JP2016153674A - Segment holder for rolling bearing, and roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of collision noise of holder elements and damage of the holder elements, by more reducing gap fluctuation due to heat expansion of the whole holder.SOLUTION: A segment holder for a rolling bearing contains respective specific base resin, reinforced-fiber material and particulate inorganic filler in a specific amount. In the segment holder, a linear expansion coefficient in a direction parallel with the reinforced-fiber material at room temperature is 0.2×10to 1.2×10/°C, a linear expansion coefficient in a direction vertical thereto is 1.3×10to 4.0×10/°C, a tensile strength is 150 MPa or more, and a Charpy impact strength is 4.0 kJ/mor more.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a segment cage for a rolling bearing constituted by connecting a plurality of cage elements in which pockets for holding the cage are formed in series in the circumferential direction, and more specifically, improvement of the forming material thereof. About. The present invention also relates to a roller bearing in which the segment cage for a rolling bearing is incorporated.

  The rolling bearing generally includes an outer ring, an inner ring, and a plurality of rolling elements disposed between the outer ring and the inner ring, and the rolling elements are held by a cage. As a cage, an integrated cage formed of a single member is usually used. However, large-sized rolling bearings used in wind power generators, steel facilities, construction machinery, etc., require assembly and maintenance. In order to facilitate, a segment cage in which a plurality of cage elements are connected in series in the circumferential direction to form an annular shape may be used.

In this segment cage, since the cage element is made of a resin material, the cage element is thermally expanded due to heat generated during the operation of the bearing, causing a dimensional change, and adjacent cage elements may be stuck together. Also, because the outer ring and inner ring are made of steel, the gap between the cage elements fluctuates due to the difference in thermal expansion coefficient between the steel and the resin material, and the cage elements collide with each other to generate a collision sound or hold The device element may be damaged. In view of such a problem, in Patent Document 1, the linear expansion coefficient of the steel material that forms the inner ring and the outer ring (1.12 × 10 6) is made of a resin material containing a filler that reduces the linear expansion coefficient. have proposed a retainer element to 1.3 × ^{10 -5} /℃~1.7×10 ^-5 / ℃ close to about ^-5 / ° C.).

Japanese Patent No. 4231082

  The filler in Patent Document 1 is carbon fiber or glass fiber, and the linear expansion coefficient is a value in a direction parallel to these fibers. However, since the linear expansion coefficient in the direction perpendicular to the fiber is about 3 to 5 times larger than the linear expansion coefficient in the direction parallel to the fiber, the difference in the linear expansion coefficient between the inner ring and the outer ring is large in the cage element as a whole. There remains considerable room for improvement in gap fluctuation.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the gap fluctuation due to the thermal expansion of the entire cage, thereby preventing the occurrence of collision noise between the cage elements and the breakage of the cage elements.

The above object of the present invention can be achieved by the following constitution.
(1) For rolling bearings that are made of a resin material and have a plurality of cage elements formed with pockets for holding rolling elements, in which circumferential end surfaces are brought into contact with each other to form a cage in the circumferential direction. In the segment cage,
The resin material is
a) Base resin selected from aromatic polyamide resin, polyphenylene sulfide resin, and polyetheretherketone resin b) Glass fiber surface-treated with a silane coupling agent having an epoxy group or amino group, polyamide or epoxy sizing agent At least one type of reinforcing fiber material selected from carbon fibers surface-treated in step c) containing a particulate inorganic filler made of calcium carbonate surface-treated with a silane coupling agent having an epoxy group or amino group, A rolling bearing characterized in that the content of the material is 25 to 40% by mass of the total amount of the resin material, the content of the particulate inorganic filler is 20 to 35% by mass of the total amount of the resin material, and has the following physical properties: Segment cage.
· Linear expansion coefficient at room temperature (reinforcing fiber material parallel direction) is ^{0.2 × 10 -5 /℃~1.2×10 -5 / ℃} (ISO11359-2)
· Linear expansion coefficient at room temperature (reinforcing fiber material and the vertical direction) is ^{1.3 × 10 -5 /℃~4.0×10 -5 / ℃} (ISO11359-2)
-Tensile strength (MPa, ISO527-1, 2) is 150 or more
・ Charpy impact strength (kJ / m ² , ISO179-1) is 4.0 or more
(2) In the rolling bearing segment cage as described in (1) above,
The cage element has a pair of side plate portions arranged in parallel in the axial direction, and a plurality of column portions that connect the pair of side plate portions in the axial direction, and the side plate portion and the column portion The entire cage is formed by forming a pocket, and the radially outer end surface and the radially inner end surface of the side plate portion are parallel to each other and arranged in the circumferential direction. Shape
The difference between the design value of the circumferential dimension of the cage element and the measured value at room temperature is 0.075% or less, and
A rolling cage segment cage, wherein a gap is formed between the inner surface of the pocket and the rolling surface of the cage element so that the cage element can be displaced in the radial direction.
(3) A cylindrical roller bearing comprising the rolling bearing segment cage according to (1) or (2).

  According to the present invention, it is possible to more reliably prevent the collision noise between the cage elements and the damage to the cage elements by further reducing the gap variation of the cage as a whole due to thermal expansion.

It is a schematic diagram which shows an example of a segment holder | retainer. It is a perspective view of the holder | retainer element which comprises the segment holder | retainer shown in FIG. It is a perspective view which shows the other example of a holder | retainer element. FIG. 4 is a circumferential sectional view of the cage element of FIG. 3. FIG. 4 is a side view of the cage element of FIG. 3. FIG. 4 is a plan view of the cage element of FIG. 3. FIG. 4 is a circumferential cross-sectional view of the cage element of FIG. 3 for explaining a radial gap between the guide portion and the cage portion. FIG. 4 is a circumferential sectional view of the cage element of FIG. 3 for explaining the shape of a guide portion. It is a top view which shows the segment holder | retainer which consists of a holder | retainer element of FIG. It is a perspective view which shows the further another example of a holder | retainer element. FIG. 11 is a side view of the cage element of FIG. 10. FIG. 11 is a plan view of the cage element of FIG. 10. It is a principal part enlarged view of FIG. In an Example, it is a schematic diagram which shows the strip-shaped test piece used for the measurement of a linear expansion coefficient.

  Hereinafter, the segment cage for rolling bearings of the present invention (hereinafter, simply referred to as “segment cage”) will be described in detail with reference to the drawings. Here, a segment cage for roller bearings will be described.

  In the present invention, as long as it is composed of a cage element formed of a specific resin material described later, there is no limitation on the shape and structure of the segment cage. For example, the segment cage 20 shown in FIG. Can do. That is, the segment retainer 20 shown in FIG. 1 forms a single cylindrical or conical retainer as a whole by connecting a plurality of retainer elements 21 formed in an arc shape in series in the circumferential direction. . As shown in FIG. 2, each cage element 21 includes a pair of side plate portions 2 and 2 each having an arc shape, and a plurality of column portions 1 and 1 that couple the side plate portions 2 and 2. The roller (see FIG. 4: reference numeral 7) is rotatably held by a portion surrounded by the inner side surfaces of the both side plate portions 2 and 2 and the circumferential side surfaces of the column portions 1 and 1 adjacent in the circumferential direction. Pockets 3 and 3 are formed. Of the inner surfaces of the pockets 3 and 3, the circumferential side surfaces of the column portions 1 and 1 serve as guide surfaces for guiding the rolling surfaces of the rollers. Each column portion 1 is formed with an oil groove 4 that opens radially inward in the axially intermediate portion and penetrates in the circumferential direction. Further, a pair of protrusions 5 and 5 provided in the axial direction are formed in the vicinity of the radially outer side of the side surface 1c of the column part 1 to prevent the rollers from falling off radially outward. Yes. Further, a pair of guide portions 6 and 6 provided at both axial ends are formed in the vicinity of the radially inner side of the column portion 1 to prevent the rollers 7 from dropping off radially inward. And the segment holder | retainer 20 shown in FIG. 1 is formed by making the circumferential direction end surface 1a contact | abut each of the several holder | retainer elements 21 in the circumferential direction.

  In the present invention, the cage element 21 is formed of a resin material. Since the resin material has high strength and low water absorption, an aromatic polyamide resin (for example, polyamide 9T or modified polyamide 6T), polyphenylene sulfide resin, or polyether ether ketone resin is used as the base resin. Of these, polyphenylene sulfide resins and polyether ether ketone resins having lower water absorption are preferable.

  In addition to reinforcing purposes, the resin material is surface-treated with glass fiber surface-treated with a silane coupling agent having an epoxy group or amino group, or with a polyamide or epoxy sizing agent in order to suppress thermal expansion. At least one type of reinforcing fiber material selected from carbon fibers and a particulate inorganic filler made of calcium carbonate surface-treated with a silane coupling agent having an epoxy group or an amino group are blended. Moreover, as the particulate inorganic filling, talc having the same surface treatment can be used. The glass fiber and carbon fiber of the reinforcing fiber are excellent in the effect of suppressing thermal expansion in addition to having a high reinforcing effect.

Further, the particulate inorganic filler has an effect of reducing the directional anisotropy of thermal expansion. As described above, in the resin material containing the reinforcing fiber material, the linear expansion coefficient in the direction perpendicular to the fiber is about 3 to 5 times higher than the linear expansion coefficient in the direction parallel to the fiber. A filler is blended to reduce the directional anisotropy of such thermal expansion. Specifically, the linear expansion coefficient of the reinforcing fibers and parallel, at room temperature (5~35 ℃), 0.2 × 10 -5 /℃~1.2×10 -5 / ℃ (ISO11359-2) and then, the linear expansion coefficient of the reinforcing fiber material and perpendicular direction ^{1.3 × 10 -5 /℃~4.0×10 -5 / ℃} (ISO11359-2). It is preferably small linear both expansion coefficient of the reinforcing fabric and horizontal linear expansion coefficient and the vertical direction, in particular vertical linear expansion coefficient 1.3 × 10 ^-5 /℃~3.0×10 ^{-5 /} ℃ It is preferable to make it.

  In order to satisfy the above linear expansion coefficient and obtain a sufficient reinforcing effect, the content of the reinforcing fiber material is set to 25 to 40% by mass of the total amount of the resin material. When the content of the reinforcing fiber material is less than 25% by mass, it is difficult to achieve a certain strength or more, and the linear expansion coefficient in the parallel direction increases, which is not preferable. When the content of the reinforcing fiber material exceeds 40% by mass, although it is possible to improve the strength and decrease the linear expansion coefficient, it is difficult to mix the particulate inorganic filler more than a certain amount, which is not preferable. Preferably, the content of the reinforcing fiber material is 30 to 35% by mass.

  On the other hand, the content of the particulate inorganic filler is 20 to 35 mass% with respect to the total amount of the resin material. When the content of the particulate inorganic filler is less than 20% by mass, the effect of reducing the directional anisotropy of the linear expansion coefficient is not sufficient, which is not preferable. When the content of the particulate inorganic filler exceeds 35% by mass, the effect of reducing the directional anisotropy of the linear expansion coefficient is sufficient, but this is not preferable because the strength is reduced. Preferably, the content of the particulate inorganic filler is 20 to 30% by mass.

  Further, the total content of the reinforcing fiber material and the particulate inorganic filler is 50 to 70% by mass of the total amount of the resin material, and if it is less than 50% by mass, the effects of the reinforcing fiber material and the particulate inorganic filler are sufficiently obtained. If it exceeds 70% by mass, the moldability deteriorates. Preferably, the total content of the reinforcing fiber material and the particulate inorganic filler is 50 to 60% by mass.

  The average fiber diameter of the reinforcing fiber material is preferably 5 to 15 μm, and the particle diameter of the particulate inorganic filler is preferably 1 to 10 μm. Each of the surface treatment agents for the reinforcing fiber material and the particulate inorganic filler may be a known one.

  The resin material may contain other materials as required.

The cage element 21 is made of the resin material having the specific composition described above, and satisfies the following mechanical strength. Thereby, a favorable holding performance can be maintained.
-Tensile strength (MPa, ISO527-1, 2) is 150 or more, preferably 155 or more
-Charpy impact strength (kJ / m ² , ISO 179-1) is 4.0 or more, preferably 5.5 or more

  By the way, in the cage element 21 shown in FIG. 2, both the radially outer end surface 2a and the radially inner end surface 2b of the side plate portions 2 and 2 are arcuate in order to form the segment cage 20 shown in FIG. Therefore, a specially shaped mold is required.

  Therefore, like the cage element 21 shown in FIGS. 3 to 8, the radially outer end surface 2a and the radially inner end surface 2b of the side plate portion 2 are parallel to each other, that is, as shown in FIG. Parallel straight lines. Further, as shown in FIG. 5, the circumferential end faces 1a and 1a of the cage element 21 are formed so as to form a predetermined inclination angle C from the radially outer side to the inner side in accordance with the cage division number. In addition, as shown in FIG. 6, the circumferential end faces 1 a and 1 a of the cage element 21 have a predetermined inclination angle from one axial direction to the other depending on the number of cage divisions and the shape of the cage 20. D is formed.

  In addition, as shown in FIG. 4, it is preferable that the relationship between the width A between the protrusions 5 and 5 facing in the circumferential direction in the column portions 1 and 1 and the diameter d of the roller 7 satisfies A <d. Moreover, it is preferable that the relationship between the width B between the guide portions 6 and 6 facing in the circumferential direction in the column portions 1 and 1 and the diameter d of the roller 7 satisfies B <d. Thereby, the roller 7 is reliably held in the pocket 3 without falling off.

  Further, the protrusion 5 and the guide 6 of the column part 1 are formed in a shape along the rolling surface of the roller 7. That is, in the illustrated cage element 21, three pockets 3 are formed, but one central pocket 3a disposed at the center and two end pockets 3b disposed on both sides in the circumferential direction of the central pocket 3a. Then, the shapes of the protrusion 5 and the guide 6 are changed. Specifically, as shown in FIGS. 7 and 8, the central pocket 3 a is provided with projections 5 a and 5 a that are formed short toward the inside in the radial direction so as not to disturb the rolling of the rollers 7. ing. Further, the guide surfaces 6 a and 6 a of the guide portion 6 in the central pocket 3 a are formed in a shape along the conical trapezoid 8 by a radius of curvature along the conical trapezoid 8 larger than the rollers 7. On the other hand, in the end pocket 3b, the protrusion 5b on the central side that is formed long inward in the radial direction so as to prevent the roller 7 from falling off, and the radial direction so as not to disturb the rolling of the roller 7. And an end-side protruding portion 5b ′ that is formed shorter toward the inside. Further, the guide surface 6b on the center side of the guide portion 6 and the guide surface 6b 'on the end portion side in the end pocket 3b have a radius of curvature along the truncated cone 8 and are centered around the rotation axis of the rolling bearing. It is formed in a shape along a truncated cone 8 rotated by a predetermined width from 3a. Thus, the protrusions 5a, 5b, 5b ′ and the guide surfaces 6a, 6b, 6b ′ are arranged along the rolling surface of the roller 7 disposed between the outer ring raceway surface 70 and the inner ring raceway surface 80 of the bearing. The roller 7 can be reliably guided by being formed into a simple shape.

  In addition, as shown in FIG. 7, it is preferable to provide a gap e in the pocket 3 between the guide portion 6 and the rolling surface of the 7 so that the cage element 21 can be displaced in the radial direction. As a result, even when the cage element 21 expands in the circumferential direction due to a temperature rise, water absorption, or the like, the cage element 21 can be displaced in the outer diameter direction within the range of the gap e. , 21 can be reduced, and distortion of the pocket 3 and breakage of the cage element 21 can be prevented.

  Then, as shown in FIG. 9, a plurality of cage elements 21, 21 are connected in series with their circumferential end faces butting in the circumferential direction, thereby forming a segment holder 20 having a substantially polygonal truncated cone shape.

  Here, in order for the cage elements 21 to be connected without gaps, assuming that the cage elements 21 have the same shape, the circumferential dimension H thereof is the inner and outer rings of the rolling bearing in which the segment cage 20 is used. , The roller size and number of the rollers 7, the gap between the pockets 3 and 7, the thickness of the segment cage 20, and the number of cage elements 21 are determined geometrically. The circumferential dimension H of the cage element 21 thus determined geometrically is referred to as “design value”. And with respect to this design value, it is preferable that the circumferential dimension of the actual cage element 21 at room temperature is 0.075% or less in absolute value. Thereby, the several retainer element 21 and 21 can be continued in the circumferential direction without a clearance gap substantially.

In addition, the cage element 21 can be variously modified, for example, as shown in FIG.
You may make it provide the protrusion part 9 which protrudes in the circumferential direction from the circumferential direction end surface 1a. As shown in FIG. 11, the circumferential end surface 1 a is formed so as to form a predetermined inclination angle F from the radially outer side to the inner side in accordance with the number of cage elements 21. Further, as shown in FIG. 12, the circumferential end surfaces 9 a and 9 a of the projecting portion 9 have a predetermined direction from one side in the axial direction to the other depending on the number of cage elements 21 and the shape of the segment cage 20. An inclination angle G is formed. Furthermore, the protrusion part 9 has the axial direction inner side end surface 9b which inclines continuously from the circumferential direction end surface 9a to the circumferential direction end surface 1a of the retainer element 21. As shown in FIG. 13, the axially inner end surface 9 b is formed so as to be positioned on the axially inner side with respect to the axially inner end surface 2 c of the side plate portion 2.

  As described above, in the cage element 21 having the protruding portion 9, the collision load of the adjacent cage elements 21 and 21 can be received by the protruding portion 9 when the segment cage 20 is formed. Therefore, when the adjacent cage elements 21, 21 collide with each other, the stress that may be generated at the corners of the pocket 3 due to the deformation of the column part 1 can be relieved by the protruding part 9.

  The cage element 21 described above can be manufactured by injection molding a resin composition containing a base resin, a reinforcing fiber material, a particulate inorganic filler, and various additives as required. Also excellent.

  The present invention also relates to a roller bearing in which the roller is held by the segment holder 20 described above. As described above, since the cage element 21 hardly causes a collision due to thermal expansion and is excellent in durability, the roller bearing incorporating the retainer element 21 is also excellent in durability.

  The present invention will be further described below with reference to examples, but the present invention is not limited thereto.

(Examples 1-3, Comparative Examples 1-3)
A resin composition was prepared with the composition shown in Table 1, and injection molded to produce a rod-shaped molded body. Then, judging from the position of the gate, the rod-shaped molded body was cut to produce a strip-shaped test piece. That is, assuming that the reinforcing fiber material is oriented along the injection direction from the gate, as schematically shown in FIG. 14, the long side S1 of the strip-shaped test piece S is set in a direction parallel to the reinforcing fiber material 100, The strip-shaped test piece S was processed so that the short side S2 was in a direction perpendicular to the reinforcing fiber material 100.

  And the linear expansion coefficient (linear expansion coefficient in a direction parallel to the reinforcing fiber material) along the long side S1 of this strip-shaped test piece S and the linear expansion coefficient (direction perpendicular to the reinforcing fiber material) along the short side S2 Linear expansion coefficient). The measurement results are also shown in Table 1.

  In addition, the same resin composition was injection-molded to prepare a test piece for tensile test and a test piece for Charpy impact test. The tensile test was performed according to ISO527-1, 2 for the tensile test and the tensile strength and test according to ISO179-1 for the Charpy impact test. Charpy impact strength was measured. The measurement results are also shown in Table 1.

  Furthermore, the same resin composition was injection-molded to form a cage element having the structure shown in FIG. 3, and this was connected in the circumferential direction to produce a segment cage. The difference between the circumferential dimension at normal temperature and the design value was 0.07%. Then, after incorporating the segment cage into the roller bearing and rotating the ambient temperature at 50 ° C. or 80 ° C. for 1000 hours, the segment cage is observed, and the durability from the damaged state such as the presence or absence of cracks in the cage element is increased. evaluated. The results are also shown in Table 1.

As shown in Table 1, in the examples containing the base resin, the reinforcing fiber and the particulate inorganic filler, and in the range defined by the present invention in both the parallel direction and the vertical direction, the tensile strength is 150 MPa or more. The Charpy impact strength is 4.0 kJ / m ² or more. Moreover, regarding durability, neither 50 degreeC nor 80 degreeC has cracked.

  On the other hand, in Comparative Example 1.2, the resin material does not include the particulate inorganic filler, and is larger than the linear expansion coefficient defined in the present invention in both the parallel and vertical directions with respect to the reinforcing fiber material. Further, although durability at 50 ° C. is not a problem, the cage element is cracked at 80 ° C., which is more severe, and the durability is inferior.

  Further, in Comparative Example 3, the content of the particulate inorganic filler is larger than that of the example, and the linear expansion coefficient is lower than that of the example both in the parallel direction and in the vertical direction with respect to the reinforcing fiber material. The decrease in the expansion coefficient is remarkable. This shows that the particulate inorganic filler is effective in reducing thermal expansion. However, the durability at 80 ° C. is inferior to that of the examples, which is because the content of the particulate inorganic filler exceeds the upper limit of the range defined in the present invention. That is, the particulate inorganic filler is effective in reducing the directional anisotropy of thermal expansion, but if it exceeds the specified amount, the strength is lowered and the durability is lowered, which is not preferable.

DESCRIPTION OF SYMBOLS 1 Column part 2 Side plate part 2a Radial direction outer side end surface 2b Radial direction inner side end surface 3 Pocket 5 Projection part 6 Guide part 7 Roller 9 Protrusion part 20 Segment holder 21 Cage element 70 Outer ring raceway surface 80 Inner ring raceway surface

Claims (3)

A segment cage for rolling bearings, which is made of a resin material and has a plurality of cage elements in which pockets for holding rolling elements are formed. In
The resin material is
a) Base resin selected from aromatic polyamide resin, polyphenylene sulfide resin, and polyetheretherketone resin b) Glass fiber surface-treated with a silane coupling agent having an epoxy group or amino group, polyamide or epoxy sizing agent At least one type of reinforcing fiber material selected from carbon fibers surface-treated in step c) containing a particulate inorganic filler made of calcium carbonate surface-treated with a silane coupling agent having an epoxy group or amino group, A rolling bearing characterized in that the content of the material is 25 to 40% by mass of the total amount of the resin material, the content of the particulate inorganic filler is 20 to 35% by mass of the total amount of the resin material, and has the following physical properties: Segment cage.
· Linear expansion coefficient at room temperature (reinforcing fiber material parallel direction) is ^{0.2 × 10 -5 /℃~1.2×10 -5 / ℃} (ISO11359-2)
· Linear expansion coefficient at room temperature (reinforcing fiber material and the vertical direction) is ^{1.3 × 10 -5 /℃~4.0×10 -5 / ℃} (ISO11359-2)
-Tensile strength (MPa, ISO527-1, 2) is 150 or more
・ Charpy impact strength (kJ / m ² , ISO179-1) is 4.0 or more The segment cage for rolling bearings according to claim 1,
The cage element has a pair of side plate portions arranged in parallel in the axial direction, and a plurality of column portions that connect the pair of side plate portions in the axial direction, and the side plate portion and the column portion The entire cage is formed by forming a pocket, and the radially outer end surface and the radially inner end surface of the side plate portion are parallel to each other and arranged in the circumferential direction. Shape
The difference between the design value of the circumferential dimension of the cage element and the measured value at room temperature is 0.075% or less, and
A segment cage for a rolling bearing, characterized in that a radially displaceable gap is formed between the pocket inner surface and the rolling surface of the cage element.   A roller bearing comprising the segment cage for a rolling bearing according to claim 1.

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