JP2010190292A - Rolling bearing device and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing device facilitating incorporation to a shaft and simplifying a structure. <P>SOLUTION: A bolt insertion through hole 27 penetrating in an axial direction is formed at an inner ring 21 of the rolling bearing 2, and the inner ring 21 is fixed on a main shaft 3 by a bolt 28 inserted through the bolt insertion through hole 27. The bolt insertion through hole 27 comprises a first hole part 27a formed in a range from an axial direction one side to a middle before heat treatment of the inner ring 21, and a second hole part 27b with a smaller hole diameter than the first hole part 27a, formed to communicate with the first hole part 27a from an axially another side after heat treatment. The bolt 28 is inserted through the bolt insertion through hole 27 from the second hole part 27b side and screwed in a main shaft 3 at the first hole part 27a side with a head part 28a positioned on the second hole part 27b side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rolling bearing device used for rotatably supporting a main shaft provided with a blade, for example, in a wind power generator, and a manufacturing method thereof.

  Patent Document 1 below discloses a technique related to a main shaft support structure of a wind power generator. The wind power generator includes a main shaft having a blade at one end, and the main shaft is rotatably supported by a rolling bearing.

  FIG. 5 is a cross-sectional explanatory view of a conventional rolling bearing device for supporting a main shaft. The rolling bearing 102 used in this rolling bearing device is a double-row tapered roller bearing, and includes an inner ring 121 having two rows of inner ring raceway surfaces on the outer periphery and two outer rings having one row of outer ring raceway surfaces on the inner periphery. 122, and two rows of tapered rollers 123 disposed between the inner ring raceway surface and the outer ring raceway surface. The outer ring 122 has an outer peripheral surface fitted to the fitting surface 141 a of the axle box 104, one axial side surface abuts on the inner side surface 142 a of the axle box 104, and the other axial side surface is the axle box 104. And a holding ring 143 fixed by a bolt 144. The inner ring 121 has an inner peripheral surface fitted to the outer peripheral surface of the main shaft 103, one axial side surface is in contact with the large diameter portion 103 a of the main shaft 103, and the other axial side surface is fitted to the main shaft 103. The seal receiving ring 135 is in contact with one side surface. The other side surface of the seal receiving ring 135 is in contact with a holding ring 134 fixed to the main shaft 103 with a bolt 133.

  Seal members 145 a and 145 b are attached to the inner peripheral surface of the axle box 104 and the inner peripheral surface of the holding ring 143, respectively, and one seal member 145 a is in sliding contact with the outer peripheral surface of the large-diameter portion 103 a of the main shaft 103. The other seal member 145 b is in sliding contact with the outer peripheral surface of the seal receiving ring 135.

JP 2006-300128 A

In the case of the conventional rolling bearing 102 shown in FIG. 5, the inner ring 121 is fitted to the outer peripheral surface of the main shaft 103 by a tight fit (tight fit) in order to prevent creep with the main shaft 103. However, since the inner diameter of the inner ring 121 is as large as about 1.5 m in a wind power generator, it is very difficult to assemble the inner ring 121 to the main shaft 103 by interference fit.
Further, since the pressing member 134 and the seal receiving ring 135 are necessary to assemble the rolling bearing 102 to the main shaft 103 and the axle box 104, the number of parts increases and the structure becomes complicated.

  The present invention provides a rolling bearing device and a method for manufacturing the rolling bearing device that can easily assemble a bearing ring to a fixed member such as a shaft, and can simplify the structure. Objective.

A rolling bearing device of the present invention includes a rolling bearing having rolling elements arranged between a first race ring, a second race ring, and first and second race rings,
A fixed member that is fitted to the first bearing ring and fixed to the first bearing ring by a bolt having a head;
A bolt insertion hole for allowing the bolt to pass through the first race is formed through the axial direction,
The bolt insertion hole includes a first hole formed from one axial side surface of the first raceway to the middle in the axial direction before heat treatment of the first raceway, and a bolt smaller than the first hole. A second hole portion having a hole diameter and formed so as to communicate with the first hole portion from the other axial side surface of the first bearing ring after the heat treatment,
The bolt is inserted into the bolt insertion hole from the second hole side, so that the head is positioned on the second hole side and connected to the fixed member on the first hole side. It is characterized by that.

The method of manufacturing a rolling bearing device according to the present invention includes a rolling bearing having a rolling element disposed between a first bearing ring, a second bearing ring, and first and second bearing rings, and the first bearing ring. And a method of manufacturing a rolling bearing device including a fixed member fixed to the one raceway ring by a bolt having a head,
Before heat treatment of the first raceway, the step of forming the first hole in the axial direction in the range from one axial side surface of the first raceway to the middle of the axial direction;
After the heat treatment of the first track ring, the second hole portion having a bolt hole diameter smaller than the first hole portion is axially connected so as to communicate with the first hole portion from the other side surface in the axial direction of the first track ring. Forming the step,
Inserting the bolt from the second hole side, positioning the head of the bolt on the second hole side, and connecting the bolt to the fixed member on the first hole side; , Including.

  According to the above configuration, since the bolt insertion hole penetrating in the axial direction is formed in the first track ring and the fixed member is fixed by the bolt inserted through the bolt insertion hole, the first track is fixed to the fixed member. Even if the wheels are not fitted with a tight fit, creep does not occur, and it is possible to fit with a clearance fit. Therefore, the first track ring can be easily assembled to the fixed member. In addition, the bolt is formed so as to penetrate the first race ring through the bolt insertion hole, and the bolt inserted from the second hole side of the bolt insertion hole is connected to the fixed member on the first hole side. As in the conventional structure shown in FIG. 5, the pressing member (reference numeral 134) is not required, and the structure can be simplified.

On the other hand, the bearing ring of a rolling bearing is usually manufactured by the following process. First, a raceway formed by forging is primarily processed by turning, and then heat treatment such as quenching and tempering is performed to increase hardness and toughness. Thereafter, secondary processing is performed by turning and then polishing finish is performed.
When the bolt insertion hole is formed in the first race ring, it is very important at which stage the machining is performed. If the bolt insertion hole is formed at a stage before the heat treatment, the bolt is deformed by the first race ring due to the heat treatment. The dimensional accuracy of the insertion hole cannot be ensured. Further, after the heat treatment, the hardness of the first raceway is increased, so that it is difficult to process the bolt insertion hole, and the wear of the tool is increased.

  In the present invention, before the heat treatment, the first hole is formed in a range from one side in the axial direction of the raceway to the middle. This first hole portion has a hole diameter dimension larger than, for example, a specified bolt hole dimension, so that even if the first race ring is deformed after heat treatment, a bolt insertion hole with a specified PCD or pitch is provided. It is made to be included in the range of the 1st hole after heat processing. Then, after the heat treatment, the second hole portion is formed so as to communicate with the first hole portion from the end surface on the other axial side of the first track ring. The bolt hole diameter of the second hole is smaller than the bolt hole diameter of the first hole, for example, a specified bolt hole diameter. Thereby, the 2nd hole after heat processing can ensure predetermined dimensional accuracy. Moreover, since the 2nd hole part is a part of bolt insertion hole, it can process easily even after heat processing.

  Then, in assembling the first track ring to the fixed member, the head of the bolt is positioned on the second hole side, and the bolt is connected to the fixed member on the first hole side. In addition, a sufficient contact area between the periphery of the second hole portion formed in the small bolt hole diameter and the head portion of the bolt can be secured, and the surface pressure applied to the head portion can be reduced. Therefore, the durability of the bolt can be improved. To reduce the surface pressure applied to the bolt head and improve the durability of the bolt, the load and moment greatly fluctuate due to constantly changing winds, as in the main shaft support structure of a wind power generator. This is very useful in situations where an excessive load is applied.

  Preferably, the fixed member is a shaft, and the first race is an inner ring that fits on an outer peripheral surface of the shaft. Accordingly, the present invention can be suitably applied as a rolling bearing device for supporting the main shaft of a wind power generator.

  Moreover, it is preferable that the said 1st track ring has a part which protrudes in an axial direction rather than the said 2nd track ring, and the seal | sticker receiving surface is formed in the outer peripheral surface of this protrusion part. Thus, unlike the conventional structure shown in FIG. 5, it is not necessary to provide a seal receiving ring (reference numeral 135) exclusively for the seal receiving on the shaft or to form a seal receiving surface on the outer peripheral surface of the shaft. Therefore, the structure can be simplified. In addition, a protrusion part and a seal | sticker receiving surface can also be formed in the axial direction both sides of a 1st track ring, and can also be formed in one side.

  The shaft may include a mounting portion protruding in a radial direction on the first hole side of the first track ring, and a female screw into which the bolt is screwed may be formed on the mounting portion. Further, a through hole that penetrates in the axial direction is formed in the mounting portion instead of a female screw, and a bolt is inserted into the through hole and a nut is screwed to fix the first bearing ring to the mounting portion. Good.

  According to the present invention, the first track ring can be easily assembled to the fixed member, and the structure can be simplified.

It is a section explanatory view of the rolling bearing device concerning a 1st embodiment of the present invention. It is sectional explanatory drawing of the rolling bearing in a manufacture process. It is a section explanatory view of a rolling bearing device concerning a 2nd embodiment of the present invention. It is a section explanatory view of a rolling bearing device concerning a 3rd embodiment of the present invention. It is sectional explanatory drawing of the rolling bearing apparatus which concerns on a prior art.

  FIG. 1 is a cross-sectional explanatory view of a rolling bearing device according to a first embodiment of the present invention. The rolling bearing device 1 is applied to a main shaft support structure of a wind power generator, and includes a rolling bearing 2, a main shaft 3, and a shaft box 4. The rolling bearing 2 is a double-row tapered roller bearing having an inner ring 21, two outer rings 22, and a tapered roller 23 as a rolling element. Two rows of inner ring raceway surfaces 21 a are formed on the outer circumferential surface of the inner ring 21, two outer rings 22 are arranged side by side in the axial direction, and outer ring raceway surfaces 22 a are formed on the inner circumferential surface of each outer ring 22. A plurality of tapered rollers 23 are provided between each inner ring raceway surface 21a and each outer ring raceway surface 22a, and the plurality of tapered rollers 23 are held at predetermined intervals in the circumferential direction by a cage 24. A spacer 25 is provided between the two outer rings 22. In the case of the rolling bearing 2 used for supporting the main shaft of a wind power generator, the outer diameter of the outer ring 22 is about 1.9 m, and the inner diameter of the inner ring 21 is about 1.5 m, which is very large.

  The axle box 4 has a main support portion 41 having a fitting surface 41a on the inner periphery of which the outer peripheral surface of the outer ring 22 is fitted, and a sub-support portion extending radially inward from one axial side portion of the main support portion 41. 42, and one side surface in the axial direction of the outer ring 22 is in contact with the inner side surface 42a of the sub-support portion 42. A female screw 41b is formed in the axial direction on the other axial side surface of the main support portion 41. A pressing ring 43 is brought into contact with the other side surface in the axial direction of the main support portion 41, and the pressing ring 43 is fixed to the main support portion 41 with a bolt 44 screwed into the female screw 41b. Accordingly, the outer ring 22 is restricted from moving in the axial direction by the sub-support portion 42 and the pressing ring 43. Further, seal members 45 a and 45 b are respectively provided on the inner peripheral surface 42 b of the sub-support portion 42 and the inner peripheral surface 43 b of the pressing ring 43.

The main shaft 3 has a fitting surface 3a with which the inner circumferential surface of the inner ring 21 is fitted on the outer periphery, and an attachment portion 31 protruding radially outward is integrally formed on one side of the fitting surface 3a in the axial direction. Has been. The mounting portion 31 is formed with an internal thread 31a that penetrates in the axial direction.
The inner ring 21 has protruding portions 26 that protrude outward in the axial direction from the outer ring 22. And the outer peripheral surface of this protrusion part 26 is made into the seal | sticker receiving surface 26a with which the sealing members 45a and 45b slidably contact.

  A plurality of bolt insertion holes 27 penetrating in the axial direction are formed in the inner ring 21 with a predetermined PCD (pitch circle diameter) and a predetermined pitch in the circumferential direction. A bolt 28 is inserted into the bolt insertion hole 27, and the inner thread 21 is connected to the main shaft 3 by screwing the male thread portion 28 b of the bolt 28 with the female thread 31 a of the mounting portion 31. A washer 29 is provided between the head 28 a of the bolt 28 and the inner ring 21.

In this way, the bolt insertion hole 27 is formed in the inner ring 21, the bolt 28 is inserted into the bolt insertion hole 27, and the male screw 28 b of the bolt 28 is screwed into the mounting portion 31 of the main shaft 3. The inner ring 21 and the inner ring 21 rotate integrally through the bolt 28 without causing creep. Therefore, it is not necessary to fit the main shaft 3 and the inner ring 21 with an interference fit, and it is possible to fit with a clearance fit. Therefore, the work of assembling the inner ring 21 to the main shaft 3 can be easily performed.
Further, since the inner ring 21 is formed with the seal receiving surface 26a, it is not necessary to form a seal receiving surface on the main shaft 3 or separately provide a member dedicated to the seal receiving, and the structure can be simplified. it can.

  Next, a method for forming the bolt insertion hole 27 in the inner ring 21 will be described. The bolt insertion hole 27 is formed in two stages in the process of manufacturing the inner ring 21. The inner ring 21 is made of bearing steel or the like, and is formed by forging, then turned, and further subjected to quenching and tempering (heat treatment). The inner ring 21 is turned again to be deformed by heat treatment, and then polished. A part of the bolt insertion hole 27 of the present embodiment is formed before heat treatment as a first step.

  Specifically, as shown in FIG. 2A, the inner ring 21 is formed with a first hole portion 27a in the axial direction from one side surface (left side) in the axial direction. The first hole 27a has a bolt hole diameter d2 larger than a prescribed bolt hole diameter d1 (see FIG. 2B) corresponding to the outer diameter (nominal diameter) of the bolt 28, and has a predetermined PCD and a predetermined pitch. Formed with. The first hole 27a does not penetrate the inner ring 21, and is formed to have a length L1 that exceeds half of the axial length L0 of the inner ring 21. The length (remaining portion length) L <b> 2 of the portion where the first hole 27 a is not formed is a dimension substantially corresponding to the nominal diameter of the bolt 28. For example, when the bolt 28 is M36, the remaining length L2 is about 30 to 40 mm, and the length L1 of the first hole 27a is about 230 to 240 mm.

Since the drilling of the first hole portion 27a is performed at a stage where the hardness of the inner ring 21 before the heat treatment is low, it can be easily performed even in a range exceeding half of the axial length L0 of the inner ring 21. The first hole portion 27a has a hole diameter d2 larger than a specified bolt hole diameter d1, and even if the inner ring 21 is deformed by heat treatment, a bolt hole having a specified bolt hole diameter d1 formed at a predetermined PCD and a predetermined pitch is formed. The first hole 27a is included in the range.
In addition, the bolt hole diameter (1-3 grade) prescribed | regulated, for example in JISB1001-1985 can be applied to the prescribed bolt hole diameter d1. According to this, for example, when the nominal diameter of the bolt is M36, the specified bolt hole diameter d1 is 37 to 42 mm. In this case, the hole diameter d2 of the first hole portion 27a is a dimension exceeding 42 mm, for example, 43 mm. The hole diameter d2 of the first hole portion 27a is determined with a margin in consideration of the deformation amount of the inner ring 21 due to the heat treatment.

  After the first hole 27a is formed, heat treatment and turning are performed, and then the remainder of the bolt insertion hole 27 is formed. Specifically, as shown in FIG. 2 (b), the second hole 27b is formed in the inner ring 21 in the axial direction from the other side (right side) in the axial direction. The second hole 27b has a specified bolt hole diameter d1 corresponding to the bolt 28, and is formed with a predetermined PCD and a predetermined pitch. The second hole 27b is formed in a range where the first hole 27a is not formed, and communicates with the first hole 27a.

When the heat treatment is performed, the hardness of the inner ring 21 is increased. However, the second hole 27b has a short range L2 in which the first hole 27a is not formed, that is, less than half of the axial length L0 of the inner ring 21. Therefore, it is possible to reduce the wear of the tool.
In FIG. 2B, the center O of the first hole 27a and the second hole 27b coincides, but when the center of the first hole 27a is shifted due to the deformation of the inner ring 21 due to heat treatment, The two do not necessarily match. However, even if the center is slightly shifted, the hole diameter d2 of the first hole portion 27a is set larger than the hole diameter d1 of the second hole portion 27b as described above. There is no hindrance.

When the inner ring 21 is manufactured and assembled to the main shaft 3, as shown in FIG. 1, the bolt 28 is inserted into the bolt insertion hole 27 from the second hole 27b side (right side) with the washer 29 attached, and the male screw 28b is inserted. Screwed onto the female screw 31a. The washer 29 is disposed between the head 28 a of the bolt 28 and the inner ring 21.
Since the head portion 28a of the bolt 28 is disposed on the second hole portion 27b side formed in the specified bolt hole diameter d1, the contact area between the second hole portion 27b and the head portion 28a (actually the washer 29). Is sufficiently secured. Therefore, the surface pressure applied to the head 28a can be reduced.
When the rolling bearing device 1 is applied to a main shaft support structure for wind power generation as in the present embodiment, the main shaft 3 is always loaded with a load that fluctuates with a change in wind, and an excessive load is applied during a gust of wind. Although it is loaded, since the surface pressure applied to the head 28a of the bolt 28 is appropriate, even if a fluctuating load or an excessive load is applied, the durability of the bolt 28 is suitably maintained. Can do.

  FIG. 3 is an explanatory cross-sectional view of a rolling bearing device according to a second embodiment of the present invention. In the present embodiment, a through hole 31 c that penetrates in the axial direction is formed in the mounting portion 31 instead of the female screw, and the bolt 28 is inserted into the through hole 31 c and the male screw 28 b of the bolt 28 on the left side of the mounting portion 31. A nut 30 is screwed. Therefore, the present embodiment has the same operational effects as the first embodiment.

  FIG. 4 is a cross-sectional explanatory view of a rolling bearing device according to a third embodiment of the present invention. In the present embodiment, the protruding portion 26 is formed only on one side (right side) in the axial direction of the inner ring 21, and one seal member 45 b is in sliding contact with the seal receiving surface 26 a of the protruding portion 26. The other seal member 45a is in sliding contact with the outer peripheral surface 31b of the attachment portion 31, and this outer peripheral surface 31b functions as a seal receiving surface. Therefore, the attachment portion 31 is also used as a member for attaching the inner ring 21 and a member for receiving a seal. Therefore, the present embodiment has the same operational effects as the first embodiment.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed in design. For example, in the above-described embodiment, the bolt insertion hole 27 is formed in the inner ring 21 and the inner ring 21 and the main shaft 3 are fixed by the bolt 28. However, while the bolt insertion hole is formed in the outer ring 22, It is also possible to adopt a configuration in which the outer ring 22 and the axle box 4 are fixed by bolts. In the above-described embodiment, the member fixed to the inner ring 21 is the rotating side, and the member fixed to the outer ring 22 is the fixing side.

DESCRIPTION OF SYMBOLS 1 Rolling bearing apparatus 2 Rolling bearing 3 Main shaft 21 Inner ring (1st ring)
22 Outer ring (second ring)
23 Tapered rollers (rolling elements)
26 Protruding portion 26a Seal receiving surface 27 Bolt insertion hole 27a First hole portion 27b Second hole portion 28 Bolt 28a Head portion 31 Mounting portion 31a Female thread

Claims (6)

A rolling bearing having rolling elements disposed between the first race ring, the second race ring, and the first and second race rings;
A fixed member that is fitted to the first bearing ring and fixed to the first bearing ring by a bolt having a head;
A bolt insertion hole for allowing the bolt to pass through the first race is formed through the axial direction,
The bolt insertion hole includes a first hole formed from one axial side surface of the first raceway to the middle in the axial direction before heat treatment of the first raceway, and a bolt smaller than the first hole. A second hole portion having a hole diameter and formed so as to communicate with the first hole portion from the other axial side surface of the first bearing ring after the heat treatment,
The bolt is inserted into the bolt insertion hole from the second hole side, so that the head is positioned on the second hole side and connected to the fixed member on the first hole side. A rolling bearing device characterized by that. The fixed member is a shaft rotatably supported by the rolling bearing;
The rolling bearing device according to claim 1, wherein the first race is an inner ring that is fitted to an outer peripheral surface of the shaft.   The rolling bearing device according to claim 2, wherein the first bearing ring has a portion protruding in an axial direction from the second bearing ring, and a seal receiving surface is formed on an outer peripheral surface of the protruding portion.   The said axis | shaft is provided with the attaching part which protrudes in the radial direction in the 1st hole part side of the said 1st track ring, The internal thread which the said volt | bolt screws in is formed in this attaching part. Rolling bearing device.   The shaft includes a mounting portion that protrudes in the radial direction on the first hole portion side of the first track ring, and a through-hole through which the bolt is inserted is formed in the mounting portion, and the bolt inserted through the through-hole. 4. The rolling bearing device according to claim 2, wherein a nut is provided to be screwed to the bolt and to fix the first bearing ring to the mounting portion together with the bolt. A first bearing ring, a second bearing ring, and a rolling bearing having a rolling element disposed between the first and second bearing rings, and a bolt fitted to the first bearing ring and having a head. A method of manufacturing a rolling bearing device comprising a fixed member fixed to the one raceway ring,
Before heat treatment of the first raceway, the step of forming the first hole in the axial direction in the range from one axial side surface of the first raceway to the middle of the axial direction;
After the heat treatment of the first track ring, the second hole portion having a bolt hole diameter smaller than the first hole portion is axially connected so as to communicate with the first hole portion from the other side surface in the axial direction of the first track ring. Forming the step,
Inserting the bolt from the second hole side, positioning the head of the bolt on the second hole side, and connecting the bolt to the fixed member on the first hole side; The manufacturing method of the rolling bearing apparatus characterized by including these.

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