JPH0448367Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a shaft seal provided at the penetrating part of the rotating shaft to seal the inside and outside of the fixed part in a rotating shaft provided through the fixed part. It is related to the device. For example, when the rotating shaft of an internal combustion engine is taken out of the crankcase, the present invention can be used as a device that is installed in the penetration part of the crankcase and the rotating shaft to seal oil mist inside the crankcase from the outside. .

[Prior Art] Conventionally, in the crankcase of an internal combustion engine, a V-shaped part as shown in FIG.
A ring-type shaft sealing device was provided. That is,
A fixing plate 1 is provided on the crankcase side as a fixing member, and the rotating shaft 2 passes through this fixing plate and projects to the outside of the case. A base portion 3a of a V-ring 3 is fixed to the rotating shaft 2 inside the fixed plate 1, and its lip portion 3b slidably contacts the inner surface of the fixed plate 1, so that the rotating shaft 2 and the fixed plate 1 are connected to each other. It seals the space between them.

Also, the technology related to this conventional example is disclosed in Japanese Patent Application Laid-open No. 1983-
Disclosed in No. 180171. As shown in FIG. 3, this sealing device includes a first sealing member 1 fixed to a rotating shaft 101 and rotating together with the rotating shaft 101.
02, and a second seal member 105 attached to the fixed side housing 103 via an L-shaped ring member 104. The second seal member 105 is also in close contact with the surface of the rotating shaft 101 with the required elasticity. By appropriately setting the weight of the portion of the first seal member 102 in close contact with the ring member 104, the contact force of the first seal member 102 during rotation of the rotating shaft 101 is reduced.

[Problems to be solved by the invention] According to the V-ring type shaft sealing device, there is a problem that leakage is likely to occur when the pressure difference between the inside and outside exceeds a certain level. As the base portion 3a of the V-ring 3 expands in diameter, the lip portion 3b rises and the contact pressure on the sealing surface decreases, so when used over a wide range of rotations, the sealing effect of the shaft is reduced at high rotation speeds. There is a problem that it decreases.

Further, according to the sealing device shown in JP-A No. 62-180171, the first sealing member 102 made of rubber etc.
There was a problem that the sealing effect could not be exhibited under all conditions. For example, in machines that are operated over a wide range of speeds from low to high speeds,
The weight of the close contact portion of the first seal member 102 is
If the sealing effect is set to be maximum at the maximum rotation, the adhesion force to the ring member 104 is too strong at the minimum rotation and becomes a frictional resistance of the rotating shaft 101. On the other hand, even if the setting is made so that a satisfactory sealing effect can be obtained at the lowest rotation, the first seal member 102 will float due to centrifugal force at the highest rotation, weakening its adhesion to the ring member 104. The sealing effect will be reduced. Furthermore, the second seal member 105 has the problem of significant wear under high rotation. As described above, this sealing device having two sealing members is also unsuitable for a wide range of rotation, like the other conventional examples described above.

[Objective of the invention] It is an object of the present invention to provide a shaft sealing device that can maintain sufficient sealing performance over the entire range even when the rotating shaft is in a wide range of rotational operating states.

[Means for Solving the Problems] The shaft sealing device of the present invention seals between the fixed member whose inside is pressurized and the rotating shaft passing through the fixed member. A shaft sealing device installed on a rotating shaft includes a base portion fixed to the rotating shaft and a lip portion that contacts the inner surface of a fixed member through which the rotating shaft is inserted, and is capable of sealing the inside and outside of the fixed member. It has a shaft sealing member with flexibility. and,
Furthermore, a minute gap is formed on the inner surface of the fixing member outwardly from a portion where the lip portion of the shaft sealing member contacts a boss portion that is fixed to the rotating shaft and prevents deformation of the base of the shaft sealing member. and a shaft sealing plate having a rigidity that allows the centrifugal plate to splash the fluid in the centrifugal direction.

[Operation] During low rotation, one end of the shaft sealing member, which is fixed to the rotating shaft and rotates, comes into sliding contact with the fixed member, sealing the inside and outside of the fixed member. On a high rotation shaft, one end of the shaft seal member rises due to centrifugal force and the contact pressure with the fixed member decreases, but the shaft seal plate fixed to the rotating shaft presses the shaft seal member against the rotating shaft and prevents leakage. Since the fluid to be prevented is kicked away in the centrifugal direction, the fluid will not leak from between the fixed member and the rotating shaft.

[Embodiment] FIG. 1 is a sectional view showing an embodiment of the present invention.

In the figure, reference numeral 10 denotes a rotating shaft of an internal combustion engine, and this rotating shaft 10 passes through a through hole 12 of a fixing member 11 fixed to a crankcase (not shown) and projects to the outside of the crankcase. A V ring 13 serving as a shaft sealing member is attached to the rotating shaft 10 inside the fixed member 11 near the through hole 12 . V
The ring 13 is an annular member having a substantially V-shaped cross section and having a lip portion 15 as one end on one end surface side of the base portion 14, and is made of, for example, synthetic rubber. The base portion 14 of the V-ring 13 is attached to the rotating shaft 10 in an enlarged diameter state, and at this time, the lip portion 15 is folded down to take a shape along the horizontal direction parallel to the rotating shaft 10, and its tip portion is in contact with the inner surface side of the fixing member 11. Next, a shaft sealing plate 16 is fixed to the rotating shaft 10 inside the fixed member 11. A recessed fitting part 18 is formed in the boss part 17 of the shaft sealing plate 16 fixed to the rotating shaft 10, and the base part 14 of the V-ring 13 fits into this recessed fitting part 18. That is, the base portion 14 of the V-ring 13 is positioned and fixed to the rotating shaft 10 by the boss portion 17 of the shaft sealing plate 16 fixed to the rotating shaft 10. A flange-shaped oil cutting plate 19 as a centrifugal plate is provided on the end surface of the boss portion 17 of the shaft sealing plate 16 on the recessed fitting portion 18 side.
is provided circumferentially protrudingly with a surface orthogonal to the rotating shaft 10. A small gap of a predetermined size is provided between the right side end surface of the oil cutting plate 19 and the inner surface of the fixing member 11.

Next, the operation of the above configuration will be explained. First, when the rotating shaft 10 is operating at a low rotation speed or during priming while the engine is stopped, the V ring 13 fixed to the rotating shaft 10 does not deform.
The lip portion 15 rotates with the fixing member 11.
maintains a sliding state with the inner surface of the Therefore, the oil mist that is generated and filled in the crankcase as the engine operates does not leak out from the gap between the through hole 12 and the rotating shaft 10. Rotating axis 1
0 becomes high rotation, the lip part 1 of the V ring 13
5 rises due to centrifugal force so as to approximate the shape along the radial direction of the rotating shaft 10, so the contact pressure between its tip and the inner surface of the fixing member 11 decreases. Therefore, wear of the lip portion 15 during high rotation is reduced. Further, since the base portion 14 of the V-ring 13 is held and fixed from the outside by the recessed fitting portion 18 of the shaft sealing plate 16, the diameter will not expand due to high rotation. At this time, the oil cutting plate 19 rotates at a high speed to generate an air flow in the centrifugal direction, and the fluid such as oil inside the fixed member 11 is splashed outward, so that the oil cutting plate 19 rotates at a high speed and the fluid such as oil inside the fixing member 11 is splashed outward. Despite the decrease in contact pressure, the internal fluid remains on the rotating shaft 10.
It will not leak out of the fixing member 11 through the gap between the fixing member 11 and the fixing member 11. In addition, in an operating state between low rotation and high rotation, most of the fluid is splashed off by the splashing effect of the oil cutter plate 19, and a small amount of fluid that has entered the vicinity of the V ring 13 is removed from the lip portion 15. Sealing is achieved by contact with the fixing member 11.

Generally, if a centrifugal plate such as the oil drain plate 19 is provided apart from a fixed member that is a sealing part, air will flow backward from the high-pressure interior to the low-pressure exterior during rotation. In addition, such leakage can be reliably prevented by using a flexible V-ring 13 and by making the oil draining plate 19 close to the inner surface of the fixing member 11 so that the gap is small.

According to this embodiment, the lip portion 15 of the V-ring 13 seals the rotating shaft 10 under low rotation,
At high rotation speeds, only the lip portion 15 is deformed to prevent its wear, and the necessary sealing effect can be obtained by the effect of the shaft sealing plate 16 being thrown off. That is, the rotating shaft 10 can be sufficiently sealed in both low rotation and high rotation operating states.

[Effects of the invention] The shaft sealing device of the present invention is attached to a rotating shaft inside a pressurized fixed member, and brings the flexible shaft sealing member into contact with the inner surface of the fixed member, and further A centrifugal plate is provided on the outside in close proximity to the same inner surface. Therefore, when the rotating shaft rotates,
Backflow of air from the inside of the high-pressure fixing member to the low-pressure outside is reliably prevented, and a complete seal can be created between the pressurized inside and the outside air. Since the flexible shaft sealing member is securely fixed by the rigid shaft sealing plate, no problems occur even during restricted rotation, and this shaft sealing device can be used in a wide range of operating conditions from low rotation to high rotation. The sealing performance of the rotating shaft can be stably ensured over a period of time.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is a sectional view showing an example of a conventional shaft sealing device, and FIG. 3 is a sectional view showing another example of a conventional shaft sealing device. 10... Rotating shaft, 11... Fixed member, 13...
A V ring as a shaft sealing member, 15...a lip portion as one end, 16...a shaft sealing plate.

Claims (1)

[Claims for Utility Model Registration] In order to seal between a fixed member whose inside is pressurized and a rotating shaft passing through the fixed member, a shaft sealing device is provided on the rotating shaft inside the fixed member, A flexible shaft sealing member that has a base fixed to the rotating shaft and a lip part that contacts the inner surface of the fixed member through which the rotating shaft is inserted, and seals the inside and outside of the fixed member, and fixed to the rotating shaft. a boss portion that prevents deformation of the base portion of the shaft sealing member; and a centrifugal portion that faces the inner surface of the fixing member with a small gap outward from the portion where the lip portion of the shaft sealing member contacts. A shaft sealing device comprising: a shaft sealing plate having a rigidity that causes fluid to be splashed in a centrifugal direction by the centrifugal plate.