Mechanical seals

Abstract

The present invention provides a mechanical seal, whose cooling and lubrication conditions are improved. The mechanical seal is an inner flow type mechanical seal, wherein a sliding portion formed by a stationary ring and a rotating ring contacting each other in the axial direction is closer to the inner diameter side than a guide plate, and the leakage direction of the sealed fluid in the sliding portion is the inner diameter side, and the root portion of the guide plate gradually tilts radially outward as it moves toward the side of the built-in cover, so that the sealed fluid guided from the supply port of the rotating shaft to the circulation space is guided to the front end portion of the guide plate, and the front end portion of the guide plate gradually tilts radially inward as it moves toward the side of the built-in cover, so that the sealed fluid is guided to the sliding portion.

Description

Technical Field

[0001] The invention relates to a mechanical seal. Background Art

[0002] In the past, in a general rotor cooling system of a drive motor, the cooling fluid entering from the end cover cools the rotor by flowing through a flow path in the rotor. At this time, in order to prevent the cooling fluid from penetrating into the motor, an outflow type mechanical seal is used between the rotor and the end cover.

[0003] The outflow type mechanical seal has the following disadvantages: the leakage direction of the cooling fluid from the sliding part between the rotating ring and the stationary ring is consistent with the centrifugal direction of the centrifugal force generated by the rotation of the motor, which makes the cooling fluid easy to leak. In order to eliminate this disadvantage, an inflow type mechanical seal is proposed.

[0004] For example, as a liquid cooling device using an internal flow type mechanical seal, there is a device that circulates by causing the coolant flowing in from the inlet pipe of the coolant tank to flow through the hole of the hollow shaft on which the rotor is mounted, thereby cooling the hollow shaft and causing the coolant to flow out from the drain port of the coolant tank. In this liquid cooling device, an internal mechanical seal is used to prevent leakage of the coolant (for example, refer to Patent Document 1).

[0005] (Prior art literature)

[0006] (Patent Document)

[0007] Patent document 1: Japanese Patent Application Laid-Open No. 7-170694. Summary of the invention

[0008] (Problem to be solved by the invention)

[0009] However, in the inflow type mechanical seal of Patent Document 1, it is desired to further improve the cooling and lubrication of the sliding portion of the mechanical seal.

[0010] The present invention has been completed in view of the above-mentioned research, and its object is to provide a mechanical seal that can further improve the cooling and lubrication conditions than before.

[0011] (Solutions used to solve problems)

[0012] In order to achieve the above-mentioned object, the present invention provides a mechanical seal, which is an internal flow type mechanical seal and includes: an external cover connected to a housing; an internal cover located between the housing and the external cover and connected to at least one of the housing or the external cover and having an opening; a guide plate having a root portion integrally formed or connected with the external cover and extending toward the internal cover; a circulation space formed on the radial inner side of the guide plate; a rotating shaft inserted into the opening of the internal cover and having a hollow portion for the sealed fluid to flow therein and a supply port for leading the sealed fluid to the circulation space; a stationary ring fixed to the housing; and a rotating shaft inserted into the opening of the internal cover. The built-in cover; and a rotating ring, which is fixed to the rotating shaft; a sliding portion, which is formed by axially contacting the stationary ring and the rotating ring with each other, the sealed fluid in the sliding portion The leakage direction is on the inner diameter side, the root portion of the guide plate is inclined radially outward as it approaches the built-in cover side, so that the sealed fluid discharged from the supply port of the rotating shaft to the circulation space is discharged to the front end portion of the guide plate, the front end portion of the guide plate is arranged on the radially outer peripheral side of the sliding portion, and is inclined radially inward as it approaches the built-in cover side, so that the sealed fluid is discharged to the sliding portion.

[0013] Preferably, the guide plate has a spiral groove formed on its inner peripheral surface.

[0014] Preferably, the guide plate or the external cover has a rising portion that is inclined from the supply port toward the root portion.

[0015] Preferably, the guide plate or the external cover has a rising portion that is inclined from the supply port toward the root portion, and a spiral groove is formed on the inner peripheral surface of the guide plate and the rising portion.

[0016] Preferably, the guide plate has an arc-shaped cross section.

[0017] Preferably, the mechanical seal is used to cool the electric motor.

[0018] (Effects of the Invention)

[0019] According to the present invention, it is possible to realize a mechanical seal having a further improved cooling and lubrication state than before. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic partially enlarged cross-sectional view showing the structure of a mechanical seal according to the first embodiment of the present invention.

[0021] Figure 2This is an enlarged cross-sectional view showing the relationship between the leakage direction of the cooling fluid and the centrifugal direction of the mechanical seal according to the first embodiment of the present invention.

[0022] Figure 3 This is a schematic cross-sectional view for explaining the flow of cooling fluid when the guide plate of the mechanical seal according to the first embodiment of the present invention is used.

[0023] Figure 4 It is a schematic partial enlarged cross-sectional view showing the structure of a mechanical seal (A) and the structure of a guide plate (B) according to a second embodiment of the present invention.

[0024] Figure 5 It is a schematic partially enlarged cross-sectional view showing the structure of a mechanical seal according to a third embodiment of the present invention.

[0025] Figure 6 This is a schematic partially enlarged cross-sectional view showing the structure (1) of a mechanical seal according to another embodiment of the present invention.

[0026] Figure 7 This is a schematic partially enlarged cross-sectional view showing the structure (2) of a mechanical seal according to another embodiment of the present invention. DETAILED DESCRIPTION

[0027] Overview of implementation methods

[0028] First, a representative embodiment of the present invention will be briefly described. In the following description, as an example, reference numerals corresponding to components of the invention in the drawings are given in parentheses.

[0029] [1] In a representative embodiment of the present invention, an inflow type mechanical seal (1, 300, 400, 200, 500) comprises: an external cover (150) connected to a housing (110); an internal cover (140) located between the housing (110) and the external cover (150) and connected to at least one of the housing (110) and the external cover (150), and having an opening (143a); and a guide plate (157, 357, 457, 257, 557) having a root portion (157b, 357b, 457b, 557) integrally formed with or connected to the external cover (150). 257b, 557b), and extending toward the built-in cover (140); a circulation space (160k), which is formed on the radial inner side of the guide plate (157, 357, 457, 257, 557); a rotating shaft (100), which has a hollow portion (101, 102) for the sealed fluid (CL) to flow therein, and a supply port (101cp) for guiding the sealed fluid (CL) to the circulation space (160k), and is inserted into the opening (143a) of the built-in cover (140); a stationary ring (210), which is fixed to the built-in cover (140); and a rotating ring (220), The invention relates to a sliding portion (215) which is fixed to the rotating shaft (100); and a sliding portion (215) which is formed by bringing the stationary ring (210) and the rotating ring (220) into contact with each other in the axial direction, wherein the sealed fluid (CL) becomes the inner diameter side in the leakage direction of the sliding portion (215), and the root portion (157b, 357b, 457b, 257b, 557b) of the guide plate (157, 357, 457, 257, 557) is inclined radially outward toward the side of the built-in cover (140) so that the supply port (101cp) of the rotating shaft (100) is led out to the circulating air. The sealed fluid (CL) in the space (160k) is discharged to the front end portion (157s, 357s, 457s, 257s, 557s) of the guide plate (157, 357, 457, 257, 557), and the front end portion (157s, 357s, 457s, 257s, 557s) of the guide plate (157, 357, 457, 257, 557) is arranged on the radial outer peripheral side of the sliding portion (215) and is inclined radially inward toward the side of the built-in cover (140) so that the sealed fluid (CL) is discharged to the sliding portion (215).

[0030] [2] In the mechanical seal (300), the guide plate (357) has a spiral groove (357nm) formed on its inner peripheral surface.

[0031] [3] In the mechanical seal (400, 500), the guide plate (457, 557) or the external cover (450) has a rising portion (457d, 557d) that gradually inclines from the supply port (101cp) toward the root portion (457b, 557b).

[0032] [4] In the mechanical seal (400, 500), the guide plate (457, 557) or the external cover (450) has a rising portion (457d, 557d) that gradually inclines from the supply port (101cp) toward the root portion (457b, 557b), and the guide plate and the rising portion (457d, 557d) have a spiral groove (357nm) formed on their inner circumferential surface.

[0033] [5] In the mechanical seal (1, 300, 400, 200), the cross section of the guide plate (157, 357, 457, 257) is arc-shaped.

[0034] [6] The mechanical seal (1, 300, 400, 200, 500) is used to cool the motor.

[0035] <First embodiment>

[0036] Next, a first embodiment of the present invention will be described in detail with reference to the drawings. Figure 1 It is a schematic partially enlarged cross-sectional view showing the structure of a mechanical seal according to a first embodiment of the present invention. Figure 2 This is an enlarged cross-sectional view showing the relationship between the leakage direction of the cooling fluid and the centrifugal direction of the mechanical seal according to the first embodiment of the present invention. Figure 3 This is a schematic cross-sectional view for explaining the flow of cooling fluid when the guide plate of the mechanical seal according to the first embodiment of the present invention is used.

[0037] Here, for the sake of convenience, the arrow a direction along the axis X is set as the left side or the inside of the motor, and the arrow b direction is set as the right side or the outside of the motor. In addition, the arrow c direction close to the axis X is set as the inner peripheral side, and the arrow d direction away from the axis X is set as the outer peripheral side. Furthermore, in the figure, the arrow e direction is set as the upper side, and the arrow f direction is set as the lower side. The upper side and the lower side here refer to the upper direction and the lower direction in the gravity direction when the mechanical seal 1 is installed on the predetermined installation object.

[0038] The mechanical seal 1 is used, for example, in a motor cooling device of an electric vehicle, and is used to seal a cooling fluid CL as a sealed fluid for cooling a rotating shaft of a driving motor, i.e., a rotor 100. The mechanical seal 1 mainly includes a rotor 100, a housing 110, a bearing 120, a cover 130, and a sliding portion 215, i.e., a sliding portion between a stationary ring 210 and a rotating ring 220. Figure 1 Only a portion of the drive motor is shown in the figure.

[0039] The rotor 100 is a rotor that is rotated at high speed by a rotor driving mechanism of a driving motor (not shown), and is a bottomed hollow rotating shaft having a cylindrical shape. The rotor 100 is pivotally supported via a bearing 120 mounted on a housing 110 so as to be able to rotate at high speed around an axis X, and a cooling fluid CL (indicated by multiple arrows) supplied from the outside of the cover 130 flows and circulates in an internal space 100SP inside the rotor 100, thereby achieving cooling.

[0040] The rotor 100 is integrally formed with a cylindrical portion 101 extending along the axis X direction with the axis X as the center and a disc-shaped bottom portion 102 with the axis X formed on the motor inner side (arrow a direction) of the cylindrical portion 101. In the rotor 100, a hollow portion is formed by the cylindrical portion 101 and the bottom portion 102, and a sealed fluid, i.e., a cooling fluid CL, flows in the internal space 100SP.

[0041] The cylindrical portion 101 of the rotor 100 includes a large diameter cylindrical portion 101a on the inner side of the motor (in the direction of arrow a), a medium diameter cylindrical portion 101b having a smaller diameter than the large diameter cylindrical portion 101a, and a small diameter cylindrical portion 101c having a diameter slightly smaller than the medium diameter cylindrical portion 101b.

[0042] The bearing 120 is installed between the outer circumferential surface of the middle diameter cylindrical portion 101b and the inner circumferential surface of the housing 110. The inner ring 123 of the bearing 120 is fixed integrally with the middle diameter cylindrical portion 101b. The outer ring 121 of the bearing 120 is fixed integrally with the housing 110, and the rolling element 122 is provided between the outer ring 121 and the inner ring 123. That is, in the bearing 120, while the outer ring 121 is integrally fixed with the housing 110 and does not rotate, the inner ring 123 is integrally rotated with the rotor 100.

[0043] In addition, the bearing 120 pivotally supporting the rotor 100 is in a state where it can contact the side wall surface 101ab between the large diameter cylindrical portion 101a and the medium diameter cylindrical portion 101b. Therefore, the presence of the bearing 120 is used to suppress further movement of the rotor 100 toward the outside of the motor (in the direction of arrow b).

[0044] The small diameter cylindrical portion 101c of the cylindrical portion 101 is formed with a supply port 101cp having a circular cross-section at the end portion on the motor outer side (in the direction of arrow b), which is used to guide the cooling fluid CL to the circulation space 160k ( Figure 2 Here, the circulation space 160k is a space formed on the radially inner side of a guide plate 157 described later. The supply port 101cp is an outlet end portion when the cooling fluid CL is introduced from the rotor 100 to the circulation space 160k.

[0045] The housing 110 is formed with a concave space 110k for surrounding the small diameter cylindrical portion 101c, which is the front end portion of the rotor 100 protruding from the bearing 120 to the motor exterior side (arrow b direction), and has a substantially "U"-shaped cross section. The housing 110 is formed of metal or the like. On the motor exterior side (arrow b direction) of the housing 110, a cover 130 is integrally mounted using a plurality of bolts 111.

[0046] The cover 130 includes an inner cover 140 and an outer cover 150. In the cover 130, the inner cover 140 and the outer cover 150 are fixed to the side surface 110s of the motor outer side (arrow b direction) of the housing 110 in an axially overlapping state by a plurality of bolts 111. The inner cover 140 is axially connected to the housing 110, and the outer cover is axially connected to the housing 110 via the inner cover.

[0047] The inner cover 140 of the cover 130 is bent from the motor outer side (arrow b direction) to the motor inner side (arrow a direction) and enters the concave space 110k of the housing 110. The inner cover 140 includes an outer annular portion 141, a truncated cone portion 142, and an inner annular portion 143.

[0048] The outer circumferential annular portion 141 of the internal cover 140 is an annular flange portion centered on the axis X and attached to the side surface 110 s of the housing 110 in a state of overlapping with the external cover 150 .

[0049] The truncated cone portion 142 of the built-in cover 140 is a truncated cone-shaped portion that extends obliquely from the inner circumferential side (arrow c direction) end of the outer circumferential side annular portion 141 toward the inner circumferential direction (arrow c direction) close to the axis X and the inner side of the motor (arrow a direction).

[0050] The inner annular portion 143 of the built-in cover 140 is an annular portion that extends linearly from the inner end of the truncated cone portion 142 toward the outer circumferential surface of the small diameter cylindrical portion 101c of the rotor 100. The inner diameter of the inner annular portion 143 of the built-in cover 140 is larger than the outer diameter of the small diameter cylindrical portion 101c of the rotor 100.

[0051] The end 143a of the inner circumference side of the inner circumference side annular portion 143 is a portion for forming the opening of the built-in cover 140, and the stationary ring 210 is integrally fixed to the inner circumference side end surface of the end 143a by a stationary side fixing member (not shown). However, the stationary ring 210 is not limited to being installed on the inner circumference side end surface of the inner circumference side annular portion 143, and can also be installed on the side of the inner circumference side annular portion 143 on the motor outer side (arrow b direction). In addition, the end 143a of the inner circumference side annular portion 143 is sometimes referred to as the opening 143a.

[0052] The stationary ring 210 is a sealing ring formed of an annular member having a rectangular cross section, and is formed of, for example, silicon carbide, ceramics, superhard alloy, carbon material, etc. The stationary ring 210 does not contact the small diameter cylindrical portion 101c of the rotor 100 and cannot rotate relative to the rotor 100. The stationary ring 210 has a sealing surface, on which a sliding portion 215 is formed that faces and contacts the rotating ring 220 in the axis X direction.

[0053] In the small diameter cylindrical portion 101c of the rotor 100, a rotating ring 220 is fixed to the outer peripheral surface of the supply port 101cp at the end portion on the motor outer side (arrow b direction) through a rotating side fixing member not shown. That is, the rotating ring 220 rotates integrally with the small diameter cylindrical portion 101c (supply port 101cp) of the rotor 100. In addition, the rotating ring 220 is not limited to being fixed to the outer peripheral surface of the supply port 101cp, and can also be fixed to the outer peripheral surface of the small diameter cylindrical portion 101c closer to the motor inner side (arrow a direction) than the supply port 101cp.

[0054] The rotating ring 220 is a mating ring formed of a ring-shaped member having a rectangular cross section, and is formed of silicon carbide, ceramic, superhard alloy, carbon material, etc., similar to the stationary ring 210. The rotating ring 220 has a sealing surface, on which a sliding portion 215 is formed that is opposed to and in contact with the stationary ring 210. When the rotor 100 rotates in a state where the sealing surface of the stationary ring 210 and the sealing surface of the rotating ring 220 are in contact with each other in the axial direction, the sliding portion 215 is formed between the stationary ring 210 and the rotating ring 220.

[0055] The external cover 150 of the cover 130 has a flat disc-shaped disk portion 151 extending in a direction perpendicular to the axis X. The external cover 150 is mounted on the side surface 110s of the housing 110 by bolts 111 in a state where the disk portion 151 overlaps with the outer peripheral side disk portion 141 of the internal cover 140. Thus, in the cover 130, a flow path 130SP of the cooling fluid CL having a substantially trapezoidal cross section and an annular shape is formed between the internal cover 140 and the external cover 150.

[0056] In the external cover 150, a supply hole 152 for the cooling fluid CL is formed coaxially with the axis X of the rotor 100, which is the center of the disk portion 151. The supply hole 152 of the external cover 150 is a through hole. A supply pipe 155 for guiding the cooling fluid CL to the vicinity of the bottom 102 of the rotor 100 is installed in the supply hole 152.

[0057] The supply pipe 155 is formed as a whole with a roughly "T"-shaped cross-section, and includes: a tubular outlet pipe portion 155a whose outer diameter is smaller than the inner diameter of the cylindrical portion 101 of the rotor 100; and a flange portion 155b formed integrally with the end of the outlet pipe portion 155a on the motor outer side (in the direction of arrow b).

[0058] The flange portion 155 b of the supply pipe 155 is a disc-shaped portion having an outer diameter larger than the inner diameter of the supply hole 152 of the external cover 150 , and is mounted on the disc portion 151 of the external cover 150 by a plurality of bolts 159 .

[0059] The outlet pipe portion 155a of the supply pipe 155 is used to guide the external cooling fluid CL to the internal space 100SP of the cylindrical portion 101 of the rotor 100. The outlet pipe portion 155a has a length that does not reach the bottom portion 102 of the rotor 100 when the flange portion 155b is attached to the disk portion 151 of the external cover 150.

[0060] Therefore, an annular flow path is formed between the inner circumferential surface of the cylindrical portion 101 that divides the internal space 100SP of the cylindrical portion 101 of the rotor 100 and the outer circumferential surface of the outlet pipe portion 155a, in which the cooling fluid CL hits the bottom 102 of the rotor 100 and is then led to the outside of the motor (in the direction of arrow b). The cooling fluid CL flowing in the annular flow path is led from the supply port 101cp of the small-diameter cylindrical portion 101c of the cylindrical portion 101 to the flow path 130SP having a substantially trapezoidal cross section formed by the internal cover 140 and the external cover 150.

[0061] Furthermore, the external cover 150 has a discharge pipe 156 for the cooling fluid CL formed on the outer circumference side (in the direction of arrow d) of the supply hole 152 in the disk portion 151 and on the upper side in the gravity direction (in the direction of arrow e).

[0062] The discharge pipe 156 of the external cover 150 protrudes a predetermined length toward the outside of the motor (in the direction of arrow b). The discharge pipe 156 is a part of the disc portion 151, and the two are formed integrally. However, this is not limited to this, and the discharge pipe 156 and the disc portion 151 of the external cover 150 can also be provided separately.

[0063] The inner diameter of the discharge pipe 156 is the same as the inner diameter of the outlet pipe portion 155a of the supply pipe 155. However, the present invention is not limited thereto, and the inner diameter of the discharge pipe 156 may be slightly larger than or slightly smaller than the inner diameter of the outlet pipe portion 155a of the supply pipe 155.

[0064] For example, when the inner diameter of the discharge pipe 156 is larger than the inner diameter of the outlet pipe portion 155a of the supply pipe 155, the cooling fluid CL in the flow path 130SP is discharged smoothly, the flow speed of the cooling fluid CL in the internal space 100SP of the rotor 100 is accelerated, and the sliding portion 215 can be effectively cooled and lubricated.

[0065] On the other hand, when the inner diameter of the discharge pipe 156 is smaller than the inner diameter of the outlet pipe portion 155a of the supply pipe 155, the flow rate of the cooling fluid CL in the internal space 100SP of the rotor 100 slows down, and the sliding portion 215 can be immersed in the cooling fluid CL.

[0066] In addition, a guide plate 157 having a substantially arc-shaped cross section is integrally formed on the inner side (arrow a direction) of the motor (hereinafter referred to as the "inner side") 151n of the disc portion 151 of the external cover 150. Specifically, the guide plate 157 is an annular portion having an arc-shaped cross section that protrudes from the inner side 151n of the disc portion 151 toward the inner side (arrow a direction) of the motor.

[0067] The guide plate 157 is coaxial with the rotation axis X of the supply pipe 155 of the disk portion 151 of the external cover 150, and has a radius centered on the rotation axis X that does not reach the discharge pipe 156. That is, the distance (radius) from the supply pipe 155 to the guide plate 157 is smaller than the distance from the supply pipe 155 to the discharge pipe 156.

[0068] The guide plate 157 is formed integrally with the inner side surface 151n of the disk portion 151 of the external cover 150. The guide plate 157 has a root portion 157b, which is a portion where the guide plate 157 is integrated with the inner side surface 151n of the disk portion 151 ( Figure 1 That is, the guide plate 157 is a portion connected to the external cover 150 via the root portion 157b and extending toward the internal cover 140 in the axial direction.

[0069] Here, the inner peripheral surface 157n for defining the guide plate 157 gradually extends in an inclined manner from the front end portion 157s to connect with the inner side surface 151n of the disk portion 151, thereby drawing an arc.

[0070] The outer peripheral surface 157g of the guide plate 157 gradually extends in an arc-shaped manner from the front end portion 157s, but extends linearly along the rotation axis X near the inner side surface 151n immediately before connecting to the disk portion 151. Therefore, the root portion 157b has a substantially triangular cross-section and functions as a portion for increasing the strength between the guide plate 157 and the disk portion 151.

[0071] Furthermore, the root portion 157b of the guide plate 157 is inclined radially outward toward the built-in cover 140 side so that the cooling fluid CL flowing out from the supply port 101cp to the circulation space 160k is led out to the front end portion 157s of the guide plate 157. In addition, since the root portion 157b includes an inner peripheral surface 157n that gradually extends in an inclined manner to draw an arc and connects the front end portion 157s and the inner side surface 151n of the disk portion 151, it functions as a lead-out portion that guides the cooling fluid CL to the sliding portion 215.

[0072] The front end portion 157s of the guide plate 157 is arranged on the radial outer peripheral side of the sliding portion 215, and gradually tilts radially inward as it moves toward the built-in cover 140 side, so that the cooling fluid CL is led out to the sliding portion 215. Specifically, the front end portion 157s tilts toward the sliding portion 215 arranged on the radial inner peripheral side. In addition, the front end portion 157s is formed in a state of being curved in an arc shape in a radial direction centered on the rotation axis X so that the front end surfaces 157st face each other. That is, the guide plate 157 has a cup shape curved in a manner of drawing a smooth semicircular arc from the inner peripheral surface 151n of the disk portion 151, and its front end portion 157s faces the sliding portions 215 of the stationary ring 210 and the rotating ring 220.

[0073] In this case, as long as the front end portion 157s of the guide plate 157 can guide the cooling fluid CL directly to the sliding portion 215, the front end portion 157s does not have to be strictly opposite to the sliding portion 215, but may also be opposite to a position slightly deviated from the sliding portion 215 toward the inner side of the motor in the direction of the axis X (in the direction of the arrow a) or the outer side of the motor in the direction of the axis X (in the direction of the arrow b).

[0074] That is, the guide plate 157 forms a circulation space 160k in which the cooling fluid CL flowing out from the supply port 101cp of the rotor 100 is circulated as indicated by the arrow through the semicircular inner peripheral surface 157n and guided to the sliding portion 215. The circulation space 160k is formed radially inside the guide plate 157 and communicates with the internal space 100SP of the rotor 100 and the flow path 130SP.

[0075] The front end portion 157s of the guide plate 157 is spaced apart from the sliding portion 215 by a predetermined distance in the radial direction orthogonal to the axis X direction. The space between the front end portion 157s of the guide plate 157 and the sliding portion 215 is a space for connecting the circulation space 160k and the flow path 130SP. Therefore, from the viewpoint of cooling the rotor 100 and cooling and lubricating the sliding portion 215, the space is set to an optimal distance.

[0076] Next, the cooling operation of the mechanical seal 1 by the cooling fluid CL will be described. In practice, the cooling fluid CL supplied from the outside via the supply pipe 155 of the external cover 150 passes through the inside of the outlet pipe portion 155a as indicated by multiple arrows and is supplied to the internal space 100SP of the rotor 100.

[0077] The cooling fluid CL collides with the bottom 102 of the rotor 100 and flows back, passes through the flow path between the outer circumferential surface of the outlet pipe portion 155a and the inner circumferential surface of the cylindrical portion 101 of the rotor 100, and flows out from the supply port 101cp of the small diameter cylindrical portion 101c of the cylindrical portion 101 to the circulation space 160k formed on the radial inner side of the guide plate 157.

[0078] The cooling fluid CL flowing out to the circulation space 160k is guided from the inner circumference side (in the direction of arrow c) to the outer circumference side (in the direction of arrow d) along the inner side surface 151n of the disk portion 151 of the external cover 150 by the centrifugal force caused by the rotation of the rotor 100.

[0079] Then, the cooling fluid CL is supplied to the sliding portion 215 along the inner circumferential surface 157n of the root portion 57b and the tip portion 157s of the guide plate 157 as shown by the arrow. In particular, the cooling fluid CL is directly supplied to the sliding portion 215 from the tip portion 157s of the guide plate 157.

[0080] Therefore, after the sliding part 215 is cooled and lubricated by the cooling fluid CL, the cooling fluid CL colliding with the sliding part 215 is knocked back by the outer peripheral surface of the stationary ring 210, and is discharged from the exhaust pipe 156 to the outside of the external cover 150 through the flow path 130SP between the built-in cover 140 and the outer peripheral surface 157g of the guide plate 157.

[0081] like Figure 2As shown, the cooling fluid CL is acted upon by a centrifugal force FC from the inner peripheral side (in the direction of arrow c) toward the outer peripheral side (in the direction of arrow d) due to the rotation of the rotor 100. In contrast, the sliding portion 215 is closer to the inner diameter side than the guide plate 157, and the cooling fluid CL leaks in the inner diameter side opposite to the centrifugal force FC in the direction LK of leakage of the sliding portion 215. Therefore, the centrifugal force FC caused by the high-speed rotation of the rotor 100 acts in a manner that prevents the cooling fluid CL from leaking from the sliding portion 215, thereby preventing the cooling fluid CL from leaking from the sliding portion 215 to the concave space 110k in advance.

[0082] In addition, if Figure 3 As shown in (A), the guide plate 157 has a smooth semicircular arc shape without corners, so the cooling fluid CL can be efficiently and directly supplied to the sliding portion 215 along its inner circumferential surface 157n, as shown by the thick arrow, drawing a smooth curve.

[0083] Thus, in the mechanical seal 1 , the sliding portion 215 can be always immersed in the cooling fluid CL. Therefore, in the mechanical seal 1 , the cooling fluid CL can always cool and lubricate the sliding portion 215 .

[0084] According to the above configuration, the mechanical seal 1 can efficiently supply the cooling fluid CL directly to the sliding portion 215 via the guide plate 157 having an arc-shaped cross section provided on the external cover 150 , thereby achieving a state in which the sliding portion 215 is cooled and lubricated better.

[0085] <Second embodiment>

[0086] Figure 4 2 is a schematic partially enlarged cross-sectional view showing the structure of the mechanical seal (A) and the structure of the guide plate (B) according to the second embodiment of the present invention. Figure 4 In the present invention, the same reference numerals are given to portions corresponding to those of the mechanical seal 1 of the first embodiment, and description thereof will be omitted.

[0087] like Figure 4 As shown in (A) and (B), the basic structure of the mechanical seal 300 of the second embodiment is the same as that of the mechanical seal 1 of the first embodiment, but the difference is that an external cover 350 is provided instead of the external cover 150.

[0088] The external cover 350 has a guide plate 357 different from the guide plate 157 of the first embodiment on the inner side surface 351n of the disk portion 351. The front end portion 357s and the root portion 357b of the guide plate 357 have a shape and function similar to the front end portion 157s and the root portion 157b of the guide plate 157, but a concave spiral groove 357nm is formed on the inner peripheral surface 357n.

[0089] Generally, the cooling fluid CL rotated by the rotor 100 is forced toward the outer circumference (in the direction of arrow d) by the centrifugal force FC, and therefore the cooling fluid CL is not easily led to the inner circumference (in the direction of arrow c).

[0090] However, the external cover 350 has a guide plate 357 having a spiral groove 357nm formed on the inner peripheral surface 357n, so that Figure 4 As shown in FIG. 2B , the cooling fluid CL can be efficiently guided to the sliding portion 215 while the cooling fluid CL draws a spiral along the spiral groove 357 nm. In addition, the external cover 350 can guide the cooling fluid CL from the vicinity of the supply pipe 155 to the sliding portion 215, so that the sliding portion 215 can be efficiently cooled and lubricated.

[0091] in addition, Figure 4 The guide plate 357 shown in (B) is for convenience of explanation. Figure 4 (A) is a simplified diagram of the flow of the cooling fluid CL driven by the guide plate 357, and its shape is similar to Figure 4 The shapes of the guide plates 357 of (A) are not completely consistent.

[0092] <Third embodiment>

[0093] Figure 5 : is a schematic partial enlarged cross-sectional view showing the structure of a mechanical seal 400 according to a third embodiment of the present invention. Figure 5 Also in the drawings, the same reference numerals are given to portions corresponding to those of the mechanical seal 1 of the first embodiment, and description thereof will be omitted.

[0094] like Figure 5 As shown, the external cover 450 has a guide plate 457 that is bent into an arc shape with a cross-section of approximately ¾ of a circle relative to the inner side surface 451n of the disk portion 451.

[0095] The guide plate 457 is connected to the end of the outlet pipe portion 155a of the supply pipe 155 on the motor outer side (arrow b direction), and is integrated with the disk portion 451. The guide plate 457 has an arc-shaped front end portion 457s, and is formed so that the front end surfaces 457st face each other in the radial direction.

[0096] That is, the guide plate 457 has a cup shape that is curved in a substantially ¾ circle with a smooth cross section from the inner side surface 451 n of the disk portion 451 , and the front end portion 457 s faces the sliding portion 215 .

[0097] In this case, the front end portion 457 s of the guide plate 457 is arranged on the radially outer peripheral side of the sliding portion 215 , and is inclined toward the sliding portion 215 arranged on the radially inner peripheral side.

[0098] In addition, as long as the front end portion 457s is inclined so as to be able to guide the cooling fluid CL directly to the sliding portion 215, the front end portion 457s does not have to be strictly opposite to the sliding portion 215, but can also be opposite to a position slightly deviated from the sliding portion 215 toward the inner side of the motor in the direction of the axis X (in the direction of the arrow a) or toward the outer side of the motor in the direction of the axis X (in the direction of the arrow b).

[0099] The guide plate 457 is formed integrally with the disk portion 451 of the external cover 450 and has a root portion 457 b which is a portion where the guide plate 457 and the disk portion 451 are integrated, and a rising portion 457 d .

[0100] Here, the root portion 457 b is basically the same as the root portion 157 b of the first embodiment, and has a substantially triangular cross-section. The root portion 457 b is used to increase the strength between the guide plate 457 and the disk portion 451 .

[0101] Furthermore, the root portion 457b is inclined radially outward toward the built-in cover 140 side so that the cooling fluid CL flowing out from the supply port 101cp to the circulation space 160k is led to the front end portion 457s of the guide plate 457. That is, the root portion 457b includes the inner peripheral surface 457n gradually inclined and extending in an arc toward the front end portion 457s, and thus also functions as a lead-out portion that guides the cooling fluid CL to the sliding portion 215.

[0102] The rising portion 457d of the guide plate 457 is a portion fixed integrally with the outer peripheral surface of the outlet pipe portion 155a of the supply pipe 155, and is a portion having a substantially triangular cross-section connected to the root portion 457b. The rising portion 457d is formed near the outlet pipe portion 155a of the supply pipe 155. The rising portion 457d gradually inclines as it moves from the supply port 101cp toward the root portion 457b, and includes an inner peripheral surface 457n that gradually inclines and extends in a circular arc between the root portion 457b and the outer peripheral surface of the outlet pipe portion 155a of the supply pipe 155.

[0103] The inner circumferential surface 457n of the guide plate 457 is continuously and smoothly connected to the tip portion 457s, the root portion 457b, and the rising portion 457d. Therefore, the cooling fluid CL flowing out from the supply port 101cp of the cylindrical portion 101 of the rotor 100 is led out to the sliding portion 215 at high speed and efficiency via the rising portion 457d, the root portion 457b, and the tip portion 457s.

[0104] The flange 155b of the supply pipe 155 is mounted on the side 457c of the motor outer side (arrow b direction) of the guide plate 457. In this case, in the guide plate 457, the starting point 457st of the arc of the guide plate 457 becomes the contact point with the outer peripheral surface of the outlet pipe part 155a of the supply pipe 155.

[0105] In the mechanical seal 400, the cooling fluid CL flowing out from the internal space 100SP of the rotor 100 to the flow path 130SP flows along the inner peripheral surface 457n of the guide plate 457 in a circle indicated by a thick arrow at high speed and efficiently, and is supplied to the sliding portion 215. The mechanical seal 400 can achieve the same operation and effects as those of the first to third embodiments.

[0106] <Other embodiments>

[0107] In the mechanical seal 1 of the first embodiment, the external cover 150 and the guide plate 157 are formed integrally and the discharge pipe 156 is provided on the upper side of the supply pipe 155 (in the direction of arrow e). However, the present invention is not limited thereto. Figure 6 As shown in the figure, in the mechanical seal 200, the external cover 250 is provided with a discharge pipe 256 on the lower side (in the direction of arrow f) of the supply pipe 155 in the gravity direction, and a separate guide plate 257 is connected to the inner side surface 251n of the disk portion 251 of the external cover 250 by fixing with bolts 259. The guide plate 257 is also formed with a spiral groove (not shown) on its inner peripheral surface like the mechanical seal 300 of the second embodiment.

[0108] In the mechanical seal 200, the front end portion 257s and the root portion 257b of the guide plate 257 have shapes and functions similar to the front end portion 157s and the root portion 157b of the guide plate 157 of the first embodiment, and the structure and effects other than the discharge pipe 256 are the same as those of the mechanical seal 1 of the first embodiment.

[0109] In addition, in the guide plate 257 of the mechanical seal 200, the junction between the outer peripheral surface of the supply pipe 155 and the inner side surface 251n of the external cover 250 may also form a rising portion (e.g., corresponding to the rising portion 457d ( Figure 5 )), which gradually inclines from the supply port 101cp of the cylindrical portion 101 of the rotor 100 toward the root portion 257b of the guide plate 257.

[0110] Similarly, in the mechanical seal 300 ( Figure 4 ) in the joint portion between the outer peripheral surface of the supply pipe 155 and the inner side surface 351n of the disk portion 351 of the external cover 350, a rising portion (e.g., corresponding to the rising portion 457d ( Figure 5 )), which gradually inclines as it approaches the root portion 357b of the guide plate 357 from the supply port 101cp of the cylindrical portion 101 of the rotor 100. The rising portion may also form a spiral groove as described above on the surface of the inner circumference side. In addition, the rising portion may also be provided on the external cover 350.

[0111] In addition, in the mechanical seal 400 ( Figure 5 ), the arc-shaped guide plate 457 is integrally formed on the external cover 450, but the present invention is not limited thereto, and may also be used as Figure 7 A mechanical seal 500 is shown.

[0112] The mechanical seal 500 includes a guide plate 557 having a cross-sectional shape different from that of the guide plate 457 of the mechanical seal 400 of the third embodiment.

[0113] The guide plate 557 is not arc-shaped in cross section, but has a front end portion 557s having a substantially isosceles triangle cross section, a root portion 557b having a substantially isosceles triangle cross section, and a rising portion 557d having a substantially right triangle cross section. The front end portion 557s and the root portion 557b of the guide plate 557 are connected to each other by an annular and thin plate-shaped cylindrical portion 557t extending parallel to the axis X. The root portion 557b and the rising portion 557d of the guide plate 557 are connected to each other by an annular annular portion 557e extending in a radial direction perpendicular to the axis X.

[0114] The rising portion 557d is a portion fixed to the outer peripheral surface of the outlet pipe portion 155a of the supply pipe 155, and the end portion on the radial upper side (arrow e direction) is connected to the annular portion 557e. The rising portion 557d is inclined from the supply port 101cp toward the root portion 557b. The rising portion 557d has an annular inclined surface 557dk, which extends obliquely from the end portion on the motor inner side (arrow a direction) in the axis X direction toward the outer peripheral side (arrow d direction) and the motor outer side (arrow b direction). That is, the rising portion 557d gradually inclines as it moves from the supply port 101cp of the cylindrical portion 101 of the rotor 100 toward the root portion 557b of the guide plate 557.

[0115] The inclined surface 557dk of the rising portion 557d is engaged with the outer peripheral surface of the outlet pipe portion 155a of the supply pipe 155, and is engaged with the end portion of the lower side (in the direction of the arrow f) of the annular portion 557e. The rising portion 557d uses the inclined surface 557dk to make the cooling fluid CL flowing out from the supply port 101cp of the cylindrical portion 101 rise and be led out to the root portion 557b. In addition, the rising portion 557d is not limited to a right-angled triangle in cross section, and may be other various cross-sectional shapes as long as it has an inclined surface 557dk that can lead the cooling fluid CL to the root portion 557b. In addition, in the rising portion 557, the spiral groove as described above may also be formed on the surface on the inner peripheral side. In addition, the rising portion 557d is not an essential component, and may only include the root portion 557 and the front end portion 557s.

[0116] The root portion 557b is arranged near the discharge pipe 156 and connected to the cylindrical portion 557t and the annular portion 557e. The root portion 557b has an annular inclined surface 557bk which extends obliquely from the end portion on the radial inner peripheral side (arrow c direction) toward the outer peripheral side (arrow d direction) and the motor inner side (arrow a direction). The inclined surface 557bk of the root portion 557b is joined to the end portion on the upper side (arrow e direction) of the annular portion 557e and the end portion on the motor outer side (arrow b direction) of the cylindrical portion 557t.

[0117] The root portion 557b gradually inclines radially outward as it moves toward the side of the built-in cover 140 in such a manner that the cooling fluid CL flowing out from the supply port 101cp is led out to the front end portion 557s of the guide plate 557. Therefore, the root portion 557b further leads the cooling fluid CL led out by the inclined surface 557dk of the rising portion 557d to the front end portion 557s through the inclined surface 557bk. That is, the root portion 557b also functions as a leading portion for the cooling fluid CL. In addition, the root portion 557b is not limited to an isosceles triangle in cross section, and may be any other cross-sectional shape as long as it has an inclined surface 557bk that can lead the cooling fluid CL to the front end portion 557s.

[0118] The front end portion 557s is a portion having a substantially isosceles triangle cross section connected to the end of the cylindrical portion 557t on the motor inner side (in the direction of arrow a). The front end portion 557s is arranged on the radial outer peripheral side of the sliding portion 215, and is inclined from the end of the cylindrical portion 557t on the motor inner side (in the direction of arrow a) toward the sliding portion 215 arranged on the radial inner peripheral side. Specifically, the front end portion 557s gradually inclines radially inward as it moves toward the built-in cover 140 side so that the cooling fluid CL is led out to the sliding portion 215, and has an annular inclined surface 557sk that extends obliquely from the end of the cylindrical portion 557t on the motor inner side (in the direction of arrow a) toward the inner peripheral side and the motor inner side (in the direction of arrow a).

[0119] The front end portion 557s supplies the cooling fluid CL guided by the inclined surface 557bk of the root portion 557b to the sliding portion 215 through the inclined surface 557sk. In addition, the front end portion 557s is not limited to the isosceles triangle cross-sectional shape, and may be any other cross-sectional shape as long as it has the inclined surface 557sk capable of supplying the cooling fluid CL to the sliding portion 215.

[0120] As described above, the guide plate 557 is not an arc shape like the guide plate 157, but includes a rising portion 557d having inclined surfaces 557dk, 557bk, and 557sk for guiding the cooling fluid CL to the sliding portion 215, a root portion 557b, and a front end portion 557s, which is also included in the scope of the present invention. In addition, the guide plate 557 may also be formed with a spiral groove (not shown) on the inner peripheral surface of the root portion 557b, the cylindrical portion 557t, and the front end portion 557s as in the mechanical seal 300 of the second embodiment.

[0121] Furthermore, in the above-mentioned first to third embodiments, if Figure 1 As shown, the inner cover 140 and the outer cover 150 are fixed to the side surface 110s of the housing 110 on the motor outer side (arrow b direction) by a plurality of bolts 111 in an axially overlapped state. However, the present invention is not limited thereto, and the following connection forms are also possible.

[0122] For example, the internal cover 140 and the external cover 150 are fixed to each other by bolts or the like while overlapping in the axial direction, and the outer peripheral end of the external cover 150 is fixed to the side surface 110 s of the housing 110 by a plurality of bolts 111 .

[0123] The inner cover 140 is connected to the housing 110 in the radial direction by bolts, and the outer peripheral end of the outer cover 150 is axially fixed to the side surface 110s of the housing 110 by a plurality of bolts 111. In this case, the inner cover 140 and the outer cover 150 do not necessarily overlap in the axial direction.

[0124] Furthermore, the internal cover 140 is fixed to the external cover 150 in the axial direction by bolts or the like, and the external cover 150 is fixed to the outer peripheral surface of the housing 110 in the radial direction by a plurality of bolts 111 .

[0125] In addition, the mechanical seals 1, 300, 400, 200, 500 according to the first to third embodiments and other embodiments are applied to the rotor cooling device of the drive motor of the electric vehicle, but the application objects of the mechanical seals 1, 300, 400, 200, 500 according to the present invention are not limited to the above-mentioned devices. The present invention can be applied to all structures that can achieve the effects of the present invention.

[0126] The first to third embodiments of the present invention are described above, but the present invention is not limited to the first to third embodiments, but includes all forms included in the concept of the present invention and the claims. In addition, each structure can be appropriately selectively combined to achieve at least part of the above-mentioned topics and effects. For example, the shape, material, configuration, etc. of each component of the above-mentioned embodiment can also be appropriately changed according to the specific use form of the present invention.

[0127] Description of Reference Numerals

[0128] 1, 200, 300, 400, 500 mechanical seal; 100SP internal space; 101 cylinder; 101a large diameter cylinder; 101b medium diameter cylinder; 101c small diameter cylinder; 102 bottom; 110 housing; 110k recessed space; 111, 159 bolts; 120 bearing; 121 outer ring; 122 rolling element; 123 inner ring; 130 cover; 140 built-in cover; 141 outer circumferential side disk; 142 conical plate; 143 inner circumferential side disk; 150 , 250, 350, 450 external cover; 151 disc portion; 152 supply hole; 155 supply pipe; 155a outlet pipe portion; 155b flange portion; 156 discharge pipe; 157, 257, 357, 457, 557 guide plate; 157s front end portion; 157b, 457b, 557b root portion; 457d, 557d rising portion; 160k circulation space; 210 stationary ring; 215 sliding portion; 220 rotating ring; 357nm spiral groove; CL cooling fluid.

Claims

1. A mechanical seal, which is an inflow mechanical seal, include: An external cover connected to the housing; an internal cover, which is located between the shell and the external cover, connected to at least one of the shell or the external cover, and has an opening; a guide plate having a root portion integrally formed with or connected to the external cover, and a front end portion extending from the root portion toward the internal cover; a circulation space formed radially inwardly of the guide plate; a rotating shaft inserted into the opening of the built-in cover and having a hollow portion in which a sealed fluid flows and a supply port for leading the sealed fluid to the circulation space; a stationary ring fixed to the built-in cover; a rotating ring fixed to the rotating shaft; as well as a sliding portion formed by bringing the stationary ring and the rotating ring into contact with each other in the axial direction, The sealed fluid is leaked from the sliding portion in the inner diameter direction. The mechanical seal is characterized in that: The root portion of the guide plate gradually inclines radially outward toward the built-in cover so that the sealed fluid discharged from the supply port of the rotating shaft to the circulation space is discharged to the front end portion of the guide plate. The front end portion of the guide plate is arranged on the outer peripheral side of the sliding portion in the radial direction, and gradually tilts radially inward toward the built-in cover side so that the sealed fluid is guided to the sliding portion. The guide plate forms a flow path on the radially outer side. The space between the front end portion of the guide plate and the sliding portion is a space for communicating the circulation space with the flow path.

2. The mechanical seal according to claim 1, in, The guide plate has a spiral groove formed on its inner peripheral surface.

3. The mechanical seal according to claim 1, in, The guide plate or the external cover has a rising portion that is inclined from the supply port toward the root portion.

4. The mechanical seal according to claim 1, in, The guide plate or the external cover has a rising portion that is inclined from the supply port toward the root portion, The guide plate and the rising portion have spiral grooves formed on their inner peripheral surfaces.

5. The mechanical seal according to any one of claims 1 to 4, in, The cross section of the guide plate is arc-shaped.

6. The mechanical seal according to claim 5, in, The mechanical seal is used to cool the electric motor.

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