JP2009092155A - Shaft support device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily assemble a shaft support device by preventing smearing damage under wide service conditions such as high speed rotation and a light load. <P>SOLUTION: This shaft support device is provided for incorporating a cylindrical roller bearing between a rotary shaft and a housing 1, and has a preload adjusting part 3 inserted between these opposed recessed parts 1b and 2b by oppositely forming the recessed parts 1b and 2b in the axial direction on an inner diameter surface 1a of the housing 1 and an outer diameter surface 2a of an outer ring 2 of the cylindrical roller bearing in a state of incorporating the cylindrical roller bearing. An insertion part of its preload adjusting part 3 is formed in a radial cross-sectional shape having an area of increasing a radial dimension in response to a turning angle around the axis in the radial direction. Rotation of the preload adjusting part 3 is prevented in its increased state by increasing a radial clearance of the cylindrical roller bearing to the negative side by pressing the outer ring 2 to the inner diameter side in a state of interposing between the opposed recessed parts 1b and 2b by rotating the preload adjusting part 3 around the axis. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a shaft support device that incorporates a cylindrical roller bearing between a shaft and a housing, and more particularly, to adjusting a preload between an outer ring and a housing.

  When cylindrical roller bearings are operated under conditions of high speed and light load, relative sliding (skidding) occurs between the cylindrical rollers and the inner ring raceway surface. As a result, smearing occurs on the inner ring raceway surface and roller rolling surface. Damage may occur.

  Therefore, in order to prevent the above smearing damage, considering the operating conditions, bearing life, etc., contact surface pressure is applied by applying radial preload to the cylindrical roller bearing or by forming crowning on the raceway surface and roller rolling surface. Or raising it.

Conventionally, there is one in which the radial clearance of the cylindrical roller bearing is partially set to be negative by forming the raceway surface of the outer ring into an elliptical shape or a triangular shape (for example, Patent Document 1). If a part with a negative radial clearance is provided as shown above, preload is applied by the cylindrical roller passing through that part, thereby preventing skidding and preventing smearing damage. Can do.
JP 2001-140877 A (abstract)

  Cylindrical roller bearings are often applied to the main shaft support of gas turbine engines typified by jet engines and power generation gas turbines. Since this type of gas turbine engine has a high-speed rotating body such as a shaft and a turbine blade, a mass difference between components causes an unbalance during rotation. In addition, since the main shaft is elongated, complicated bending of the shaft also occurs. The vibration (load and displacement) generated by the rotation of the main shaft system of the engine is transmitted as it is to the bearing portion composed of parts having higher rigidity than the main shaft. Such vibration leads to problems such as shortening the bearing life.

However, the cylindrical roller bearing in which the outer ring raceway surface or the like is formed in an elliptical shape or a triangular shape is troublesome to assemble because the non-round outer ring is shrink-fitted on the inner diameter of the perfect housing.
Further, when the contact surface pressure is increased by forming the crowning, since the shape is determined for each individual device, smearing damage cannot be prevented under a wide range of usage conditions.

  The problem to be solved by the present invention is to prevent smearing damage under a wide range of usage conditions such as high-speed rotation and light load, and to facilitate the assembly of the shaft support device.

  In order to solve the above problems, in a shaft support device incorporating a cylindrical roller bearing between a rotating shaft and a housing, the inner diameter surface of the housing and the outer diameter surface of the outer ring of the cylindrical roller bearing are aligned along the axial direction. The concave portion is formed so as to face each other with the cylindrical roller bearing incorporated therein, and includes a preload adjusting component that is inserted between the facing concave portions, and the insertion portion of the preload adjusting component is set according to the rotation angle about the axis in the axial direction. A radial cross-sectional shape having a region in which a radial dimension increases, and by rotating the preload adjusting component around the axis, the outer ring is pressed toward the inner diameter side while being interposed between the facing recesses, and the cylindrical roller bearing The radial clearance was increased to the negative side, and the preload adjusting component was prevented from rotating in the increased state.

In this way, since the radial clearance between the housing and the outer ring is negative between the recesses, it is possible to prevent skidding, and it is not necessary to shrink-fit the outer ring into the housing, and assembly is easy.
Moreover, the desired preload according to use conditions, such as a high-speed rotation and a light load, can be given only by changing suitably the radial dimension in the radial cross section of the part inserted between the recessed parts of a preload adjustment component.
In addition, the radial clearance can be increased to the negative side simply by inserting the preload adjusting component between the recesses and rotating it. Therefore, only by press-fitting the preload adjusting part between the recesses, it is possible to insert with a small pressure input or to avoid press-fitting as compared with the case where the radial clearance is changed negatively.
Further, the preload adjusting component does not rotate around the axial line from the state in which the radial clearance of the cylindrical roller bearing is increased to the negative side.

  Further, if the radial cross section of the concave portion is formed in an arc shape, the rotational resistance when the preload adjusting component is rotated becomes small, and therefore the preload adjusting component can be easily rotated.

  Moreover, the radial cross section of the insertion part of a preload adjustment component can also be formed in an arc shape. If it does in this way, since rotation resistance when rotating a preload adjustment part becomes small, a preload adjustment part can be rotated easily. If the radial cross sections of both the recess and the preload adjusting part are formed in an arc shape, the preload adjusting part can be rotated more easily.

  Further, if the preload adjusting component is provided with a gripping portion that protrudes in the axial direction from between the concave portions while being inserted between the concave portions, the gripping portion can be picked with a tool such as a wrench. Easy to rotate around the axis.

  Further, if two surfaces parallel to the axial direction are provided on the grip portion, the two parallel surfaces can be picked with a tool such as a wrench to give a larger rotational torque.

A small-diameter region that can be inserted between the recesses in a non-contact manner and a large-diameter region that is interposed between the recesses and presses the outer ring toward the inner diameter side can be formed in the insertion portion of the preload adjusting component.
In this way, since the preload adjusting component can be inserted without being pressed between the recesses using the small diameter region, the preload adjusting component is easily interposed between the recesses, and after inserting the preload adjusting component, by rotation, The radial clearance of the cylindrical roller bearing can be changed negatively by pressing the outer ring toward the inner diameter side in the large diameter region.

  In addition, if a plurality of the recesses facing each other are provided on the outer diameter surface of the outer ring and the inner diameter surface of the housing, and the recesses are arranged at a certain interval in the circumferential direction, a preload is equally applied in the circumferential direction. Therefore, the balance is good when the shaft rotates.

Further, as the detent, it is possible to adopt a method in which a pin is press-fitted into the gap remaining between the recesses, and the preload adjusting component is detented by contact between the pin, the preload adjusting component and the recess.
As described above, when the pin is prevented from being detached by press-fitting between the preload adjusting part and the recess, no separate retaining operation is required.

In addition, a flange is provided on the outer diameter surface on one end side in the axial direction of the housing, a recess is formed on the inner diameter surface on the other end side, and a hole penetrating the housing in the radial direction is provided between the recess and the flange in the circumferential direction. It is possible to employ a configuration in which a plurality of squeeze film dampers for attenuating vibration are provided in a portion located on the outer diameter side of the concave portion of the outer diameter surface of the housing, using a plurality formed at a constant interval. it can.
When the hole is formed in this way, radial displacement of the outer ring due to vibration can be absorbed by the spring system including the hole. Moreover, if the structure provided with the squeeze film damper is employed, the spring system can be damped.

As described above, according to the present invention, the inner surface of the housing and the outer surface of the outer ring are formed with recesses facing each other, and a preload adjusting component is interposed between the recesses, thereby providing a radial clearance between the housing and the outer ring. Therefore, smudling damage can be prevented as a result of preventing skidding. Further, it is not necessary to shrink fit the outer ring on the housing, and assembly is easy.
In addition, according to the present invention, a desired preload according to use conditions such as high-speed rotation and light load can be applied only by appropriately changing the radial dimension in the radial section of the insertion portion of the preload adjusting component.

  Hereinafter, a shaft support device according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a longitudinal side view showing an overall configuration of a shaft support device according to an embodiment of the present invention. FIG. 2 is a partially enlarged sectional view of FIG. 1 cut along an axial plane. As shown in FIGS. 1 and 2, the shaft support device according to this embodiment includes a recess 1 b extending in the axial direction so as to face each other on an inner diameter surface 1 a of a housing 1 and an outer diameter surface 2 a of an outer ring 2 of a cylindrical roller bearing. 2b is formed, and preload adjusting parts 3 and 3 are inserted between the recesses 1b and 2b.

The housing 1 is formed in a cylindrical shape. A flange 4 is provided on the outer diameter surface 1c on the one end side in the axial direction of the housing 1, and the flange 4 can be attached to a fixing member with a bolt or a nut. The other end side inner diameter surface 1 a of the housing 1 is provided with a shoulder 5, and a recess 1 b is formed on the other end side of the shoulder 5.
Between the shoulder 5 and the flange 4, a plurality of oblong holes 6 penetrating the housing 1 in the radial direction are formed at regular intervals in the circumferential direction. Thereby, the radial displacement of the outer ring 2 due to vibration can be absorbed by the spring system constituted by the oblong holes 6.

  Further, circumferential grooves 7 and 7 are formed in a portion of the outer diameter surface 1c of the housing 1 located on the outer diameter side of the recess 1b, and rings 8 and 8 are fitted into the circumferential grooves 7 and 7, respectively. ing. A supply device 9 that supplies viscous incompressible oil is fixed to the outer diameter side of the rings 8 and 8, and is formed by the supply device 9 and the rings 8 and 8 by the supply device 9. The damper gap 10 is filled with the oil. Thereby, the squeeze film damper which produces the damping force with respect to a vibration according to the relative speed of the direction which increases / decreases the damper clearance gap 10 is comprised.

  The outer ring 2 is clearance-fitted to the housing 1, and the inner ring 11 is fixed to a shaft (not shown). That is, this embodiment is a shaft support device that incorporates a cylindrical roller bearing between the shaft and the housing 1, and is provided in an inner ring rotation system. A plurality of cylindrical rollers 6 are equally arranged in the circumferential interval by the cage 12 between the outer ring 2 and the inner ring 11.

  The recesses 1b, 2b facing each other on the housing 1 side and the outer ring 2 side are equally arranged at two locations in the circumferential direction. The radial cross sections of the recesses 1b and 2b are formed as grooves having an elliptical arc shape. The recess 1b on the housing 1 side is open at one end in the axial direction, and the preload adjusting component 3 can be inserted between the recesses 1b and 2b from the axial direction. When the preload adjusting component 3 is inserted between the recesses 1b and 2b, the preload adjusting component 3 is in contact with the shoulder 5.

  Further, in the state where the preload adjusting component 3 is in contact with the shoulder 5, the gripping portion 13 protrudes in the axial direction from between the recesses 1b and 2b. This is so that the grip portion 13 can be picked with a tool such as a wrench. As shown in FIG. 3, the gripping portion 13 is provided with two surfaces 13a and 13b parallel to the axial direction, and a large rotational torque is applied by picking the two parallel surfaces with a tool such as a wrench. Can be done. On the other hand, the radial cross section of the insertion part of the preload adjusting component 3 is formed in an elliptical shape.

  FIG. 4 shows a state in which the preload adjusting component 3 is inserted between the recesses 1b and 2b by a solid line, and a state in which the inserted preload adjusting component 3 is rotated by 90 degrees around the axial line in the axial direction. The major axis dimension in the radial section of the insertion portion of the preload adjusting component 3 is such that the groove depth DH of the recess 1b on the housing 1 side, the groove depth DO of the recess 2b on the outer ring 2 side, and between the housing 1 and the outer ring 2 It is a value obtained by adding half the radial clearance COH and a preset preload amount dimension PLD (PLD1 + PLD2). Therefore, the preload adjusting component 3 is interposed between the recesses 1b and 2b in a state where the long axis is directed in the radial direction, and can press the outer ring 2 toward the inner diameter side to make the radial clearance of the cylindrical roller bearing negative. .

  On the other hand, the minor axis dimension in the radial cross section of the insertion portion of the preload adjusting component 3 is such that the groove depth DH of the recess 1b on the housing 1 side, the groove depth DO of the recess 2b on the outer ring 2 side, the housing 1 and the outer ring 2 Since the half of the radial clearance COH is smaller than the sum, the preload adjusting component 3 can be inserted without being pressed between the recesses 1b and 2b. Therefore, after inserting the preload adjusting part 3 without press-fitting, while rotating the preload adjusting part 3 about the axis in the axial direction, the radial dimension between the recesses 1b and 2b according to the rotation angle of the insertion part. Accordingly, the outer ring 2 can be pressed against the inner diameter side by interposing it between the recesses 1b and 2b, and the radial clearance of the cylindrical roller bearing can be changed negatively.

  The preload amount dimension PLD is such that when the preload adjusting part 3 is rotated 90 degrees around the axial axis, the housing 1 and the outer ring 2 are deformed in the radial direction, and the radial clearance of the bearing is 0 or less, that is, a negative radial clearance. Is a value that becomes The negative radial clearance setting value can be obtained by calculation or experiment.

  The shaft support device having the above configuration can apply a preload to the cylindrical roller bearing incorporated between the shaft and the housing 1 as follows. First, since the gap between the recesses 1b and 2b is opened in the axial direction, the preload adjusting component 3 is inserted from the axial direction (solid line in FIG. 4). After the insertion, the grip 13 is picked with a tool such as a wrench, and is rotated 90 degrees about the axial axis as shown by a two-dot chain line shown in FIG. 4, and the preload adjusting component 3 is interposed between the recesses 1b and 2b. . As a result, the outer ring 2 is pressed inward, and the radial clearance of the cylindrical roller bearing is changed negatively. At this time, since the compression locations are equally arranged at two locations in the circumferential direction, the raceway surface 2c of the outer ring 2 is deformed into an oval shape as a whole as shown in FIG.

As shown in FIG. 5, the pins 14 and 14 sandwich the preload adjusting component 3 from both sides in the circumferential direction in the space remaining between the recesses 1b and 2b when the preload adjusting component 3 is rotated 90 degrees. It is press-fitted. The pins 14, 14 prevent the preload adjusting component 3 from rotating by contact between the concave portions 1 b, 2 b and the preload adjusting component 3.
In this way, if the pin 14 is prevented from coming off by press-fitting between the preload adjusting component 3 and the recesses 1b and 2b, no separate work is prevented.

  In this shaft support device, the inner surface 1a of the housing 1 and the outer surface 2a of the outer ring 2 are formed with recesses 1b, 2b facing each other, and a preload adjusting component 3 is interposed between the recesses 1b, 2b, thereby providing a radial clearance. Is increased to the negative side, so that skidding is prevented and smearing damage can be prevented. Further, it is not necessary to shrink fit the outer ring 2 on the housing 1, and assembly is easy.

  This shaft support device takes into account use conditions such as high-speed rotation and light load, and can be obtained by appropriately changing the major axis dimension in the radial cross section of the portion inserted between the recesses 1b and 2b of the preload adjusting component 3. Preload can be applied.

  In the above embodiment, the radial clearance of the cylindrical roller bearing is changed negatively by rotating the preload adjusting component 3 around the axis in a state in which the preload adjusting component 3 is inserted without being pressed between the recesses 1b and 2b. The radial clearance of the cylindrical roller bearing may be increased to the negative side by rotating the adjustment component 3 around the axial line in a state where the adjustment component 3 is interposed between the recesses 1b and 2b.

  In the above embodiment, the radial cross section of the insertion portion of the preload adjusting component 3 has an elliptical shape. However, the insertion portion of the preload adjusting component 3 has a radial area in which the radial dimension increases in accordance with the rotation angle around the axial axis. A cross-sectional shape is sufficient. For example, the radial cross-sectional shape may be a square or a polygon.

  In the said embodiment, although the radial cross section of the recessed parts 1b and 2b was made into elliptical arc shape, it is not limited to this, The radial cross section of a recessed part should just be arc shape. Further, in the above embodiment, the preload adjusting component 3 is in point contact with both the concave portions 1b and 2b while being rotated by 90 degrees. However, as shown in FIG. 6, the preload adjusting component 3 is rotated by 90 degrees. Sometimes, a groove into which one end in the major axis direction of the preload adjusting component 3 is fitted may be formed in the recess 2b on the outer ring 2 side. If it does in this way, compared with what made the radial cross section of the recessed part arc-shaped, the preload adjustment component 3 is hard to rotate.

  In the above embodiment, the radial cross section of the insertion portion of the preload adjusting component 3 has an elliptical shape. However, the radial cross section of the portion to be inserted between the recesses of the preload adjusting component is not limited to an elliptical shape. It only needs to be formed in an arc shape.

  In the above embodiment, the grip portion 13 is formed in an I-shape, but may be an L-shape (see FIG. 3D) or a T-shape. When formed in an L-shape or a T-shape, the grip portion 13 is longer in the radial direction than in the I-shape, so that a larger rotational torque can be applied.

  In the above embodiment, the grip portion 13 is configured by forming the two surfaces 13a and 13b parallel to the axial direction. However, two or three surfaces parallel to the axial direction may be formed. At this time, the shape of the gripping part is a quadrangular shape or a hexagonal shape. In short, it is sufficient that there is at least one of two surfaces parallel to the axial direction.

  In the above embodiment, the grip 13 is projected in the axial direction from between the recesses 1b and 2b with the preload adjusting component 3 inserted. However, the grip may not be projected in the axial direction.

In the above embodiment, the preload adjusting parts 3 are evenly arranged at two locations in the circumferential direction. However, as long as the smearing damage can be prevented, the number of the preload adjusting parts 3 interposed is at least in the circumferential direction. What is necessary is just to interpose in one place.
For example, if the number of the preload adjusting parts 3 interposed is three and they are equally distributed in the circumferential direction (120 ° intervals around the axis), the raceway surface 2c of the outer ring 2 is deformed into a triangular shape.

  Although the NU type cylindrical roller bearing is illustrated in the above embodiment, the present invention can also be applied to an N type cylindrical roller bearing or other types of cylindrical roller bearings.

The longitudinal side view which cut | disconnected the whole structure of embodiment of this invention by the radial plane Partial enlarged sectional view of FIG. 1 cut along an axial plane It is a figure which shows the shape of the preload adjustment component of embodiment of this invention, (a) is a left view with a holding part having an I shape, (b) is a front view with a holding part having an I shape, and (c) is a front view. The holding part is an I-shaped perspective view, (d) is an L-shaped perspective view of the holding part. Operational diagram of the preload adjusting component of the embodiment of the present invention The partial expanded sectional view which shows the state which interposed the preload adjustment component of embodiment of this invention between the recessed parts, and stopped The partial expanded sectional view which shows the state which interposed the preload adjustment component of embodiment of this invention in the recessed part in which the groove | channel was formed, and stopped rotating

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 1a Inner-diameter surface 1b, 2b Recessed part 1c, 2a Outer-diameter surface 2 Outer ring 3 Preload adjustment component 4 Flange 5 Shoulder 6 Oval hole 13 Grip part 13a, 13b Two parallel 14 pins

Claims (9)

  In a shaft support device incorporating a cylindrical roller bearing between a rotary shaft and a housing (1), an inner diameter surface (1a) of the housing (1) and an outer diameter surface (2a) of an outer ring (2) of the cylindrical roller bearing, In addition, a recess (1b, 2b) along the axial direction is formed so as to face each other in a state where the cylindrical roller bearing is incorporated, and a preload adjusting part (3) inserted between the facing recesses (1b, 2b) is provided, The insertion portion of the preload adjusting component (3) has a radial cross-sectional shape having a region in which the radial dimension increases in accordance with the rotation angle about the axial axis in the axial direction, and the preload adjusting component (3) is rotated about the axis. As a result, the outer ring (2) was pressed toward the inner diameter side while being interposed between the facing recesses (1b, 2b), and the radial clearance of the cylindrical roller bearing was increased to the negative side, and the increase was made. Shaft support device, characterized by detent of the preload adjustment component (3) in state.   The shaft support device according to claim 1, wherein a radial cross section of the recess (1b, 2b) is formed in an arc shape.   The shaft support device according to claim 1 or 2, wherein a radial cross section of an insertion portion of the preload adjusting component (3) is formed in an arc shape.   The holding part (13) which protrudes to an axial direction from the recessed part (1b, 2b) in the state inserted in the said recessed part (1b, 2b) in the said preload adjustment component (3) is provided. Shaft support device.   The shaft support device according to claim 4, wherein the grip portion (13) is provided with two surfaces (13a, 13b) parallel to the axial direction.   A small-diameter region that can be inserted in a non-contact manner between the recesses (1b, 2b) and an outer ring (2) interposed between the recesses (1b, 2b) by the rotation at the insertion portion of the preload adjusting component (3). The shaft support device according to any one of claims 1 to 5, wherein a large-diameter region that presses the inner diameter side toward the inner diameter side is formed.   A plurality of the recesses (1b, 2b) facing each other are provided on the outer diameter surface (2a) of the outer ring (2) and the inner diameter surface (1a) of the housing (1), and the recesses (1b, 2b) are provided in the circumferential direction. The shaft support device according to claim 1, wherein the shaft support device is disposed at a predetermined interval.   The detent includes press-fitting a pin (14) into a space remaining between the recesses (1b, 2b), and the recess (1b, 2b) facing the pin (14) and the preload adjusting component (3). The shaft support device according to any one of claims 1 to 7, wherein the preload adjusting component (3) is prevented from rotating by contact with the shaft.   A flange (4) is provided on the outer diameter surface (1c) on one end side in the axial direction of the housing (1), and a recess (1b) is formed on the inner diameter surface (1a) on the other end side. The outer diameter surface (1c) of the housing (1) is formed by using a plurality of holes (6) penetrating the housing (1) in the radial direction at regular intervals in (4). The shaft support device according to any one of claims 1 to 8, wherein a squeeze film damper that attenuates vibration is provided in a portion of the recess (1b) located on the outer diameter side.

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