JP3609846B2 - Shaft seal device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a shaft seal device that seals shafts by sliding sliding rings arranged on a stationary side and a rotating side in close contact with each other between axially opposed end faces, and in particular, the sliding rings are circular. The present invention relates to a structure having a structure divided in the circumferential direction.
[0002]
[Prior art]
Some fluid devices such as industrial pumps, water turbines, and compressors are extremely difficult to disassemble and assemble when they are large-sized devices. Therefore, the shaft seal device attached to such equipment has a structure in which some or all of the parts are divided in the circumferential direction in order to reduce the labor of disassembling and assembling the equipment during maintenance. It is common to do.
[0003]
FIG. 3 shows a typical conventional example of this type of shaft seal device, in which reference numeral 1 is a housing of an apparatus and 2 is a rotating shaft. The shaft seal device 3 includes a pair of sliding rings 31 and 32 in which a plurality of arc-shaped pieces are combined in an annular shape. Of these, one stationary-side sliding ring 31 is held in the housing 1 via the packing 34 so as to be axially movable, and a circumferential groove extending in the circumferential direction of the stationary-side retainer 33 that is prevented from rotating by a pin 35. The other rotating side sliding ring 32 is incorporated in a circumferential groove 36a extending in the circumferential direction of the rotating side retainer 36 fixed to the collar 37 on the outer periphery of the rotating shaft 2 via a bolt 38. It is. The stationary-side sliding ring 31 is hermetically slidably contacted with the rotating-side sliding ring 32 that rotates together with the rotating shaft 2 by being axially pressed by a spring (not shown) via the retainer 33, and rotates with the housing 1. A shaft seal with the shaft 2 is performed.
[0004]
The housing 1, the retainers 33 and 36, and the collar 37 also have a structure that is divided at a plurality of locations in the circumferential direction, like the sliding rings 31 and 32, and are connected in an annular shape through bolts. Among these, the retainers 33 and 36 are formed by annularly integrating the projecting pieces 33b and 36b projecting from the outer circumferential portions at both ends in the circumferential direction of the arc-shaped piece through bolts 33c and 36c. Yes.
[0005]
[Problems to be solved by the invention]
In the conventional shaft seal device, the following problems are pointed out.
The projecting piece 36b of the rotating side retainer 36 rotates integrally with the rotating shaft 2, thereby generating a pumping force similar to that of the impeller and forcibly rotating the surrounding fluid. Since this fluid collides with the projecting piece 33b of the stationary retainer 33 and loads the fluid pressure, the sliding ring 31, 32 slides on the pin 35 which prevents the stationary retaining retainer 33 from rotating. In addition to the friction torque on the surface S, the torque by the fluid pressure acts. For this reason, the pin 35 is significantly worn by friction with the inner surface of the engagement hole 1a on the housing 1 side. In order for the stationary-side and rotating-side sliding rings 31 and 32 to always maintain an appropriate close contact state on the sliding surface S and to obtain excellent sealing performance, the rotating-side sliding ring 32 due to axial displacement of the rotating shaft 2 is obtained. The stationary side sealing member consisting of the stationary side retainer 33 and stationary side sliding ring 31 and the like follows the axial direction with good response to the axial behavior of the rotating side sealing member consisting of the retainer 36 and the collar 37. However, if the pin 35 is worn and a step is formed on the surface thereof, the follow-up operability of the stationary sealing member in the axial direction is impaired, so that excessive leakage from the sliding surface S occurs. Or abnormal wear or heat generation may occur on the sliding surface S.
[0006]
Further, the projecting pieces 33b and 36b on the outer periphery of the retainers 33 and 36 act as a kind of heat radiating plate, and release heat from the sliding surface S of the sliding rings 31 and 32 into the fluid. However, since the protrusions 33b and 36b are present at intervals such as two positions in the circumferential direction, the retainers 33 and 36 have non-uniform temperatures in the circumferential direction and are distorted due to the difference in thermal expansion. Accordingly, a gap due to thermal strain is generated between the sliding surfaces S of the sliding rings 31 and 32 and excessive leakage occurs, or the sliding surface S is in a local contact state due to strain. The increased contact pressure may cause abnormal wear.
[0007]
Therefore, the main object of the present invention is to suppress the deterioration of the axial operability of the sealing member due to excessive torque and the occurrence of thermal distortion of the retainer, and to seal the sliding surfaces of the stationary and rotating sliding rings. The purpose of this is to reduce the wear on the sliding surface.
[0008]
[Means for Solving the Problems]
The technical problem described above can be effectively solved by the present invention.
That is, in the shaft seal device of the present invention, each arc-shaped piece of the retainer is joined by the projecting pieces that are formed to project at both ends in the circumferential direction, and the projecting piece of the stationary retainer is formed on the stationary housing. It is housed in a hole-like notch in a loosely fitted state and is engaged with the notch in the circumferential direction, and the protrusion of the rotating side retainer is loosely fitted in the hole-like notch formed on the rotating side collar. And is engaged with the notch in the circumferential direction.
[0009]
[Action]
The projecting pieces at both ends in the circumferential direction of the arcuate piece of the retainer are connected to each other in the circumferential direction between the coupling means for joining the pieces in an annular shape and the stationary housing or the rotating collar ( It also serves as a means for preventing rotation. This circumferential engagement is performed in a state in which each protruding piece is accommodated in a notch formed in the housing and the collar, so that forced rotation of the fluid by the protruding piece of the retainer on the rotating side is suppressed. In addition, an increase in torque due to the resistance of the fluid is also suppressed, and the occurrence of uneven temperature in the circumferential direction of the retainer due to the heat radiation action of the projecting piece is also suppressed. Moreover, since each said protrusion piece contacts the inner surface of each said notch part by planes, since a contact area increases compared with the engagement structure by the conventional pin, the abrasion of a contact part is suppressed.
[0010]
【Example】
1 and 2 show a preferred embodiment of a shaft seal device according to the present invention. Reference numeral 1 denotes a device housing and 2 denotes a rotating shaft. The housing 1 is divided into two parts in the circumferential direction, and the divided part is joined to the flange 11 via a plurality of bolts 12 and a gasket (not shown), and also divided into two in the circumferential direction, and the divided parts are plural. A plurality of annular members such as a seal case 13 having an inner diameter smaller than the inner diameter of the flange 11 are connected in the axial direction via bolts 15 and 16 and packings 17 and 18. Is.
[0011]
The shaft seal device 10 of this embodiment that seals the space between the housing 1 and the rotary shaft 2 includes a stationary side and a rotary side in which two semicircular arc-shaped sliding ring pieces made of SiC, for example, are annularly combined. A pair of sliding rings 101 and 102 is provided. A metal stationary retainer 103 is supported on the seal case 13 of the housing 1 so as to be axially movable through a packing 104 that is in sliding contact with the inner peripheral surface thereof, and is fixed to the sleeve 21 of the rotary shaft 2. In the collar 106, a rotating side retainer 105 that is opposed to the stationary side retainer 103 in the axial direction is disposed via a packing 107. Circumferential grooves 103 a and 105 a extending in the circumferential direction are formed on the opposing end surfaces of the retainers 103 and 105, and the stationary-side sliding ring 101 rotates and rotates in the circumferential groove 103 a of the stationary-side retainer 103. The side sliding rings 102 are respectively incorporated in the circumferential grooves 105 a of the rotation side retainer 105.
[0012]
The retainers 103 and 105 are each divided into semicircular arc shaped retainer pieces at two circumferential positions. Reference numerals 103 </ b> A and 103 </ b> B in FIG. 2 indicate retainer fragments constituting the stationary retainer 103. Plate-shaped projecting pieces 103b and 105b extending in the radial direction are respectively provided on the back surfaces (surfaces opposite to the end surfaces on which the circumferential grooves 103a and 105a are formed) of both ends of each retainer piece in the circumferential direction. The annular retainers 103 and 105 are assembled by fastening the opposing protruding pieces 103b and 105b with the required number of fastening members 108 and 109, respectively. In addition, the rotation-side collar 106 is also divided into a semicircular arc shape at two locations in the circumferential direction, and has a structure in which the rotation-side collar 106 is annularly coupled via a coupling means such as a bolt (not shown).
[0013]
On the outer peripheral surfaces of the sliding rings 101 and 102, buffer rings 110 and 111 having an annular shape (O-ring shape) are attached by bonding both ends of an elongated elastomer member having a circular cross-sectional shape. Metal holders 112 and 113 are disposed on the outer peripheral side of the buffer rings 110 and 111, and are fastened and fixed to the retainers 103 and 105 via bolts 114 and 115, respectively. Each piece of the sliding rings 101 and 102 is compressed by being compressed between the tapered surfaces formed on the inner diameters of the holders 112 and 113, the outer peripheral surfaces of the sliding rings 101 and 102, and the end surfaces of the retainers 103 and 105. Is tightened from the outer periphery and fixed to the peripheral grooves 103a and 105a.
[0014]
Constraining portions 116 and 117 are formed on the inner circumferential side of the circumferential grooves 103a and 105a of the retainers 103 and 105 so that the radial widths of the circumferential grooves 103a and 105a are gradually narrowed toward the opposing end surfaces of the retainers 103 and 105. Has been. On the other hand, on the inner peripheral surfaces of the sliding rings 101 and 102, the radial widths of both the sliding rings 101 and 102 are set to the sealing sliding surface S side corresponding to the tapered outer peripheral surfaces of the restraining portions 116 and 117. A taper surface that gradually narrows toward is formed, and the taper surface engages with the restraining portions 116 and 117, whereby the sliding rings 101 and 102 are prevented from falling off from the circumferential grooves 103a and 105a in the axial direction. ing.
[0015]
The end surface of the seal case 13 of the housing 1 on the side of the retainer 103 is formed with, for example, notches 118 at two circumferential positions located in the divided portion, and the end surface of the collar 106 on the retainer 105 side is similarly Notch portions 119 are formed at two locations in the circumferential direction located in the divided portion. The protruding pieces 103b of the stationary retainer 103 coupled to each other are accommodated in the notch 118 of the seal case 13 in a loosely fitted state, and the protruding pieces 105b of the rotating retainer 105 are The part 119 is accommodated in a loosely fitted state. In addition, as shown in FIG. 2, the protruding piece 103 b of the stationary retainer 103 and the cutout portion 118 of the seal case 13 are in contact with each other in a plane extending in the radial direction, and the protruding piece 105 b of the rotating side retainer 105. The same applies to the notch 119 of the collar 106.
[0016]
A plurality of holes (not shown) are formed on the end surface of the seal case 13 of the housing 1 facing the stationary retainer 103 at equal intervals in the circumferential direction, and coil springs (not shown) are respectively held in these holes. Has been. The stationary side retainer 103 is pressed and urged in the axial direction by this coil spring, and the stationary side sliding ring 101 is urged in the axial direction via the stationary side retainer 103 to thereby slide on the rotating side. The ring 102 and its opposite end surfaces are in close contact with each other, and sealing sliding is performed.
[0017]
In this embodiment, the projecting piece 103b of the stationary retainer 103 is a coupling portion for coupling the semicircular arc shaped retainer pieces 103A and 103B in an annular manner via the fastening member 108, and is attached to the seal case 13 of the housing 1. By being accommodated in the formed notch 118 in a loosely fitted state, it has a function as a detent means for maintaining the stationary side retainer 103 in a non-rotating state. Similarly, the projecting piece 105 b of the rotation side retainer 105 is a coupling part for annularly coupling the semicircular arc shaped retainer piece of the retainer 105 via the screw member 109, and is fixed to the rotation shaft 2. By being housed in the notched portion 119 of the collar 106 in a loosely fitted state, it has a function as a circumferential engagement means for receiving the rotational force of the collar 106 and rotating integrally.
[0018]
Although it is inevitable that the fluid in contact with the surface is rotated by the rotation of the rotation-side collar 106, the retainer 105, the holder 113, etc., the protruding piece 105 b of the rotation-side retainer 105 is accommodated in the notch 119 of the collar 106. Therefore, the fluid stirring action by the impeller action of the projecting piece 105b hardly occurs. Therefore, the pressing force acting on the abutting surface between the projecting piece 105b and the notch 119 is reduced by the fluid resistance, and the flow speed of the fluid in the rotation direction is also suppressed. Further, since the protruding piece 103b of the stationary retainer 103 is housed in the notch 118 of the seal case 13 so as to be loosely fitted, the rotating fluid is unlikely to collide with the protruding piece 103b. As described above, since the fluid flow rate is also low, the pressing force acting on the abutting surface between the projecting piece 103b and the notch 118 is reduced.
[0019]
The stationary-side sealing member including the sliding ring 101, the retainer 103, the holder 114, and the like is supported in the axial direction (right side in the drawing) by the spring while the retainer 103 is supported by the seal case 13 of the housing 1 so as to be movable in the axial direction. Is pressed against the axial displacement of the rotary side sealing member composed of the sliding ring 102, the retainer 105, the holder 113, the collar 106, and the like in accordance with the axial displacement of the rotating shaft 2 during driving. The sliding surface S always follows the axial direction so as to be in sliding contact with an appropriate contact pressure. For this reason, the protruding piece 103b of the stationary retainer 103 is rubbed against the notch 118 of the seal case 13 by the axial follow-up operation. The protruding piece 103b and the notch 118 are flat surfaces extending in the radial direction. Because of the abutting, the contact pressure due to the engagement is small, and the progress of wear on the abutting surface is effectively reduced.
[0020]
Further, since the protrusions 103b and 105b are accommodated in the notches 118 and 119, heat exchange with the fluid is not concentrated on the protrusions 103b and 105b. Therefore, a gap between the sliding surfaces S of the sliding rings 101 and 102 due to thermal strain due to a temperature difference in the circumferential direction of the retainers 103 and 105 is generated, and a local contact pressure of the sliding surface S is increased. Is prevented.
[0021]
In the above embodiment, the sliding rings 101 and 102, the retainers 103 and 105, the collar 106, the holders 112 and 113, etc. are described as being divided into two in the circumferential direction, but the number of divisions is particularly limited. It is not something.
[0022]
【The invention's effect】
According to the present invention, the projecting piece for connecting the arc-shaped pieces of the retainer to each other also serves as the circumferential engagement means with the stationary housing or the rotation side collar. There is no need to provide them separately. Further, since the projecting piece is housed in the notch formed in the housing and the collar, power loss due to fluid resistance due to the stirring action of the projecting piece of the rotating side retainer and fluid to the projecting piece of the stationary side retainer Since the pressing force between the projecting piece and the notch due to the impact of the actuator is reduced and the wear of the abutment surface is effectively suppressed, the stationary side consisting of the stationary side retainer and the stationary side sliding ring held by this The axial followability of the sealing member is maintained well. Moreover, thermal strain due to a temperature difference in the circumferential direction of the retainer is also prevented. For this reason, while being able to improve the sealing performance between the sliding surfaces of the stationary-side and rotating-side sliding rings, it is possible to prevent abnormal wear of the sliding surfaces.
[Brief description of the drawings]
FIG. 1 is a half cross-sectional view showing a preferred embodiment of a shaft seal device according to the present invention by cutting along a plane passing through an axis.
FIG. 2 is a partial cross-sectional view showing the stationary retainer in the above embodiment cut along a plane orthogonal to the axis.
FIG. 3 is a half sectional view showing an example of a conventional shaft seal device cut along a plane passing through an axis.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Housing 2 Rotating shaft 10 Shaft seal device 101, 102 Sliding rings 103, 105 Retainer 103a, 105a Circumferential groove 103A, 103B Retainer fragment 106 Collar 103b, 105b Projection piece 118, 119 Notch

Claims (1)

A pair of sliding rings which are divided at a plurality of locations in the circumferential direction and which are in sliding contact with each other at their axially opposed end faces which are combined in an annular shape;
A pair of retainers which are divided at a plurality of locations in the circumferential direction and arranged in a ring shape and arranged on the stationary side and the rotating side, respectively.
In the shaft seal device in which each sliding ring is held in a circumferential groove formed to extend in a circumferential direction on the mutually facing end surfaces of each retainer,
Each arcuate piece of the retainer is joined by projecting pieces protruding at both ends in the circumferential direction, and the projecting piece of the stationary retainer is loosely fitted into a hole-shaped notch formed in the stationary housing. The protrusion of the rotating retainer is accommodated in the circumferential direction in a state of being accommodated in the state, and the protruding piece of the rotating side retainer is housed in a loosely fitted state in the hole-shaped notch formed in the rotating side collar. A shaft seal device engaged in a circumferential direction.

Images