Mechanical seal device

Abstract

To provide a mechanical seal device which can circulate a sealing liquid at a necessary flow rate even in a rotary device which rotates at low speed.SOLUTION: A circulation pump mechanism 30 of a mechanical seal device 1 includes: a rotor 31 attached to a rotary shaft 51; vanes 32 which protrude or retract relative to an outer peripheral surface 31b of the rotor 31; biasing members 33 which bias the vanes 32 in a direction such that the vanes 32 protrude; a housing 34 which is formed eccentrically relative to the outer peripheral surface 31b of the rotor 31, has an inner peripheral surface 35b on which protruding ends 32a of the vanes 32 slide in conjunction with rotation of the rotor 31, and is attached to a seal case 2; and pump chambers 38 defined by the vanes 32 between the outer peripheral surface 31b of the rotor 31 and the inner peripheral surface 35b of the housing 34. The housing 34 has: a suction port 36a which suctions a sealing liquid into the pump chamber 38; and a discharge port 37a which discharges the sealing liquid from the pump chamber 38.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a mechanical seal device. [Background technology]

[0002] Mechanical seals installed in rotating equipment are equipped with a circulation structure that circulates a sealing liquid to increase the lubrication between the seal surfaces of a rotating seal ring and a stationary seal ring and to remove the sliding heat generated between the seal surfaces (see, for example, Patent Document 1). The mechanical seal in Patent Document 1 is equipped with a pumping ring as the circulation structure that circulates the sealing liquid by utilizing the centrifugal force caused by the rotation of the rotating shaft of the rotating equipment. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2014 / 208235 Summary of the Invention [Problem to be solved by the invention]

[0004] In the mechanical seal of Patent Document 1, the circulating flow rate of the sealing liquid depends on the magnitude of the centrifugal force. Therefore, in a rotating device that rotates at high speed, such as a pump, the centrifugal force is large, so it is possible to circulate the required flow rate of sealing liquid, but in a rotating device that rotates at low speed, such as a mixer, the centrifugal force is small, so it may not be possible to circulate the required flow rate of sealing liquid.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a mechanical seal device that can circulate a required flow rate of sealing liquid even in rotating equipment that rotates at a low speed. [Means for solving the problem]

[0006] The mechanical seal device of the present invention comprises a seal case that surrounds a rotating shaft of a rotating device and divides an in-machine area and an out-machine area of ​​the rotating device, at least one mechanical seal disposed between the seal case and the rotating shaft, an annular sealing liquid chamber that is formed in the seal case and into which a sealing liquid that lubricates a sliding part of the mechanical seal is introduced, and a circulation pump mechanism that circulates the sealing liquid in the sealing liquid chamber, the circulation pump mechanism comprising a rotor that is attached to the rotating shaft side so as to be integrally rotatable with the rotating shaft, a plurality of vanes that are provided at predetermined intervals in the circumferential direction of the rotor and can freely protrude and retract from the outer circumferential surface of the rotor, and a circulation pump mechanism that circulates the sealing liquid in the sealing liquid chamber. a housing attached to the seal case, the housing having an inner periphery formed eccentrically with respect to the outer periphery of the rotor and a sliding surface along which the protruding ends of the vanes slide as the rotor rotates; and a plurality of pump chambers partitioned by the plurality of vanes between the outer periphery of the rotor and the sliding surface of the housing, the housing having a suction port through which sealing liquid is sucked from the sealing liquid chamber to the pump chamber, and a discharge port through which sealing liquid is discharged from the pump chamber to the sealing liquid chamber.

[0007] According to the present invention, in the circulation pump mechanism, when the rotor rotates together with the rotating shaft of the rotating device, the protruding end of each vane, which is biased in the protruding direction by the biasing member, rotates while sliding on the eccentric sliding surface of the housing, changing the volume of each pump chamber. This change in volume causes the sealing liquid in the sealing liquid chamber to be sucked into the pump chamber from the suction port and the sealing liquid in the pump chamber to be discharged from the discharge port to the sealing liquid chamber, thereby circulating the sealing liquid in the sealing liquid chamber. As a result, the circulation pump mechanism functions as a vane pump and can circulate a constant volume of sealing liquid with each rotation of the rotor, so that a required flow rate of sealing liquid can be circulated even in a rotating device that rotates at a low speed.

[0008] The housing preferably has a cam ring having an inner circumferential surface which is the sliding surface, and a pair of outer plates arranged on either axial side of the cam ring, the cam ring and the pair of outer plates being attached so as to be freely movable in the axial direction relative to the seal case, and the mechanical seal device preferably comprises a pressing portion which presses one of the pair of outer plates toward one axial side which is the cam ring side, and a regulating portion which regulates the other of the pair of outer plates from moving toward the one axial side beyond a predetermined position relative to the seal case.

[0009] In this case, the cam ring and the pair of outer plates in the housing are held in a state in which they are pressed to one axial side by the pressing portion and are sandwiched from both axial sides by the restricting portion and the pressing portion. This brings the outer plates into close contact with both axial sides of the cam ring, thereby preventing the sealing liquid in the pump chamber from leaking to the outside. As a result, a decrease in the circulation efficiency of the sealing liquid can be prevented. In addition, since the cam ring and the pair of outer plates are movable to the other axial side against the pressing force of the pressing portion, even if the rotating shaft moves to the other axial side due to axial wobble or the like, the entire housing can move to the other axial side following the movement. As a result, damage to the circulation pump mechanism can be prevented.

[0010] The at least one mechanical seal preferably includes a first mechanical seal disposed in the inboard area and a second mechanical seal disposed in the outboard area. In this case, in a mechanical seal device in which a double-type mechanical seal is formed by a first mechanical seal and a second mechanical seal, a relatively large amount of sealing liquid needs to be circulated to lubricate the sliding parts of each mechanical seal. However, even in such a mechanical seal device, a constant volume of sealing liquid can be circulated for each rotation of the rotor as described above, so that the required flow rate of sealing liquid can be circulated even in rotating equipment that rotates at a low speed.

[0011] The circulation pump mechanism is preferably disposed between the first mechanical seal and the second mechanical seal. In this case, the circulation pump mechanism does not overlap with the first mechanical seal and the second mechanical seal in the radial direction, so that the mechanical seal device can be configured to be compact in the radial direction.

[0012] It is preferable that the seal case has a supply path that supplies sealing liquid to the sealing liquid chamber and a discharge path that discharges the sealing liquid from the sealing liquid chamber, and the mechanical seal device has a circulation path that returns the sealing liquid discharged from the discharge path to the supply path, and a first cooling mechanism that is provided in the circulation path and cools the sealing liquid. In this case, even if the temperature of the sealing liquid rises in the sealing liquid chamber due to sliding heat or the like generated at the sliding part of the mechanical seal, the heated sealing liquid can be cooled by the first cooling mechanism while passing through the circulation path from the discharge path to the supply path.

[0013] The first cooling mechanism preferably includes a tank for temporarily storing the sealing liquid, and a cooling coil provided in the tank and having a cooling medium flowing therethrough. In this case, when the heated sealing liquid is temporarily stored in the tank, the sealing liquid can be cooled by the cooling coil, and the tank for temporarily storing the sealing liquid can be used as a part of the first cooling mechanism, thereby simplifying the configuration of the first cooling mechanism.

[0014] The mechanical seal device preferably includes a second cooling mechanism that is provided on the supply passage side of the circulation passage relative to the first cooling mechanism and that cools the sealing liquid. In this case, the sealing liquid that has not been completely cooled by the first cooling mechanism can be cooled by the second cooling mechanism, and therefore the cooling capacity for the sealing liquid can be improved. Effect of the Invention

[0015] According to the present invention, even in a rotating device that rotates at a low speed, a required flow rate of sealing liquid can be circulated. [Brief description of the drawings]

[0016] [Figure 1] 1 is a cross-sectional view of a mechanical seal device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along the line II in FIG. [Diagram 3] 2 is an enlarged cross-sectional view of a main part of FIG. 1 showing a circulation pump mechanism. FIG. [Figure 4] FIG. 4 is a side view of the first outer panel as seen from the outside of the aircraft. [Diagram 5] FIG. 4 is a side view of the second outer panel as seen from the outside of the aircraft. [Figure 6] FIG. 4 is a schematic configuration diagram of a mechanical seal device according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a cross-sectional view of a first cooling mechanism of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Next, preferred embodiments of the present invention will be described with reference to the accompanying drawings. First Embodiment [Overall configuration] 1 is a cross-sectional view of a mechanical seal device according to a first embodiment of the present invention. The mechanical seal device 1 is provided in a rotating device 50 such as a pump or an agitator that handles a sealed fluid. The mechanical seal device 1 includes a seal case 2, a first mechanical seal 6, a second mechanical seal 7, a sealing liquid chamber 8, and a circulating pump mechanism 30.

[0018] The seal case 2 is fixed to a casing (not shown) of the rotating device 50, and divides an in-machine area A and an outside-machine area B of the rotating device 50. The seal case 2 of this embodiment has, in order from the outside-machine area B side to the in-machine area A side, a first case body 3, a second case body 4, and a third case body 5. The first case body 3, the second case body 4, and the third case body 5 are each formed in an annular shape and surround a rotation shaft 51 of the rotating device 50. Hereinafter, in this specification, the in-machine area A side is referred to as the inside side, and the outside-machine area B side is referred to as the outside side.

[0019] The first mechanical seal 6 and the second mechanical seal 7 constitute a double-type mechanical seal, and are arranged at a predetermined interval between the seal case 2 and the rotating shaft 51 in the axial direction of the rotating shaft 51 (hereinafter simply referred to as the "axial direction"). The first mechanical seal 6 is arranged on the inside of the machine, and provides a seal between the inside area A and the sealing liquid chamber 8 (described later). The second mechanical seal 7 is arranged on the outside of the machine, and provides a seal between the outside area B and the sealing liquid chamber 8.

[0020] The first mechanical seal 6 includes a spring retainer 11, a spring 12, a drive pin 13, a drive collar 14, a retainer 15, a rotating seal ring 16, a stationary seal ring 17, a set screw 18, a pin 19, an O-ring 20, and an O-ring 21.

[0021] The spring retainer 11 is formed in an annular shape, and is fixed to the outer periphery of the rotating shaft 51 via a sleeve 9. The spring retainer 11 is formed with a plurality of radially penetrating screw holes 11a (only one is shown in FIG. 1) at predetermined intervals in the circumferential direction. A set screw 18 is screwed into each screw hole 11a, and the tip of the set screw 18 presses against the outer periphery of the sleeve 9. In this way, the spring retainer 11 is fixed to the rotating shaft 51 side by the set screw 18.

[0022] A plurality of through holes 11b (only one is shown in FIG. 1) penetrating in the axial direction are formed at predetermined intervals in the circumferential direction in the spring retainer 11. A drive pin 13 is inserted into each through hole 11b, and the drive pin 13 is held relative to the spring retainer 11 so as to be freely movable within a predetermined range in the axial direction.

[0023] An end portion on the inboard side of the drive pin 13 is fixed to an annular drive collar 14 attached to the outer circumferential surface of the sleeve 9 so as to be axially movable on the inboard side of the spring retainer 11. Specifically, the drive collar 14 is formed with a plurality of screw holes 14a (only one is shown in FIG. 1 ) penetrating in the axial direction at predetermined intervals in the circumferential direction. Male threads 13a formed on the end portion on the inboard side of each drive pin 13 are screwed into each screw hole 14a. As a result, the drive collar 14 is held axially movable relative to the spring retainer 11 via the drive pin 13, while its relative rotation with respect to the spring retainer 11 is restricted.

[0024] The spring retainer 11 holds one end of a plurality of springs 12 (only one is shown in FIG. 1) spaced at a predetermined interval in the circumferential direction. The other end of the spring 12 abuts against the end face of the drive collar 14 on the outer side of the machine. As a result, the drive collar 14 is biased toward the inner side by the biasing force of the spring 12.

[0025] An annular retainer 15 is disposed adjacent to the drive collar 14 on the inboard side. The retainer 15 is attached so as to be movable in the axial direction relative to the outer circumferential surface of the sleeve 9. A plurality of engagement pins 15a (only one is shown in FIG. 1 ) protruding outward are provided at a predetermined interval in the circumferential direction on the outboard end surface of the retainer 15.

[0026] Each engagement pin 15a is engaged with an engagement hole 14b formed in the drive collar 14. As a result, the retainer 15 is held axially movable together with the drive collar 14 with respect to the rotation shaft 51, while its relative rotation with respect to the drive collar 14 is restricted. A rubber O-ring 20 is provided on the inner periphery of the retainer 15 to provide a seal (secondary seal) between the retainer 15 and the outer periphery of the sleeve 9.

[0027] An annular rotary seal ring 16 is fitted and fixed to the inboard side of the retainer 15. The inboard end face of the rotary seal ring 16 is formed as a seal surface 16a. A stationary seal ring 17 is disposed adjacent to the inboard side of the rotary seal ring 16. The stationary seal ring 17 is fitted and fixed to the inner periphery of the third case body 5. The outboard end face of the stationary seal ring 17 is formed as a seal surface 17a against which the seal surface 16a of the rotary seal ring 16 slides.

[0028] A plurality of pin grooves 17b (only one shown in FIG. 1) are formed at a predetermined interval in the circumferential direction on the inboard side of the stationary seal ring 17. A pin 19 that is fixed on the inner circumferential side of the third case body 5 and protrudes outward is inserted into each pin groove 17b. This restricts the relative rotation of the stationary seal ring 17 with respect to the third case body 5. A rubber O-ring 21 is provided on the outer periphery of the stationary seal ring 17 to provide a seal (secondary seal) between the stationary seal ring 17 and the inner circumferential surface of the third case body 5.

[0029] Similar to the first mechanical seal 6, the second mechanical seal 7 includes a spring retainer 11, a spring 12, a drive pin 13, a drive collar 14, a retainer 15, a rotating seal ring 16, a stationary seal ring 17, a set screw 18, a pin 19, an O-ring 20, and an O-ring 21. The spring retainer 11 to the O-ring 21 which are components of the second mechanical seal 7 are disposed axially symmetrically with the spring retainer 11 to the O-ring 21 which are components of the first mechanical seal 6, with the circulation pump mechanism 30 in between.

[0030] The pin 19 of the second mechanical seal 7 is fixed to protrude toward the inside of the machine on the inner periphery side of the first case body 3. The O-ring 21 of the second mechanical seal 7 provides a seal (secondary seal) between the stationary seal ring 17 and the first case body 3. Other configurations of the second mechanical seal 7 are similar to those of the first mechanical seal 6, so description thereof will be omitted.

[0031] The sealing liquid chamber 8 is an annular space formed inside the seal case 2. A sealing liquid is introduced into the sealing liquid chamber 8 to lubricate and cool the sliding portion between the seal surfaces 16a, 17a of the first mechanical seal 6 and the sliding portion between the seal surfaces 16a, 17a of the second mechanical seal 7. As the sealing liquid, water, oil, solvent, etc. that will not cause any problems if mixed into the sealed fluid is used according to the sealed fluid.

[0032] The second case body 4 is formed with a supply path 4a for supplying the sealing liquid from the outside to the sealing liquid chamber 8. The first case body 3 is formed with a discharge path 3a for discharging the sealing liquid from the sealing liquid chamber 8 to the outside. As a result, the sealing liquid supplied from the supply path 4a to the sealing liquid chamber 8 during operation of the rotating device 50 lubricates and cools each sliding portion of the first and second mechanical seals 6, 7, and is discharged to the outside from the discharge path 3a.

[0033] [Circulation pump mechanism] Fig. 2 is a cross-sectional view taken along the line II in Fig. 1. In Fig. 1 and Fig. 2, the circulation pump mechanism 30 circulates the sealing liquid in the sealing liquid chamber 8, and is disposed between the first mechanical seal 6 and the second mechanical seal 7 in the seal case 2. The circulation pump mechanism 30 includes a rotor 31, a plurality of vanes 32, a plurality of biasing members 33, a housing 34, and a plurality of pump chambers 38.

[0034] The rotor 31 is made of an annular member made of a metal such as stainless steel, and is fixed to the outer periphery of the sleeve 9. Specifically, a key 39 fixed to the outer periphery of the sleeve 9 engages with a key groove 31a formed on the inner periphery of the rotor 31, thereby fixing the rotor 31 to the outer periphery of the sleeve 9. As a result, the rotor 31 is attached to the rotating shaft 51 side so as to be able to rotate integrally therewith, and the rotational torque of the rotating shaft 51 is transmitted to the rotor 31 via the sleeve 9.

[0035] Fig. 3 is an enlarged cross-sectional view of the main part of Fig. 1 showing the circulation pump mechanism 30. In Fig. 2 and Fig. 3, the rotor 31 is formed with a plurality of mounting grooves 31c (four in Fig. 2) that open on its outer circumferential surface 31b at predetermined intervals in the circumferential direction. Each mounting groove 31c is formed over the entire width of the rotor 31 (left and right direction in Fig. 3).

[0036] A vane 32 is inserted into each mounting groove 31c so as to be freely projected and retracted from the outer circumferential surface 31b of the rotor 31. The vane 32 is made of, for example, a flat plate member, and the width of the vane 32 is set to be substantially the same dimension as the width of the mounting groove 31c (rotor 31). Further, a predetermined number of (three in FIG. 3) biasing members 33 are arranged in the width direction of the rotor 31 on the inner side of each mounting groove 31c relative to the vane 32. The biasing members 33 are made of, for example, compression coil springs, and bias the vane 32 in a direction to protrude from the outer circumferential surface 31b of the rotor 31.

[0037] The housing 34 is attached to the seal case 2, and has a cam ring 35, and a first outer plate 36 and a second outer plate 37 arranged on both sides of the cam ring 35 in the axial direction. The cam ring 35 is made of an annular member made of a metal such as stainless steel, and is disposed between the first case body 3 and the rotor 31.

[0038] The width of the cam ring 35 is set to be approximately the same dimension as the width of the rotor 31. The outer peripheral surface 35a of the cam ring 35 is a circumferential surface centered on the axis C1 of the rotating shaft 51. The inner peripheral surface 35b of the cam ring 35 is a circumferential surface centered on a position eccentric to the axis C1 of the rotating shaft 51, which is a center C2. As a result, the inner peripheral surface 35b of the cam ring 35 is eccentric with respect to the outer peripheral surface 31b of the rotor 31. The inner peripheral surface 35b of the cam ring 35 is a sliding surface against which the protruding ends 32a of the vanes 32 slide as the rotor 31 rotates.

[0039] The first outer plate 36 and the second outer plate 37 are made of, for example, carbon disk members, and are disposed between the first case body 3 and the sleeve 9. Both axial side surfaces of the rotor 31 slide against the outer side surface of the first outer plate 36 and the inner side surface of the second outer plate 37, respectively.

[0040] With the above configuration, a plurality of pump chambers 38 (four in FIG. 2) are formed between the outer peripheral surface 31b of the rotor 31 and the inner peripheral surface 35b of the cam ring 35 inside the housing 34, partitioned by the vanes 32, 32 adjacent in the circumferential direction. The volume of each pump chamber 38 changes with the rotation of the rotor 31. For example, in this embodiment, with each rotation of the rotor 31 in the direction of arrow E, the volume of the pump chamber 38 changes so as to gradually increase in a first angle range θ1 from 6 o'clock to 12 o'clock in FIG. 2, and the volume of the pump chamber 38 changes so as to gradually decrease in a second angle range θ2 from 12 o'clock to 6 o'clock in FIG. 2.

[0041] 4 is a side view of the first outer plate 36 as viewed from the outside of the machine. As shown in FIG. 1 and FIG. 4, in the first angle range θ1 of the first outer plate 36, a plurality of (three in FIG. 4) suction ports 36a are formed at a predetermined interval in the circumferential direction. As a result, when each pump chamber 38 passes through the first angle range θ1 due to the rotation of the rotor 31, the volume of the pump chamber 38 gradually increases, and the pressure inside the pump chamber 38 changes from positive pressure to negative pressure. As a result of the negative pressure inside the pump chamber 38, an action of sucking the seal liquid into the pump chamber 38 from each suction port 36a occurs. As a result, the seal liquid in the seal liquid chamber 8 is sucked into the pump chamber 38 from each suction port 36a.

[0042] 5 is a side view of the second outer plate 37 as seen from the outside of the machine. As shown in FIG. 1 and FIG. 5, in the second angle range θ2 of the second outer plate 37, a plurality of (three in FIG. 4) discharge ports 37a are formed at a predetermined interval in the circumferential direction. As a result, when each pump chamber 38 passes through the second angle range θ2 due to the rotation of the rotor 31, the volume of the pump chamber 38 gradually decreases, and the pressure inside the pump chamber 38 changes from negative pressure to positive pressure. As a result of the positive pressure inside the pump chamber 38, an action of discharging the sealing liquid from each discharge port 37a to the outside of the pump chamber 38 occurs. As a result, the sealing liquid in the pump chamber 38 is discharged from each discharge port 37a to the sealing liquid chamber 8.

[0043] With the above configuration, the circulation pump mechanism 30 functions as a vane pump and can circulate a constant volume of sealing liquid for each rotation of the rotor 31. For ease of understanding, the positions of the suction port 36a and the discharge port 37a are shifted in Fig. 1 (the same applies to Fig. 3).

[0044] [Pressing and Regulating Parts] In Fig. 3, an annular stepped surface 3b is formed on the inner circumference of the first case body 3 on the machine inboard side of the second mechanical seal 7. An annular protruding portion 4b is formed on the inner circumference of the second case body 4, protruding toward the machine outboard side on the radially inner side of the inner peripheral surface of the first case body 3. A protruding end surface 4c of the protruding portion 4b is disposed on the machine outboard side of the first mechanical seal 6, and is disposed axially opposite the stepped surface 3b of the first case body 3. A rubber O-ring 25 is provided on the outer circumference of the protruding portion 4b to provide a seal (secondary seal) between the protruding portion 4b and the inner peripheral surface of the first case body 3.

[0045] The housing 34 of the circulation pump mechanism 30 is disposed between the step surface 3b of the first case body 3 and the protruding end surface 4c of the second case body 4. The axial width of the housing 34 is formed shorter than the axial distance between the step surface 3b and the protruding end surface 4c. As a result, the cam ring 35, the first outer plate 36, and the second outer plate 37 of the housing 34 are attached to the seal case 2 so as to be freely movable in the axial direction.

[0046] As shown in Figures 1 and 2, a plurality of (three in Figure 2) through holes 35c are formed in the cam ring 35 at predetermined intervals in the circumferential direction and extend therethrough in the axial direction. As shown in Figures 1 and 4, a plurality of (three in Figure 4) through holes 36c are formed in the first outer plate 36 at predetermined intervals in the circumferential direction and extend therethrough in the axial direction. As shown in Figures 1 and 5, a plurality of (three in Figure 5) through holes 37c are formed in the second outer plate 37 at predetermined intervals in the circumferential direction and extend therethrough in the axial direction.

[0047] 1, a pin 40 passes through each of the through holes 35c, 36c, 37c of the cam ring 35, the first outer plate 36, and the second outer plate 37. The inboard end of the pin 40 is inserted into a pin groove 4d formed in the second case body 4. The outboard end of the pin 40 is inserted into a pin groove 3d formed in the first case body 3. As a result, the pin 40 restricts the cam ring 35, the first outer plate 36, and the second outer plate 37 from rotating relative to the seal case 2.

[0048] As shown in Fig. 3, the protruding portion 4b of the second case body 4 has a plurality of mounting grooves 4e (only one in Fig. 3) formed at a predetermined interval in the circumferential direction and opening at the protruding end face 4c. A pressing portion 41 made of, for example, a compression coil spring is inserted into each mounting groove 4e. One end of the pressing portion 41 abuts on the bottom of the mounting groove 4e, and the other end of the pressing portion 41 protrudes outward beyond the protruding end face 4c and abuts on the side surface of the first outer plate 36 on the inboard side. As a result, the pressing portion 41 presses the first outer plate 36 toward the outboard side (one axial direction side).

[0049] As described above, by the pressing portion 41 pressing the first outer plate 36 toward the outside of the aircraft, the housing 34 is positioned biased toward the outside of the aircraft between the step surface 3b of the first case body 3 and the protruding end surface 4c of the second case body 4, and the outside side of the second outer plate 37 abuts against the step surface 3b of the first case body 3.

[0050] Therefore, the step surface 3b of the first case body 3 functions as a restricting portion that restricts the second outer plate 37 from moving toward the outside (one axial side) beyond a predetermined position with respect to the seal case 2. As a result, the housing 34 is held in a state where it is sandwiched from both axial sides by the restricting portion (step surface) 3b and the pressing portion 41, and is freely movable toward the inside (the other axial side) against the pressing force of the pressing portion 41.

[0051] As described above, the mechanical seal device 1 includes the restricting portion (step surface) 3b and the pressing portion 41, which hold the housing 34 in a sandwiched state from both axial sides and allow the housing 34 to move toward the inboard side. By sandwiching the housing 34 from both axial sides between the restricting portion 3b and the pressing portion 41, the outboard side surface of the first outer plate 36 and the inboard side surface of the second outer plate 37 are in close contact with both axial side surfaces of the cam ring 35, respectively. Note that the restricting portion may be provided separately from the first case body 3.

[0052] [Effects of the first embodiment] As described above, according to the mechanical seal device 1 of this embodiment, in the circulation pump mechanism 30, when the rotor 31 rotates together with the rotating shaft 51 of the rotating equipment 50, the protruding end 32a of each vane 32, which is biased in a protruding direction by the biasing member 33, rotates while sliding on the eccentric inner circumferential surface 35b of the housing 34, thereby changing the volume of each pump chamber 38. Due to this change in volume, an action of sucking the sealing liquid in the sealing liquid chamber 8 from the suction port 36a into the pump chamber 38 and an action of discharging the sealing liquid in the pump chamber 38 from the discharge port 37a to the sealing liquid chamber 8 occur, so that the sealing liquid in the sealing liquid chamber 8 can be circulated.

[0053] As a result, the circulating pump mechanism 30 functions as a vane pump and can circulate a constant volume of sealing liquid for each rotation of the rotor 31, so that a required flow rate of sealing liquid can be circulated even in a rotating device 50 that rotates at a low speed. In particular, in a mechanical seal device 1 equipped with a double type mechanical seal as in this embodiment, a relatively large amount of sealing liquid needs to be circulated to lubricate and cool the sliding parts of each of the mechanical seals 6 and 7, so that application of the present invention is more effective.

[0054] In addition, the housing 34 of the circulation pump mechanism 30 is held in a state in which it is pressed toward the outside of the machine by the pressing portion 41 and is sandwiched from both axial sides by the restricting portion 3b and the pressing portion 41. As a result, the first outer plate 36 and the second outer plate 37 are in close contact with both axial sides of the cam ring 35, so that the sealing liquid in the pump chamber 38 can be prevented from leaking to the outside. As a result, the circulation efficiency of the sealing liquid can be prevented from decreasing. In addition, since the cam ring 35, the first outer plate 36, and the second outer plate 37 are movable toward the inside of the machine against the pressing force of the pressing portion 41, even if the rotating shaft 51 moves toward the inside of the machine due to axial wobble or the like, the entire housing 34 can move toward the inside of the machine following the movement. As a result, the circulation pump mechanism 30 can be prevented from being damaged.

[0055] In addition, since the circulation pump mechanism 30 is disposed between the first mechanical seal 6 and the second mechanical seal 7, the circulation pump mechanism 30 does not overlap in the radial direction with the first mechanical seal 6 and the second mechanical seal 7. As a result, the mechanical seal device 1 can be configured to be compact in the radial direction.

[0056] <Second embodiment> 6 is a schematic diagram of a mechanical seal device according to a second embodiment of the present invention. The mechanical seal device 1 of this embodiment differs from the first embodiment in that it is provided with a cooling mechanism for cooling the sealing liquid. The mechanical seal device 1 of this embodiment is provided with a circulation path 60 provided outside the seal case 2, and a first cooling mechanism 70 and a second cooling mechanism 80 provided in the circulation path 60.

[0057] [Circulation path] The circulation path 60 is a flow path for returning the sealing liquid discharged to the outside from the discharge path 3a of the seal case 2 to the supply path 4a. The circulation path 60 in this embodiment has a first flow path 61, a second flow path 62, and a third flow path 63. The first flow path 61, the second flow path 62, and the third flow path 63 are formed of, for example, pipes.

[0058] One end of the first flow path 61 is connected to the discharge path 3a of the seal case 2, and the other end of the first flow path 61 is connected to an inlet 71a (described later) of a first cooling mechanism 70. A first opening / closing valve 64 that opens and closes the first flow path 61 is provided in the first flow path 61.

[0059] One end of the second flow path 62 is connected to an outlet 71b (described later) of the first cooling mechanism 70, and the other end of the second flow path 62 is connected to an inlet 81 (described later) of the second cooling mechanism 80. A second on-off valve 65 that opens and closes the second flow path 62 is provided in the second flow path 62.

[0060] One end of the third flow path 63 is connected to an outlet 82 (described later) of the second cooling mechanism 80, and the other end of the third flow path 63 is connected to the supply path 4a of the seal case 2. With the above-described configuration, the sealing liquid discharged from the discharge path 3a passes through the first flow path 61, the first cooling mechanism 70, the second flow path 62, the second cooling mechanism 80, and the third flow path 63 in this order, and then is returned to the supply path 4a.

[0061] [First cooling mechanism] 7 is a cross-sectional view of the first cooling mechanism 70. The first cooling mechanism 70 cools the sealing liquid discharged from the discharge path 3a. The first cooling mechanism 70 of the present embodiment has a tank 71 and a cooling coil 76. The tank 71 temporarily stores sealing liquid therein. The tank 71 in this embodiment is a pressurized tank whose internal space is pressurized by a compressor (not shown).

[0062] The tank 71 has a cylindrical tank main body 72, a first wall 73 that closes the opening at one axial end side (left side in Figure 6) of the tank main body 72, and a second wall 74 that closes the opening at the other axial end side (right side in Figure 6) of the tank main body 72.

[0063] An inlet 71a for allowing sealing liquid to flow into the tank 71 is formed at a predetermined circumferential position of the tank body 72. The first wall 73 is fixed by bolts 75 to a flange 72a formed on one axial end side of the tank body 72. An outlet 71b for allowing sealing liquid in the tank 71 to flow out to the outside is formed in the second wall 74.

[0064] The cooling coil 76 is provided in the tank 71. The cooling coil 76 is, for example, made of a pipe through which a cooling medium flows. As the cooling medium, for example, a liquid such as water or a gas such as air is used. In this embodiment, low-temperature water is used as the cooling medium.

[0065] The cooling coil 76 of this embodiment has a helical tube 77, a first straight tube 78, and a second straight tube 79. The helical tube 77 is formed in a helical shape and extends in the axial direction of the tank main body 72. The first straight tube 78 extends linearly from one axial end (left end in FIG. 6) of the helical tube 77 toward the first wall portion 73. The second straight tube 79 extends linearly from the other axial end (right end in FIG. 6) of the helical tube 77 toward the first wall portion 73. The second straight tube 79 is disposed radially inward of the helical tube 77 in the tank main body 72.

[0066] The first wall portion 73 is formed with a supply port 71c for supplying a cooling medium to the cooling coil 76 from the outside, and a discharge port 71d for discharging the cooling medium from the cooling coil 76 to the outside. An end of a first straight pipe 78 of the cooling coil 76 is connected to the supply port 71c. An end of a second straight pipe 79 of the cooling coil 76 is connected to the discharge port 71d. As a result, the cooling medium passes from the supply port 71c through the first straight pipe 78, the helical pipe 77, and the second straight pipe 79 of the cooling coil 76 in this order, and is then discharged to the outside from the discharge port 71d.

[0067] [Second cooling mechanism] 6, the second cooling mechanism 80 is provided closer to the supply path 4a side of the seal case 2 than the first cooling mechanism 70, and further cools the sealing liquid cooled by the first cooling mechanism 70. The second cooling mechanism 80 is, for example, a coil-type cooler, and cools the sealing liquid flowing inside a coil (spiral piping) (not shown) by a cooling medium (water, air, etc.) circulating outside the coil.

[0068] The second cooling mechanism 80 has an inlet 81 for allowing the sealing liquid to flow into the coil, and an outlet 82 for allowing the sealing liquid in the coil to flow out to the outside. Other configurations of this embodiment are similar to those of the first embodiment, so the same reference numerals are used and the description thereof is omitted.

[0069] [Effects of the second embodiment] As described above, the mechanical seal device 1 of this embodiment provides the same effects as those of the first embodiment, as well as the following effects. In the sealing liquid chamber 8, the temperature of the sealing liquid may rise due to sliding heat generated at each sliding portion of the first mechanical seal 6 and the second mechanical seal 7. However, even if the temperature of the sealing liquid rises, the first cooling mechanism 70 can cool the heated sealing liquid while the heated sealing liquid passes from the discharge passage 3a through the circulation passage 60 and is returned to the supply passage 4a. This is particularly effective in cases where the sealed fluid is at a high temperature, since the sealing liquid is likely to rise due to the effects of both the temperature of the sealed fluid and the sliding heat.

[0070] Furthermore, when the heated sealing liquid is temporarily stored in the tank 71, the first cooling mechanism 70 can cool the sealing liquid by the cooling coil 76. This allows the tank 71, which temporarily stores the sealing liquid, to be used as a part of the first cooling mechanism 70, thereby simplifying the configuration of the first cooling mechanism 70.

[0071] Furthermore, the sealing liquid that has not been completely cooled by the first cooling mechanism 70 can be cooled by the second cooling mechanism 80, so that the cooling capacity of the sealing liquid can be improved.

[0072] <Other> Although the mechanical seal device of the present invention is provided with a double type mechanical seal, it is sufficient that it is provided with at least one mechanical seal, such as a single type mechanical seal. Although the pressing portion 41 in the above embodiment presses the first outer plate 36 toward the outer side of the machine, it may press the second outer plate 37 toward the inner side of the machine. In that case, the protruding end surface 4c of the protruding portion 4b of the second case body 4 may be a restricting portion that restricts the first outer plate 36 from moving toward the inner side (one axial direction side) beyond a predetermined position with respect to the seal case 2, or the restricting portion may be provided separately from the second case body 4.

[0073] The mechanical seal device 1 of the second embodiment includes the first cooling mechanism 70 and the second cooling mechanism 80, but it is sufficient that the mechanical seal device 1 includes at least the first cooling mechanism 70. The first cooling mechanism 70 is not limited to the configuration of this embodiment, and may be, for example, the same coil-type cooler as the second cooling mechanism 80. The second cooling mechanism 80 is not limited to the configuration of this embodiment, and may be, for example, the same configuration as the first cooling mechanism 70.

[0074] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the above meaning, and is intended to include all modifications within the scope of the claims and the meaning equivalent thereto. [Explanation of symbols]

[0075] 1 Mechanical seal device 2 Seal Case 3a Exhaust channel 3b Step surface (regulating part) 4a Supply route 6 No. 1 mechanical seal (mechanical seal) 7 Second mechanical seal (mechanical seal) 8 Sealing liquid chamber 30 Circulation pump mechanism 31 Rotor 31b Outer surface 32 Vane 32a protruding end 33 Pressurizing member 34 Housing 35 Cam Ring 35b Inner peripheral surface (sliding surface) 36 First outer plate (outer plate) 36a Intake port 37 Second outer plate (outer plate) 37a Discharge port 38 Pump Room 41 Pressing part 50 Rotating Equipment 51 Rotation axis 60 Circulation path 70 1st cooling mechanism 71 Tank 76 Cooling coil 80 Second cooling mechanism A Cabin Area B. Outside the aircraft

Claims

1. a seal case that surrounds a rotation shaft of a rotating device and divides an interior area and an exterior area of ​​the rotating device; at least one mechanical seal disposed between the seal case and the rotating shaft; a ring-shaped sealing liquid chamber formed in the seal case, into which a sealing liquid for lubricating a sliding portion of the mechanical seal is introduced; a circulating pump mechanism for circulating the sealing liquid in the sealing liquid chamber, The circulation pump mechanism includes: a rotor attached to the rotating shaft so as to be integrally rotatable therewith; a plurality of vanes provided at predetermined intervals in a circumferential direction of the rotor and movable in and out of an outer circumferential surface of the rotor; a plurality of biasing members provided on the rotor and biasing each of the vanes in a direction in which the vanes protrude from an outer circumferential surface of the rotor; a housing attached to the seal case, the housing having an inner periphery with a sliding surface formed eccentrically with respect to an outer periphery of the rotor and against which a protruding end of the vane slides as the rotor rotates; a plurality of pump chambers defined by the vanes between an outer circumferential surface of the rotor and a sliding surface of the housing, The housing has a suction port through which sealing liquid is sucked from the sealing liquid chamber to the pump chamber, and a discharge port through which sealing liquid is discharged from the pump chamber to the sealing liquid chamber.

2. The housing includes a cam ring having an inner circumferential surface that is the sliding surface, and a pair of outer plates disposed on both axial sides of the cam ring, the cam ring and the pair of outer plates are attached to the seal case so as to be movable in the axial direction, a pressing portion that presses one of the pair of outer plates toward one axial side that is the cam ring side; 2. The mechanical seal device according to claim 1, further comprising a restricting portion that restricts the other of the pair of outer plates from moving toward the one axial side beyond a predetermined position relative to the seal case.

3. 3. The mechanical seal device according to claim 1, wherein the at least one mechanical seal includes a first mechanical seal arranged in an inboard area and a second mechanical seal arranged in an outboard area.

4. The mechanical seal device according to claim 3 , wherein the circulation pump mechanism is disposed between the first mechanical seal and the second mechanical seal.

5. the seal case has a supply path for supplying a sealing liquid to the sealing liquid chamber and a discharge path for discharging the sealing liquid from the sealing liquid chamber, a circulation path for returning the sealing liquid discharged from the discharge path to the supply path; The mechanical seal device according to claim 1 , further comprising: a first cooling mechanism provided in the circulation path for cooling the sealing liquid.

6. The first cooling mechanism includes: A tank for temporarily storing the sealing liquid; The mechanical seal device according to claim 5 , further comprising: a cooling coil provided in the tank, through which a cooling medium flows.

7. The mechanical seal device according to claim 5 or 6, further comprising a second cooling mechanism that is provided on the supply passage side of the circulation passage relative to the first cooling mechanism and that cools the sealing liquid.

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