JP2006342830A - Preload applying method of double-row tapered roller bearing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a method capable of applying proper preload on a double-row tapered roller bearing unit 1a which stabilizes attitudes of tapered rollers 4a and 4b at each row and obtains superior rotational accuracy. <P>SOLUTION: An enlarged amount of a gap between both end faces opposing with each other of both inner ring elements 6a and 6b is calculated while both inner ring elements 6a and 6b are externally fitted on a shaft 16 at the basis of inner diameters R<SB>6</SB>of both inner ring elements 6a and 6b and an outer diameter D<SB>16</SB>of the shaft 16. Then, an inner ring spacer 20 being shorter by an axial gap than the sum of the enlarged amount and separately measured gap of both end faces, which is necessary to apply desired preload, is prepared. The inner ring spacer 20 is arranged between both inner ring elements 6a and 6b, and an inner ring assembly 2a organized by the inner ring spacer 20 and both inner ring elements 6a and 6b are strongly pushed between a nut 18 and step section 17. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is incorporated in a rotation support portion such as a shaft portion (rotation shaft) of a cylinder for a printing press to which a large radial load and thrust load are applied (or the rigidity in the radial direction and the thrust direction needs to be sufficiently increased). The present invention relates to an improvement in a preload application method for a double-row tapered roller bearing unit that is used to rotatably support various members such as the cylinder.

  Double-row tapered roller bearings used to construct rotating support parts that are subject to large radial loads and thrust loads (the radial and thrust directions need to have sufficiently high rigidity), such as the cylinders of printing presses. As the unit, for example, those described in Patent Documents 1 to 3 are known. FIG. 2 shows a double row tapered roller bearing unit 1 described in Patent Document 1 among them. The double row tapered roller bearing unit 1 includes an inner ring assembly 2, an outer ring assembly 3, and a plurality of tapered rollers 4a and 4b. Of these, the inner ring assembly 2 has a pair of inner ring elements 6a and 6b each having an inner ring raceway 5 that is conical and convex on the outer peripheral surface thereof, and the small diameter side ends of the inner ring raceways 5 and 5 are opposed to each other. Combining by state. These inner ring elements 6a and 6b have a small diameter side flange 7 on the outer peripheral surface of the small diameter side end, a large diameter side flange 8 on the outer peripheral surface of the large diameter side end, and the inner ring raceway 5 from both sides in the axial direction. It is formed in a sandwiched state.

  Further, the outer ring assembly 3 includes a pair of outer ring elements 10a and 10b having outer ring raceways 9 that are conical and concave on the respective inner peripheral surfaces, and the inclination directions of the outer ring raceways 9 and 9 are opposite to each other ( In a state of being arranged in such a manner that the inner diameter becomes smaller toward the central portion in the axial direction), the outer ring spacer 11 is abutted. The tapered rollers 4a and 4b are placed between the inner ring raceways 5 and 5 on the outer peripheral surface of the inner ring elements 6a and 6b and the outer ring raceways 9 and 9 on the inner peripheral surfaces of the outer ring elements 10a and 10b. In a state of being held by the cages 12 and 12, it is provided so as to be freely rollable. The outer ring spacer 11 is provided with a lubricating oil passage 13 for feeding the lubricating oil into the double row tapered roller bearing unit 1.

  FIG. 3 shows a state in which the end of the cylinder 14 of the printing press is rotatably supported by the bearing housing 15 provided on the frame (support) by the double row tapered roller bearing unit 1 as described above. Shaft portions 16 are provided concentrically with the cylinder 14 at both axial end surfaces of the cylinder 14, and the inner ring assembly 2 constituting the double-row tapered roller bearing unit 1 is connected to the shaft portion 16. A predetermined preload is applied by external fitting. In order to apply this preload, the inner ring assembly 2 is screwed onto a stepped portion 17 provided on the end face of the cylinder 14 and a male threaded portion at the tip end portion (left end portion in FIG. 3) of the shaft portion 16. 18 is sandwiched between. That is, after the inner ring assembly 2 is externally fitted to the shaft portion 16, for example, before the outer ring assembly 3 is fitted to the bearing housing 15, the nut 18 is rotated with a predetermined torque to The inner ring elements 6a and 6b are pressed toward each other, and a desired preload is applied to the tapered rollers 4a and 4b. Thereafter, the outer ring assembly 3 is fitted and fixed to the bearing housing 15. However, this preload application operation can also be performed after the outer ring assembly 3 is fitted and fixed to the bearing housing 15.

  For example, in the case of the double row tapered roller bearing unit 1 incorporated in the rotation support portion of the cylinder 14 of the printing press, such preload needs to be regulated to an appropriate value for the following reason. First, the minimum value of the preload is regulated from the viewpoint of maintaining the printing quality. If the preload is too low and the rigidity of the double-row tapered roller bearing unit 1 is insufficient, the displacement of the cylinder 14 cannot be suppressed, and a printing failure that deteriorates printing quality occurs. On the other hand, the maximum value of the preload is restricted from the viewpoint of ensuring the durability of the double row tapered roller bearing unit 1. If the preload is too high, the rolling fatigue life of the rolling surfaces of the inner and outer races 5, 9 and the tapered rollers 4a, 4b will be reduced, and the durability of the double-row tapered roller bearing unit 1 will be insufficient. End up.

  In order to ensure the printing quality and the durability of the double row tapered roller bearing unit 1, it is necessary to regulate the preload of the double row tapered roller bearing unit 1 to an appropriate value. For this purpose, the preload of the double-row tapered roller bearing unit 1 for rotatably supporting the cylinder of the printing press, for example, from the dynamic torque (rotational torque) when the double-row tapered roller bearing unit 1 rotates at a low speed. It has been conventionally performed to obtain an appropriate value. That is, the dynamic torque of the double row tapered roller bearing unit 1 increases as the preload (preload) increases. Therefore, a load in a direction approaching each other is applied to the pair of inner ring elements 6a and 6b constituting the inner ring assembly 2 of the double row tapered roller bearing unit 1 until a dynamic torque corresponding to a predetermined preload (set preload) is obtained. Appropriate preload is applied to the double row tapered roller bearing unit 1.

  Thus, in order to apply an appropriate preload to the double-row tapered roller bearing unit 1 for rotatably supporting the shaft portion 16 of the cylinder 14 of the printing press, this double-row tapered roller bearing unit has been conventionally used. No inner ring spacer was used for the inner ring assembly 2 constituting 1. That is, the inner ring assembly 2 is composed of only a pair of inner ring elements 6a and 6b, and a gap 19 is interposed between the opposed end surfaces of the inner ring elements 6a and 6b. Based on the presence of such a gap 19, the inner ring element 6a closer to the tip of the shaft portion 16 (left side in FIG. 3) of the inner ring elements 6a and 6b cannot always be attached with high accuracy, and the double row tapered roller is not necessarily attached. There is a possibility that the rotational accuracy of the cylinder 14 supported by the bearing unit 1 cannot be sufficiently secured. The reason will be described in detail below.

  When the inner ring assembly 2 is sandwiched between the stepped portion 17 and the nut 18 for preloading work, of the inner ring elements 6a and 6b, the shaft portion 16 is closer to the center (right side in FIG. 3). ) Of the inner ring element 6 b is pressed against the stepped portion 17. Since the stepped portion 17 is accurately finished in a plane perpendicular to the central axis of the cylinder 14 and the shaft portion 16, the posture of the inner ring element 6b near the center is stabilized. On the other hand, the axial inner end surface (the right end surface in FIG. 3) of the nut 18 that presses the large-diameter end surface (the left end surface in FIG. 3) of the inner ring element 6a near the tip is from the start of the preloading operation. The inner ring element 6a near the tip is not strongly abutted against the end face on the large diameter side. Moreover, the accuracy of the inner end surface in the axial direction of the nut 18 is not as good as that of the stepped portion 17 due to the effect of a gap or the like that is necessarily present in the threaded portion between the nut 18 and the male screw portion (much worse). ). Rather, the attitude of the inner end face in the axial direction of the nut 18 (such as the tilt direction) tends to be determined in a state of following the end face on the large diameter side of the inner ring element 6a near the tip. Therefore, the posture of the inner ring element 6a near the tip cannot be stabilized by the axially inner end face of the nut 18.

  The posture of the inner ring element 6a near the tip is determined by the stepped portion 17 between the inner ring element 6b near the center of the shaft part 16, the tapered roller 4b in the inner (right side in FIG. 3) row, the inner outer ring element 10b, and the outer ring. It is regulated via the seat 11, the outer ring element 10a on the outer side (left side in FIG. 3), and the tapered roller 4a in the outer row. Therefore, the posture of the inner ring element 6a near the tip is hardly stabilized due to the integration of manufacturing errors and assembly errors of these members 6b, 4b, 10b, 11, 10a, and 4a. In particular, since it is difficult to stabilize the posture of the tapered roller 4a in the outer row, it is difficult to stabilize the posture of the inner ring element 6a closer to the tip even if the accuracy in manufacturing and assembling other members is improved. In other words, the large-diameter side end face of the inner ring element 6a near the tip is accurately positioned on a plane orthogonal to the central axis of the cylinder 14 and the shaft part 16, and the central axis of the inner ring element 6a and the shaft part 16 are positioned. It is difficult to accurately match the center axis of.

  For this reason, when the central axis of the inner ring element 6a near the tip and the central axis of the shaft portion 16 do not coincide with each other, the rolling of the outer row tapered rollers 4a arranged around the inner ring element 6a. Becomes unstable. As a result, the rotational accuracy of the double-row tapered roller bearing unit 1, and hence the rotational accuracy of the cylinder 14 supported by the double-row tapered roller bearing unit 1, is deteriorated, and the above-described printing trouble occurs.

  On the other hand, Patent Documents 2 and 3 describe a structure in which an inner ring spacer is sandwiched between a pair of inner rings constituting an inner ring assembly, or axial end surfaces of a pair of inner rings are directly butted together. ing. According to such a structure, it is possible to prevent the posture of the inner ring near the tip of the shaft portion from becoming unstable due to the above-described causes. However, in the case of the conventional structures described in Patent Documents 2 and 3, an inner ring spacer having a large rigidity is sandwiched between the axial end faces of a pair of inner rings, or the axial end faces of both inner rings are Since these are directly abutted, it is difficult to change the distance between the axial end faces of these inner rings. Therefore, in order to give an appropriate preload to the double-row tapered roller bearing unit, it is not only necessary to finish the dimensions and shapes of the constituent members with extremely high accuracy, but also to give the desired preload accurately, very difficult. This point will be described with reference to FIGS.

FIGS. 4 to 5 show two examples of structures previously considered corresponding to the above-mentioned Patent Document 3 in order to stabilize the posture of the tapered rollers 4a in the outer row. In the case of the double-row tapered roller bearing unit 1a of the first example shown in FIG. 4, an inner ring spacer 20 is sandwiched between a pair of inner ring elements 6a and 6b to form an inner ring assembly 2a. Yes. Then, both end surfaces in the axial direction of the inner ring spacer 20 are planes orthogonal to the central axis of the inner ring spacer 20 so that the posture of the inner ring element 6a near the tip of the shaft portion 16 (see FIG. 3) is stabilized. ing.
In the case of the double-row tapered roller bearing unit 1b of the second example shown in FIG. 5, an integrated outer ring element 21 having double-row outer ring raceways 9 and 9 on the inner peripheral surface is provided as an outer ring assembly 3a. It is used as

In the case of the double-row tapered roller bearing units 1a and 1b previously considered shown in FIGS. 4 to 5, it is difficult to accurately apply a desired preload to each tapered roller 4a and 4b as described above. The reason is as follows. To adjust the preload in the structure shown in FIG. 4-5, changing the axial dimension L ₂₀ of the inner ring spacer 20 sandwiched between the two inner ring elements 6a, 6b with each other. Then, in a state before the nut 18 (see FIG. 3) is tightened, there is a gap existing between the axial end surfaces of the inner ring spacer 20 and the axial end surfaces of the inner ring elements 6a and 6b facing each other. Change the thickness (dimension in the axial direction). The preload is applied by an amount corresponding to the thickness dimension of the gap. Therefore, in order to make this preload appropriate, not only the axial dimension L ₂₀ of the inner ring spacer ₂₀ is made appropriate, but also the inner ring elements 6a, 6b in a state before the nut 18 is tightened. It is necessary to make the distance D ₆ (see FIG. 2) between the axial end faces facing each other appropriate.

However, the distance D ₆ also changes even before the nut 18 is tightened. This reason will be described with reference to FIG. 1 showing an embodiment of the present invention. In the case of the double row tapered roller bearing unit 1a for rotatably supporting the shaft portion 16 of the cylinder for printing press, the inner ring elements 6a and 6b are fastened to the shaft portion 16 in order to ensure a high degree of rotational accuracy. It is fitted by fitting. For this reason, the diameters of both the inner ring elements 6a and 6b change (increase) from the state indicated by the chain line in FIG. With this change in diameter, based on the engagement between the inner ring raceways 5, 5 formed on the outer peripheral surfaces of the inner ring elements 6a, 6b and the tapered rollers 4a, 4b (both inner ring raceways 5, 5 and a force D applied to the rolling contact portion of each of these tapered rollers 4a and 4b, based on a component force directed in the axial direction), the distance D ₆ between these inner ring elements 6a and 6b is: The state changes from the state indicated by the chain line in FIG. 1 to the state indicated by the solid line (increases). That is, the distance D ₆ is D _6b ( _b : before) before the external fitting to the shaft portion 16, but is increased to D _6a ( _a : after) after the external fitting (D _6b <D _6a ).

The preload application to the tapered rollers 4a and 4b is performed in a state where the distance between the axial end surfaces facing each other of the inner ring elements 6a and 6b is widened up to the state shown by the solid line in FIG. Accordingly, in order to stabilize the posture of the tapered rollers 4a in the outer row and to give an appropriate preload to the tapered rollers 4a, 4b in each row with the structure shown in FIGS. 6a, the axial dimension of the inner ring spacer 20 sandwiched between 6b between must be regulated on the basis of the distance D _6a after fitting out above.

On the other hand, the distance D _6a after the external fitting is not only the distance D _6b before the external fitting, but also the degree of interference fit of the inner ring elements 6a, 6b to the shaft portion 16, that is, each is free. It also changes depending on the difference (D ₁₆ −R ₆ ) between the inner diameter R ₆ of the inner ring elements 6 a and 6 b and the outer diameter D ₁₆ of the shaft portion 16 in the state. Conventionally, no preload is applied to each of the tapered rollers 4a and 4b in consideration of the variation in the distance between the axial end surfaces of the inner ring elements 6a and 6b based on such an interference fit. . For this reason, this preload could not be regulated appropriately. For example, to measure the outer fitting previous interval D _6b, when said determined axial dimension L ₂₀ of the inner ring spacer 20, the respective tapered rollers 4a, is applied to 4b on the basis of the interval D _6b The preload becomes larger than the appropriate value. If the distance D _6a after the external fitting can be measured, the axial dimension L ₂₀ of the inner ring spacer 20 can be made appropriate and the preload can be set to an appropriate value. However, the distance D _6a after the external fitting can be measured. Impossible or extremely difficult.

JP 2001-182753 A JP 2002-52685 A JP 2004-60758 A

  In view of the circumstances as described above, the present invention is to realize a method capable of applying an appropriate preload to a double row tapered roller bearing unit that can stabilize the posture of each row of tapered rollers and obtain excellent rotational accuracy. Invented.

The double-row tapered roller bearing unit that is the subject of the preload application method of the present invention is similar to the conventionally known double-row tapered roller bearing unit, and includes an inner ring assembly, an outer ring assembly, and a plurality of tapered rollers. Is provided.
Among these, the inner ring assembly includes a pair of inner ring elements each having a double row inner ring raceway having a conical convex shape on the outer peripheral surface, and an inner ring spacer sandwiched between the two inner ring elements. The inner ring elements are fixed to the outer peripheral surface of the shaft in a state in which the inner ring elements are externally fitted to the outer peripheral surface of the shaft.
The outer ring assembly has double-row outer ring raceways each having a conical concave shape on the inner peripheral surface. Then, it is fitted and fixed to the housing.
Further, a plurality of each tapered roller is provided between each inner ring raceway and each outer ring raceway so as to roll freely for each row.
The preload applying method that is the subject of the present invention is a method of pressing the inner ring elements constituting the inner ring assembly in a direction approaching each other in the axial direction, and the axial end surfaces of the inner ring elements facing each other and the inner ring spacer. A desired preload is applied to the tapered rollers in each row in a state where both end surfaces in the axial direction are in contact with each other.

In particular, in the case of the preload application method for the double row tapered roller bearing unit of the present invention, first, the inner diameter of the inner ring elements in the free state, the outer diameter of the shaft in the free state, The distance between the axial end faces facing each other is measured. The distance between the axial end surfaces of the inner ring elements is measured by bringing the inner ring elements close to each other with a force that does not cause elastic deformation of the members in a state where the outer ring assembly and the tapered rollers are combined. It is performed in a state of pressing in the direction.
Thereafter, based on the difference between the inner diameters of the inner ring elements and the outer diameter of the shaft, the amount of expansion of the interval between the axial end faces in a state where the inner ring elements are fitted onto the shaft is obtained. The work for determining the amount of expansion includes the specifications of the double-row tapered roller bearing unit, such as the materials and dimensions of the materials constituting the inner ring elements and the shaft, and the inclination angle of each inner ring raceway (or the contact angle of each tapered roller). In addition to being obtained by calculation based on the above, it can also be obtained experimentally (from an empirical formula derived from a plurality of experiments performed in advance).
Next, an inner ring spacer is prepared that is shorter than the sum of the amount of enlargement and the measured interval by an axial gap necessary for applying the desired preload.
Then, after the inner ring spacer is disposed between the inner ring elements, the inner ring assembly including the inner ring spacer and the inner ring elements is pressed from both sides in the axial direction. Then, the axial clearance is eliminated and the axial end surfaces of the inner ring elements facing each other are brought into contact with both axial end surfaces of the inner ring spacer.

According to the preloading method of the double row tapered roller bearing unit of the present invention configured as described above, the double row tapered roller bearing unit capable of stabilizing the posture of the tapered roller in each row and obtaining excellent rotational accuracy is suitable. Can give a preload.
First, since the axial end faces of the pair of inner ring elements facing each other are abutted via the inner ring spacer, the postures of these inner ring elements are stabilized, and the cones arranged around these inner ring elements It is possible to stabilize the rolling of the rollers and improve the rotation accuracy of the double row tapered roller bearing unit.
Also, in order to regulate the axial dimension of the inner ring spacer in a state that compensates for the diameter expansion of both inner ring elements accompanying the outer fitting of both inner ring elements, the interference fit of these inner ring elements to the shaft Regardless of the degree, the preload applied to each tapered roller can be made appropriate.
As a result, it is possible to maintain the rotational accuracy and ensure the durability of the double row tapered roller bearing unit at a high level.

In carrying out the present invention, preferably, as described in claim 2, the distance between the axial end surfaces of the inner ring elements facing each other is measured in a state where the outer ring assembly is fixedly fitted in the housing. .
If comprised in this way, the variation | change_quantity (shrinkage | contraction amount) of the diameter of this outer ring assembly accompanying the inner fitting fixing of the said outer ring assembly to the said housing can be disregarded.
That is, for example, in the case of a double row tapered roller bearing unit for rotatably supporting a shaft portion of a printing press cylinder, the outer ring assembly is fitted into the housing with an interference fit to obtain a high degree of rotational accuracy. In many cases, it is fixed internally. In such a case, the diameter of the outer ring assembly also changes with the internal fitting to the housing. However, even after the outer ring assembly is fixed to the housing, the pair of inner ring elements constituting the inner ring assembly are opposed to each other before the inner ring assembly is fixed to the shaft. It is possible to measure the distance between the axial end faces. In addition, by removing one of the inner ring elements and reassembling after the measurement, an inner ring spacer having a desired axial dimension can be sandwiched between the inner ring elements.
Therefore, if the configuration as described in claim 2 is adopted, a desired preload can be accurately applied to each tapered roller regardless of the change in the diameter of the outer ring assembly.

Further, when the present invention is carried out, for example, as described in claim 3, inner ring spacers that are short by an axial gap necessary for applying a desired preload are provided in a plurality of types having different axial dimensions. Select from the inner ring spacer.
Alternatively, as described in claim 4, the inner ring spacer that is shorter than the axial clearance necessary for applying the desired preload is required, and the end portion of the inner ring spacer having a larger axial dimension is required. Obtained by scraping.
In any case, an inner ring spacer having an appropriate axial dimension corresponding to a desired preload value can be obtained, and a desired preload can be applied to each tapered roller.

Further, when implementing the present invention, preferably, as described in claim 7, the double-row tapered roller bearing unit is incorporated in a rotation support portion for supporting a shaft portion of a cylinder of a printing press.
Such a rotation support portion needs to strictly regulate the preload as described above, and is required to have a high degree of rotation accuracy. Therefore, a large effect can be obtained by implementing the present invention.

  An embodiment of the present invention will be described with reference to FIG. The feature of the present invention is to compensate for the diameter expansion of both the inner ring elements 6a and 6b when the pair of inner ring elements 6a and 6b constituting the inner ring assembly 2a are fitted to the shaft portion 16. It is in. That is, a preload to be applied to each tapered roller 4a, 4b is compensated by compensating for the diameter expansion of both the inner ring elements 6a, 6b, regardless of the degree of interference between the inner ring elements 6a, 6b with respect to the shaft portion 16. It is in the point to regulate appropriately. The basic configuration of the double row tapered roller bearing unit 1a is the same as that of the conventional structure shown in FIGS. 2 to 3, and the inner ring element 6a near the tip of the shaft portion 16 using the inner ring spacer 20 is used. The point of stabilizing the posture is the same as the above-described structure shown in FIG. 4 (also in FIG. 5). Accordingly, the description of the structure is omitted, and the preload application method of the present invention for applying a desired preload to each of the tapered rollers 4a and 4b will be described below.

When applying a desired preload to the tapered rollers 4a and 4b, first, the following three dimensions shown in (a) to (c) are measured.
(a) Inner diameter R ₆ of the inner ring elements 6a and 6b in a free state (a state before being fitted to the shaft portion 16 shown by a chain line in FIG. 1).
(b) Outer diameter D _{16 in} a free state of the shaft portion 16 (a state before the inner ring elements 6a and 6b are externally fitted).
(c) The inner ring elements 6a and 6b are combined with the inner ring elements 6a and 6b, the outer ring assembly 3, and the tapered rollers 4a and 4b (for example, as shown in FIG. 2). the respective members 6a, 6b, 3, 4a, 4b are in a state of being pressed toward each other with a force so as not to elastically deform, the both inner ring element 6a, spacing D _6b between the axial end faces facing each other of 6b
When measuring D _6b , the outer ring assembly 3 is preferably fitted in the bearing housing 15 with an interference fit, and the diameter change of the outer ring assembly 3 due to the interference fit is measured. To eliminate the effects of When measuring the dimension (c), it is a matter of course that other members including the shaft portion 16 are not inserted on the inner diameter side of the inner ring elements 6a and 6b.

After measuring the three dimensions shown in the above (a) to (c), the difference “D ₁₆ −R ₆ ” between the inner diameter R ₆ of the inner ring elements 6 a and 6 b and the outer diameter D ₁₆ of the shaft portion 16 is measured. ”(The size of the interference fit), the amount of enlargement of the distance D ₆ between the axial end faces in a state where both the inner ring elements 6a, 6b are externally fitted to the shaft portion 16 is obtained. That is, the distance D _{6b in} the state before the outer ring elements 6a and 6b are externally fitted to the shaft portion 16 shown by a chain line in FIG. 1 and the both inner ring elements 6a and 6b also shown by a solid line are shown. A difference “D _6a −D _6b ” from the distance D _{6a in} the state after being fitted onto the shaft portion 16 is obtained. The work for obtaining the amount of expansion includes the materials and dimensions of the materials constituting the inner ring elements 6a and 6b and the shaft 16, and the inclination of the inner ring raceways 5 and 5 formed on the outer peripheral surfaces of the inner ring elements 6a and 6b. In addition to calculation based on the specifications of the double-row tapered roller bearing unit 1a, such as the angle θ (or contact angle of each tapered roller 4a, 4b), it is obtained experimentally (derived from a plurality of experiments conducted in advance). It can also be obtained from the experimental formula. That is, from the difference “D ₁₆ −R ₆ ” alone, the distance D _6a in the state after the inner ring elements 6a and 6b are externally fitted to the shaft portion 16 cannot be obtained. The enlargement amount “D _6a -D _6b ” is obtained.

As described above, when the amount of expansion “D _6a -D _6b ” of the distance D ₆ is obtained by fitting the inner ring elements 6a and 6b to the shaft portion 16 by interference fitting, By adding this enlarged amount “D _6a -D _6b ” to the measured value D _6b of (c), the distance D _{6a in} the state after the inner ring elements 6 a, 6 b are externally fitted to the shaft portion 16. the seek _{(D 6b + D 6a -D 6b} = D 6a). By this sum, a distance D _6a in a state after both the inner ring elements 6a and 6b are externally fitted to the shaft portion 16 can be obtained. Therefore, the tapered rollers 4a and 4b are more desirable than the distance D _6a . An inner ring spacer 20 is prepared that is shorter by an axial clearance (for example, 20 μm) required for applying the preload. The inner ring spacer 20 having such dimensions is selected from, for example, a plurality of types of inner ring spacers prepared in advance and having axial dimensions that are slightly different from each other (for example, 2 μm). Alternatively, it is obtained by scraping a necessary amount of the end portion of the inner ring spacer having a larger axial dimension. Which method is used to obtain the inner ring spacer 20 having a predetermined size is determined by design selection.

In any method, the inner ring spacer 20 is obtained which is shorter than the distance D _{6a in} the state after the inner ring elements 6a and 6b are fitted on the shaft portion 16 by an appropriate amount corresponding to the preload to be applied. If so, the inner ring spacer 20 is sandwiched between the inner ring elements 6a and 6b. In this operation, one inner ring element 6a (left side in FIG. 1) is once extracted from the inner diameter side of the outer ring assembly 3, and then the selected inner ring spacer 20 and the selected inner ring spacer 20 are arranged on the inner diameter side of the outer ring assembly 3. This is performed by sequentially incorporating one inner ring element 6a. At this time, both the inner ring elements 6 a and 6 b and the inner ring spacer 20 are externally fitted to the shaft portion 16. Note that both end surfaces in the axial direction of the inner ring spacer 20 are flat surfaces that exist in a direction perpendicular to the central axis.

  As described above, when the inner ring spacer 20 is sandwiched between the inner ring elements 6a and 6b, the inner rings are tightened by tightening the nut 18 screwed into the end of the shaft portion 16. The inner ring assembly 2a including the elements 6a and 6b and the inner ring spacer 20 is strongly pressed from both sides in the axial direction between the nut 18 and the stepped portion 17 of the cylinder 14. And the clearance gap which exists between the axial direction end surface of the said inner ring spacer 20 and the other axial direction surface of the said both inner ring elements 6a and 6b is eliminated, and the axial direction end surfaces which these inner ring elements 6a and 6b mutually oppose And both end surfaces in the axial direction of the inner ring spacer 20 are brought into contact with each other.

If a preload is applied to the double row tapered roller bearing unit 1a as described above, the posture of the tapered rollers 4a and 4b in each row is stabilized, and the rotational accuracy of the double row tapered roller bearing unit 1a is improved. Appropriate preload can be applied.
First, both axial end surfaces of the inner ring spacer 20 sandwiched between the axial end surfaces facing each other of the inner ring elements 6a, 6b are flat surfaces that are perpendicular to the central axis of the inner ring spacer 20. Therefore, the postures of both the inner ring elements 6a and 6b can be stabilized. And the rolling of the tapered rollers 4a and 4b arranged around these inner ring elements 6a and 6b can be stabilized, and the rotational accuracy of the double row tapered roller bearing unit 1a can be improved.

  Further, the axial dimension of the inner ring spacer 20 is regulated in a state in which the diameter expansion of both the inner ring elements 6a and 6b accompanying the outer fitting of the inner ring elements 6a and 6b to the shaft portion 16 is compensated. Therefore, the preload applied to the tapered rollers 4a and 4b can be made appropriate regardless of the degree of interference between the inner ring elements 6a and 6b with respect to the shaft portion 16. As a result, it is possible to maintain the rotational accuracy and ensure the durability of the double-row tapered roller bearing unit 1a at a high level. Of course, the outer ring assembly may be an integral type as shown in FIG.

  The present invention has a structure in which three or more inner rings and three or more outer rings are provided, or a bearing ring provided with a double row raceway surface on the circumferential surface and another bearing ring in an axially adjacent state. It can also be applied to row tapered roller bearing units. In this case, a spacer is provided between the adjacent bearing rings in the axial direction to stabilize the posture of the tapered rollers in each row to obtain excellent rotational accuracy, and to change the diameter of the bearing ring based on the interference fit. It is clear that when a structure capable of appropriately regulating the preload is realized while taking into consideration, the structure belongs to the technical scope of the present invention.

Furthermore, the technical idea of the present invention is that the inside and outside of the structure shown in FIG. 1 are reversed, and a front combination type contact angle is given to each tapered roller, as shown in FIG. It can also be used to give an appropriate preload to the double row tapered roller bearing unit 1c. In this case, the outer ring spacer 11 is sandwiched between a pair of outer ring elements 10a and 10b that are fitted into the bearing housing 15 with an interference fit. The outer diameter D ₁₀ of the outer ring elements 10a and 10b in the free state, the inner diameter R ₁₅ of the bearing housing 15, and the distance D _10b between the axial end surfaces of the outer ring elements 10a and 10b facing each other. And an outer ring spacer 11 having an appropriate axial dimension is selected and sandwiched between the outer ring elements 10a and 10b. In this case, the work of measuring the distance between the end faces in the axial direction is performed by fitting the inner ring 22 constituting the inner ring assembly 2a to the shaft portion 16 and then fixing the outer ring assembly 3 to the bearing housing 15. Perform before fitting. The outer ring assembly 3 is strongly clamped between a nut 18 a screwed into the bearing housing 15 and a stepped portion 17 a formed on the inner peripheral surface of the bearing housing 15. Of course, the inner ring assembly may be a separate type.

The half part sectional view of the rotation support part of the axial part of the cylinder for printing machines which incorporated the double row tapered roller bearing unit which shows the example of the present invention. The half part sectional view which shows an example of the double row tapered roller bearing unit conventionally known. The half part sectional view of the rotation support part of the axis part of the cylinder for printing machines which incorporated the double row tapered roller bearing unit known conventionally. The half part sectional view which shows the 1st example of the structure which can stabilize the attitude | position of a tapered roller. Sectional sectional drawing which shows the 2nd example. The half part sectional view of the rotation support part of the axial part of the cylinder for printing machines which shows another example of the double row tapered roller bearing unit which can apply the technical idea of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b, 1c Double row tapered roller bearing unit 2, 2a Inner ring assembly 3, 3a Outer ring assembly 4a, 4b Tapered roller 5 Inner ring track 6a, 6b Inner ring element 7 Small diameter side collar 8 Large diameter side collar 9 Outer ring raceway 10a, 10b Outer ring element 11 Outer ring spacer 12 Cage 13 Lubricating oil flow path 14 Cylinder 15 Bearing housing 16 Shaft part 17, 17a Stepped part 18, 18a Nut 19 Clearance 20 Inner ring spacer 21 Outer ring 22 Inner ring

Claims (7)

  A pair of inner ring elements having double-row inner ring raceways each having a conical convex shape on the outer peripheral surface, and an inner ring spacer sandwiched between the two inner ring elements, are provided on the outer peripheral surface of the shaft. An inner ring assembly that is fixed to the outer peripheral surface of this shaft in an externally fitted state by an interference fit, and an outer ring that has a double row outer ring raceway each having a conical concave shape on the inner peripheral surface and is fixed to the housing. The two inner rings constituting the inner ring assembly, comprising an assembly, and a plurality of tapered rollers provided in a row between the outer ring raceways and the inner ring raceways. The elements are pressed in a direction approaching each other in the axial direction, and the axial ends of the inner ring elements facing each other and the axial end faces of the inner ring spacer are in contact with each other, the taper rollers in each row are desired. Of double row tapered roller bearing units A pressure applying method comprising: combining the inner diameter of the inner ring elements in a free state, the outer diameter of the shaft in a free state, the inner ring elements, the outer ring assembly, and the tapered rollers. After measuring the distance between the axial end surfaces of the inner ring elements facing each other in a state where the inner ring elements are pressed in a direction in which the inner ring elements approach each other with a force that does not cause elastic deformation of each member, Based on the difference between the inner diameter and the outer diameter of the shaft, the amount of enlargement of the distance between the axial end faces accompanying fitting these inner ring elements to the shaft is obtained, and this amount of enlargement and the measured distance Prepare an inner ring spacer that is shorter than the sum required by the axial clearance required to apply the desired preload, and place the inner ring spacer between the inner ring elements, and then The inner ring assembly consisting of the inner ring spacer and both inner ring elements is pivoted. Presses from direction sides, facing each other are brought into contact with the axial end face and the axial end surfaces of the inner ring spacer which, preload application method of double row tapered roller bearing unit of both the inner ring element.   The method for applying a preload to a double-row tapered roller bearing unit according to claim 1, wherein the measurement of the distance between the axial end surfaces of the inner ring elements facing each other is performed in a state where the outer ring assembly is fitted and fixed to the housing.   The inner ring spacer that is shorter than the axial clearance necessary for applying the desired preload is selected from a plurality of types of inner ring spacers having different axial dimensions. A preload application method for a double row tapered roller bearing unit according to any one of the above.   The inner ring spacer that is shorter than the axial clearance required to provide the desired preload is obtained by scraping the end of the inner ring spacer having a larger axial dimension by a necessary amount. Item 3. A preloading method for a double row tapered roller bearing unit according to any one of Items 1 and 2.   1 has a double-row inner ring raceway, each of which has a conical convex shape on the outer peripheral surface, and an inner ring assembly that is externally fixed to the shaft, and a double-row outer ring raceway, each of which has a conical concave shape on the inner peripheral surface. A pair of outer ring elements and an outer ring spacer sandwiched between the two outer ring elements are provided, and both the outer ring elements are fixed to the inner peripheral surface of the housing in a state of being fitted into the inner peripheral surface of the housing by an interference fit. The outer ring assembly, and a plurality of tapered rollers each provided in a row between each of the inner ring raceways and the outer ring raceways. The outer ring elements are pressed in a direction approaching each other in the axial direction so that the axial end faces of the outer ring elements facing each other and the both axial end faces of the outer ring spacer are in contact with each other, the cones in each row. Double row tapered roller bearing unit that applies desired preload to rollers A preload applying method for the outer ring element, a combination of the outer diameter of the outer ring elements in a free state, the inner diameter of the housing in a free state, the outer ring elements, the inner ring assembly, and the tapered rollers. And measuring the distance between the axial end surfaces of the two outer ring elements facing each other in a state in which the two outer ring elements are pressed in a direction in which they are close to each other with a force that does not cause elastic deformation of each member. Based on the difference between the outer diameter of the outer ring element and the inner diameter of the housing, the amount of expansion of the interval between the axial end faces associated with fitting both the outer ring elements into the housing is obtained. Prepare an outer ring spacer that is shorter than the sum of the measured intervals by the axial clearance required to apply the desired preload, and place the outer ring spacer between the outer ring elements. From these outer ring spacers and A double-row tapered roller bearing unit that presses an outer ring assembly composed of outer ring elements from both axial sides so that axial end surfaces facing each other and both axial end surfaces of the outer ring spacer are in contact with each other. Preloading method.   The method for applying a preload to a double-row tapered roller bearing unit according to claim 5, wherein the measurement of the distance between the axial end faces of the two outer ring elements facing each other is performed with the inner ring assembly fitted and fixed to the shaft.   The double-row tapered roller bearing unit according to any one of claims 1 to 6, wherein the double-row tapered roller bearing unit is incorporated in a rotation support portion for supporting a shaft portion of a cylinder of a printing press. Unit preloading method.

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