, or a polycyanoaryl ether resin such as polyether nitrile as a main component, a tetrafluoroethylene resin, graphite, glass A material to which an appropriate amount of filler such as fiber is added can be used.

Further, a perfluoroalkoxy resin containing a heat resistant fiber is also preferable, and the heat resistant fiber is 5 to 40% by weight.
And 30 to 90% by weight of perfluoroalkoxy resin,
One or more powder additive materials 5 to 3 selected from molybdenum powder, molybdenum compound powder and calcium compound powder
A composition containing 0% by weight is also preferable. Specific examples of the heat-resistant fiber in this case, glass fiber, carbon fiber, graphite fiber, wollastonite, potassium titanate whiskers, silicon carbide whiskers, inorganic fibers and whiskers such as sapphire whiskers, steel wire, copper wire Examples include metal fibers such as stainless wires, tungsten fibers or carbon fibers, so-called boron fibers obtained by vapor deposition of polon, silicon carbide, etc., composite fibers such as silicon carbide fibers, and heat-resistant organic fibers such as aromatic polyimide fibers. I can. From the viewpoint of ease of injection molding, the form of the fiber is preferably a fibrous powder having a length of 10 mm or less, preferably 6 mm or less and a diameter of 2 to 15 μm. It is also desirable to treat the fibers with a treating agent such as a silane coupling agent for the purpose of increasing the affinity between the fibers and the resin.

The molybdenum compound powder in this composition is various molybdenum divalent to hexavalent compounds such as molybdenum disulfide and molybdenum trioxide. Examples of the calcium compound powder include calcium fluoride, calcium carbonate, calcium oxide and the like. The particle size of the above powder and molybdenum powder is preferably 50 μm or less in order to improve the mechanical durability and lubricity of the spacer. Here, the amount of the heat-resistant fiber added to the perfluoroalkoxy resin is 10 parts by weight of the entire component.
0 is preferably 50 to 95% by weight of perfluoroalkoxy resin and 5 to 50% by weight of heat resistant fiber,
Particularly, it is more preferable that the perfluoroalkoxy resin is 60 to 90% by weight and the heat resistant fiber is 10 to 40% by weight.
This is because when the amount of the heat-resistant fiber added is less than 5% by weight, improvement in mechanical properties and abrasion resistance of the composition can hardly be expected, and when it is more than 50% by weight, moldability deteriorates. This is because it is not preferable because it causes deterioration of mechanical properties. Furthermore, when one or more powder fillers selected from molybdenum powder, molybdenum compound powder and calcium compound powder are added to the above two components, the compounding ratio is 5 to 40% by weight of heat resistant fiber, 30 to 90% of perfluoroalkoxy resin. Powder filler is 5 to 30% by weight with respect to% by weight. Because the amount of powder filler added is 5% by weight
If it is less than 30% by weight, the lubricity is not improved, and if it exceeds 30% by weight, the mechanical durability of the spacer is not preferable.

Further, various fillers other than the above may be added. Generally, the amount added is preferably 10% or less of the total amount. As such fillers, aromatic polyetherketone resins, polyetherimide resins, polyethersulfone resins, polyamideimide resins, polyphenylene sulfide resins, heat resistant polyamide resins, phenolic resins, aromatic polyester resins, heat Starting with organic heat-resistant polymer materials such as plastic polyimide resin, silicone resin, fluorine-based resin, graphite or zinc, aluminum, inorganic powder for improving heat conduction such as metal or oxide such as magnesium, glass beads, silica balloon, Omiaceous earth, asbestos, inorganic powder such as magnesium carbonate, graphite, carbon, mica, inorganic powder for improving lubricity such as talc, and iron oxide, cadmium sulfide, cadmium selenide, inorganic pigments such as carbon black, silicone oil, S Ruoiru, fluorine oil, polyphenylene ether oils, waxes, can be exemplified a number of things such as internal lubricant additives, such as zinc stearate. The mixing method of the above-mentioned perfluoroalkoxy resin, fibrous reinforcing material and other additives is not particularly limited, and after heat-mixing with a mixer such as a Henschel mixer, a ball mill or a tumbler mixer, heat For example, pellets may be formed as a molding material by melt-mixing with a roll, a kneader, a Banbury mixer, a melt extruder, etc., and this may be melt-molded into a predetermined shape as a spacer by an injection molding machine or the like. Molding conditions are not particularly limited, and may be carried out under normal molding conditions of perfluoroalkoxy resin.

As a molding method in the case of this composition, each material is dry blended at a predetermined ratio and then fed to a twin-screw melt extruder at 360 ° C. and a screw rotation speed of 150 rp.
While extruding from a strand die having 5 holes with a diameter of 3 mm while melt-kneading at m, pellets are produced by continuously cutting the extruded strands, and the obtained pellets are injection-molded (barrel temperature 320 to 380 ° C., A method of molding into a predetermined spacer shape by applying a mold temperature of 210 ° C. and an injection pressure of 800 kg / cm ² can be adopted. By adopting the injection molding method as described above, it is possible to relatively easily form the lubricant retaining recess shape in the spacer.

[0024]

According to the present invention, in a rolling bearing in which a spacer is interposed between rolling elements adjacent to each other in the circumferential direction, a lubricant retaining recess is provided on the rolling element contact surface of the spacer, so that the surrounding lubricant is reduced. Then, the lubricant retained in the recess is supplied to the contact surface, and smooth rotation is maintained for a long period of time. Particularly in the case of a cylindrical roller bearing, smooth rotation can be effectively maintained by forming such a lubricant retaining recess. Further, even when the rolling element is spherical, the smooth rotation can be effectively maintained by forming the lubricant retaining recess.

[Brief description of drawings]

1A is a partially cutaway front view showing a rolling bearing according to an embodiment of the present invention, FIG. 1B is a partially cutaway side view thereof, and FIG. 1C is an enlarged perspective view of a spacer thereof.

2A to 2F are perspective views showing various modified examples of a lubricant holding recessed portion of a spacer.

3A to 3I are cross-sectional views showing various modified examples of the cross-sectional shape of the lubricant retaining recess of the spacer.

FIG. 4 is a sectional view of a bearing according to still another embodiment of the present invention and an enlarged perspective view of a spacer thereof.

5A and 5B are a plan view, an enlarged sectional view, a sectional view of a spacer thereof, and a perspective view of the spacer according to still another embodiment of the present invention.

FIG. 6 is a partially cutaway front view of a conventional example and an enlarged perspective view of a spacer thereof.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inner ring, 2 ... Outer ring, 3 ... Rolling element, 4 ... Spacer, 4a ... Rolling element contact surface, 5 ... Lubricant holding recess, 24, 34, 44 ...
Spacers, 24a, 34a, 34b, 44a ... Roller contact surface

Claims (3)

[Claims] 1. A rolling bearing in which a spacer is interposed between rolling elements adjacent to each other in the circumferential direction, wherein a rolling bearing contact surface of the spacer is provided with a lubricant retaining recess. 2. The rolling bearing is a cylindrical roller bearing,
2. The rolling bearing according to claim 1, wherein the spacer has a concave cylindrical surface-shaped rolling element contact surface on both sides. 3. The rolling bearing according to claim 1, wherein the rolling element has a spherical shape, and the spacer has a concave spherical contact surface on both sides.