Mechanical Seal Device

Abstract

To provide a mechanical seal device capable of inhibiting a spring of a circulation pump mechanism from wearing in contact with a rotor.SOLUTION: A mechanical seal device 1 includes a circulation pump mechanism 30 for circulating sealing liquid in a sealing liquid chamber 8. The circulation pump mechanism 30 includes a rotor 31 provided on a rotary shaft 51 in an integrally rotatable manner and formed with a mounting groove 31c opened in an outer peripheral face 31b, a plurality of vanes 32 provided in the mounting groove 31c and freely retractable from an outer peripheral face 31b of the rotor 31, a spring 33 provided in the mounting groove 31c at its corner side further than the vane 32 for energizing the vane 32 to be protruded from the outer peripheral face 31b of the rotor 31, and a holding member 42 provided in the mounting groove 31c at its corner side further than the vane 32 and formed with an insertion hole 42a into which the spring 33 is inserted.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] A mechanical seal device installed in a rotating device is equipped with a circulation pump mechanism that circulates sealing liquid to increase the lubrication between the seal surfaces of a rotating seal ring and a stationary seal ring and to remove sliding heat generated between the seal surfaces (see, for example, Patent Document 1). The mechanical seal device in Patent Document 1 is equipped with a circulation pump mechanism that functions as a vane pump. The circulation pump mechanism includes a rotor that rotates integrally with the rotating shaft of the rotating device, multiple vanes that can be freely extended and retracted from the outer circumferential surface of the rotor, a cylindrical spring that biases the vanes in a direction that causes them to protrude, and multiple pump chambers defined between adjacent vanes. This circulation pump mechanism can circulate a constant volume of sealing liquid with each rotation of the rotor, so it can circulate the required flow rate of sealing liquid even in rotating devices that rotate at low speeds, such as agitators. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-18073 Summary of the Invention [Problem to be solved by the invention]

[0004] In the circulation pump mechanism of Patent Document 1, a mounting groove into which a vane is inserted is formed on the rotor, and a spring is disposed within the mounting groove, further back than the vane. The spring is simply disposed within the mounting groove with its longitudinal ends abutting the bottom surface of the mounting groove and the back surface of the vane, respectively. Therefore, if the longitudinal middle portion of the spring buckles, the middle portion is likely to come into contact with the side surface of the mounting groove. Therefore, if the circulation pump mechanism is used for a long period of time, the contact between the middle portion of the spring and the side surface of the mounting groove will cause wear of the spring, which may result in damage to the spring.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a mechanical seal device that can prevent the spring of a circulation pump mechanism from coming into contact with a rotor and wearing out. [Means for solving the problem]

[0006] (1) The present disclosure provides a mechanical seal device comprising: a seal case that surrounds a rotating shaft of a rotating device and separates 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 sealing liquid chamber formed within the seal case into which a sealing liquid that lubricates a sliding portion of the mechanical seal is introduced; and a circulation pump mechanism that circulates the sealing liquid within the sealing liquid chamber, wherein the circulation pump mechanism comprises: an annular rotor that is rotatable integrally with the rotating shaft and has a mounting groove that opens on its outer peripheral surface; a vane that is provided in the mounting groove and can freely protrude and retract relative to the outer peripheral surface of the rotor; a spring that is provided in the mounting groove further back than the vane and biases the vane in a direction that causes it to protrude from the outer peripheral surface of the rotor; and a retaining member that is provided in the mounting groove further back than the vane and has an insertion hole into which the spring is inserted.

[0007] According to the mechanical seal device of the present disclosure, a spring is inserted into an insertion hole of a retaining member provided on the rear side of the vane in the mounting groove of the rotor of the circulation pump mechanism. Therefore, the middle portion of the spring in the longitudinal direction is held by the retaining member. This prevents the middle portion of the spring from buckling and coming into contact with the side surface of the mounting groove. As a result, wear of the spring due to contact with the rotor can be prevented.

[0008] (2) In the mechanical seal device of (1) above, it is preferable that the spring is a conical coil spring, and that a small diameter end side of the conical coil spring is exposed from the retaining member to the vane side. In this case, the portion of the conical coil spring that is exposed from the retaining member has a smaller diameter than the other portions of the conical coil spring, which further prevents the exposed portion of the conical coil spring from contacting the side surface of the mounting groove, thereby further preventing the spring (conical coil spring) from contacting the rotor and becoming worn.

[0009] (3) In the mechanical seal device of (1) or (2), it is preferable that the circulation pump mechanism includes a plurality of the springs provided in the mounting groove, and the retaining member is formed with a plurality of the insertion holes into which the plurality of the springs are individually inserted. In this case, the plurality of springs are individually inserted into the plurality of insertion holes of the holding member, so that the springs can be prevented from coming into contact with each other and becoming worn.

[0010] (4) In the mechanical seal device of any one of (1) to (3), it is preferable that the spring has an exposed portion that is exposed from the retaining member toward the vane, and that the vane has a recess into which the exposed portion is inserted. In this case, the exposed portion of the spring that is exposed from the retaining member is inserted into the recess of the vane, which further prevents the exposed portion of the spring from contacting the side surface of the mounting groove, thereby further preventing the spring from coming into contact with the rotor and becoming worn.

[0011] (5) In the mechanical seal device of (4), it is preferable that the circulation pump mechanism includes a plurality of the springs arranged in the mounting groove, and the vane is formed with a plurality of the recesses into which the exposed portions of the plurality of the springs are individually inserted. In this case, the exposed portions of the multiple springs are individually inserted into the multiple recesses of the vane, so that the exposed portions of the springs can be prevented from coming into contact with each other and becoming worn.

[0012] (6) From another perspective, the present disclosure provides a mechanical seal device comprising: a seal case that surrounds a rotating shaft of a rotating device and separates 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 sealing liquid chamber formed within the seal case into which a sealing liquid that lubricates a sliding portion of the mechanical seal is introduced; and a circulation pump mechanism that circulates the sealing liquid within the sealing liquid chamber, wherein the circulation pump mechanism comprises: an annular rotor that is rotatable integrally with the rotating shaft and has a mounting groove that opens on its outer peripheral surface; a vane that is provided in the mounting groove and is capable of freely protruding and retracting from the outer peripheral surface of the rotor; and a spring that is provided in the mounting groove deeper than the vane and biases the vane in a direction that causes it to protrude from the outer peripheral surface of the rotor, wherein the spring is a conical coil spring.

[0013] According to the mechanical seal device of the present disclosure, a conical coil spring is provided in the mounting groove of the rotor of the circulation pump mechanism, further back than the vane, as a spring for biasing the vane. By making the outer diameter of the large-diameter end of the conical coil spring equal to or smaller than the outer diameter of a conventional cylindrical spring, it is possible to prevent the longitudinal middle portion of the conical coil spring from contacting the side surface of the mounting groove. As a result, it is possible to prevent the spring (conical coil spring) from contacting the rotor and becoming worn. [Effects of the Invention]

[0014] According to the mechanical seal device of the present disclosure, it is possible to prevent the spring of the circulation pump mechanism from coming into contact with the rotor and becoming worn. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a cross-sectional view showing a mechanical seal device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view taken along the line II in FIG. [Figure 3] 3 is an enlarged cross-sectional view showing the 6 o'clock area of ​​the circulation pump mechanism in FIG. 2. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 4 is a side view of the first outer plate of the housing as seen from the outside of the aircraft. [Figure 7] FIG. 10 is a side view of the second outer plate of the housing as seen from the outside of the aircraft. [Figure 8] FIG. 2 is an enlarged perspective view showing the vicinity of a notched groove of the rotor. [Figure 9] FIG. 6 is a cross-sectional view showing a circulation pump mechanism of a mechanical seal device according to a second embodiment of the present disclosure. [Figure 10] 10 is an enlarged cross-sectional view showing the vicinity of 6 o'clock in FIG. 9 in the circulation pump mechanism of the second embodiment. [Figure 11] FIG. 10 is an enlarged perspective view showing the vicinity of a mounting groove of a rotor according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Next, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that at least some of the embodiments described below may be combined in any manner. First Embodiment [Mechanical seal device] 1 is a cross-sectional view showing a mechanical seal device 1 according to a first embodiment of the present disclosure. The mechanical seal device 1 is provided in a rotating device 50 such as a pump or a mixer 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 circulation pump mechanism 30.

[0017] The seal case 2 is fixed to a casing (not shown) of the rotating device 50, and separates an in-machine area A and an out-machine area B of the rotating device 50. The seal case 2 of this embodiment has, in order from the out-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 will be referred to as the in-machine side, and the out-machine area B side will be referred to as the out-machine side.

[0018] The first mechanical seal 6 and the second mechanical seal 7 constitute a double-type mechanical seal, and are arranged between the seal case 2 and the rotating shaft 51 at a predetermined distance 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 a 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.

[0019] 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 rotary seal ring 16, a stationary seal ring 17, a set screw 18, a pin 19, an O-ring 20, and an O-ring 21.

[0020] The spring retainer 11 is formed in an annular shape and is fixed to the outer periphery of the rotary shaft 51 via a sleeve 9. A plurality of radially penetrating screw holes 11a (only one is shown in FIG. 1 ) are formed in the spring retainer 11 at predetermined intervals in the circumferential direction. A set screw 18 is threaded 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 rotary shaft 51 side by the set screw 18.

[0021] A plurality of through holes 11b (only one of which 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 in the spring retainer 11 so as to be movable within a predetermined range in the axial direction.

[0022] An inboard end of the drive pin 13 is fixed to an annular drive collar 14, which is attached to the outer peripheral surface of the sleeve 9 and is axially movable relative to the inner side of the spring retainer 11. Specifically, the drive collar 14 has a plurality of axially penetrating threaded holes 14a (only one is shown in FIG. 1 ) formed at predetermined intervals in the circumferential direction. Male threads 13a formed on the inboard end of each drive pin 13 are threadedly engaged with each threaded 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.

[0023] The spring retainer 11 holds one end of a plurality of springs 12 (only one is shown in FIG. 1 ) spaced at predetermined intervals in the circumferential direction. The other end of the spring 12 abuts against the end face of the drive collar 14 on the outboard side. As a result, the drive collar 14 is biased toward the inboard side by the biasing force of the spring 12.

[0024] 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 peripheral 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 end surface of the retainer 15 on the outboard side.

[0025] 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 relative 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.

[0026] 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 static seal ring 17 is arranged adjacent to the inboard side of the rotary seal ring 16. The static seal ring 17 is fitted and fixed to the inner periphery of the third case body 5. The outboard end face of the static seal ring 17 is formed as a seal surface 17a against which the seal surface 16a of the rotary seal ring 16 slides.

[0027] A plurality of pin grooves 17b (only one is shown in FIG. 1 ) are formed at predetermined intervals in the circumferential direction on the inboard side of the stationary seal ring 17. A pin 19 is inserted into each pin groove 17b. The pin 19 is fixed to the inner circumferential side of the third case body 5 and protrudes outboard. 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.

[0028] 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 arranged 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 sandwiched between them.

[0029] The pin 19 of the second mechanical seal 7 is fixed to the inner circumferential side of the first case body 3, protruding toward the inside of the machine. 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. The other configuration of the second mechanical seal 7 is the same as that of the first mechanical seal 6, so a description thereof will be omitted.

[0030] 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. Depending on the sealed fluid, water, oil, solvent, or the like is used as the sealing liquid, as long as it does not cause any problems even if it is mixed into the sealed fluid.

[0031] The second case body 4 is formed with a supply path 4a for supplying 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 the sliding parts of the first and second mechanical seals 6 and 7, and is discharged to the outside from the discharge path 3a.

[0032] [Circulation pump mechanism] Fig. 2 is a cross-sectional view taken along the arrow II in Fig. 1. In Figs. 1 and 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 springs (biasing members) 33, a housing 34, a plurality of pump chambers 38, and a retaining member 42. Note that cross sections of the rotary shaft 51, the vanes 32, and the retaining member 42 are omitted in Fig. 2.

[0033] The rotor 31 is an annular member made of a metal such as stainless steel. The rotor 31 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 with the rotating shaft 51, and the rotational torque of the rotating shaft 51 is transmitted to the rotor 31 via the sleeve 9.

[0034] [Mounting groove] Figure 3 is an enlarged cross-sectional view showing the 6 o'clock area of ​​the circulation pump mechanism 30 in Figure 2. In Figures 2 and 3, rotor 31 has a plurality of mounting grooves 31c (four in Figure 2) that open onto its outer circumferential surface 31b and are formed at predetermined intervals in the circumferential direction. Each mounting groove 31c is formed over the entire axial direction of rotor 31 (the direction perpendicular to the plane of Figure 3).

[0035] Each mounting groove 31c has a first groove portion 31d and a second groove portion 31e. The first groove portion 31d is formed on the bottom side (rear side) of the mounting groove 31c. The second groove portion 31e is formed on the opening side of the mounting groove 31c. The groove width W1 of the first groove portion 31d is larger than the groove width W2 of the second groove portion 31e. The depth of the first groove portion 31d is shallower than the depth of the second groove portion 31e.

[0036] [Holding member] A retaining member 42 is fitted into the first groove portion 31d of each mounting groove 31c from the axial outside thereof. FIG. 4 is a perspective view showing the retaining member 42. In FIGS. 3 and 4, the retaining member 42 is a rectangular parallelepiped member made of synthetic resin. The retaining member 42 of this embodiment is made of a fluororesin such as polytetrafluoroethylene (PTFE). The retaining member 42 is fitted into a pair of side surfaces 31d1 of the first groove portion 31d with an interference fit. This fixes the retaining member 42 to the first groove portion 31d.

[0037] The holding member 42 has an insertion hole 42a into which the spring 33 is inserted. A plurality of insertion holes 42a (two in FIG. 4) are formed in the holding member 42 and aligned in the axial direction of the rotor 31. Each insertion hole 42a penetrates the holding member 42 in the depth direction of the first groove portion 31d. Each insertion hole 42a communicates with the second groove portion 31e.

[0038] [Spring] A plurality of springs 33 are provided in each mounting groove 31c. Specifically, a plurality of springs 33 (two in this example) are individually inserted into a plurality of insertion holes 42a of a holding member 42 fixed to each first groove portion 31d. The springs 33 are conical coil springs made of metal such as stainless steel. The conical coil springs 33 are inserted into the mounting grooves 31c with their large diameter ends positioned at the back. The large diameter ends of the conical coil springs 33 pass through the insertion holes 42a and abut against the bottom surface of the first groove portion 31d.

[0039] The longitudinal length of the conical coil spring 33 in the most contracted state (the state shown in FIG. 3) is longer than the depth of the first groove portion 31d. Therefore, the conical coil spring 33 has an exposed portion 33a that is always exposed inside the second groove portion 31e from the insertion hole 42a of the holding member 42. In this embodiment, the small diameter end side of the conical coil spring 33 forms the exposed portion 33a.

[0040] [Vane] 2 and 3, a vane 32 is inserted into the second groove portion 31e of each mounting groove 31c. The vane 32 is made of a flat plate-like member made of, for example, carbon. The axial length of the vane 32 (the direction perpendicular to the paper surface of FIG. 3) is approximately the same as the axial length of the mounting groove 31c. The vane 32 is slidable on a pair of side surfaces 31e1 of the second groove portion 31e. This allows the vane 32 to freely appear and disappear from the outer peripheral surface 31b of the rotor 31 in the second groove portion 31e.

[0041] Fig. 5 is a perspective view showing vane 32. In Fig. 3 and Fig. 5, recessed portions 32c are formed in back surface 32b (surface located on the rear side of second groove portion 31e) of vane 32. A plurality of recessed portions 32c (two in Fig. 5) are formed in vane 32 and aligned in the axial direction of rotor 31.

[0042] Each recess 32c is formed to a size that allows a portion of the tip (small diameter end) side of the exposed portion 33a to be inserted thereinto. As a result, the tip sides of the exposed portions 33a of the plurality of conical coil springs 33 that are exposed from the retaining member 42 to the vane 32 side are individually inserted into the plurality of recesses 32c.

[0043] The tip of the exposed portion 33a inserted into the recess 32c abuts against the bottom surface of the recess 32c. As a result, the multiple conical coil springs 33 in each mounting groove 31c urge the vane 32 in a direction that causes it to protrude from the outer peripheral surface 31b of the rotor 31. The other part of the exposed portion 33a of each conical coil spring 33 is exposed in the space S1 of the second groove portion 31e.

[0044] Space S1 is a space formed on the rear side of vane 32 in second groove portion 31e. The volume of space S1 increases or decreases as vane 32 protrudes from or retracts into rotor 31. Specifically, the volume of space S1 increases as vane 32 protrudes from rotor 31, and decreases as vane 32 retracts into rotor 31.

[0045] [housing] 1 and 2, the housing 34 of the circulation pump mechanism 30 is attached to the inner circumferential side of the seal case 2. Specifically, the housing 34 is disposed between the stepped surface 3b of the first case body 3 and the protruding end surface 4c of the second case body 4. The housing 34 has a cam ring 35, and a first outer plate 36 and a second outer plate 37 disposed on both axial sides of the cam ring 35. The cam ring 35, the first outer plate 36, and the second outer plate 37 are restricted from rotating relative to the seal case 2 by a plurality of pins 40 (three in FIG. 2) that axially penetrate the cam ring 35, the first outer plate 36, and the second outer plate 37.

[0046] A plurality of springs 41 (only one in FIG. 1 ) are provided between the first outer plate 36 and the second case body 4 at predetermined intervals in the circumferential direction. The spring 41 presses the first outer plate 36 toward the outboard side relative to the second case body 4. As a result, the housing 34 is held biased toward the outboard side between the stepped surface 3b of the first case body 3 and the protruding end surface 4c of the second case body 4, and is movable toward the inboard side against the biasing force of the spring 41. The spring 41 may be disposed between the first case body 3 and the second outer plate 37 and press the second outer plate 37 toward the inboard side relative to the first case body 3.

[0047] Cam ring 35 is an annular member made of metal such as stainless steel. Cam ring 35 is disposed between first case body 3 and rotor 31. The axial length of cam ring 35 is substantially the same as the axial length of rotor 31. Outer peripheral surface 35a of cam ring 35 is a circumferential surface centered on axis C1 of rotary shaft 51.

[0048] Inner peripheral surface 35b of cam ring 35 is a circumferential surface with center C2 located at a position eccentric to axis C1 of rotary shaft 51. In this embodiment, center C2 of inner peripheral surface 35b of cam ring 35 is eccentric to the upper side in FIG. 2 with respect to axis C1 of rotary shaft 51. As a result, inner peripheral surface 35b of cam ring 35 is eccentric to outer peripheral surface 31b of rotor 31. Specifically, inner peripheral surface 35b of cam ring 35 is eccentric so as to gradually move away from outer peripheral surface 31b of rotor 31 in a first angle range θ1 from 6 o'clock to 12 o'clock in FIG. 2. Furthermore, inner peripheral surface 35b of cam ring 35 is eccentric so as to gradually move closer to outer peripheral surface 31b of rotor 31 in a second angle range θ2 from 12 o'clock to 6 o'clock in FIG. 2.

[0049] Inner peripheral surface 35b of cam ring 35 serves as a sliding surface along which tip end 32a of each vane 32 slides as rotor 31 rotates. Each time rotor 31 rotates once in the direction of arrow E, each vane 32 alternately moves between protruding from mounting groove 31c and sinking into mounting groove 31c while sliding along inner peripheral surface 35b of cam ring 35. In this embodiment, each vane 32 moves protruding in the first angle range θ1 and sinking in the second angle range θ2.

[0050] In the first angle range θ1, each vane 32 gradually moves protrudingly from its most recessed state (6 o'clock state) in the mounting groove 31c to its most protruding state (12 o'clock state) from the mounting groove 31c by the biasing force of the spring 33. In the second angle range θ2, each vane 32 gradually moves retractedly against the biasing force of the spring 33 by being pressed against the inner peripheral surface 35b of the cam ring 35 from the most protruding state (12 o'clock state) to the most recessed state (6 o'clock state).

[0051] The first outer plate 36 and the second outer plate 37 are made of, for example, carbon disk members and are arranged 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.

[0052] With the above configuration, a plurality of pump chambers 38 (four in FIG. 2) are defined by the circumferentially adjacent vanes 32, 32 inside the housing 34 between the outer peripheral surface 31b of the rotor 31 and the inner peripheral surface 35b of the cam ring 35. Each pump chamber 38 is a space into which sealing liquid is sucked and discharged.

[0053] The volume of each pump chamber 38 changes with the rotation of the rotor 31. In this embodiment, with each rotation of the rotor 31 in the direction of arrow E, the volume of the pump chamber 38 gradually increases in the first angle range θ1, and gradually decreases in the second angle range θ2.

[0054] FIG. 6 is a side view of the first outer plate 36 of the housing 34 as seen from the outside of the machine. As shown in FIGS. 1 and 6, a plurality of (three in FIG. 6) suction ports 36a are formed at predetermined intervals in the circumferential direction within the first angular range θ1 of the first outer plate 36. As a result, when each pump chamber 38 passes through the first angular range θ1 due to the rotation of the rotor 31, the volume of the pump chamber 38 gradually increases, causing the pressure inside the pump chamber 38 to change from positive to negative. This negative pressure inside the pump chamber 38 causes the sealing liquid to be sucked into the pump chamber 38 through each suction port 36a. As a result, the sealing liquid in the sealing liquid chamber 8 is sucked into the pump chamber 38 through each suction port 36a.

[0055] FIG. 7 is a side view of the second outer plate 37 of the housing 34 as seen from the outside of the machine. As shown in FIGS. 1 and 7, a plurality of (three in FIG. 7) discharge ports 37a are formed at predetermined intervals in the circumferential direction in the second angle range θ2 of the second outer plate 37. 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 to positive. As the pressure inside the pump chamber 38 becomes positive in this way, an action occurs in which the seal liquid is discharged from each discharge port 37a to the outside of the pump chamber 38. As a result, the seal liquid in the pump chamber 38 is discharged from each discharge port 37a to the seal liquid chamber 8.

[0056] With the above configuration, the circulation pump mechanism 30 functions as a vane pump and can circulate a fixed volume of sealing liquid with each rotation of the rotor 31. For ease of understanding, in Fig. 1, the positions of the suction port 36a and the discharge port 37a are shown shifted in the circumferential direction.

[0057] Notched Groove 2 and 3, a plurality of notched grooves 31f are formed at intervals in the circumferential direction on the outer peripheral surface 31b of the rotor 31. The number of notched grooves 31f is the same as the number of vanes 32 (four). Each notched groove 31f is formed on the outer peripheral surface 31b of the rotor 31 at a position slightly further forward in the direction of rotation of the rotor 31 than the tip end 32a of each vane 32. Each notched groove 31f is formed in a V-shape when viewed in the axial direction.

[0058] Each notch groove 31f has a first side surface 31g and a second side surface 31h. The first side surface 31g is formed on the front side in the rotation direction of the rotor 31. The second side surface 31h is formed on the front side in the rotation direction of the rotor 31. The angle α formed by the first side surface 31g and the second side surface 31h is set to a size that allows a processing tool (such as a drill) to easily access the first side surface 31g when forming a communication flow path 45 (described later) in the rotor 31 with the tool.

[0059] [Communicating flow path] The circulation pump mechanism 30 further includes a plurality of communication passages 45 formed in the rotor 31. The number of communication passages 45 is the same (four) as the number of vanes 32. Each communication passage 45 is a passage that communicates between the space S1 of the mounting groove 31c and the pump chamber 38. In this embodiment, each communication passage 45 is formed in the rotor 31 independently of the mounting groove 31c.

[0060] FIG. 8 is an enlarged perspective view showing the vicinity of the cutout groove 31f of the rotor 31. In FIGS. 3 and 8, each communication flow path 45 has a plurality of flow path portions 46 arranged at intervals in the axial direction of the rotor 31 (the up-and-down direction in FIG. 8). Each flow path portion 46 is formed, for example, by a hole having a circular cross section. One longitudinal end of each flow path portion 46 opens at the first side surface (side surface) 31g of the cutout groove 31f. The other longitudinal end of each flow path portion 46 opens at the side surface 31e1 of the second groove portion 31e of the mounting groove 31c. As described above, the flow path portion 46 of each communication flow path 45 communicates the space S1 of each mounting groove 31c with the pump chamber 38 defined further forward in the rotational direction of the rotor 31 than the tip 32a of the vane 32 inserted into the mounting groove 31c.

[0061] 2 and 3, when the rotor 31 rotates through the first angle range θ1, the multiple flow passages 46 function as supply flow passages that supply seal liquid from the pump chamber 38 to the space S1 of the mounting groove 31c. Specifically, in the first angle range θ1, seal liquid is sucked into the pump chamber 38 through the suction port 36a of the first outer plate 36. As a result, the seal liquid in the pump chamber 38 flows from the notched groove 31f formed in the outer peripheral surface 31b of the rotor 31 facing the pump chamber 38 into the multiple flow passages 46 that open at the first side surface 31g of the notched groove 31f. The seal liquid that has flowed into the multiple flow passages 46 flows into the space S1 of the mounting groove 31c that communicates with these flow passages 46. Therefore, when the rotor 31 rotates through the first angle range θ1, the pressure of the seal liquid that has flowed into the space S1 acts as back pressure on the back surface 32b of the vane 32.

[0062] When the rotor 31 rotates within the second angle range θ2, the plurality of flow path portions 46 function as discharge flow paths that discharge the sealing liquid in the space S1 into the pump chamber 38. Specifically, within the second angle range θ2, the vane 32 moves and sinks into the mounting groove 31c against the biasing force of the conical coil spring 33, as described above. As a result, the sealing liquid in the space S1 passes through the plurality of flow path portions 46 and is discharged from the notched groove 31f into the pump chamber 38. At that time, dust in the space S1 is discharged into the pump chamber 38 together with the sealing liquid via the plurality of flow path portions 46, so the plurality of flow path portions 46 also function as flow paths for cleaning the space S1.

[0063] [Action and effect] As described above, according to the mechanical seal device 1 of this embodiment, the spring 33 is inserted into the insertion hole 42a of the retaining member 42, which is provided on the rear side of the vane 32 in the mounting groove 31c of the rotor 31 of the circulation pump mechanism 30. Therefore, the middle portion of the spring 33 in the longitudinal direction is held by the retaining member 42. This prevents the middle portion of the spring 33 from buckling and coming into contact with the side surfaces 31d1, 31e1 of the mounting groove 31c. As a result, the spring 33 can be prevented from coming into contact with the rotor 31 and becoming worn.

[0064] Furthermore, the spring 33 is a conical coil spring, and the small diameter end of the conical coil spring 33 forms an exposed portion 33a that is exposed from the retaining member 42 toward the vane 32. This makes the exposed portion 33a of the conical coil spring 33 smaller in diameter than the other portions of the conical coil spring 33. This further prevents the exposed portion 33a of the conical coil spring 33 from contacting the side surfaces 31d1, 31e1 of the mounting groove 31c. As a result, it is possible to further prevent the spring (conical coil spring) 33 from coming into contact with the rotor 31 and becoming worn.

[0065] Furthermore, the plurality of springs 33 are individually inserted into the plurality of insertion holes 42a formed in the holding member 42. This makes it possible to prevent the springs 33 from coming into contact with each other and becoming worn.

[0066] Furthermore, exposed portion 33a of spring 33 is inserted into recess 32c formed in back surface 32b of vane 32. This further prevents exposed portion 33a of spring 33 from contacting side surfaces 31d1, 31e1 of mounting groove 31c. As a result, wear of spring 33 due to contact with rotor 31 can be further prevented.

[0067] Furthermore, a plurality of springs 33 are individually inserted into a plurality of recesses 32c formed in the back surface 32b of the vane 32. This makes it possible to prevent the exposed portions 33a of the springs 33 from coming into contact with each other and becoming worn.

[0068] Second Embodiment Fig. 9 is a cross-sectional view showing a circulation pump mechanism 30 of a mechanical seal device 1 according to a second embodiment of the present disclosure. Fig. 10 is an enlarged cross-sectional view showing the 6 o'clock area of ​​the circulation pump mechanism 30 in Fig. 9. The circulation pump mechanism 30 of this embodiment differs from the first embodiment in that it does not include a retaining member 42 (see Fig. 2) into which the spring 33 is inserted, and in that the configurations of the mounting groove 31c of the rotor 31 and the communication flow path 45 are different.

[0069] 9 and 10, each mounting groove 31c of the rotor 31 in the circulation pump mechanism 30 of this embodiment has a constant groove width W3 throughout its entire depth direction (see also FIG. 11). Each mounting groove 31c has a first side surface 31i and a second side surface 31j that face each other. The first side surface 31i is formed on the leading side in the rotation direction of the rotor 31. The second side surface 31j is formed on the leading side in the rotation direction of the rotor 31.

[0070] Figure 11 is an enlarged perspective view showing the vicinity of the mounting groove 31c of the rotor 31. In Figures 10 and 11, a plurality of small grooves 31k (three in Figure 11) are formed in the first side surface 31i of each mounting groove 31c and aligned in the axial direction of the rotor 31. Each small groove 31k is formed in an arc-shaped cross section. Each small groove 31k is formed throughout the entire depth direction of the mounting groove 31c. Each small groove 31k is formed to a size that allows a portion of the circumferential direction of the large diameter end of the conical coil spring 33 to be inserted therein.

[0071] A conical coil spring 33 is inserted into each mounting groove 31c so that a portion of the conical coil spring 33 in the circumferential direction is positioned in each of the multiple small grooves 31k. A vane 32 is inserted in front of the conical coil spring 33 in each mounting groove 31c. The vane 32 is slidable relative to the first side surface 31i and the second side surface 31j of the mounting groove 31c. The small diameter end of the conical coil spring 33 abuts against the back surface 32b of the vane 32.

[0072] With the above configuration, a plurality of (here, three) conical coil springs 33 are arranged side by side in the axial direction in the space S2 of each mounting groove 31c on the rear side of the vane 32. These conical coil springs 33 bias the vane 32 in a direction that causes it to protrude from the outer peripheral surface 31b of the rotor 31. Note that, although the conical coil springs 33 in this embodiment are inserted into the mounting grooves 31c with their large diameter ends positioned at the rear side, they may also be inserted into the mounting grooves 31c with their small diameter ends positioned at the rear side.

[0073] 9 and 10, the plurality of small grooves 31k formed in each mounting groove 31c communicate with the space S2 at the rear side of the mounting groove 31c. Each of the plurality of small grooves 31k opens at the outer peripheral surface 31b of the rotor 31. As a result, the plurality of small grooves 31k communicates the space S2 of each mounting groove 31c with the pump chamber 38 defined further forward in the rotation direction of the rotor 31 than the mounting groove 31c. Therefore, in this embodiment, the plurality of small grooves 31k formed in each mounting groove 31c function as a plurality of flow path portions 46 of the communication flow path 45.

[0074] The small groove 31k functions both to position a portion of the conical coil spring 33 in the circumferential direction and as the flow path 46, but it may also function only as the flow path 46. In that case, the conical coil spring 33 only needs to be sized to be inserted within the groove width W3 of the mounting groove 31c. The other configurations of this embodiment are the same as those of the first embodiment, so the same reference numerals are used and their description will be omitted.

[0075] As described above, according to the mechanical seal device 1 of this embodiment, a conical coil spring is provided as the spring 33 that biases the vane 32 in the mounting groove 31c of the rotor 31 of the circulation pump mechanism 30, further back than the vane 32. This makes it possible to prevent the longitudinal middle portion of the conical coil spring 33 from contacting the side surfaces 31d1, 31e1 of the mounting groove 31c by making the outer diameter of the large-diameter end of the conical coil spring 33 equal to or smaller than the outer diameter of a conventional cylindrical spring. As a result, it is possible to prevent the spring (conical coil spring) 33 from contacting the rotor 31 and becoming worn.

[0076] <Other> Although the mechanical seal device 1 of the present disclosure is equipped with a double-type mechanical seal, it is sufficient to have at least one mechanical seal, such as a single-type mechanical seal. The circulation pump mechanism 30 does not need to be equipped with a communicating flow path 45 if the biasing force of the spring 33 is greater than the pressure of the sealing liquid in the pump chamber 38.

[0077] The number of springs 33 provided in each mounting groove 31c, the number of insertion holes 42a formed in the holding member 42, and the number of recesses 32c formed in the vane 32 are not limited to those in the above embodiment. The springs 33 in the first embodiment are not limited to conical coil springs, and may be, for example, cylindrical springs.

[0078] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. 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 and meaning equivalent to the claims. [Explanation of symbols]

[0079] 1 Mechanical seal device 2 Seal Case 6. First mechanical seal (mechanical seal) 7 Second mechanical seal (mechanical seal) 8 Sealing liquid chamber 30 Circulation pump mechanism 31 Rotor 31b Outer surface 31c Mounting groove 32 vanes 32c recess 33 Spring (conical coil spring) 33a Exposed part 42 Retaining member 42a Insertion hole 50 Rotating Equipment 51 Rotation axis A. Cabin area B. Outside the aircraft

Claims

1. a seal case that surrounds a rotation shaft of the rotating device and separates 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 sealing liquid chamber formed in the seal case, into which a sealing liquid is introduced to lubricate a sliding portion of the mechanical seal; a circulation pump mechanism that circulates the sealing liquid in the sealing liquid chamber, The circulation pump mechanism includes: an annular rotor provided on the rotary shaft side so as to be integrally rotatable, the rotor having an attachment groove formed on an outer peripheral surface thereof; a vane provided in the mounting groove and adapted to freely protrude from and retract into an outer peripheral surface of the rotor; a spring provided in the mounting groove at a position deeper than the vane and biasing the vane in a direction that causes the vane to protrude from the outer peripheral surface of the rotor; a retaining member provided in the mounting groove on a deeper side than the vane, the retaining member having an insertion hole into which the spring is inserted, The insertion hole is formed in the holding member so as to penetrate in a depth direction of the mounting groove, The spring abuts against the bottom surface of the mounting groove when inserted into the insertion hole. Mechanical seal device.

2. the spring is a conical coil spring, The mechanical seal device according to claim 1 , wherein a small diameter end of the conical coil spring is exposed from the retaining member toward the vane.

3. the circulation pump mechanism includes a plurality of the springs provided in the mounting grooves, 3. The mechanical seal device according to claim 1, wherein the retaining member is formed with a plurality of insertion holes into which a plurality of the springs are individually inserted.

4. the spring has an exposed portion that is exposed from the retaining member toward the vane, The mechanical seal device according to claim 1 or 2, wherein the vane is formed with a recess into which the exposed portion is inserted.

5. the circulation pump mechanism includes a plurality of the springs disposed in the mounting groove; The mechanical seal device according to claim 4 , wherein the vane is formed with a plurality of recesses into which the exposed portions of the springs are individually inserted.

6. The mounting groove has a first groove portion formed on the inner side of the mounting groove and into which the retaining member is fitted, and a second groove portion formed on the opening side of the mounting groove, 3. The mechanical seal device according to claim 1, wherein a groove width of the first groove portion and a thickness of the holding member in the groove width direction of the first groove portion are greater than a groove width of the second groove portion.

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