JP2017089800A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device which can make an external fluid self-circulate without the necessity for a pump or the like, in a double-type sealing device using two mechanical seals.SOLUTION: A sealing device comprises: a rotating ring 140 which rotates together with a rotating shaft 200; a first fixed ring 150 which is fixed to a housing 300, and slides with respect to an end face of the rotating ring 140 at a sealing objective fluid side (F); a second fixed ring 160 which is fixed to the housing 300, and slides with respect to an end face of the rotating ring 140 at an atmosphere side (A); and a partial impeller 170 which is fixed to an external peripheral face of the rotating ring 140, and guides external fluids in regions at both the sealing objective fluid side (F) and the atmosphere side (A) to the radial outer side by rotating together with the rotating ring 140.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sealing device including a mechanical seal.

  Conventionally, a sealing device including a mechanical seal is known for sealing an annular gap between a rotating shaft and a housing. A double-type sealing device using two mechanical seals is also known for the purpose of reducing leakage of a fluid to be sealed (see Patent Documents 1 and 2). In the sealing device including the double type mechanical seal, in order to cool and wash the sliding portion between the rotating ring and the stationary ring constituting the mechanical seal, an external fluid is poured into the sliding portion. Generally composed. However, in the case of the double type sealing device using the mechanical seal according to the conventional example, a pump or the like is required to supply the external fluid.

JP 2012-107609 A International Publication No. 2010/001683

  An object of the present invention is to provide a sealing device capable of self-circulating an external fluid without requiring a pump or the like in a double-type sealing device using two mechanical seals.

  The present invention employs the following means in order to solve the above problems.

That is, the sealing device of the present invention is
A sealing device for sealing an annular gap between a rotating shaft and a housing having a shaft hole of the rotating shaft,
A rotating ring that rotates with the rotating shaft;
A first fixed ring fixed to the housing and sliding with respect to an end surface of the rotating ring on the fluid side to be sealed;
A second fixed ring that is fixed to the housing and that slides on an end surface of the rotating ring opposite to the fluid to be sealed;
A partial impeller that is fixed to the outer peripheral surface of the rotating ring and guides the external fluid in both the region to be sealed and the side opposite to the sealing target fluid side radially outward by rotating together with the rotating ring;
It is characterized by providing.

The present invention includes a first fixed ring and a second fixed ring that slide relative to both end faces of the rotating ring. That is, the present invention is a double-type sealing device using two mechanical seals. In the present invention, since the partial impeller that rotates together with the rotating ring is provided, the external fluid can be self-circulated without requiring a pump or the like. The partial impeller is fixed to the outer peripheral surface of the rotating ring. Therefore, since the partial impeller exists near the sliding part between the rotating ring and the first stationary ring and the sliding part between the rotating ring and the second stationary ring, the external fluid is effectively applied to each sliding part. Can be supplied.

A seal cover fixed to the housing and having the rotating ring, the first fixed ring, and the second fixed ring disposed on the inner peripheral surface thereof;
The seal cover includes
A first inflow hole for allowing an external fluid to flow in from a radially outer side than an outer peripheral surface of the first fixed ring and the rotating ring toward a sliding surface between the first fixed ring and the rotating ring;
A second inflow hole for allowing an external fluid to flow in from a radially outer side than the outer peripheral surface of the second fixed ring and the rotating ring toward the sliding surface of the second fixed ring and the rotating ring;
An outflow hole having an inlet for introducing external fluid is formed at a position facing the outer peripheral surface of the partial impeller, and
The sliding surface of the first stationary ring and the rotating ring is located between the position of the opening at the tip of the first inflow hole and the position of the introduction port in the axial direction,
The sliding surface between the second stationary ring and the rotating ring may be located between the position of the opening at the tip of the second inlet hole and the position of the inlet in the axial direction.

  As a result, the external fluid can be more reliably supplied to both the sliding portion between the rotating ring and the first stationary ring and the sliding portion between the rotating ring and the second stationary ring. Further, both the external fluid after being sent to the sliding portion between the rotating ring and the first fixed ring and the external fluid after being sent to the sliding portion between the rotating ring and the second fixed ring are common outflows. Guided to the hole. Therefore, it can suppress that the structure of a flow path becomes complicated. Thereby, it can suppress that the flow path of the external fluid in a sealing device becomes long. Further, in the present invention, the external fluid after being sent to the sliding portion between the rotating ring and the first fixed ring and the external fluid after being sent to the sliding portion between the rotating ring and the second fixed ring In either case, a common partial impeller is used to lead to the outflow hole. Therefore, an increase in the number of parts can be suppressed.

  The partial impeller may be fixed to the outer peripheral surface of the rotating ring by shrink fitting.

  Thereby, even if the rotating ring is made of a brittle material such as carbon or SiC, the partial impeller can be fixed.

  In addition, said each structure can be employ | adopted combining as much as possible.

  As described above, according to the present invention, in the double type sealing device using two mechanical seals, the external fluid can be self-circulated without requiring a pump or the like.

FIG. 1 is a schematic cross-sectional view showing a mounting state of a sealing device according to an embodiment of the present invention. FIG. 2 is a plan view of the partial impeller according to the embodiment of the present invention. FIG. 3 is a sectional view of a partial impeller according to an embodiment of the present invention. FIG. 4 is a partial cross-sectional view of a seal cover according to an embodiment of the present invention. FIG. 5 is a part of a plan view of a partial impeller according to a modification of the present invention. FIG. 6 is a part of a sectional view of a partial impeller according to a modification of the present invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .

(Example)
A sealing device according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic cross-sectional view showing a mounting state of a sealing device according to an embodiment of the present invention. 1 is a cross-sectional view including the central axis of the sealing device. However, in FIG. 1, for convenience of explanation, in order to show characteristic parts, the phase of the cutting position (position in the circumferential direction) is appropriately different. FIG. 2 is a plan view of the partial impeller according to the embodiment of the present invention. FIG. 3 is a cross-sectional view of the partial impeller according to the embodiment of the present invention, and is a BB cross-sectional view in FIG. 4 is a part of a cross-sectional view of the seal cover according to the embodiment of the present invention, and corresponds to a cross-sectional view taken along line AA in the seal cover in FIG.

<Entire sealing device>
In particular, with reference to FIG. 1, the overall configuration of a sealing device according to an embodiment of the present invention will be described. The sealing device 100 according to the present embodiment is provided to seal an annular gap between the rotating shaft 200 and the housing 300 having the shaft hole of the rotating shaft 200. The sealing device 100 according to the present embodiment is a double-type sealing device including two mechanical seals. In the present embodiment, two mechanical seals are provided between the first seal cover 110 and the second seal cover 120 fixed to the housing 300 and the sleeve 130 attached to the outer periphery of the rotating shaft 200. . The first seal cover 110 and the second seal cover 120 are both annular members. The sleeve 130 is attached to the rotary shaft 200 by fixing a sleeve collar 135 attached to the outer peripheral surface of the sleeve 130 with a set screw 135a. Further, the second seal cover 120 is attached to the end surface of the housing 300 on the atmosphere side (A) opposite to the fluid side (F) to be sealed. Further, the first seal cover 110 is attached to the end surface of the second seal cover 120 on the atmosphere side (A). The first seal cover 110 and the second seal cover 120 are fixed to the housing 300 by bolts (not shown).

<Mechanical seal>
The configuration of the mechanical seal according to the present embodiment will be described in more detail. The mechanical seal according to the present embodiment includes a rotary ring 140 that rotates together with the rotary shaft 200, and a first fixed ring 150 and a second fixed ring 160 that are both fixed to the housing 300. The first fixed ring 150 is fixed to the housing 300 by being fixed to the second seal cover 120. The first fixed ring 150 is configured to slide with respect to the end surface on the sealing target fluid side (F) of the rotating ring 140. The first fixed ring 150 is biased toward the rotating ring 140 by a spring 155. The second fixed ring 160 is fixed to the housing 300 by being fixed to the first seal cover 110. The second stationary ring 160 is configured to slide with respect to the end surface on the atmosphere side (A) that is the opposite side to the sealing target fluid side of the rotating ring 140. The second fixed ring 160 is biased toward the rotating ring 140 by a spring 165.

  In the sealing device 100 according to the present embodiment, a partial impeller 170 that generates power for circulating the external fluid by rotating together with the rotating ring 140 is provided on the outer peripheral surface of the rotating ring 140.

<Partial impeller>
The partial impeller 170 according to the present embodiment will be described in more detail. The partial impeller 170 is fixed to the outer peripheral surface of the rotating ring 140 by shrink fitting. In addition, the partial impeller 170 plays a role of guiding the external fluid in both the region to be sealed fluid side (F) and the atmosphere side (A) radially outward by rotating together with the rotary ring 140. More specifically, the partial impeller 170 is formed of an annular member, and a plurality of cutouts 171 and 172 having an arcuate cross section are provided on both side surfaces thereof (see FIGS. 2 and 3). ). Thus, when the partial impeller 170 rotates, the external fluid in both the sealing target fluid side (F) and the atmosphere side (A) is guided radially outward by the plurality of notches 171 and 172.

<Seal cover>
The seal cover according to the present embodiment will be described in more detail. As described above, the seal covers (the first seal cover 110 and the second seal cover 120) according to the present embodiment are fixed to the housing 300, and the rotary ring 140 and the first fixed ring 150 are provided on the inner peripheral surface side thereof. And the second stationary ring 160 is disposed. The first seal cover 110 is formed with an outflow hole 111 provided at one place in the circumferential direction and a plurality of inflow holes 112 provided at intervals in the circumferential direction. The outflow hole 111 and the inflow hole 112 are formed at different positions in the circumferential direction.

  The outflow hole 111 has an introduction port 111 a that guides the external fluid at a position facing the outer peripheral surface of the partial impeller 170. Further, a connection port 111b to which a pipe is connected is provided on the outer peripheral surface side of the first seal cover 110 in the outflow hole 111. Further, a blank piece 113 is provided on the inner peripheral surface side of the first seal cover 110. The blank piece 113 is provided in the vicinity of the end edge on the downstream side in the rotation direction of the partial impeller 170 at the introduction port 111a (the arrow Y direction in FIG. 4). Further, the blank piece 113 is provided so as to protrude inward in the radial direction. Thus, the external fluid guided radially outward by the partial impeller 170 is efficiently guided to the inlet 111a by the blank piece 113.

  The inflow hole 112 is provided on the outer peripheral surface side of the first seal cover 110, and includes a connection port 112c to which piping is connected, and a first inflow hole 112a and a second inflow hole 112b branched from the connection port 112c. The The first inflow hole 112a serves to allow the external fluid to flow in from the radially outer side than the outer peripheral surfaces of the first fixed ring 150 and the rotary ring 140 toward the sliding surface between the first fixed ring 150 and the rotary ring 140. I'm in charge. In addition, the second inflow hole 112 b allows the external fluid to flow in from the radially outer side than the outer peripheral surfaces of the second fixed ring 160 and the rotating ring 140 toward the sliding surface between the second fixed ring 160 and the rotating ring 140. Have a role.

  Here, the sliding surface S1 between the first fixed ring 150 and the rotating ring 140 is positioned and introduced in the axial direction (the central axial direction of the rotating shaft 200; the same applies hereinafter) at the tip opening 112a1 in the first inflow hole 112a. It is located between the position of the mouth 111a. The sliding surface S2 between the second fixed ring 160 and the rotating ring 140 is located between the position of the opening 112b1 at the tip of the second inflow hole 112b and the position of the introduction port 111a in the axial direction.

  The sealing device 100 is provided with a plurality of seal rings O such as O-rings that seal the gaps between the members. Further, in the sealing device 100, a plurality of pins P for preventing rotation of the members are provided. Since a sealing device having a mechanical seal is provided with a plurality of these seal rings O and pins P, a detailed description thereof will be omitted.

<Operation of sealing device>
An operation of the sealing device 100 according to the present embodiment will be described. According to the sealing device 100 configured as described above, the rotating ring 140 rotates with the rotation of the rotating shaft 200, and the end faces of the rotating stationary ring 140 that slide with the first stationary ring 150 in a stationary state slide. In addition, the end surfaces of the second stationary ring 160 that is stationary and the rotating ring 140 that rotates are slid. Here, the plurality of springs 155 provided in the circumferential direction biases the first fixed ring 150 toward the rotary ring 140, so that the first fixed ring 150 and the rotary ring 140 are kept in a sliding state. Further, since the second fixed ring 160 is biased toward the rotating ring 140 by the plurality of springs 165 provided in the circumferential direction, the second fixed ring 160 and the rotating ring 140 are also kept in a sliding state. With the above configuration, the fluid on the fluid to be sealed side (F) is prevented from leaking from the inner peripheral surface side to the outer peripheral surface side of the mechanical seal by the sliding portion between the first fixed ring 150 and the rotating ring 140. . Note that leakage from other than the sliding portion is suppressed by the plurality of seal rings O. Further, even when the sealing target fluid leaks to the outer peripheral surface side of the mechanical seal, the sealing target fluid leaks to the atmosphere side (A) due to the sliding portion of the second stationary ring 160 and the rotating ring 140. Is suppressed.

  Then, the rotation of the rotary shaft 200 causes the rotating ring 140 and the partial impeller 170 to rotate, whereby the external fluid circulates. The external fluid is supplied to the inside of the sealing device 100 for the purpose of cooling the two sliding portions described above and cleaning various members. Hereinafter, the flow path configuration in which the external fluid circulates will be described in more detail.

  On the outer peripheral surface side of the mechanical seal, there is a space (intermediate chamber) separated from both the region where the fluid to be sealed is sealed and the region exposed to the atmosphere by the two sliding portions described above. Existing. This space is filled with external fluid. Further, this space is divided by a partial impeller 170 into a region to be sealed fluid side (F) and a region on the atmosphere side (A). Then, as described above, the partial impeller 170 rotates together with the rotating ring 140, whereby the external fluid in both the sealing target fluid side (F) and the atmosphere side (A) is guided to the outflow hole 111. The external fluid that has flowed out of the sealing device 100 from the outflow hole 111 flows into the flow path 400 provided outside the sealing device 100.

  The flow path 400 is simply illustrated in FIG. The flow path 400 includes a tank 410 that stores external fluid, a cooler 420 that cools the external fluid, and a plurality of pipes. In addition, the cooler 420 which concerns on a present Example is comprised by piping formed in spiral. Further, an arrow X in FIG. 1 indicates the direction in which the external fluid flows. The cooler does not need to be provided in the flow path, and it is sufficient that the external fluid is cooled when flowing into the sealing device. For example, a mechanism for cooling the external fluid may be provided in the tank.

  The external fluid flowing out from the outflow hole 111 to the flow path 400 provided outside the sealing device 100 flows into the inflow hole 112. Then, the external fluid flows into the area to be sealed (F) and the atmosphere (A), which are separated by the partial impeller 170, by the first inlet 112a and the second inlet 112b, respectively.

  As described above, the external fluid circulates between the inside of the sealing device 100 and the flow path 400 provided outside the sealing device 100 while the partial impeller 170 rotates together with the rotating ring 140.

<Excellent point of sealing device according to this embodiment>
As described above, the sealing device 100 according to the present embodiment includes the first fixed ring 150 and the second fixed ring 160 that slide with respect to both end surfaces of the rotating ring 140, respectively. That is, the sealing device 100 according to the present embodiment is a double-type sealing device using two mechanical seals. In this embodiment, since the partial impeller 170 that rotates together with the rotary ring 140 is provided, the external fluid can be self-circulated without requiring a pump or the like.

  The partial impeller 170 is fixed to the outer peripheral surface of the rotating ring 140. Therefore, since the partial impeller 170 exists near the sliding portion between the rotating ring 140 and the first fixed ring 150 and the sliding portion between the rotating ring 140 and the second fixed ring 160, The external fluid can be supplied effectively.

  Further, in the sealing device 100 according to the present embodiment, the first inflow hole 112a through which the external fluid flows into the first seal cover 110 toward the sliding surface S1 between the first stationary ring 150 and the rotating ring 140, A second inflow hole 112b through which the external fluid flows is formed toward the sliding surface S2 between the second fixed ring 160 and the rotating ring 140. The first seal cover 110 is also formed with an outflow hole 111 having an introduction port 111a for guiding external fluid at a position facing the outer peripheral surface of the partial impeller 170. The sliding surface S1 between the first fixed ring 150 and the rotary ring 140 is located between the position of the opening 112a1 at the tip of the first inflow hole 112a and the position of the inlet 111a in the axial direction. The sliding surface S2 between the second fixed ring 160 and the rotating ring 140 is located between the position of the opening 112b1 at the tip of the second inflow hole 112b and the position of the introduction port 111a in the axial direction.

  By being configured as described above, both the sliding portion of the rotating ring 140 and the first fixed ring 150 and the sliding portion of the rotating ring 140 and the second fixed ring 160 are more reliably external. Fluid can be supplied. Thereby, it can suppress that deterioration progresses only in either one. Further, since not only the sliding portion but also the springs 155 and 165 and the pin P are cleaned, it is possible to prevent foreign matters from accumulating and lowering their functions.

  Further, either the external fluid after being sent to the sliding portion between the rotating ring 140 and the first fixed ring 150 or the external fluid after being sent to the sliding portion between the rotating ring 140 and the second fixed ring 160. Are also led to a common outflow hole 111. Therefore, it can suppress that the structure of a flow path becomes complicated. Thereby, it can suppress that the flow path of the external fluid in the sealing device 100 becomes long. Therefore, since the power by the partial impeller 170 can be small, it is not necessary to increase the size of the partial impeller 170. Alternatively, since the flow path in the sealing device 100 may be short, the flow path outside the sealing device 100 can be lengthened. Accordingly, the cooling function can be enhanced by lengthening the pipe line of the cooler 420.

  In this embodiment, the external fluid after being sent to the sliding portion between the rotating ring 140 and the first fixed ring 150 and the sliding portion between the rotating ring 140 and the second fixed ring 160 are sent. All of the subsequent external fluids are configured to be guided to the outflow hole 111 using a common partial impeller 170. Therefore, an increase in the number of parts can be suppressed.

  Furthermore, the partial impeller 170 according to the present embodiment is fixed to the outer peripheral surface of the rotary ring 140 by shrink fitting. Thereby, even if the rotating ring 140 is made of a brittle material such as carbon or SiC, the partial impeller 170 can be fixed.

(Other)
In the partial impeller 170 which concerns on the said Example, the case where it comprises so that the shape and magnitude | size of the notches 171 and 172 and the number of arrangement | positioning provided in the to-be-sealed fluid side (F) and the atmosphere side (A) may become equal is shown. . However, the shape, size, and number of notches 171 and 172 can be set as appropriate according to the size of the apparatus and environmental conditions. That is, it is possible to adopt a shape in which the notch shape and size are different between the sealing target region side (F) and the atmosphere side (A), or to set the number of both to be different.

  Further, in the partial impeller 170 according to the above-described embodiment, in order to exert a function of guiding the external fluid in both the region to be sealed fluid side (F) and the atmosphere side (A) to the outside in the radial direction, The structure provided with the notches 171 and 172 is adopted. However, the partial impeller in the present invention is not limited to such a configuration. Hereinafter, modified examples of the partial impeller will be described with reference to FIGS. 5 and 6. FIG. 5 is a part of a plan view of a partial impeller according to a modification of the present invention. FIG. 6 is a part of a sectional view of a partial impeller according to a modification of the present invention, and is a sectional view taken on line CC in FIG.

  A partial impeller 170X according to the illustrated modification is configured by an annular member, and a plurality of grooves 171X having an arcuate cross section are provided on the inner peripheral surface side thereof at intervals in the circumferential direction. Each groove 171X is provided with a through-hole 172X that penetrates from the groove bottom to the outer peripheral surface.

  Also in the partial impeller 170X configured as described above, as in the partial impeller 170 shown in the first embodiment, the external fluid in both the region to be sealed fluid side (F) and the atmosphere side (A) is reduced in diameter. The function of guiding to the outside in the direction can be exhibited. In addition, forming the plurality of grooves 171 and the through holes 172 by machining has an advantage that the plurality of notches 171 and 172 are easier to process than forming by machining.

100 sealing device 110 first seal cover 111 outflow hole 111a introduction port 111b connection port 112 inflow hole 112a first inflow hole 112a1 opening 112b second inflow hole 112b1 opening 112c connection port 113 blank piece 120 second seal cover 130 sleeve 135 Sleeve collar 135a Set screw 140 Rotary ring 150 First fixed ring 155 Spring 160 Second fixed ring 165 Spring 170, 170X Partial impeller 171, 172 Notch 171X Groove 172X Through hole 200 Rotating shaft 300 Housing 400 Flow path 410 Tank 420 Cooler O Seal ring P pin

Claims (3)

A sealing device for sealing an annular gap between a rotating shaft and a housing having a shaft hole of the rotating shaft,
A rotating ring that rotates with the rotating shaft;
A first fixed ring fixed to the housing and sliding with respect to an end surface of the rotating ring on the fluid side to be sealed;
A second fixed ring that is fixed to the housing and that slides on an end surface of the rotating ring opposite to the fluid to be sealed;
A partial impeller that is fixed to the outer peripheral surface of the rotating ring and guides the external fluid in both the region to be sealed and the side opposite to the sealing target fluid side radially outward by rotating together with the rotating ring;
A sealing device comprising: A seal cover fixed to the housing and having the rotating ring, the first fixed ring, and the second fixed ring disposed on the inner peripheral surface thereof;
The seal cover includes
A first inflow hole for allowing an external fluid to flow in from a radially outer side than an outer peripheral surface of the first fixed ring and the rotating ring toward a sliding surface between the first fixed ring and the rotating ring;
A second inflow hole for allowing an external fluid to flow in from a radially outer side than the outer peripheral surface of the second fixed ring and the rotating ring toward the sliding surface of the second fixed ring and the rotating ring;
An outflow hole having an inlet for introducing external fluid is formed at a position facing the outer peripheral surface of the partial impeller, and
The sliding surface of the first stationary ring and the rotating ring is located between the position of the opening at the tip of the first inflow hole and the position of the introduction port in the axial direction,
The sliding surface of the second stationary ring and the rotating ring is located between the position of the opening at the tip of the second inflow hole and the position of the introduction port in the axial direction. The sealing device as described.   The sealing device according to claim 1, wherein the partial impeller is fixed to the outer peripheral surface of the rotating ring by shrink fitting.

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