JP2005240996A - Lip type end face sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lip type end face sealing device 6 having excellent sealing property for different kinds of liquids on both sides in the axial direction and excellent durability. <P>SOLUTION: A case 61 fitted into an inner peripheral face 2a of a housing 2 is composed of case members 611, 612. A pair of seal lips 62, 63 provided integrally in its inner peripheral flange parts 611b, 612b and opened into a tapered shape in which they go against each other for the axial direction come into slide-contact with collar parts 64b, 65b of slingers 64, 65 fitted in the outer periphery of a rotary shaft 3. A seal internal space S2 among both seal lips 62, 63 and both slingers 64, 65 is opened by pressure through a vent hole 22 opened on the inner peripheral face 2a of the housing 2, a ventilation hole 611c and provided in the case 61 opened, and a section between the case members 611 and 612 and prevents occurrence of negative pressure in the seal internal space 2 due to rotation of the slingers 64, 65. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lip type end face sealing device that performs sealing by bringing a seal lip into close contact with an end face.

A typical prior art of a sealing device that seals between engine oil and clutch oil in a wet engine is disclosed, for example, in Patent Document 1 below.
Japanese Utility Model Publication No. 6-49856

  FIG. 16 is a half sectional view showing a conventional sealing device 100 of the same type as that described in FIG. That is, the seal device 100 is formed of a rubber-like elastic material on an annular metal case 101 that is press-fitted to the inner peripheral surface of the housing 120, and a pair of radial seal lips 102 that face each other in the axial direction. 103, and extension springs 104 and 105 for applying a pressing force to the rotating shaft 130 are mounted on the outer periphery thereof. One radial seal lip 102 targets engine oil for sealing, and the other radial seal lip 103 targets clutch oil for sealing.

  However, the sealing device 100 shown in FIG. 16 has a relatively short seal life because the radial seal lips 102 and 103 are worn by the pressing force to the rotating shaft 130 and is slightly eccentric with respect to the rotating shaft 130. When mounted in a state, the sliding surface pressure with the rotary shaft 130 becomes excessive or part of the radial seal lips 102, 103 in the circumferential direction, or a gap is generated, so that different liquids on both sides in the axial direction There is a risk of mixing. In addition, when extrapolated to the rotary shaft 130, it is necessary to pay close attention so as not to damage the radial seal lips 102 and 103.

  From this point of view, in recent years, as described in FIG. 1 of Patent Document 1, an end face seal type end face sealing device in which a seal lip is slidably contacted with an end face of a slinger perpendicular to the shaft center. There is a tendency to change. However, in the case of the end face seal type, negative pressure is generated in the seal internal space sealed by the sliding portions of both seal lips due to the centrifugal force at the time of rotation, so that the seal lip strikes the end surface of the slinger and slides. There was a risk that the dynamic load increased, resulting in a decrease in sealing performance.

  The present invention has been made in view of the above problems, and a technical problem thereof is to provide a lip type end face sealing device having excellent sealing performance and excellent durability.

  As a means for effectively solving the above technical problem, a lip-type end face seal device according to the invention of claim 1 is provided integrally with an annular case fixed to the inner peripheral surface of the housing and is axially provided. A pair of seal lips opened in a taper shape opposite to each other, and a pair of slinger closely fitted on the outer periphery of the rotating shaft inserted through the inner periphery of the housing and in sliding contact with the seal lips at the flange portion And a vent passage for releasing the pressure in the seal internal space between the sliding portions of the seal lips and the slinger. For this reason, even if air is discharged from the seal internal space between the sliding portions of the seal lips and the slinger due to the centrifugal force generated by the rotation of the slinger, no negative pressure is generated.

  According to a second aspect of the present invention, there is provided a lip-type end face sealing device according to the first aspect, wherein the case is composed of a pair of case members, and the vent path is a vent hole opened in the inner peripheral surface of the housing; The case includes a vent hole that is opened to face a fitting surface with the inner peripheral surface of the housing between the pair of case members and communicates with the vent hole. That is, the seal internal space between the sliding portions of both seal lips and both slinger is configured to release pressure from between the pair of case members constituting the case through the vent hole of the case and the vent hole of the housing. It is.

  According to a third aspect of the present invention, there is provided the lip type end face sealing device according to the first aspect, wherein the ventilation path has a vent hole opened in the inner peripheral surface of the housing, and one end connected to the vent hole. Consists of a ventilation tube communicating with the seal internal space between the sliding portions of both seal lips and both slinger. That is, the seal internal space between the sliding portions of both the seal lips and both slinger is configured to release pressure from the vent tube through the vent hole of the housing.

  According to a fourth aspect of the present invention, there is provided a lip-type end face sealing device according to the first aspect, wherein one seal lip has liquid as a sealing target, and the other sealing lip has atmospheric dust as a sealing target. Is formed in the slinger, and the seal internal space between the sliding portions of both seal lips and both slinger is communicated with the atmosphere side through a dust filter. For this reason, it is not necessary to form a ventilation path on the housing side, and the air sucked into the seal internal space between the sliding portions of both seal lips and both slinger is filtered by the dust filter.

  According to a fifth aspect of the present invention, there is provided a lip-type end face sealing device integrally provided in an annular case fixed to an inner peripheral surface of a housing and opened in a tapered shape toward the liquid to be sealed, A slinger that is tightly fitted to the outer periphery of the rotating shaft inserted through the inner periphery and is in sliding contact with the seal lip at the flange portion, and a duster that is closely fitted to the outer periphery of the rotating shaft and located on the atmosphere side of the slinger. Is provided with a dust cover that is slidably contacted with the flange portion of the case, and an air passage is formed in the dust cover to release the pressure in the seal internal space between the seal lip and the sliding portion of the dust lip to the atmosphere side. In addition, a dust filter is provided in the air passage. For this reason, even if air is discharged from the seal inner space between the sliding part of the seal lip and the slinger and the sliding part of the dust lip and the case by the centrifugal force acting on the sliding part, the inner space of the seal remains in the air passage. Since the pressure is released via the negative pressure, no negative pressure is generated.

  A lip-type end face sealing device according to a sixth aspect of the present invention is the structure according to any one of the first to fifth aspects, wherein the seal lip and the slinger come into contact with each other on the outer peripheral side as the slinger rotates. A spiral groove for pumping is formed.

  According to a seventh aspect of the present invention, there is provided the lip type end face sealing device according to the fifth aspect, wherein the air passage is formed in a slit shape at a portion penetrating the rubber layer. That is, the portion of the air passage that passes through the rubber layer and forms a slit is normally closed, and operates so as to open when negative pressure is generated in the seal internal space. There is no constant exposure to external dust, and the intrusion of large dust particles is also blocked.

  In the lip-type end face sealing device according to an eighth aspect of the present invention, in the configuration according to the fifth aspect, the air passage extends in a spiral manner at the fitting portion with the rotation shaft in the inner peripheral portion of the dust cover. Thereby, the filtration path by the dust filter in the ventilation path can be lengthened.

  The lip-type end face sealing device according to the invention of claim 9 is positioned by the inner peripheral portion of the dust cover contacting the end portion of the slinger on the atmosphere side in the configuration of claim 5. . According to this configuration, the dust cover can be positioned with respect to the slinger by bringing the inner peripheral portion of the dust cover into contact with the end of the slinger on the atmosphere side in the process of attaching the seal.

  According to a tenth aspect of the present invention, there is provided a lip-type end face sealing device integrally provided in an annular case fixed to an inner peripheral surface of a housing and opened in a tapered shape toward the liquid to be sealed; A slinger that is tightly fitted to the outer periphery of the rotating shaft inserted through the inner periphery and is in sliding contact with the seal lip at the flange portion, and a duster that is closely fitted to the outer periphery of the rotating shaft and located on the atmosphere side of the slinger. A dust cover that is slidably contacted with the case, and the dust lip is separated from the case by centrifugal force at a rotational speed greater than or equal to a predetermined speed, thereby releasing the pressure in the space inside the dust cover to the outside. is there.

  The lip-type end face sealing device according to the invention of claim 11 is provided integrally with an annular case fixed to the inner peripheral surface of the housing and is opened in a tapered shape toward the liquid to be sealed; A slinger that is tightly fitted to the outer periphery of the rotating shaft inserted through the inner periphery and is in sliding contact with the seal lip at the flange portion, and a duster that is closely fitted to the outer periphery of the rotating shaft and located on the atmosphere side of the slinger. Is provided with a dust cover that is slidably contacted with the case, and at least one of the dust strip and the sliding surface of the case that are slidably contacted with each other is roughened. As a result, a myriad of minute labyrinth-like air passages are formed between the case and the case.

  According to the lip type end face sealing device according to the first to fourth aspects of the present invention, since the seal lip is brought into close contact with the flange portion of the slinger, the load caused by sliding is small, and the sliding of both the seal lip and both slinger Since the space inside the seal between the moving parts is released through the air passage, the space does not become negative pressure as the slinger rotates, and therefore the sticking between the seal lip and slinger due to the negative pressure also occurs. It is prevented and excellent sealing performance can be maintained over a long period of time.

  According to the lip type end face sealing device of the invention of claim 4, in addition to the effect of claim 1, dust in the atmosphere does not enter the liquid to be sealed, and a simple sealing structure is provided. be able to.

  According to the lip type end face sealing device of the fifth to ninth aspects of the present invention, since the pressure in the seal internal space is released through the air passage, the sticking of the seal lip and the dust lip due to negative pressure is prevented, and Excellent sealability can be maintained over a period of time. In addition, since it is not necessary to form a ventilation hole on the housing side, a simple seal structure can be achieved, and air sucked into the seal internal space is filtered by the dust filter, so that dust in the atmosphere is sealed. There is no penetration into the liquid.

  According to the lip-type end face sealing device of the sixth aspect of the invention, the spiral groove is sealed so as to enter the sliding portion between the seal lip and the slinger from the outer peripheral side by the pumping action generated with the rotation of the slinger. The target liquid can be eliminated, and thus the sealing performance can be significantly improved.

  According to the lip-type end face sealing device of the seventh aspect of the invention, the dust filter is not always exposed to external dust, and intrusion of large dust particles is also blocked. Further, the dust removing function is further enhanced, and the dust filter can be hardly clogged.

  According to the lip type end face sealing device of the eighth aspect of the invention, in addition to the effect of the fifth aspect, since the filtration path by the dust filter becomes longer, the dust removing function can be further enhanced.

  According to the lip type end face sealing device of the ninth aspect of the invention, in addition to the effect of the fifth aspect, the dust cover can be easily positioned with respect to the slinger when the seal is attached.

  According to the lip-type end face sealing device of the tenth aspect of the invention, during rotation, the dust lip is opened by centrifugal force and the seal internal space is released from pressure, so that the seal lip and dust lip are prevented from sticking to each other due to negative pressure. And excellent sealing performance can be maintained over a long period of time. In addition, since it is not necessary to form a vent hole, a simple seal structure can be achieved, and the air sucked into the seal internal space is filtered by the dust filter, so that dust in the atmosphere is contained in the liquid to be sealed. There is no invasion.

  According to the lip type end face sealing device of the invention of claim 11, since the internal space of the seal is released through the labyrinth gap formed by roughing the sliding portion of the dust lip, the seal lip and da The sticking of the strip is prevented, and excellent sealing performance can be maintained over a long period of time. In addition, since it is not necessary to form a vent hole, a simple seal structure can be obtained, and air sucked into the seal internal space is filtered by the labyrinth gap and the dust filter, so that dust in the atmosphere is sealed. Does not penetrate into the liquid.

  FIG. 1 shows a mounting state of a preferred first embodiment in which the lip type end face sealing device according to the present invention is applied as a sealing means between engine oil and clutch oil in a wet engine such as a construction machine. FIG. 2 is a half sectional view showing a non-mounted state by cutting along a plane passing through the axis.

  First, in FIG. 1, reference numeral 1 is a crankcase of a wet engine, 2 is a housing attached to the outer periphery of the opening of a shaft hole 1a in the crankcase 1, and 3 is inserted through the shaft hole 1a of the crankcase 1 in a substantially horizontal direction. A crankshaft rotatably supported by a bearing 11, 4 is a flywheel attached to a rear end portion 3 a of the crankshaft 3 by a bolt 41, and 5 is rotated on the inner periphery of the flywheel 4 through a bearing 51. A transmission shaft supported freely. The crankshaft 3 corresponds to the rotary shaft described in claim 1, and includes an inner peripheral surface of the housing 2 and an outer peripheral surface of the rear end portion 3 a of the crankshaft 3 protruding from the shaft hole 1 a of the crankcase 1. In between, the lip type end face seal device 6 according to the first embodiment of the present invention is mounted.

  The lip-type end face sealing device 6 includes an annular case 61 that is tightly fitted to the inner peripheral surface 2 a of the housing 2, and a pair of seal lips (first and second seals) that are integrally provided on the inner periphery of the case 61. Lip) 62, 63 and a pair of slinger (first and second slinger) 64, 65 attached to the outer peripheral surface of the rear end portion 3 a of the crankshaft 3.

  As shown in FIGS. 1 and 2, the case 61 includes a pair of case members (first and second case members) 611 and 612 obtained by stamping and pressing a metal plate such as a steel plate. Specifically, the first case member 611 includes a fitting cylinder portion 611a that is press-fitted into the inner peripheral surface 2a of the housing 2 with a predetermined allowance and is closely fitted, and an inner peripheral flange portion 611b that extends from one end to the inner peripheral side. Become. The second case member 612 includes a fitting cylinder portion 612a that is press-fitted into the inner peripheral surface of the fitting cylinder portion 611a in the first case member 611 and closely attached, and an inner circumference that extends from one end to the inner circumference side. It consists of a flange portion 612b. A ventilation space S1 extending in the radial direction is formed between the inner peripheral flange parts 611b and 612b, and the fitting cylinder part 612a of the second case member 612 in the fitting cylinder part 611a of the first case member 611 is formed. A vent hole 611c facing the vent space S1 is opened inside the fitting portion.

  The first and second seal lips 62 and 63 are formed of a rubber-like elastic material, and the base portions 62a and 63a are inner flanges of the first and second case members 611 and 612 in the case 61, respectively. It is integrally vulcanized and bonded to the portions 611b and 612b so as to enclose the inner peripheral portion thereof, and is formed from the base portions 62a and 63a to the outer peripheral side so as to open in a tapered shape opposite to each other in the axial direction. Has been. In addition, tongue pieces 62b and 63b are formed on the inner peripheries of the bases 62a and 63a so as to face in directions opposite to each other with respect to the axial direction.

  The first and second slinger 64, 65 are obtained by stamping and pressing a metal plate such as a steel plate, and have fitting tube portions 64a, 65a on the inner periphery, respectively. They are integrated by being press-fitted in close contact with each other. And the fitting cylinder part 65a of the slinger 65 which is relatively on the inner peripheral side is press-fitted in close contact with the outer peripheral surface of the rear end part 3a of the crankshaft 3 with a predetermined allowance.

  The first slinger 64 has a flange portion 64 b positioned on the inner side in the axial direction (crankcase 1 side) of the inner peripheral flange portion 611 b of the first case member 611 in the case 61, and the second slinger 65 is the second slinger 65 in the case 61. It has the collar part 65b located in the axial direction outer side (flywheel 4 side) of the inner peripheral flange part 612b of the two case members 612. The first and second seal lips 62 and 63 have their edges 62c and 63c opposite to each other slightly bent and deformed toward the inner peripheral flange portions 611b and 612b of the first and second case members 611 and 612. In this state, it is in close contact with the end faces of the flanges 64b and 65b that are substantially perpendicular to the axis.

  On the sliding surface of the flange portion 64b of the first slinger 64 with the first seal lip 62, a plurality of (for example, four strips) spiral grooves 64c that have a pumping action of pushing the fluid to the outer peripheral side by rotation are formed. Further, the sliding surface of the flange portion 65b of the second slinger 65 with the second seal lip 63 is a smooth surface, but a spiral groove symmetrical to the spiral groove 64c of the first slinger 64 is formed so that the fluid flows during rotation. You may make it show the pumping action which pushes out to the outer peripheral side.

  The first seal lip 62 is set with a first case member 611 in which a vulcanized adhesive is applied in advance to an inner peripheral flange portion 611b in a predetermined mold (not shown). A non-vulcanized rubber material for molding is filled in an annular cavity defined so as to extend from the periphery of 611b, and heated and pressurized to be integrated with the first case member 611 simultaneously with vulcanization molding. Is. Similarly, the second seal lip 63 is formed integrally with the second case member 612. After molding, the first and second seal lips 62 and 63 are integrally formed by press-fitting the fitting cylinder 612a of the second case member 612 into the fitting cylinder 611a of the first case member 611. If the first and second slinger 64, 65 are integrated by press-fitting the fitting cylinder portions 64a, 65a from both sides in the axial direction, the unit is formed as shown in FIG. The

  An annular groove 21 is formed on the inner peripheral surface 2a of the housing 2 shown in FIG. 1 at an axial position corresponding to the vent hole 611c when the case 61 of the lip type end face seal device 6 is press-fitted and fixed. A vent hole 22 is opened at a part of the annular groove 21 in the circumferential direction. The ventilation space S1, the ventilation hole 611c, the ventilation groove 21, and the vent hole 22 constitute the ventilation path described in claim 1, that is, in the illustrated mounting state, the first and second seal lips 62, 63 and the seal internal space S2 between the sliding portions by the first and second slinger 64, 65 are a ventilation space S1, a ventilation hole 611c, a ventilation space between the first case member 611 and the second case member 612 in the case 61. The air is released through the groove 21 and the vent hole 22.

  In the above configuration, an appropriate amount of engine oil (not shown) that lubricates the bearing 11 and the pistons inside the engine is stored in the lower part of the crank chamber S3 in the crankcase 1. In the chamber (right side in FIG. 1), clutch oil (not shown) supplied from the injection port 5b to the clutch plate through the inner peripheral hole 5a of the transmission shaft 5 is stored. The lip-type end face seal device 6 prevents the engine oil scattered in the crank chamber S3 and the clutch oil scattered in the housing 2 from mixing with each other via the shaft periphery of the rear end portion 3a of the crankshaft 3. As such, this is to be sealed.

  Specifically, when the crankshaft 3 is rotated, the flange portions 64b and 65b of the first and second slinger 64 and 65 that are rotated together with the crankshaft 3 are the case 61 (first and second case members 611 and 612). And the end edges 62c and 63c of the non-rotating first and second seal lips 62 and 63 fixed to the housing 2 side. Then, the engine oil that has reached the space S4 between the lip type end face seal device 6 and the crankcase 1 will pass through the sliding portion between the flange portion 64b of the first slinger 64 and the first seal lip 62 toward the inner peripheral side. Even so, the engine oil is removed to the outer peripheral side by the centrifugal force accompanying the rotation of the flange 64b. Similarly, the clutch oil splash that has reached the space S5 between the lip type end face seal device 6 and the flywheel 4 causes the sliding portion between the flange portion 65b of the second slinger 65 and the second seal lip 63 to be on the inner peripheral side. Even when trying to pass through, the clutch oil is removed to the outer peripheral side by the centrifugal force accompanying the rotation of the flange 65b.

  Here, the amount of engine oil reaching the space S4 from the crank chamber S3 is much larger than the amount of clutch oil scattered in the space S5. However, in the sliding portion between the flange portion 64b of the first slinger 64 and the first seal lip 62 that seals the engine oil, the spiral groove 64c formed in the flange portion 64b is formed along with the rotation of the first slinger 64. Since the pumping action of removing the fluid to the outer peripheral side is exerted, the excellent sealing performance is exhibited in combination with the centrifugal force due to the rotation of the flange portion 64b.

  Further, the air existing in the seal internal space S2 in the lip type end face seal device 6 is pumped and centrifugally generated by the spiral groove 64c in the sliding portion between the flange portion 64b of the first slinger 64 and the first seal lip 62. Force and the centrifugal force generated at the sliding portion between the flange portion 65b of the second slinger 65 and the second seal lip 63 are removed from the sliding portion to the outer peripheral side. Since the air is released to the atmosphere through the ventilation space S1, the ventilation hole 611c, the ventilation groove 21 and the vent hole 22 between the first case member 611 and the second case member 612 in 61, there is no negative pressure. Therefore, the first and second seal lips 62, 63 do not stick to the flanges 64b, 65b of the first and second slinger 64, 65 due to negative pressure. In addition, the first and second seal lips 62, 63 are in close contact with the first and second slinger 64, 65 by an axial bending reaction force, unlike the radial seal lip as shown in FIG. The contact pressure is small. Therefore, an increase in sliding load and early wear of the first and second seal lips 62 and 63 due to the increase can be effectively prevented.

  A slight amount of engine oil from the upper half portion of the sliding portion between the flange portions 64b, 65b of the first and second slinger 64, 65 and the first and second seal lips 62, 63 to the inner peripheral side thereof. Or when clutch oil enters, this leakage is pushed back to the outer peripheral side by centrifugal force or pumping action on the flanges 64b, 65b side, but on the upper half side of the first and second seal lips 62, 63, It flows downward along the tapered surface and is received by the tongue pieces 62b and 63b. Further, the liquid leaks along the circumferential groove between the tongue pieces 62b and 63b and the first and second seal lips 62 and 63 to the lower half thereof, and the first and second seal lips 62 and 63 Since it flows down downward, that is, to the outer peripheral side through the tapered surface of the lower half, it is pushed back to the outer peripheral side by centrifugal force or pumping action from the sliding part with the flange parts 64b and 65b.

  Next, FIG. 3 shows a second preferred embodiment in which the lip-type end face sealing device according to the present invention is applied as a sealing means between engine oil and clutch oil in a wet engine such as a construction machine. It is a half sectional view cut and shown by a plane. That is, the lip-type end face sealing device 6 includes an annular case 61 that is tightly fitted to the inner peripheral surface 2 a of the housing 2, and a pair of seal lips (first and second) integrally provided on the inner periphery of the case 61. Two seal lips) 62 and 63, and a pair of slinger (first and second slinger) 64 and 65 attached to the outer peripheral surface of the rear end portion of the crankshaft (not shown).

  The case 61 is formed by punching a metal plate such as a steel plate and press-molding. The case 61 is press-fitted into the inner peripheral surface 2a of the housing 2 with a predetermined tightening margin and is closely fitted, and an inner periphery from one end thereof. It consists of an inner peripheral flange portion 61b extending to the side.

  The first and second seal lips 62 and 63 are formed of a rubber-like elastic material, and are continuous with each other via a base 66 that is shared with each other, and have a tapered shape that is opposite to the axial direction. It is formed in an open shape. Further, the base 66 is integrally vulcanized and bonded to the case 61, and the outer peripheral portion of the base 66 wraps around the outer peripheral side of the fitting cylinder portion 61 a of the case 61, and is attached to the inner peripheral surface 2 a of the housing 2. A gasket portion 66a that is brought into close contact with the crushing margin is configured.

  The first and second slinger 64, 65 is the same as the embodiment shown in FIGS. 1 and 2 described above, and on the sliding surface of the flange portion 64b of the first slinger 64 with the first seal lip 62. Are formed with a plurality of (for example, four) spiral grooves 64c that have a pumping action of pushing fluid toward the outer peripheral side by rotation. Also in this embodiment, the sliding surface of the flange portion 65b of the second slinger 65 with the second seal lip 63 is a smooth surface, but a spiral groove symmetrical to the spiral groove 64c of the first slinger 64 is formed. May be.

  The first and second seal lips 62, 63 have their opposite edges 62c, 63c slightly bent and deformed toward the inner peripheral flange portions 611b, 612b of the first and second case members 611, 612. Thus, the first and second slinger 64, 65 that is substantially perpendicular to the axial center are in close contact with the flanges 64b, 65b.

  A ventilation tube 67 is inserted into the inner peripheral portion of the base portion 66 of the first and second seal lips 62 and 63, and the outer peripheral surface of the ventilation tube 67 and the base portion 66 are sealed together. One end 67 a of the ventilation tube 67 opens to the inner periphery of the base 66, and the other end 67 b can be closely connected to the vent hole 22 opened to the inner peripheral surface 2 a of the housing 2. That is, in the mounted state of the lip type end face seal device 6, the seal internal space S2 between the first and second seal lips 62, 63 and the sliding portions by the flange portions 64b, 65b of the first and second slinger 64, 65. Is opened to the atmosphere through the ventilation tube 67 and the vent hole 22.

  Similarly to the first embodiment, the lip-type end face sealing device 6 according to the second embodiment having the above configuration is also provided with the case 61 attached to the inner peripheral surface 2a of the housing 2, and the first and second slinger 64, 65 are The engine oil in the crank chamber S3 shown in FIG. 1 and the clutch oil scattered in the housing 2 are attached to the outer peripheral surface of the rear end portion 3a of the crankshaft 3. The first and second seal lips 62 and 63 and the flange portions 64b and 65b of the first and second slinger 64 and 65 are sealed so as not to mix with each other through the circumference. .

  In this case as well, the engine oil that has reached the sliding portion between the first seal lip 62 and the flange portion 64b of the first slinger 64 has an outer peripheral side due to the centrifugal force accompanying the rotation of the flange portion 64b and the pumping action of the spiral groove 64c. The clutch oil splash that reaches the sliding portion between the second seal lip 63 and the flange portion 65b of the second slinger 65 is excluded to the outer peripheral side by the centrifugal force accompanying the rotation of the flange portion 65b.

  Further, the seal internal space S2 between the sliding portions between the first and second seal lips 62 and 63 and the flange portions 64b and 65b of the first and second slinger 64 and 65 passes through the ventilation tube 67 and the vent hole 22. Since it is open to the atmosphere, the pumping action and centrifugal force generated at the sliding portion between the flange portion 64b of the first slinger 64 and the first seal lip 62, and the flange between the second slinger 65 and the second seal lip 63 are described. No negative pressure is generated by the centrifugal force generated in the sliding portion with the portion 65b. Therefore, the first and second seal lips 62 and 63 do not stick to the flanges 64b and 65b of the first and second slinger 64 and 65 due to negative pressure, and the first and second seal lips 62 63 are in close contact with the flange portions 64b and 65b due to the bending reaction force in the axial direction, and the surface pressure is small, so that the sliding load increases and the first and second seal lips 62 resulting from this increase. 63 can be prevented effectively.

  The first embodiment shown in FIGS. 1 and 2 and the second embodiment shown in FIG. 3 both integrate the first and second seal lips 62 and 63, and The second slinger 64, 65 is fitted and integrated, but the first seal lip 62 and the first slinger 64 that are intended to seal engine oil, and the second seal lip 63 and the second slinger that are intended to seal clutch oil. 65 may be separate members. FIG. 4 is a half cross-sectional view showing the lip-type end face sealing device according to the third embodiment of the present invention having such a structure, cut along a plane passing through the axis.

  That is, the lip-type end face seal device 6 includes a pair of end face seals 6A and 6B. Of these, the first end face seal 6A is closer to the crankcase on the inner peripheral surface 2a of the housing 2 (the left side in FIG. 4). ), A seal lip 62 provided integrally with the case 61A, and a crankcase 3 on the outer peripheral surface of the rear end portion of the crankshaft 3 (the left side in FIG. 4). One slinger 64. The same applies to the second end face seal 6B, and an annular case 61B closely fitted near the flywheel (right side in FIG. 4) on the inner peripheral surface 2a of the housing 2, and a seal provided integrally with the case 61B. A lip 63 and a second slinger 65 attached to the flywheel side (right side in FIG. 4) on the outer peripheral surface of the rear end portion of the crankshaft 3 are provided.

  The cases 61A and 61B are formed by stamping and pressing a metal plate such as a steel plate, both of which are a fitting cylinder portion 61a that is press-fitted into the inner peripheral surface 2a of the housing 2 with a predetermined tightening margin and tightly fitted thereto, It consists of an inner peripheral flange portion 61b extending from one end to the inner peripheral side, and the inner peripheral flange portions 61b are arranged in a state of facing each other back to back.

  The first seal lip 62 in the first end face seal 6A is formed of a rubber-like elastic material, and is formed in a shape that opens in a tapered shape toward the crankcase side (left side in FIG. 4). The base portion 62a of the first seal lip 62 is integrally vulcanized and bonded to the case 61A, and the outer peripheral portion of the base portion 62a goes around to the outer peripheral side of the fitting cylinder portion 61a of the case 61A, so that the housing 2 A gasket portion 62d is configured to be in close contact with the inner peripheral surface 2a with a predetermined crushing allowance. A tongue piece 62b facing the crankcase side (left side in FIG. 4) is formed on the inner periphery of the base 62a.

  The second seal lip 63 in the second end face seal 6B is the same, and is arranged symmetrically with the first seal lip 62, that is, formed in a tapered shape toward the flywheel side (right side in FIG. 4). ing. The base portion 63a of the second seal lip 63 is integrally vulcanized and bonded to the case 61B, and the outer peripheral portion of the base portion 63a goes around the outer peripheral side of the fitting cylinder portion 61a of the case 61B. A gasket portion 63d is formed which is in close contact with the inner peripheral surface 2a with a predetermined crushing allowance. A tongue piece 63b facing the flywheel side (the right side in FIG. 4) is formed on the inner periphery of the base 63a.

  The first slinger 64 in the first end face seal 6A is formed by stamping and pressing a metal plate such as a steel plate, and is press-fitted to the outer peripheral surface of the rear end portion of the crankshaft 3 in a close contact state with a predetermined allowance. In the state where the first seal lip 62 is slightly bent and deformed toward the inner peripheral flange portion 61b of the case 61A, the flange portion 64b has a fitting cylindrical portion 64a and is substantially perpendicular to the shaft center. The edge 62c is in close contact. In addition, a plurality of (for example, four) spiral grooves 64c are formed on the sliding surface of the flange portion 64b of the first slinger 64 with the first seal lip 62 to exert a pumping action to push the fluid to the outer peripheral side by rotation. Yes.

  On the other hand, the second slinger 65 in the second end face seal 6B is similarly formed by stamping and pressing a metal plate such as a steel plate, and press-fitted to the outer peripheral surface of the rear end portion of the crankshaft 3 in a close contact state with a predetermined tightening margin. A fitting cylinder portion 65a to be attached is disposed symmetrically with the first slinger 64, and a second seal lip 63 is provided on the flange portion 65b substantially perpendicular to the axis, and the inner peripheral flange portion 61b of the case 61B. The outer peripheral edge 63c is brought into close contact with being slightly bent and deformed to the side. The sliding surface of the flange portion 65b of the second slinger 65 with the second seal lip 63 is a smooth surface, but a spiral groove symmetrical to the spiral groove 64c of the first slinger 64 may be formed.

  A vent hole 22 is opened in the inner peripheral surface 2a of the housing 2 between the mounting position of the case 61A in the first end face seal 6A and the mounting position of the case 61B in the second end face seal 6B. . That is, in the mounted state of the first end face seal 6A and the second end face seal 6B, the seal internal space S2 between the sliding portions by the first and second seal lips 62, 63 and the first and second slinger 64, 65 is The air is released through the vent hole 22.

  Therefore, also in the lip type end face sealing device 6 according to the third embodiment, the same effects as those of the first embodiment or the second embodiment described above can be obtained. That is, since the seal internal space S2 defined between the first end face seal 6A and the second end face seal 6B is open to the atmosphere through the vent hole 22, the flange portion 64b of the first slinger 64 and the first seal lip No negative pressure is generated by the pumping action and centrifugal force generated at the sliding portion with 62 and the centrifugal force generated at the sliding portion between the flange portion 65b of the second slinger 65 and the second seal lip 63. An increase in dynamic load and early wear of the first and second seal lips 62 and 63 due to this increase can be effectively prevented. The tongue pieces 62b and 63b also have the same function as described in the first embodiment.

  Next, FIG. 5 shows a lip type end face sealing device according to a fourth embodiment of the present invention applied as a sealing means between engine oil and the atmosphere in an engine having a severe external dust environment such as an engine of a construction machine. FIG. 3 is a half cross-sectional view cut along a plane passing through the axis. That is, the lip type end face sealing device 6 includes an annular case 61 that is press-fitted into the inner peripheral surface 2a of the housing 2 in the fitting cylinder portion 61a, as in the second embodiment (FIG. 3) described above, A pair of seal lips (first and second seal lips) 62, 63 provided integrally on the inner periphery of 61, and a pair of slinger (first and second) attached to the outer peripheral surface of the rear end portion of the crankshaft 3. Slinger) 64, 65. The first seal lip 62 has the engine oil on the left side in the figure as a sealing target, and the second seal lip 63 has the dust in the atmosphere on the right side in the figure as a sealing target.

  The first slinger 64 will be described in detail with respect to the second embodiment. The first slinger 64 is press-fitted and fitted in close contact with the outer peripheral surface of the rear end portion 3a of the crankshaft 3 with a predetermined tightening margin in the fitting cylinder portion 64a. The flange portion 64b that is substantially perpendicular to the shaft center is in close contact with the end edge 62c of the first seal lip 62. On the other hand, the second slinger 65 has a predetermined tightening margin from the fitting cylinder 65a that is press-fitted to the outer peripheral surface of the fitting cylinder 64a of the first slinger 64 near the crankcase side (left side in FIG. 5). A holding cylinder portion 65c extending toward the outside in the axial direction (the right side in FIG. 5) is formed, and the flange portion 65b substantially perpendicular to the axial center extends from the end of the holding cylinder portion 65c.

  The first and second slinger 64, 65 has a plurality of (for example, four) spiral grooves 64c, 65d that exert a pumping action to push the fluid to the outer peripheral side by rotation on the sliding surfaces of both flange portions 64b, 65b. Are formed symmetrically with each other. The sliding portion between the flange 65b of the second slinger 65 on the atmosphere side and the second seal lip 63 is filled with grease (not shown) for lubrication.

  The inner peripheral surface of the holding cylinder portion 65c in the second slinger 65 is larger in diameter than the outer peripheral surface of the fitting cylinder portion 64a of the first slinger 64, that is, the holding cylinder portion 65c of the second slinger 65 and the first slinger. A ventilation space S6 is formed between the 64 fitting cylinder portions 64a. Further, a vent hole 65e is formed at a position near the fitting cylinder portion 65a in the holding cylinder portion 65c, and the first and second seal lips 62, 63 and the first seal lip 62, 63 are formed by the vent hole 65e and the vent space S6. An air passage that opens the seal internal space S2 between the sliding portions by the first and second slinger 64, 65 to the atmosphere side (the right side in FIG. 5) is formed.

  The ventilation space S <b> 6 is filled with a dust filter 68, and is prevented from coming off by a caulking portion 64 d formed at an end portion of the fitting cylinder portion 64 a of the first slinger 64. The dust filter 68 is made of a fiber assembly such as a synthetic fiber fabric or cotton, and has air permeability due to a fine gap between the fibers.

  In the lip type end face sealing device 6 according to the fourth embodiment having the above-described configuration, the case 61 is attached to the inner peripheral surface 2a of the housing 2, and the first and second slinger 64, 65 are the rear end portions of the crankshaft 3. The engine oil in the crank chamber of the engine is prevented from leaking out of the machine at the sliding portion between the first seal lip 62 and the flange portion 64b of the first slinger 64. At the sliding portion between the lip 63 and the flange portion 65b of the second slinger 65, dust in the atmosphere is prevented from entering the crank chamber of the engine. Further, the space between the inner peripheral surface 2 a of the housing 2 and the fitting cylinder portion 61 a of the case 61 is sealed by a gasket portion 66 a extending from the shared base portion 66 of the first and second seal lips 62 and 63.

  And in the sliding part of the collar parts 64b and 65b of the 1st and 2nd slinger 64 and 65, and the 1st and 2nd seal lips 62 and 63, the spiral formed in the collar parts 64b and 65b with rotation. Since the grooves 64c and 65d have a pumping action for removing the fluid to the outer peripheral side, excellent sealing performance is exhibited in combination with the centrifugal force generated by the rotation of the flange portions 64b and 65b. The tongue piece 62b has the same function as described in the first embodiment.

  Further, air existing in the seal internal space S2 in the lip type end face seal device 6 is caused by the pumping action and centrifugal force from the sliding portion between the flange portions 64b and 65b and the first and second seal lips 62 and 63. Since it is excluded to the outer peripheral side, outside air is sucked into the seal inner space S2 through the dust filter 68 and the vent hole 65e in the vent space S6. Therefore, the first and second seal lips 62 and 63 do not stick to the flanges 64b and 65b of the first and second slinger 64 and 65 due to negative pressure, and the first and second seal lips 62 , 63 is in close contact with the first and second slinger 64, 65 due to the bending reaction force in the axial direction, so that the surface pressure is small, and the sliding load increases or the first caused by this. And the early wear of the 2nd seal lips 62 and 63 etc. can be prevented effectively.

  Further, dust contained in the outside air sucked into the seal inner space S2 through the vent space S6 and the vent hole 65e is separated by the dust filter 68 filled in the vent space S6. Clean air is inhaled. Accordingly, it is possible to prevent dust from entering the engine oil in the crank chamber from the sliding portion between the flange portion 64b of the first slinger 64 and the first seal lip 62.

  According to this configuration, the dust filter 68 is not worn by sliding unlike when it is interposed between the stationary side and the rotating side, and a gap is generated by the eccentricity of the housing 2 and the crankshaft 3. There is nothing. Then, as shown in the figure, the dust filter 68 is formed in a cylindrical shape, and the air hole 65e is formed at the end of the dust filter 68, so that the air filtration path becomes longer. Excellent removal performance can be obtained. In addition, according to this embodiment, since the ventilation path including the ventilation space S6 and the ventilation hole 65e is configured only by the lip type end surface sealing device 6, it is not necessary to form a vent hole or the like in the housing 2.

  6 and 7 are half cross-sectional views showing examples of the shape change of the lip-type end face sealing device according to the fourth embodiment shown in FIG. 5 described above, cut along a plane passing through the axis.

  First, the lip type end face sealing device 6 shown in FIG. 6 is basically integrated with the annular case 61 press-fitted into the inner peripheral surface 2a of the housing 2 and the inner periphery of the case 61, as in FIG. First and second seal lips 62 and 63 are provided, and first and second slinger 64 and 65 attached to the crankshaft 3 side. The first seal lip 62 is intended for sealing the engine oil on the left side in the figure, and the second seal lip 63 is targeted for dust in the atmosphere on the right side in the figure.

  5 will be described in detail. An annular holder 69 is press-fitted on the outer peripheral surface of the fitting cylinder portion 64a of the first slinger 64, and the second slinger 65 has a fitting cylinder portion 65a. The annular holder 69 is press-fitted to the outer peripheral surface of the fitting cylinder portion 69a. The annular holder 69 is formed by stamping and pressing a metal plate such as a steel plate, and has a flange portion 69b substantially perpendicular to the axis, similar to the second slinger 65, and the flange portion 69b is a second slinger. A ventilation space S7 is formed between the 65 flange portions 65b. A vent hole 65e is formed at a position near the inner periphery of the flange portion 65b of the second slinger 65, and the first and second seal lips 62, 63 and the first seal lip 62, 63 are formed by the vent hole 65e and the vent space S7. An air passage that opens the seal internal space S2 between the sliding portions of the first and second slinger 64, 65 to the atmosphere side (the right side in FIG. 6) is configured.

  A dust filter 68 is filled in the ventilation space S7. The dust filter 68 has an annular shape that is flat with respect to the axial direction, that is, a disk shape, and is made of a fiber assembly such as a synthetic fabric or cotton, similar to that shown in FIG. It has air permeability.

  According to the lip type end face sealing device 6 of FIG. 6 having the above configuration, basically the same function as that of the embodiment of FIG. 5 is exhibited. That is, as the air in the seal internal space S2 is removed from the sliding portion between the flange portions 64b, 65b of the first and second slinger 64, 65 and the first and second seal lips 62, 63 during rotation. Since the outside air is sucked through the ventilation space S7 and the ventilation hole 65e between the flange 69b of the annular holder 69 and the flange 65b of the second slinger 65, the generation of negative pressure in the seal internal space S2 is prevented. The dust contained in the air outside the machine to be sucked is removed by the dust filter 68 filled in the ventilation space S7.

  Further, according to this embodiment, since the dust filter 68 is formed in a disc shape, by opening the vent hole 65e in the flange portion 65b of the second slinger 65 so as to be positioned on the inner peripheral portion of the dust filter 68, Since the air filtration path becomes long, it is possible to obtain excellent dust removal performance, and it is not necessary to form a vent hole or the like in the housing 2 as in FIG. Moreover, according to this embodiment, since the dust filter 68 is sandwiched between the flange portions 65b and 69b, there is no possibility that the dust filter 68 is displaced or damaged during assembly.

  On the other hand, the lip-type end face seal device 6 shown in FIG. 7 is basically configured in the same manner as in FIG. 5, and the first seal lip 62 targets the engine oil on the left side in FIG. Reference numeral 63 designates dust in the atmosphere on the right side in the figure as a sealing target.

  The difference from the embodiment shown in FIG. 5 or FIG. 6 will be described in detail. The fitting cylinder 65a of the second slinger 65 is press-fitted to the outer peripheral surface of the fitting cylinder 64a of the first slinger 64. A vent hole 65e is formed in the inner peripheral portion of the flange portion 65b of the second slinger 65. An annular dust filter 68 is attached to the inner side surface of the inner peripheral portion of the flange portion 65b so as to close the vent hole 65e. The dust filter 68 is also made of a fiber assembly such as a synthetic fiber fabric or cotton, has air permeability due to a fine gap between the fibers, and is fixed by an appropriate adhesive or the like.

  The lip type end face sealing device 6 of FIG. 7 having the above configuration basically exhibits the same function as that of the embodiment of FIG. Then, during the rotation, the sliding portions between the flange portions 64b, 65b of the first and second slinger 64, 65 and the first and second seal lips 62, 63 are sealed by centrifugal force or the pumping action of the spiral grooves 64c, 65d. As the air in the internal space S2 is removed, the air outside the machine is sucked through the vent hole 65e formed in the flange 65b of the second slinger 65, thus preventing the generation of negative pressure in the seal internal space S2. The dust contained in the air outside the machine to be sucked is removed by the dust filter 68 provided in the vent hole 65e.

  Further, according to this embodiment, the air passage for releasing the pressure in the seal internal space S2 to the atmosphere side is composed only of the air holes 65e formed in the flange portion 65b of the second slinger 65, and the dust filter 68 is provided with the second slinger 65. Therefore, the number of components can be reduced and the structure can be simplified.

  Next, FIG. 8 shows a lip-type end face sealing device according to a fifth embodiment of the present invention applied as a sealing means between engine oil and air in an engine having a severe external dust environment, cut along a plane passing through the axis. FIG.

  The lip-type end face sealing device 6 includes an end face seal 6C and a dust cover 6D. Of these, the end face seal 6C is an annular shape that is press-fitted into the inner peripheral surface 2a of the housing 2 at the fitting cylinder portion 61a. A case 61, a seal lip 62 provided integrally on the inner periphery of the case 61, a slinger 64 attached to the outer peripheral surface of the crankshaft 3, and a first dust filter 68A are provided.

  The case 61 in the end face seal 6C is obtained by stamping and pressing a metal plate such as a steel plate, and a fitting tube portion 61a that is press-fitted into the inner peripheral surface 2a of the housing 2 with a predetermined tightening margin and tightly fitted thereto, The outer peripheral flange portion 61c extends from one end to the inner peripheral side, and the inner peripheral flange portion 61b extends from the inner periphery to the inner peripheral side via an intermediate portion 61d extending to the crankcase side (left side in FIG. 8).

  The seal lip 62 in the end face seal 6C is formed of a rubber-like elastic material, and is formed in a shape opened in a tapered shape toward the crankcase side (left side in FIG. 8). The base portion 62a of the seal lip 62 is integrally vulcanized and bonded to the case 61. The outer peripheral portion of the base portion 62a goes around to the outer peripheral side of the fitting tube portion 61a of the case 61, and the inner periphery of the housing 2 A gasket portion 62d is formed that is in close contact with the surface 2a with a predetermined crushing allowance. A tongue piece 62b facing the crankcase is formed on the inner periphery of the base 62a. The end surface of the outer peripheral flange 61c of the case 61 facing the atmosphere side (the right side in FIG. 8) is a seal lip. It is exposed from the rubber layer extending from the base 62a of 62.

  The slinger 64 in the end face seal 6C is formed by stamping and pressing a metal plate such as a steel plate, and has a fitting cylinder portion 64a that is press-fitted to the outer peripheral surface of the crankshaft 3 with a predetermined tightening margin. The outer peripheral edge 62c is slidably in close contact with the flange 64b substantially perpendicular to the shaft center in a state of being bent and deformed so that the seal lip 62 is slightly opened. Moreover, you may form in the sliding surface with the seal lip 62 in the collar part 64b of the slinger 64 several spiral grooves which show | play the pumping effect | action which extrudes a fluid to an outer peripheral side by rotation.

  The first dust filter 68A is attached to the inner peripheral portion of the end face seal 6C so as to be positioned on the atmosphere side of the tongue piece portion 62b. The first dust filter 68A is made of a fiber assembly such as a synthetic fiber fabric or cotton, and has air permeability due to a fine gap between the fibers. The inner peripheral portion of the first dust filter 68A is a fitting cylinder portion 64a having a slinger 64. Is slidably in contact with the outer peripheral surface of the.

  The dust cover 6D includes a dust lip 70 formed of a rubber-like elastic material, a reinforcing ring 71 formed by stamping and pressing a metal plate such as a steel plate, and embedded in an inner peripheral base portion 70c of the dust lip 70, and a second The dust filter 68B. The dust lip 70 is formed in a shape in which the lip main body portion 70a is tapered toward the crankcase side (the left side in FIG. 8). The seal 6C is slidably in close contact with the end surface of the outer peripheral flange portion 61c of the case 61, and the inner peripheral base portion 70c is closely fitted to the outer peripheral surface of the crankshaft 3 on the atmosphere side of the slinger 64.

  Between the lip main body portion 70a and the inner peripheral base portion 70c in the dust cover 6D (the dust lip 70), there is a vent hole 70d that penetrates the rubber layer of the inner peripheral portion of the dust lip 70 and the reinforcing ring 71 embedded therein. It is established in one or more places in the circumferential direction. The vent hole 70d is for releasing the pressure in the seal internal spaces S2, S8 between the sliding portion of the seal lip 62 in the end face seal 6C and the sliding portion of the dust lip 70 in the dust cover 6D to the atmosphere side. This corresponds to the air passage described in claim 6 and is provided at one or more places in the circumferential direction.

  The second dust filter 68B is made of a fiber assembly such as a synthetic fiber fabric or cotton, and has air permeability due to a fine gap between the fibers. It is fixed with an adhesive or the like so as to close the vent hole 70d on the side.

  Therefore, according to the above-described configuration, the end face seal 6C prevents the engine oil in the crank chamber of the engine from leaking out of the machine at the sliding portion between the seal lip 62 and the flange 64b of the slinger 64. The dust cover 6D prevents dust in the atmosphere from entering the crank chamber side of the engine at the sliding portion of the dust lip 70 with the outer peripheral flange portion 61c of the case 61 in the end face seal 6C. The tongue piece 62b has the same function as that described in the first embodiment.

  Further, the air present in the seal internal space S2 of the end face seal 6C is caused by the centrifugal force generated by the rotation of the sliding portion between the flange portion 64b of the slinger 64 and the seal lip 62 or the pumping action of the spiral groove. The air existing in the seal inner space S8 between the end face seal 6C and the dust cover 6D is also removed to the outer peripheral side by the centrifugal force generated by the rotation in the sliding portion of the dust lip 70. However, along with such an air exclusion action, outside air is sucked into the seal internal space S8 through the vent hole 70d and the second dust filter 68B. Further, a part of the air sucked into the seal inner space S8 is sucked into the seal inner space S2 of the end face seal 6C through the first dust filter 68A.

  Therefore, the seal lip 62 and the dust lip 70 do not make a solid contact with the flange portion 64b of the slinger 64 and the outer peripheral flange portion 61c of the case 61 due to negative pressure, and the seal lip 62 and the dust lip 70 are bent in the axial direction. Since the contact force is obtained only by the force, the surface pressure is small, and it is possible to effectively prevent an increase in sliding load and early wear of the seal lip 62 and dust lip 70 resulting from this. it can. In addition, according to this embodiment, since the ventilation path is constituted only by the ventilation hole 70d of the dust cover 6D, it is not necessary to form a vent hole or the like in the housing 2.

  Further, dust contained in the outside air sucked into the seal inner spaces S8 and S2 is separated by the second dust filter 68B and the first dust filter 68A during the suction process, so that the seal inner space Clean air is inhaled into S8 and S2. Therefore, it is possible to prevent dust from entering the engine oil in the crank chamber from the sliding portion between the flange portion 64b of the slinger 64 and the seal lip 62.

  The first dust filter 68A is worn over time due to sliding with the fitting cylinder portion 64a of the rotating slinger 64, but the second dust filter 68B is non-sliding, so that wear is not caused. Absent. For this reason, the excellent removal performance with respect to dust is maintained.

  Next, FIG. 9 is a half sectional view showing a shape modification example of the lip-type end face sealing device according to the fifth embodiment shown in FIG. 8 described above, cut along a plane passing through the axis, and FIG. FIG.

In this lip type end face sealing device 6, the vent hole 70d of the dust cover 6D has a slit shape as shown in FIG. 10, and other parts are configured in the same manner as in FIG. Specifically, the rubber layer forming the dust lip 70 is formed in a relatively thin film shape in the portion covering the atmosphere side of the reinforcing ring 71, and the vent hole 70d is a reinforcement embedded in the dust cover 6D. In the inner vent hole 70d ₁ penetrating the ring 71, as shown by a broken line in FIG. 10, for example, a circular hole shape is formed. However, the outer vent hole 70d ₂ penetrating the film-like rubber layer 70e on the atmosphere side. Then, it is formed in a slit shape.

According to this embodiment, the vent hole 70d of the dust cover. 6D, since forms a slit shape outside the vent hole 70d ₂ formed in the rubber layer 70e, the outer vent hole 70d ₂ is in the normal closed state, the pressure difference between the atmospheric side when the negative pressure is generated in the seal inner space S8, S2, when the rubber layer is subjected to deformation, to operate as the outer vent hole 70d ₂ slightly open. That is, the second dust filter 68B located inside the vent hole 70d is not always exposed to external dust, and the intrusion of dust with large particles is also blocked. Therefore, in addition to the effect of the embodiment shown in FIG. 8, it is possible to provide an effect that the dust removing function is further enhanced and the second dust filter 68B is not easily clogged.

  Next, FIG. 11 is a half sectional view showing another example of the shape change of the lip-type end face sealing device according to the fifth embodiment shown in FIG. 8 described above, cut along a plane passing through the axis.

  In the lip type end face sealing device 6, the inner peripheral base part 70c of the dust lip 70 in the dust cover 6D faces the fitting cylinder part 64a side of the slinger 64 in the end face seal 6C. The same configuration as in FIG. The inner peripheral base portion 70c corresponds to the inner peripheral portion of the dust cover described in claim 9.

  Specifically, the inner peripheral base portion 70c of the dust lip 70 closely fitted to the outer peripheral surface of the crankshaft 3 faces the fitting cylindrical portion 64a side together with the inner peripheral cylindrical portion 71a of the reinforcing ring 71 embedded therein. In a state where the end portion of the lip body portion 70a of the dust lip 70 is in contact with the end portion of the fitting cylinder portion 64a, the end surface 70b of the lip body portion 70a of the dust lip 70 is the outer periphery of the case 61 in the end surface seal 6C. The end face of the flange portion 61c is in close contact with an appropriate surface pressure. Further, when the end face seal 6C is not attached, the case 61 (seal lip 62) and the slinger 64 are relatively positioned in the axial direction by a suitable auxiliary metal fitting (not shown) that can be attached and detached. Yes.

  A fitting groove 70f is formed on the outer peripheral surface of the inner base 70c of the dust lip 70, and the inner periphery of the second dust filter 68B is fitted in the fitting groove 70f. . That is, the second dust filter 68B is non-adhered to the inside of the vent hole 70d by fitting with the fitting groove 70f.

  Therefore, according to this embodiment, when the dust cover 6D is attached to the outer peripheral surface of the crankshaft 3, the tip end portion of the inner peripheral base portion 70c of the dust lip 70 is brought into contact with the fitting cylinder portion 64a of the slinger 64. The dust cover 6D can be easily positioned in a state in which the front end surface 70b of the dust lip 70 is in close contact with the outer peripheral flange portion 61c of the case 61 with an appropriate surface pressure.

  Further, also in the embodiment shown in FIG. 11, the vent hole 70d can be configured in the same manner as in FIGS.

  Next, FIG. 12 is a half sectional view showing still another modification of the shape of the lip-type end face sealing device according to the fifth embodiment shown in FIG. 8, cut by a plane passing through its axis, and FIG. FIG. 13 is a half sectional view showing the dust cover in FIG. 12 cut along a plane passing through the axis.

  In the lip type end face sealing device 6, the vent hole 70d extends in a spiral manner in the fitting portion with the crankshaft 3 in the inner peripheral base portion 70c of the dust cover 6D. The other parts are basically configured in the same manner as in FIG.

  Specifically, as shown in FIG. 13, the dust cover 6 </ b> D is formed on the inner peripheral surface of the inner peripheral base portion 70 c that is tightly fitted to the outer peripheral surface of the crankshaft 3. A groove 72 (hereinafter, referred to as a spiral groove) 72 that is spirally continuous with the end portion is formed, and the spiral groove 72 is filled with a second dust filter 68B. The second dust filter 68B is made of a fiber assembly such as a synthetic fiber fabric or cotton, or a felt, has air permeability by a fine gap between fibers, and is fixed with an adhesive or the like.

  The end face seal 6C has the same structure as that shown in FIG. 8, and prevents the engine oil in the engine crank chamber from leaking outside the machine at the sliding portion between the seal lip 62 and the flange 64b of the slinger 64. Therefore, the air present in the seal internal space S2 of the end face seal 6C is caused by the centrifugal force generated by the rotation of the sliding portion between the flange portion 64b of the slinger 64 and the seal lip 62 or the spiral provided in the sliding portion. By the pumping action of the groove, it is excluded from the sliding part to the outer peripheral side. Further, the air existing in the seal internal space S8 between the end face seal 6C and the dust cover 6D is also removed to the outer peripheral side by the centrifugal force generated by the rotation of the sliding portion of the dust lip 70. As a result of such an air exhausting action, outside air is sucked into the seal internal space S8 through the spiral groove 72 and the vent hole 70d made of the second dust filter 68B filled therein. Further, a part of the air sucked into the seal inner space S8 is sucked into the seal inner space S2 of the end face seal 6C through the first dust filter 68A.

  Accordingly, the seal lip 62 and the dust lip 70 are prevented from sticking to the flange portion 64b of the slinger 64 and the outer peripheral flange portion 61c of the case 61 due to negative pressure, thereby increasing the sliding load and the seal resulting from this. Early wear of the lip 62 and the dust lip 70 can be effectively prevented.

  The dust contained in the air outside the machine sucked into the seal inner spaces S8 and S2 is separated by the second dust filter 68B and the first dust filter 68A during the suction process. In addition, the ventilation hole 70d formed in the inner peripheral base portion 70c of the dust cover 6D and the second dust filter 68B filled therein extend long in a spiral shape, so that the dust removal effect is high. Yes. Therefore, since only clean air is sucked into the seal internal space S2, it is possible to prevent dust from entering the engine oil in the crank chamber from the sliding portion between the flange 64b of the slinger 64 and the seal lip 62. it can.

  The second dust filter 68B is appropriately compressed by the tightening margin of the inner peripheral base portion 70c of the dust cover 6D with respect to the crankshaft 3, so that the fiber density may be somewhat coarse.

  Next, FIG. 14 shows a lip-type end face sealing device according to a sixth embodiment of the present invention, which is applied as a sealing means between engine oil and air in an engine having a severe external dust environment, cut along a plane passing through the axis. The end face seal 6C is configured in the same manner as in FIG.

  The dust cover 6D is formed in a ring shape from a rubber-like elastic material similar to the seal lip 62 in the end face seal 6C, and the inner peripheral surface of the thick base portion 70c is more than the fitting cylinder portion 64a in the slinger 64. The tip end surface 70b of the dust lip 70 that is tightly fitted to the outer peripheral surface of the crankshaft 3 on the atmosphere side and opens in a tapered shape toward the end surface seal 6C side slides on the end surface of the outer peripheral flange portion 61c of the case 61 in the end surface seal 6C. It is closely movable.

  On the dust cover 6 </ b> D that rotates together with the crankshaft 3, the centrifugal force due to the rotation acts so as to expand and deform the dust lip 70. At a predetermined rotation speed or higher, as shown by a one-dot chain line in FIG. 14, the front end surface 70b of the dust lip 70 that expands and deforms due to an increase in centrifugal force is the end surface of the outer peripheral flange 61c of the case 61 in the end surface seal 6C. The rigidity and mass of the dust lip 70 are set so as to be away from each other.

  According to the above configuration, the end face seal 6C prevents the engine oil in the crank chamber of the engine from leaking out of the machine at the sliding portion between the seal lip 62 and the flange 64b of the slinger 64, as in FIG. Is. Here, at the time of low-speed rotation, the centrifugal force that acts to expand and deform the dust lip 70 of the dust cover 6D that rotates together with the crankshaft 3 is small, and the centrifugal force that acts on the air in the seal internal spaces S2 and S8 is also small. . For this reason, an air exhaust force large enough to push open the seal lip 62 and the dust lip 70 is not generated, and therefore, the seal internal spaces S2 and S8 hardly have negative pressure. For this reason, the dust lip 70 is in sliding contact with the end face of the outer peripheral flange portion 61c of the case 61 in the end face seal 6C, and blocks dust from entering from the atmosphere side.

  When the rotational speed of the crankshaft 3 is increased from this state, the sliding portion between the seal lip 62 and the flange portion 64b of the slinger 64 is provided with centrifugal force acting on the air or the sliding portion. Although the air rejection force due to the pumping action of the spiral groove is increased, the centrifugal force acting on the dust lip 70 of the dust cover 6D that rotates together with the crankshaft 3 also increases, so this dust lip 70 is shown by a one-dot chain line in FIG. Since the tip end surface 70b is slightly separated from the end face of the outer peripheral flange portion 61c of the case 61 in the end face seal 6C, the negative pressure generated in the seal internal spaces S2, S8 is eliminated. Accordingly, the seal lip 62 and the dust lip 70 are prevented from sticking to the flange portion 64b of the slinger 64 and the outer peripheral flange portion 61c of the case 61 due to negative pressure, thereby increasing the sliding load and the seal resulting from this. Early wear of the lip 62 and the dust lip 70 can be effectively prevented.

  In this state, air outside the machine is sucked into the seal internal space S8 through a slight gap formed between the front end surface 70b of the dust lip 70 and the outer peripheral flange portion 61c of the case 61. Although sucked into the seal internal space S <b> 2 of the seal 6 </ b> C, dust contained in the air is separated by the dust filter 68. Therefore, since only clean air is sucked into the seal internal space S2, it is possible to prevent dust from entering the engine oil in the crank chamber from the sliding portion between the flange 64b of the slinger 64 and the seal lip 62. it can.

  In order to ensure that the operation described above occurs in the dust lip 70, for example, weights for increasing the diameter expansion force due to centrifugal force are embedded in the outer periphery of the dust lip 70 at equal intervals in the circumferential direction. Alternatively, it is conceivable to form thin portions on the dust strip 70 at predetermined intervals in the circumferential direction so that the dust strip 70 can be easily expanded in diameter.

  Next, FIG. 15 shows a lip type end face sealing device according to a seventh embodiment of the present invention, which is applied as a sealing means between engine oil and the atmosphere in an engine having a severe external dust environment, cut along a plane passing through the axis. The end face seal 6C is configured in the same manner as in FIG.

  As in FIG. 14, the dust cover 6 </ b> D is basically closely fitted to the outer peripheral surface of the crankshaft 3 such that the inner peripheral surface of the thick base portion 70 c is located on the atmosphere side of the fitting cylinder portion 64 a of the slinger 64. The tip end surface 70b of the dust lip 70 opened in a tapered shape toward the end face seal 6C is in close contact with the end face of the outer peripheral flange portion 61c of the case 61 in the end face seal 6C. Further, the dust lip 70 is sufficiently thicker than that of FIG. 14 described above. For this reason, the sliding width with respect to the end face 61e of the outer peripheral flange portion 61c of the case 61 in the end face seal 6C, in other words, The radial width of the front end surface 70b of the dust lip 70 is relatively large.

  Either one or both of the end surface 61e of the outer peripheral flange portion 61c of the case 61 in the end surface seal 6C and the front end surface 70b of the dust lip 70 that is slidably contacted with the end surface seal 6C are roughened by a satin finish process. . For this reason, an infinite number of fine labyrinth air passages (not shown) are formed between the end surface 61e and the front end surface 70b in contact with each other.

  According to the above configuration, the end face seal 6C prevents the engine oil in the crank chamber of the engine from leaking out of the machine at the sliding portion between the seal lip 62 and the flange 64b of the slinger 64, as in FIG. Therefore, the air present in the seal internal space S2 is caused by the centrifugal force generated by the rotation of the sliding portion between the flange portion 64b of the slinger 64 and the seal lip 62 or the pumping of the spiral groove provided in the sliding portion. By the action, it is excluded from the sliding portion to the outer peripheral side. However, the seal internal space S2 is formed in a sliding portion between the dust filter 68, the seal internal space S8 inside the dust cover 6D, the end surface 61e of the outer peripheral flange portion 61c of the case 61, and the front end surface 70b of the dust lip 70. Since the air is released to the atmosphere through an infinite number of labyrinth-shaped air passages formed by roughening, no significant negative pressure is generated in the seal internal spaces S2 and S8 due to the air exclusion action. Accordingly, the seal lip 62 and the dust lip 70 are prevented from sticking to the flange portion 64b of the slinger 64 and the outer peripheral flange portion 61c of the case 61 due to negative pressure, thereby increasing the sliding load and the seal resulting from this. Early wear of the lip 62 and the dust lip 70 can be effectively prevented.

  In addition, due to the above-described air evacuation action, the seal inner space S8 inside the dust cover 6D has a sliding portion between the end surface 61e of the outer peripheral flange portion 61c of the case 61 and the front end surface 70b of the dust lip 70. Air outside the machine is inhaled through a myriad of labyrinth-shaped air passages, but this air passage is a fine one formed by a satin treatment, and because it forms a labyrinth, dust contained in the inhaled air is sealed It cannot easily pass into the internal space S8. Further, even if dust is contained in the air flowing into the seal internal space S8, the dust is separated by the dust filter 68 in the process of being sucked into the seal internal space S2 of the end face seal 6C. Therefore, since only clean air is sucked into the seal internal space S2, it is possible to prevent dust from entering the engine oil in the crank chamber from the sliding portion between the flange 64b of the slinger 64 and the seal lip 62. it can.

It is a half sectional view which cuts and shows the wearing state of the lip type end face seal device by the 1st form of the present invention by the plane which passes along an axis. FIG. 3 is a half cross-sectional view showing a state where the lip-type end face seal device according to the first embodiment of the present invention is not attached, cut along a plane passing through the axis. FIG. 6 is a half sectional view showing a lip type end face sealing device according to a second embodiment of the present invention by cutting along a plane passing through an axis. FIG. 6 is a half sectional view showing a lip-type end face sealing device according to a third embodiment of the present invention by cutting along a plane passing through an axis. FIG. 6 is a half sectional view showing a lip type end face sealing device according to a fourth embodiment of the present invention by cutting along a plane passing through an axis. It is a semi-sectional view which shows the example of a shape change of the lip type end face seal device by the 4th form cut by the plane which passes along an axis. It is a semi-sectional view which shows the example of a shape change of the lip type end face seal device by the 4th form cut by the plane which passes along an axis. FIG. 10 is a half sectional view showing a lip-type end face sealing device according to a fifth embodiment of the present invention by cutting along a plane passing through an axis. It is a semi-sectional view which shows the example of a shape change of the lip type end face sealing device according to the fifth embodiment by cutting along a plane passing through the axis. It is an arrow view of the X direction in FIG. FIG. 10 is a half cross-sectional view showing another example of the shape change of the lip-type end face sealing device according to the fifth embodiment, cut along a plane passing through the axis. FIG. 10 is a half sectional view showing still another modification of the shape of the lip-type end face sealing device according to the fifth embodiment by cutting along a plane passing through the axis. FIG. 13 is a half sectional view showing the dust cover in FIG. 12 cut along a plane passing through the axis. FIG. 10 is a half sectional view showing a lip-type end face sealing device according to a sixth embodiment of the present invention by cutting along a plane passing through an axis. FIG. 10 is a half sectional view showing a lip-type end face sealing device according to a seventh embodiment of the present invention by cutting along a plane passing through an axis. It is a half sectional view showing a conventional lip type end face sealing device.

Explanation of symbols

2 Housing 2a Inner peripheral surface 21 Annular groove (air passage)
22 Vent hole (air passage)
3 Crankshaft (Rotating shaft)
6 Lip type end face seal device 6A First end face seal 6B Second end face seal 6C End face seal 6D Dust cover 61, 61A, 61B Case 61c Outer flange portion 61e End faces 611, 612 Case members 611b, 612b Inner flange portions 611c, 65e, 70d Ventilation hole (ventilation passage)
62, 63 Seal lip 62a, 63a, 66 Base part 62b, 63b Tongue piece part 62c, 63c End edge 64, 65 Slinger 64a, 65a Fitting cylinder part 64b, 65b Gutter part 64c Spiral groove 62d, 66a Gasket part 67 Venting tube ( Air passage)
68, 68A, 68B Dust filter 69 Annular holder 70 Dustrip 70b Tip surface 70c Inner peripheral base (inner peripheral part)
70d ₁ Inner vent hole 70d ₂ Outer vent hole 70e Rubber layer 70f Fitting groove 71 Reinforcement ring 72 Spiral grooves S1, S6, S7 Ventilation space (air passage)
S2, S8 Seal internal space

Claims (11)

  A pair of sealing lips (62, 63) which are integrally provided in an annular case (61) fixed to the inner peripheral surface (2a) of the housing (2) and which open in a tapered manner opposite to each other in the axial direction. And a pair of slinger that is tightly fitted to the outer periphery of the rotary shaft (3) inserted through the inner periphery of the housing (2) and is in sliding contact with the seal lips (62, 63) at the flanges (64b, 65b). (64, 65) and an air passage for releasing the pressure in the seal internal space (S2) between the sliding portions of the seal lips (62, 63) and the slinger (64, 65). A lip-type end face sealing device.   The case (61) is composed of a pair of case members (611, 612), and the air passage is formed in the vent hole (22) opened in the inner peripheral surface (2a) of the housing (2) and the case (61). A vent hole (611c) which is opened on the fitting surface with the inner peripheral surface (2a) of the housing (2) between the pair of case members (611, 612) and communicates with the vent hole (22). The lip type end face sealing device according to claim 1, comprising:   A vent path (22) opened in the inner peripheral surface (2a) of the housing (2), one end (67a) is connected to the vent hole (22), and the other end (67b) is both seal lips ( The lip type according to claim 1, further comprising a ventilation tube (67) communicating with the seal internal space (S2) between the sliding portions of the slinger (64, 65). End face seal device.   One seal lip (62) is intended for sealing liquid, the other seal lip (63) is intended for sealing dust on the atmosphere side, and an air passage is formed in the slinger (65). Both seal lips (62, 63) The seal internal space (S2) between the sliding parts between the two and the slinger (64, 65) is communicated with the atmosphere side through a dust filter (68). Lip type end face seal device.   A seal lip (62) integrally provided in an annular case (61) fixed to the inner peripheral surface (2a) of the housing (2) and opened in a tapered manner toward the liquid to be sealed; and the housing (2) A slinger (64) that is tightly fitted to the outer periphery of the rotating shaft (3) inserted through the inner periphery of the shaft and is in sliding contact with the seal lip (62) at the flange (64b); and an outer periphery of the rotating shaft (3). The dust cover (6D) is provided with a dust cover (6D) positioned on the atmosphere side of the slinger (64) and tightly fitted, and the outer periphery dust strip (70) is in sliding contact with the case (61). An air passage (70d) is formed to release the pressure in the seal internal space (S2) between the sliding portion of the seal lip (62) and the dust lip (70) to the atmosphere side, and dust is formed in the air passage (70d). The feature is that a filter (68) is provided. That the lip-type face seal device.   A spiral groove (pumping to the outer peripheral side in accordance with the rotation of the slinger (64, 65) is formed on one of the sliding surfaces of the seal lip (62, 63) and the slinger (64, 65). 64. The lip type end face sealing device according to any one of claims 1 to 5, wherein 64c) is formed. Air passage lip type end face seal device according to claim 5, characterized in that it is formed in a slit shape in the portion (70d ₂₎ which penetrates a rubber layer (70e).   The lip-type end face sealing device according to claim 5, wherein the ventilation path extends in a spiral manner at a fitting portion with the rotation shaft (3) in the inner peripheral portion (70c) of the dust cover (6D).   The lip type end face sealing device according to claim 5, wherein the inner peripheral portion (70c) of the dust cover (70) is positioned by being brought into contact with an end portion of the slinger (64) on the atmosphere side.   A seal lip (62) integrally provided in an annular case (61) fixed to the inner peripheral surface (2a) of the housing (2) and opened in a tapered manner toward the liquid to be sealed; and the housing (2) A slinger (64) that is tightly fitted to the outer periphery of the rotating shaft (3) inserted through the inner periphery of the shaft and is in sliding contact with the seal lip (62) at the flange (64b); and an outer periphery of the rotating shaft (3). A dust cover (6D) positioned on the atmosphere side of the slinger (64) and tightly fitted, and an outer periphery dust strip (70) is slidably contacted with the case (61), the dust strip (70), A lip-type end face sealing device, wherein the lip type end face sealing device is separated from the case (61) by centrifugal force at a rotational speed of a predetermined value or more.   A seal lip (62) integrally provided in an annular case (61) fixed to the inner peripheral surface (2a) of the housing (2) and opened in a tapered manner toward the liquid to be sealed; and the housing (2) A slinger (64) that is tightly fitted to the outer periphery of the rotating shaft (3) inserted through the inner periphery of the shaft and is in sliding contact with the seal lip (62) at the flange (64b); and an outer periphery of the rotating shaft (3). A dust cover (6D) that is tightly fitted and positioned on the atmosphere side of the slinger (64) and that is in sliding contact with the case (61) and that is in sliding contact with each other. (70) A lip type end face sealing device, wherein at least one of the sliding surfaces of the case (61) is roughened.

Images