JPH0723657Y2 - Sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a sealing device having a structure excellent in sealing effect particularly against water.

<Prior Art> Here, an example is given of a sealing structure used in a gear device of a railway vehicle. FIG. 3 shows a part of the gear device. In the figure, 1 is a housing, 2 is a gear shaft supported on the housing 1 via tapered roller bearings 3, 3, and 4 is a small gear mounted on the gear shaft 2 between the both tapered roller bearings 3, 3.
Is an oil seal attached to the housing 1 via a holder 6 on one side of one tapered roller bearing 3, and 7 is a small gear 4
It is a large gear that meshes with and is attached to the axle of a railway vehicle (not shown).

As shown in detail in FIG. 4, the oil seal 5 is made of rubber or the like on a core metal 8 having a substantially L-shaped cross section composed of an outer diameter cylindrical portion and a flange portion extending radially inward from one end of the cylindrical portion. The main lip 9 and the auxiliary lip 10 are attached and have a substantially U-shaped cross section. The main lip 9 is pressed against the outer peripheral surface of the base ring 12 fixed to the outer periphery of the gear shaft 2 by the tightening force of the coil spring 11 to form a contact seal portion, while the auxiliary lip 10 is the outer peripheral surface of the base ring 12. The non-contact sealing part is formed so as to be opposed to the above with a minute gap therebetween. The main lip 9
Has its tip end directed to the outside of the device to prevent foreign matter from entering the inside of the device while allowing a slight leakage of oil inside the device. Reference numeral 15 is an oil draining ring fixed between the pedestal ring 12 and one tapered roller bearing 3 and fixed to the outer periphery of the gear shaft 2.

By the way, in a normal oil seal, the tip of the main lip is used with the oil side facing toward the oil side. However, in the railway vehicle as described above, muddy water is very likely to splash on the gear device, Even if the oil leakage is slightly sacrificed, it is necessary to attach importance to the sealing performance against foreign matter such as muddy water and dust from the outside of the device. From this relationship, as shown in the figure, the oil seal 5 is opposite to the normal use. The direction, that is, the tip of the main lip 9 is oriented toward the outside of the device.

Further, since the main lip 9 of the oil seal 5 cannot prevent the oil leakage from the inside of the device, an auxiliary lip 10 is separately provided on the inside of the device for the oil seal 5, and the auxiliary lip 10 and the pedestal ring 12 are hermetically sealed. It is considered to form a portion to prevent oil leakage.

The holder 6 that holds the oil seal 5 is provided with a flange 13 that extends inward in the radial direction to shield the main lip 9 of the oil seal 5 from the outside.
Thus, muddy water or the like is prevented from directly splashing on the main lip 9 side. The flange 13 has a uniform width in the axial direction.

As described above, the conventional sealing structure in the gear device of the railway vehicle is a two-stage sealing structure of the oil seal 5 and the flange 13.

<Problems to be Solved by the Invention> By the way, the inner peripheral edge of the flange 13 is opposed to the outer peripheral surface of the pedestal ring 12 in a non-contact manner. However, if this gap is increased, the main lip 9 side of the oil seal 5 is closed. Although water can easily be allowed to enter the conversely, and conversely, if the gap is made small, the labyrinth action can enhance the sealing performance, but the gear shaft 2 to which the pedestal ring 12 is attached and the flange 13 are in the radial direction. If even a slight relative displacement occurs at the point of collision, it will collide, resulting in wear, damage and temperature rise, and increase in friction resistance.

Thus, in the conventional structure, when the shielding function of the flange 13 is important, a collision of the flange 13 with the pedestal ring 12 occurs, and conversely, when it is important to avoid the collision, the shielding function of the flange 13 deteriorates. There is a problem of doing.

Therefore, conventionally, it is considered that the oil seal 5 can secure a sufficient sealing property even if the shielding function of the flange 13 is sacrificed. Therefore, in order to avoid the collision, the gap between the flange 13 and the pedestal ring 12 is increased. Was. However, in this case, as described above, water easily intrudes into the main lip 9 side of the oil seal 5 and adheres to the main lip 9, so that when used in an extremely cold region, for example, the main lip The water attached to 9 freezes and the main lip 9
Therefore, there is a problem that the intended sealing function of the oil seal 5 is deteriorated.

Further, in the above structure, since the auxiliary lip 10 located on the inner side of the device where oil is present forms a non-contact sealing portion, the oil is inevitably absorbed from the auxiliary lip 10 by this auxiliary lip 10.
Since the main lip 9 can easily leak oil to the outside, inadequate oil sealing performance cannot be avoided.

The present invention was devised in view of such circumstances, and prevents damage due to a collision and prevents deterioration of the main lip 9 forming the contact sealing portion to stably exhibit a desired sealing function for a long period of time. The purpose is to be able to.

<Means for Solving the Problem> In order to achieve such an object, the present invention has the following configuration.

The sealing device according to the present invention is an oil seal having a substantially U-shaped cross section, in which an outer diameter cylindrical portion, a radially inwardly formed flange portion formed at one end thereof, and a main lip made of an elastic material formed at an end portion of the flange portion. The outer diameter cylindrical portion is fixed to the housing, and a main lip that is arranged toward the outside and is slidably in contact with a rotating member that is inserted into the housing is provided with foreign matter such as dust or water. The oil seal sealed between the inside where oil or the like exists, and the synthetic resin that is held on the inner peripheral surface of the outer diameter cylindrical portion of the oil seal on the outer side of the oil seal to shield the main lip from the outside A sling made by the slinger is formed on the inner peripheral edge of the body of the slinger, the lip being thinner than the body and having a diameter reduced and projected obliquely from the root side toward the outer side from the root side. Li Seal is formed between the rotary member and the.

Further, an auxiliary lip extending obliquely so as to expand the diameter toward the inner side is formed on the flange portion of the oil seal, and the auxiliary lip is provided on a vertical side surface of a large-diameter portion of the integral or separate body provided on the rotating member. It is made to slide. The auxiliary lip may be provided with a plurality of oil return ribs or grooves.

<Operation> In the above configuration, the oil seal and the slinger have a two-stage sealing structure, and since the inner peripheral edge of the slinger has flexibility, a mating member that forms the sealing portion of the oil seal (see FIG. 1). When the slinger and the slinger are displaced relative to each other in the radial direction and collide with each other, the impact is attenuated at the flexible portion and damage to both is avoided.
Since the slinger has such a buffering action,
Not only can the facing gap between the inner peripheral edge of this slinger and the mating member be set minutely so as to have a labyrinth effect, but it is also possible to form a contact sealing portion,
The slinger can effectively prevent water from entering the sealed portion formed by the oil seal. Also, since the slinger is held on the inner peripheral surface of the outer diameter cylindrical part of the oil seal, the entire sealing device can be made compact and it can be easily handled when it is attached to the target location such as the housing. Not only is it necessary to provide only the oil seal mounting portion at the target location, but it is not necessary to provide the slinger mounting portion, and thus unnecessary processing can be omitted.

Further, in the above structure, the auxiliary lip is slantingly extended and slidably in contact with the vertical side surface of the large diameter portion of the rotating member, so that oil leakage is prevented. Moreover, when the rib or the groove group is formed on the auxiliary lip, the rib or the groove group causes a pumping action with the rotation. Therefore, the oil that has passed over the auxiliary lip and is about to flow out to the main lip side is returned to the inside by the pumping action of the ribs or the groove groups of the auxiliary lip accompanying the rotation.

<Embodiment> An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In the figure,
The same parts and portions as those shown in FIG. 3 of the conventional example are designated by the same reference numerals, and the description thereof will be omitted.

The sealing device 20 of the present embodiment includes an oil seal 30 and a slinger.
It is a combination of 40 and they are configured as follows.

The oil seal 30 includes a metal core 31 having a substantially L-shaped cross section having a cylindrical portion 31a and a flange portion 31b extending radially inward from one end of the cylindrical portion 31a, and three lips 32 made of rubber or the like.
~ 34 is attached. The cylindrical part of this core 31
The inner surface of 31a and the side surface of the flange portion 31b on the main lip side are exposed. In the figure, the leftmost lip 32 is the main lip,
The middle lip 33 is called a first auxiliary lip, and the rightmost lip 34 is called a second auxiliary lip (or side lip). The main lip 32 is a pedestal ring fixed to the gear shaft 2 by the tightening force of the coil spring 35 molded on the outer peripheral side thereof.
The main lip 32 is pressed against the outer peripheral surface of 12 to form a contact seal portion, and this main lip 32 is directed toward the outside of the device, similarly to the conventional structure, so that foreign matter from the outside is prevented. It is formed in a shape that prevents the oil inside the device from leaking while preventing the oil from entering the inside. The first auxiliary lip 33 forms a non-contact sealing portion having a minute gap with the outer circumference 14 of the pedestal ring 12, and is formed in a shape in which the tip end side extends obliquely toward the inside of the apparatus to reduce the diameter. . The second auxiliary lip 34 forms a contact sealing portion by contacting the vertical side surface of the oil draining ring 15 provided on the inner side of the device with respect to the pedestal ring 12, and the tip end side extends radially outward in an oblique direction to expand the diameter. It is formed in a protruding shape. As a result, when the gear shaft 2 rotates, the oil is splattered by the centrifugal force along the second auxiliary lip 34 toward the inside of the device.

The slinger 40 includes a slinger main body 41 having a substantially L-shaped cross section and a lip 42 provided on the inner peripheral edge of the slinger main body 41, and is formed of, for example, a polyamide synthetic resin. Although the radial portion of the slinger main body 41 is set wide so that the axial width is uniform and the mechanical strength is high, the lip 42 is formed thinner than the slinger main body 41 and has a base. From the side, the tip side is formed in a shape in which the diameter is reduced and projected obliquely toward the outside of the apparatus so that it can work flexibly.

Then, the slinger 40 is opposed to the oil seal 30 so that the tip ends of the cylindrical portion 31a of the core metal 31 and the cylindrical portion 41a of the slinger 40 face each other, and the oil seal 30
It is assembled by being press-fitted into the inner circumference of the cylindrical portion 31a of the core metal 31. When the entire width of the cylindrical portion 41a of the slinger 40 is pressed into the cylindrical portion 31a of the core metal 31 of the oil seal 30,
Since the press fit interference may cause the core metal 31 to warp outward in the radial direction and cause abnormal deformation, which may impair the functions of the lips 32 to 34, in the present embodiment, as shown in the figure, the slinger body 41 is provided. The hollow portion 43 is provided on the tip side of the outer diameter surface of the cylindrical portion 41a, and only the corner portion of the slinger main body 41 (the boundary between the cylindrical portion 41a and the annular plate 41b) is partially attached to the core metal 31 of the oil seal 30. The abnormal deformation of the cored bar 31 is suppressed by fitting it to the.

Even when the slinger 40 and the pedestal ring 12 are relatively displaced in the radial direction and collide with each other in the state where the sealing device 20 is assembled as shown in the figure, the lip 42 of the slinger 40 is flexible, so Since no damage is required, the gap between the tip of the lip 42 of the slinger 40 and the outer peripheral surface of the pedestal ring 12 can be made small to form a non-contact sealed portion having a high sealing effect. The lip 42 and the pedestal ring 12 may be brought into contact with each other to form a contact sealing portion having a higher sealing property. By the way, there should be a large gap between the inner peripheral edge of the flange 12 of the holder 6 and the outer peripheral surface of the pedestal ring 12 so that they do not collide with each other even if there is some relative displacement in the radial direction. It is set. further,
In this embodiment, the spaces A to C formed when the sealing device 20 is assembled as shown in the figure are filled with grease.

In such a structure, the opening inside the device is almost closed by the lip 42 of the slinger 40 in the gap between the flange 13 of the holder 6 and the pedestal ring 12, and from this gap to the oil seal 30 side. Almost no water or dust can enter. Even if water enters the oil seal 30 side, it mixes with the grease inside the sealing device 20, and therefore water drops do not adhere to the main lip 32 of the oil seal 30.

Furthermore, since the coil spring 35 is embedded and protected inside the main lip 32, the coil spring 35 is
However, there is no risk of rusting due to the water content.

Further, FIG. 2 shows another embodiment, in which the oil return ribs 50 are arranged at predetermined intervals on the inclined surface (the surface located on the outside of the apparatus) of the inner circumference of the end of the second auxiliary lip 34. They are provided so that each V shape is formed. The two pairs of ribs 50 are positioned such that the narrower spacing is on the tip side of the second auxiliary lip 34, and the wider spacing is on the root side of the second auxiliary lip 34. As a result, the oil inside the device leaks from the contact sealing portion between the second auxiliary lip 34 of the oil seal 30 and the side surface of the oil draining ring 15 to the first auxiliary lip 33 side, and the second
When the oil moves to the inclined surface on the inner peripheral side of the auxiliary lip 34, this oil is secondly moved by the pumping action of one of the ribs 50 accompanying the rotation.
The contact sealing portion formed by the auxiliary lip 34 is returned to the inside of the apparatus, and the movement of oil to the main lip 32 side is prevented.

In the above embodiment, the rib 50 is provided on the second auxiliary lip 34, but it is also possible to form a concave groove functioning for oil return instead of the rib 50. , The first auxiliary lip 33 is brought into sliding contact with the outer peripheral surface of the pedestal ring 12, and the rib 50 is attached to the first auxiliary lip 33.
It is also possible to form a groove. Further, the present invention also includes an oil seal 30 that does not include either the first auxiliary lip 33 or the second auxiliary lip 34. in this case,
It goes without saying that the rib 50 and the concave groove are formed on the remaining auxiliary lip.

<Effects of the Invention> As described above, according to the present invention, it is possible to prevent muddy water or the like from directly entering the sealing portion side of the oil seal, and the oil seal can be sealed even when used in extremely cold regions. Since the deterioration of the portion forming portion (lip) can be avoided and the leakage of oil inside can be prevented, the desired sealing function can be stably exerted for a long period of time. In addition, since the slinger is held on the inner peripheral surface of the outer diameter cylindrical portion of the oil seal, the entire sealing device can be made compact, and handling at the time of installation in a target location such as a housing is easy. Not only is it easy, but it suffices to provide only the oil seal mounting portion at the target location, and there is no need to provide the slinger mounting portion.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a sealing device according to an embodiment of the present invention in use, and FIG. 2 is a view corresponding to FIG. 1 of another embodiment of the present invention. FIGS. 3 and 4 relate to a conventional example, FIG. 3 is a vertical cross-sectional side view showing a main part of a gear device of a railway vehicle, and FIG. 4 is an enlarged cross-sectional view of a sealing device. 1 ... Housing, 12 ... Pedestal ring (corresponding to rotating member), 20 ... Sealing device, 30 ... Oil seal, 31a ...
Cylindrical part, 31b …… Flange part, 32 …… Main lip, 40 ……
Slinger, 41 …… The slinger body.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliography Hei 1-92558 (JP, U) Rikai 56-59353 (JP, U) Rikai 63-170679 (JP, U)

Claims (3)

[Scope of utility model registration request] 1. An oil seal having a substantially U-shaped cross section, wherein an outer diameter cylindrical portion, a radially inwardly formed flange portion formed at one end thereof, and a main lip made of an elastic material formed at an end portion of the flange portion. The outer diameter cylindrical portion is fixed to the housing and the main lip that is slidably contacted with the rotating member that is disposed toward the outside and is inserted into the housing is in contact with the outside where foreign matter such as dust or water exists and oil. And the synthetic resin slinger that is held on the inner peripheral surface of the outer diameter cylindrical portion of the oil seal on the outer side of the oil seal to shield the main lip from the outside. And a lip having a thickness smaller than that of the main body of the slinger and having a diameter reduced and projected obliquely from the root side toward the outer side from the root side is formed at the inner peripheral edge of the main body of the slinger. The above A sealing device, wherein a sealing portion is formed between rotating members. 2. A flange portion of the oil seal is formed with an auxiliary lip extending obliquely so as to expand toward the inner side, and the auxiliary lip is provided on the rotating member and is a large-diameter portion which is an integral or separate body. The sealing device according to claim 1, wherein the sealing device is in sliding contact with a vertical side surface of the. 3. The auxiliary lip is provided with a plurality of oil returning ribs or concave grooves.
The sealing device according to the paragraph.