JPH11123340A - Fitting structure for hydraulic cylinder for roller pressing in vertical roller mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fitting structure which can easily and smoothly fit a supporting shaft connecting the bottom part of the hydraulic cylinder with a fixing position such as a base plate in a hydraulic cylinder for roller pressing in a vertical roller mill. SOLUTION: An axial hole 49 is formed in a crevice 48 of a hydraulic cylinder 41 and a spherical face sliding bearing 57 is mounted in this axial hole 49 and a sleeve 56 whose inner peripheral face is a truncated cone is mounted on an inner ring 63 of the spherical sliding bearing 57. A supporting shaft 45 is mounted on a pair of brackets 44a and 44b to form a truncated cone part 52 on an axial part 50 between brackets 44a and 44b and the sleeve 56 is inserted in this truncated cone part 52 so as to arrange the sleeve 56 therein.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical roller mill for finely crushing an object to be crushed such as a cement clinker supplied on a table rotated around a vertical axis by a plurality of crushing rollers. The present invention relates to a mounting structure for a clevis-type hydraulic cylinder that pulls pressure on a rotary table.

[0002]

2. Description of the Related Art In a vertical roller mill, a plurality of crushing rollers press against an annular crushing portion of a rotary table having a vertical rotation axis from above, and the rotary table is driven to rotate around the vertical rotation axis. The crushing roller rotates following the rotation of the rotary table, and frictionally crushes and compresses the crushed object such as cement clinker supplied near the center position of the table on the crushing section. It is configured such that the object to be pulverized between the pulverizing roller and the pulverizing roller can be pulverized into particles or powder.

FIG. 4 is a sectional view showing a mounting structure of a roller pressing hydraulic cylinder 1 of a conventional vertical roller mill. As described above, the vertical roller mill is provided with a plurality of pulverizing rollers for crushing an object to be pulverized on a rotary table. For example, a roller pressing hydraulic cylinder (hereinafter, referred to as a pressure cylinder) for pressing the pulverizing roller onto the rotary table. 1) is provided.

The pressurizing cylinder 1 pulls down each crushing roller with a very large force of the order of 100 tons, and each crushing roller repeats fine swinging in the vertical and horizontal directions by the material to be crushed on the rotary table. The lower part 2 of the pressure cylinder 1 is structured to allow three-dimensional movement of the pressure cylinder 1. That is, a pair of brackets 4a and 4b are provided upright on the base plate 3 of the vertical roller mill at intervals. The lower part 2 of the pressurizing cylinder 1 is integrally formed with a head cover 6 for closing one end of the cylinder tube 5 in the axial direction, and a clevis 7 as a lower end part protruding downward from substantially the center of the head cover 6. The clevis 7 has a shaft hole 10 in which a support shaft 8 and a spherical slide bearing 9 are mounted.

[0005] The spherical plain bearing 9 has a straight cylindrical inner peripheral surface and a spherical outer peripheral surface.
And an outer ring 16 having a spherical inner peripheral surface and a right cylindrical outer peripheral surface. The outer ring 16 has one end in the axial direction supported by an annular stepped surface 17 and the other end in the axial direction pressed by a retainer 18, which is fixed to the clevis 7 by a bolt (not shown). 16 and thus the spherical plain bearing 9 is
It is attached in a state where it is stopped within 0.

The support shaft 8 has a head portion 21 and a shaft portion 22 having a smaller diameter than the head portion 21.
2, screw holes 23 and 24 are formed on the same axis. An annular step surface 25 is formed between the head 21 and the shaft 22 on an imaginary plane perpendicular to the axis of the support shaft 8. One end in the axial direction of the inner race 13 that is extrapolated to the shaft portion 22 abuts on the step surface 25, whereby the spherical plain bearing 9 is positioned near the center of the support shaft 8 in the direction of the axis 37.

One bracket 4a has an insertion hole 26 into which the shaft portion 22 of the support shaft 8 is inserted, and the other bracket 4b has an insertion hole 27 into which the head 21 of the support shaft 8 is inserted. . An end plate 2 is provided on the outer surface of each bracket 4a, 4b.
8 and 29 are fixed by a plurality of mounting bolts 30 and 31, and the respective insertion holes 26 and 27 are closed by the respective end plates 28 and 29. Each end plate 28, 29 has a bolt insertion hole 32, 3
3 are respectively formed, and the set bolts 34 and 35 are inserted through the bolt insertion holes 32 and 33 so that the respective screw holes 2 of the support shaft 8 are formed.
3 and 24 are screwed. The spindle 8 inserted between the end plates 28 and 29 into the insertion holes 26 and 27 of the brackets 4a and 4b.
Is supported by the brackets 4a and 4b in a state where displacement in the axial direction is prevented.

Since the lower portion 2 of the pressure cylinder 1 is connected to the base plate 3 in this manner, when the pressure cylinder 1 retracts the piston rod in order to press the pulverizing roller of the vertical roller mill, the support shaft 8 is moved. , A tensile force F acts upward from the clevis 7. Further, since the crushing roller rolls on the crushed object on the rotary table, even if the pressing cylinder 1 swings on a virtual plane including the axis 36 and the axis 37 of the support shaft 8, the crushing roller 7 Since the spherical plain bearing 9 is interposed between the support shaft 8 and the support shaft 8, displacement due to swing of the pressurizing cylinder 1 along the virtual plane can be allowed,
The pressurizing cylinder 1 that performs three-dimensional movement can be pivotally supported.

Since a large tensile load acts on such a spherical slide bearing 9, a gap between the support shaft 8 and the spherical slide bearing 9, more specifically, an outer periphery of the shaft portion 22 of the support shaft 8, is required in terms of strength. The gap between the surface and the inner peripheral surface of the inner ring 13 of the spherical plain bearing 9 is as small as possible, for example, 0.02 to 0.07 mm.
It is designed to meet a certain degree of tolerance.

As another prior art, a self-aligning roller bearing may be used in place of the spherical plain bearing 9 in some cases.
Also in this case, similarly to the above-mentioned spherical plain bearing 9, the pressure cylinder 1 is configured to allow a three-dimensional movement.

The spherical plain bearing 9 or the self-aligning roller bearing as described above is applied to a clevis pin of a pressurizing cylinder disclosed in, for example, JP-A-58-49448 and JP-A-5-23606. ing.

[0012]

In such a conventional technique, the mounting bolts 30, 31 and the set bolts 34, 35 are removed during maintenance of the pressurizing cylinder 1 and the like, and the end plates 28, 29 are attached to the brackets. 4a and 4b, the bolt 21 is screwed into the screw hole 24 of the head 21 of the support shaft 8 and removed, or the end of the shaft portion 22 of the support shaft 8 is connected to the axis 37 of the support shaft 8. In order to remove the support shaft 8 by pressing the support shaft 8 in the direction, a cement clinker or the like is provided between the outer peripheral surface of the shaft portion 22 of the support shaft 8 and the inner peripheral surface of the inner ring 13 of the spherical plain bearing 9. Dust such as fine powder and airborne substances generated by the pulverization of the material to be pulverized intrudes into the inner ring 13 and the support shaft 8.
In many cases, there is a problem that the support shaft 8 cannot be easily removed. This means that as the vertical roller mill becomes larger, various members related to the mounting structure such as the support shaft 8 and the spherical plain bearing 9 become larger and the fixing force becomes larger, so that the support shaft 8 cannot be easily removed. The tendency becomes stronger. The problem that the support shaft 8 cannot be removed is not limited to the spherical plain bearing 9 but also applies to the case where the above-described self-aligning roller bearing is used.

As described above, in the prior art, the spherical plain bearing 9
In addition, since the inner ring of a bearing such as a self-aligning roller bearing and the outer peripheral surface of the shaft portion 22 of the support shaft 8 are parallel to each other at the fitting surface, it is extremely difficult to remove the support shaft 8 once it is fixed. This is difficult, and the support shaft 8 itself must be melted during maintenance, which requires labor and high cost for maintenance, and lowers the operating rate of the vertical roller mill.

SUMMARY OF THE INVENTION An object of the present invention is to provide a mounting structure of a hydraulic cylinder for pressurizing a roller of a vertical roller mill in which a support shaft can be easily and smoothly extracted.

[0015]

According to the first aspect of the present invention, a lower end of a hydraulic cylinder for pressing a pulverizing roller of a vertical roller mill onto a rotary table is fixed to a fixed position below the rotary table. In a mounting structure of a roller pressing hydraulic cylinder of a vertical roller mill interposed between a pair of brackets and pivotally supported by a support shaft fitted into each bracket, a shaft portion disposed between the brackets of the support shaft is , Is formed in a truncated cone shape, a sleeve having a truncated cone shaped inner peripheral surface is extrapolated to the shaft portion of the truncated cone shape, and between the sleeve and the lower end portion of the hydraulic cylinder, A hydraulic pressure for roller pressing of a vertical roller mill, wherein a bearing capable of swinging a hydraulic cylinder around the axis of the support shaft and capable of angular displacement in an imaginary plane including the axis of the support shaft is provided. Mounting the cylinder It is an elephant.

According to the present invention, the lower portion of the hydraulic cylinder for pulling the pulverizing roller of the vertical roller mill onto the rotary table is interposed between a pair of brackets fixed at a fixed position, for example, on the base plate of the vertical roller mill. And pivoted by a support shaft. The support shaft fitted into each bracket has a shaft portion disposed between the brackets, and the shaft portion is formed in a truncated cone shape. A sleeve whose inner peripheral surface is shaped like a truncated cone is attached to such a shaft portion, and a bearing is interposed between the sleeve and a lower portion of the hydraulic cylinder. Such bearings include spherical plain bearings and self-aligning roller bearings which can swing freely around an axis capable of supporting a hydraulic cylinder and can be angularly displaced in an imaginary plane including the axis of the support shaft. Used. Such a bearing allows displacement of the hydraulic cylinder due to three-dimensional movement of the crushing roller due to the object to be crushed on the rotary table, and excessive bending stress is generated in the lower portion of the hydraulic cylinder, the spindle, and each bracket. Is prevented. When removing the support shaft during maintenance, the support shaft is pressed by a jack in a direction in which the small-diameter portion of the shaft portion of the support shaft approaches the large-diameter portion of the inner peripheral surface of the sleeve, or the shaft of the support shaft is removed. Use a jig such as a bolt to pull out the end of the large diameter side of the part, and easily and smoothly remove the spindle even if dust is fixed on the mating surface between the sleeve and the spindle be able to.

According to a second aspect of the present invention, in addition to the first aspect, the sleeve is divided at one location by a slit extending in the axial direction.

According to the present invention, since the sleeve is divided at one location by a slit extending in the axial direction, when the shaft portion of the support shaft is inserted into the sleeve, the sleeve is easily spread in the radial direction. Thereby, the gap between the fitting surface between the support shaft and the sleeve and the gap between the sleeve and the bearing inner ring can be eliminated. Therefore, it is possible to prevent dust from intruding and fixing between the fitting surfaces, and when the reaction force of the pulling force from the hydraulic cylinder acts on the support shaft, the support shaft can be compared with the case where there is a gap. In addition, the strength of the clevis is advantageous.

[0019]

FIG. 1 is a sectional view showing a mounting structure of a roller pressing hydraulic cylinder of a vertical roller mill according to an embodiment of the present invention. Lower part 42 of hydraulic cylinder 41 for pulling the pulverizing roller of a vertical roller mill onto a rotary table
Is interposed between a pair of brackets 44a and 44b fixed to the base plate 43 of the vertical roller mill at the other fixed position of the rotary table, and each bracket 4
It is pivotally supported by a support shaft 45 fitted into 4a, 44b.

The lower part 42 includes a head cover 47 for closing one end of the cylinder tube 46 in the axial direction, and a head cover 4.
7 and a clevis 48, which is a lower end portion integrally formed so as to protrude downward from substantially the center of the end face. Clevis 4
8, a shaft hole 49 through which the support shaft 45 is inserted is formed.
A shaft portion 50 disposed between the brackets 44a and 44b of the support shaft 45 is integrally formed with a frustum portion 52 having an outer peripheral surface 51 formed in a frustum shape, and one end portion of the frustum portion 52 in the axial direction. The outer peripheral surface 53 has a right cylindrical portion 54 having a right cylindrical shape. A frustum-shaped sleeve 56 having an inner peripheral surface 55 is externally inserted into the frustum portion 52 of the shaft portion 50, and a spherical plain bearing 57 is interposed between the sleeve 56 and the clevis 48. You. At the other end in the axial direction of the frustum portion 52, a head portion 59 whose outer peripheral surface is a straight cylindrical shape is integrally formed coaxially, and an axis 60 is provided between the head portion 59 and the frustum portion 52. A step surface 61 extending annularly in an imaginary plane perpendicular to is formed.

The outer peripheral surface 62 of the sleeve 56 has a straight cylindrical shape, and the inner ring 63 of the spherical plain bearing 57 is extrapolated on the outer peripheral surface 62. The inner peripheral surface 64 of the inner ring 63 has a right cylindrical shape, and the outer peripheral surface 65 has a spherical shape. An outer ring 66 is extrapolated on an outer peripheral surface 65 of the inner ring 63. The inner peripheral surface 67 of the outer ring 66 has a spherical shape, and the outer peripheral surface 68 has a right cylindrical shape. The outer ring 66 is prevented from being pulled out into the shaft hole 49 by the retainer 69, and the end face of one end in the axial direction on the side where the thickness of the sleeve 56 is small is in contact with the stepped surface 61 together with the inner ring 63. It is stopped. The spacer ring 70 has an inner peripheral surface and an outer peripheral surface that are both straight cylindrical, and an end surface at one axial end facing the sleeve 56 abuts an end surface at the other axial end on the side where the thickness of the sleeve 56 is large. ing.

One of the brackets 44a has the support shaft 4
An insertion hole 71 into which the right cylindrical portion 54 is inserted is formed.
The insertion hole 71 is closed from the outside by an end plate 72, and the end plate 72 is fixed to the one bracket 44 a by a plurality of mounting bolts 73. At the approximate center of the end plate 72, a bolt insertion hole 75 through which the shaft portion of the set bolt 74 is inserted.
The set bolt 74 inserted through the bolt insertion hole 75 is screwed into a screw hole 76 formed on the axis 60 of the straight cylindrical portion 54 of the support shaft 45.

The other bracket 44b has an insertion hole 77 into which the head 59 of the support shaft 45 is inserted. The insertion hole 77 is closed by an end plate 78 from the outside. This end plate 7
8 is fixed to the other bracket 44b by a plurality of mounting bolts 79. At substantially the center of the end plate 78, a bolt insertion hole 81 through which the shaft of the set bolt 80 is inserted is formed. Set bolt 8 inserted through bolt insertion hole 81
0 is screwed into a screw hole 82 formed on the axis 60 in the head 59. With these set bolts 74 and 80, the support shaft 45 is positioned and fixed at a position where the center of the frustum portion 52 in the direction of the axis 60 is orthogonal to the center axis 83 of the hydraulic cylinder 41.

FIG. 2 is a simplified sectional view of a vertical roller mill 91 as an embodiment in which the mounting structure shown in FIG. 1 is implemented. The vertical roller mill 91 has a substantially cylindrical housing 92, and a rotary table 94 having a vertical rotation axis 93 is arranged in the housing 92. The rotary table 94 is driven to rotate around the vertical rotation axis 93 by a motor 96 via a speed reducer 95 provided below the rotary table 94.

On the rotary table 94, a plurality (three in this embodiment) of crushing rollers 97 are arranged on the crushing orbit radius R at intervals in the circumferential direction. Each grinding roller 97 has a rotation axis 98 extending in the radial direction of the rotary table 94, and is pivotally supported by a swing arm 99. The swing arm 99 has a pivot 101 having a horizontal swing axis 100.
Thus, it is connected to the upper end of a column 103 erected on the floor 102 so as to be swingable around the swing axis 100. The crushing roller 97 and the oscillating arm 99 are imaginary lines 1
As indicated by reference numeral 04, it is possible to retreat by being angularly displaced radially outward and to perform maintenance and inspection.

The swing arm 99 is provided with a pin 106 on the piston rod 105 of the hydraulic cylinder 41 constituting the pressurizing device.
And the lower portion 42 of the hydraulic cylinder 41
As described above, each bracket 44 is
a, 44b. By retracting the piston rod 105 of the hydraulic cylinder 41, the crushing roller 97 can be pressed against the rotary table 94 to be pressed and pressed.

A supply chute 107 having a common axis to the vertical rotation axis 93 is provided on the housing 92 so as to extend to near the center of the turntable 94. Objects to be ground such as cement clinker and limestone are supplied into the supply chute 107 as indicated by an arrow 108. From the lower part of the supply chute 107, the material to be ground falls to the center of the turntable 94 and is supplied. The material to be crushed supplied to the center portion of the turntable 94 moves on the crushing track of the radius R of the turntable 94, is caught and crushed, and is crushed. The crushed object moves outward in the radial direction of the rotary table 94 and falls on an endless annular receiving table 109 provided below the rotary table 94. The pulverized material on the pedestal 109 is moved in the circumferential direction by a scraper 110 that is driven to rotate together with the rotary table 94, and is discharged from a discharge hole 111 of the pedestal 109 via a discharge chute 112.

The tensile force applied by the hydraulic cylinder 41 for efficient pulverization in this manner is a very large force of the order of 100 tons, and the reaction force acts on the support shaft 45.

The lower portion 42 of the hydraulic cylinder 41, which generates a large tensile force in this manner, is connected to the brackets 44a, 44b erected on the base plate 43 at the fixed position by the mounting structure shown in FIG. .

FIG. 3 is a perspective view of the sleeve 56. The sleeve 56 is made of the same material as the support shaft 45, for example, carbon steel for machine structure. The sleeve 56 extends in the axial direction and is divided by a slit 113 having an interval Δt of about 0.5 to 1.5 mm in a circumferential length.
The thickness T of one end in the axial direction where the diameter of the sleeve 56 is large, that is, the thickness T of the right end in FIG. 1 is selected to be, for example, 5.0 mm, and is 1/50 to 1 from the one end in the axial direction to the other end. It is formed so that the thickness becomes smaller at a change rate of / 100. In a state where such a sleeve 56 is mounted on the support shaft 45, as shown in FIG. 1, the end surface 115 of the axial end portion 114 having the largest inner diameter is
The support shaft 45 is separated from the step surface 61 by a small gap ΔL. In this state, the inner peripheral surface 55 of the sleeve 56 elastically contacts the outer peripheral surface 51 of the frustum 52 of the support shaft 45 over the entire circumference in the circumferential direction, and there is no gap. Further, there is no gap between the outer peripheral surface 62 of the sleeve 56 and the inner peripheral surface 64 of the bearing inner ring 63. This prevents a problem that dust, such as finely pulverized cement clinker, enters and is fixed between the sleeve 56 and the support shaft 45 and between the sleeve 56 and the bearing inner ring 63. When removing the support shaft 45 during maintenance, the support shaft 45 is removed.
The support shaft 45 is pulled out with the end plate 78 removed from the other bracket 44a into which is fitted, or the other end plate 72 attached to one of the brackets 44a is removed, and the jack is pressed against the other bracket 44b by a jack. do it,
The support shaft 45 can be easily and smoothly removed.

As another embodiment of the present invention, a self-aligning roller bearing may be used instead of the spherical plain bearing 57.

[0032]

According to the first aspect of the present invention, the lower portion of the hydraulic cylinder for pulling the pulverizing roller of the vertical roller mill onto the rotary table is a fixed position, for example, a pair fixed on the base plate of the vertical roller mill. And is pivotally supported by a support shaft. The support shaft fitted into each bracket has a shaft portion disposed between the brackets, and the shaft portion is formed in a truncated cone shape. A sleeve whose inner peripheral surface is shaped like a truncated cone is attached to such a shaft, and a bearing is interposed between the sleeve and a lower portion of the hydraulic cylinder. Such a bearing can be swingably supported around an axis capable of supporting a hydraulic cylinder and can be angularly displaced in an imaginary plane including the axis of the support shaft, such as a spherical plain bearing or a self-aligning roller bearing. Is used.

With such a bearing, displacement of the hydraulic cylinder accompanying the three-dimensional movement of the crushing roller due to the crushed object on the rotary table is allowed, and excessive bending stress is applied to the lower portion of the hydraulic cylinder, the support shaft, and each bracket. It is prevented from occurring.

When the support shaft is to be removed during maintenance, the support shaft is axially pressed by a jack in a direction in which the small-diameter portion of the shaft portion of the support shaft approaches the large-diameter portion of the inner peripheral surface of the sleeve. Even if dust is fixed to the mating surface between the sleeve and the spindle by pulling out the end of the spindle part on the large diameter side of the shaft part using a jig such as a bolt, etc., it is easy and smooth The support shaft can be removed.

According to the second aspect of the present invention, since the sleeve is divided by the slit extending in the axial direction, when the support shaft is inserted into the sleeve, the outer peripheral surface of the shaft portion of the support shaft is formed by the sleeve. Since the outer diameter of the sleeve can be easily enlarged by contacting the inner peripheral surface, it is possible to eliminate not only the gap between the mating surface of the support shaft and the sleeve but also the gap between the fitting surface of the sleeve and the bearing inner ring. it can. Therefore, it is possible to prevent dust from intruding and fixing between the fitting surfaces, and when the reaction force of the pulling force from the hydraulic cylinder acts on the support shaft, the support shaft can be compared with the case where there is a gap. In addition, the strength of the clevis is advantageous.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a mounting structure of a roller pressing hydraulic cylinder of a vertical roller mill according to an embodiment of the present invention.

FIG. 2 is a simplified sectional view of a vertical roller mill in which the mounting structure shown in FIG. 1 is implemented.

FIG. 3 is a perspective view of a sleeve 56.

FIG. 4 is a cross-sectional view showing a mounting structure of a roller pressing hydraulic cylinder 1 of a conventional vertical roller mill.

[Explanation of symbols]

 41 Hydraulic cylinder 42 Lower part 43 Base plate 44a, 44b Bracket 45 Support shaft 46 Cylinder tube 47 Head cover 48 Clevis 49 Shaft hole 50 Shaft part 52 Truncated cone part 56 Sleeve 57 Spherical sliding bearing 59 Head 61 Step surface 69 Retainer 70 Spacer ring 72 , 78 End plate 73, 79 Mounting bolt 74, 80 Set bolt 91 Vertical roller mill 92 Housing 94 Rotary table 97 Crush roller 99 Swing arm 105 Piston rod

Claims (2)

[Claims] 1. A lower end of a hydraulic cylinder for pulling a crushing roller of a vertical roller mill onto a rotary table is interposed between a pair of brackets fixed to a fixed position below the rotary table, and fitted into each bracket. In a mounting structure for a roller pressing hydraulic cylinder of a vertical roller mill pivotally supported by a supporting shaft, a shaft portion disposed between the brackets of the supporting shaft is formed in a truncated cone shape. A sleeve having a truncated cone-shaped inner peripheral surface is extrapolated to the shaft portion, and the hydraulic cylinder is swung about the axis of the support shaft between the sleeve and the lower end portion of the hydraulic cylinder. Freely
A mounting structure for a hydraulic cylinder for pressurizing a roller of a vertical roller mill, wherein a bearing capable of angular displacement is interposed in a virtual plane including the axis of the support shaft. 2. A mounting structure for a hydraulic cylinder for pressurizing a roller of a vertical roller mill according to claim 1, wherein the sleeve is divided at one location by a slit extending in the axial direction.