JPS5836928Y2 - Shaft sealing device - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a shaft seal device in which an oil seal is interposed between opposing surfaces of a rotating member and a support member that supports the rotating member.
To stably improve the sealing effect of the surface where the lip of the oil seal makes sliding contact, to reduce the friction loss of the sliding contact, and to prevent foreign matter from entering the contact surface, thereby increasing the life of the shaft sealing device. This is the purpose.

2. Description of the Related Art Shaft sealing devices are widely used in which a main body of an oil seal is supported on one of relatively rotating opposing surfaces of a rotating member and a supporting member, and a lip of the oil seal is brought into sliding contact with the other opposing surface.

The lip of this oil seal slides directly on the opposite surface of the other party that rotates relative to the other, and the pressure contact with the opposite surface of the other party is generated by its own elasticity or by the elasticity of the spring by bringing a garter spring into contact with the back surface of the lip. Given.

This pressing force or tension force is usually quite large in order to avoid shaft vibration or non-contact during rotation.

For this reason, the material and surface roughness (of the case) of the member with which the lip of the oil seal comes into sliding contact have a large effect on the sealing effect, and the pressure or tension force of the lip is strong, so the lip and the member are Frictional resistance is large, and there is a risk that heat generation may cause deterioration of the seal rubber or cause wear marks on the sliding contact surface of the member.

In view of this problem, the present invention fixes an insert with a flat surface to the sliding surface of the member that contacts the lip provided on the oil seal and the sealing material, and insulates the surface of the insert with a low-friction material such as fluororesin. A thin layer of a wear-resistant material, preferably made of tetrafluoroethylene resin as the main material, is coated with powders of Pb1 and Zn (after cutting), which have good lubricity, and At203.5i02. A thin layer made of a material with a grindable surface added with a hard additive such as TiC is formed, and the surface of the thin layer is formed into a smooth surface, and the insert is formed on the surface in contact with the sealing material. This is a device in which a labyrinth groove reaching up to 100 mm is carved, and the above object is achieved by extremely simple machining.

The present invention will be explained below based on embodiments shown in the drawings.

FIG. 1 is a sectional view of an embodiment of the present invention, in which a rotating shaft 1 connected to a power source or a driven body (none of which is shown) as a rotating member is supported by a bearing device (not shown). An oil seal 3 is interposed between the opposing surfaces of the rotary shaft 1 and the sleeve 2, and a main body 4 of the oil seal 3 is fitted into a support plate 5, so that the support plate 5 is fixed to the inner circumferential surface of the sleeve 2, and the lip 6 is directed toward the rotating shaft 1, thereby forming a shaft sealing device for sealing the internal space 20 of the device from the outside air 21.

A cylindrical insert 7 having a flat outer peripheral surface is fixed to the rotating shaft 1 by means such as shrink fitting, and a thin layer 8 of fluororesin (described later) is formed on the flat outer peripheral surface of the insert 7. The outer surface of the thin layer 8 is mechanically ground and polished to form a smooth surface 9.

The thin layer 8 is made of a low-friction, wear-resistant material such as a fluororesin, preferably 50-90% by weight of tetrafluoroethylene resin and a total of 9-40% of PB and ( or) Zn and a total of 1-20% At203.5i0
2. It is made of a grindable material consisting of one type of hard additive such as TiC and a mixture of two or more types.

In the figure, reference numeral 10 denotes a garter spring that presses the lip 6 against the thin layer 8 on the rear surface of the lip 6 of the oil seal 3 to generate a tension force on the lip 6, and as in a known garter spring, a helical spring is formed into an annular shape. It is bent and connected at both ends.

Dimension 11 is an annular seal preferably made of felt, which is formed by forming one side edge of the main body 4 of the oil seal 3 into a thick annular part 12 and fitting into a groove 13 carved in the inner peripheral surface of the thick annular part 12. The inner circumferential surface of the sealing material 11 is formed of a thin layer 8 having a plurality of labyrinth grooves 14 cut from the smooth surface 9 of the thin layer 8 of the fluororesin to a depth reaching the insert 7. It must be in contact with the surface.

In the shaft sealing device constructed as shown in FIG. Therefore, the sealing effect of the shaft sealing device is constant due to the sliding contact between the lip 6 of the oil seal 3 and the smooth surface 9 of the thin layer 8.

The inner peripheral surface of the annular sealing material 11 provided on one side edge of the main body 4 of the oil seal 3 has the labyrinth groove 14 carved at a position slightly apart from the lip 6 of the oil seal 3. Since it contacts and slides on the smooth surface 9 of the thin layer 8 provided, a labyrinth seal is formed on the contact sliding surface.

The key to the present invention is that, as described above, the lip provided on the oil seal and the other surface that makes sliding contact with the sealing material are made of a thin layer made of a low-friction, wear-resistant material such as fluororesin. By making the surface of the layer smooth, there is less frictional resistance between the lip and the thin layer, so the seal rubber is less likely to reach high temperatures due to frictional heat or deteriorate due to heat generation. There is little wear caused by sliding, and the labyrinth seal composed of the sealing material and the labyrinth groove prevents foreign matter from entering the sliding contact surface of the lip of the oil seal with a thin layer. This has the effect of improving the sealing effect of the sliding contact surface more stably, reducing the friction loss of sliding contact, and improving the life of the shaft sealing device.

A thin layer of fluororesin etc. is 0. Oh++m to 0.03rr
Since the above-mentioned effect is sufficiently exhibited if the thickness is about vn, the thin layer may be formed by molding, but it can also be formed by simple means such as painting or spraying. is not formed directly on the rotating member or supporting member,
Since it is formed on the surface of the insert fixed to the member, there is no need for pre-processing to form a thin layer when processing the rotating member or supporting member, and there is no need for an oil seal between the rotating member and the supporting member. The dimensional accuracy of the part to be attached can be adjusted by adjusting the thickness of the insert and the thickness of the thin layer, making it possible to simplify the processing of rotating parts and supporting members. It does not require any special working method.

The thickness of old inserts is usually 2 mm or less, and if the thickness of the commonly used bushing is 1.2 mm, it will stick even if it is shrink-fitted. By varying the thickness, sufficient dimensional accuracy can be guaranteed.

Moreover, the labyrinth groove can be formed by carving the insert slightly from the surface of the thin layer to obtain a sufficient labyrinth effect, so it is only necessary to process the insert, and the member to which the insert is to be fixed is not processed, so forming the labyrinth groove is extremely easy. It is.

Furthermore, when the material is made of a thin layer of grindable material such as fluororesin, the resin layer is made thicker (e.g., 40 to 50 microns) than the desired thickness of the thin layer (e.g., 30 microns), and then the surface thereof is By mechanically grinding or polishing the oil to form a thin layer of the desired thickness, and at the same time finishing the surface smooth, the frictional resistance with the lip of the oil seal can be further reduced, and the finish can be finished with high dimensional accuracy. can.

In the present invention, the main material for the thin layer is the above-mentioned tetrafluoroethylene resin, and a material made of a mixture of PB and (for the case) Zn and hard additives is used, and the surface is ground to a dimension or When polishing to make a smooth surface, the hard additive increases the hardness of the thin layer, and the Pb and Zn particles provide compatibility with the lip of the oil seal on the sliding surface and prevent it from moving during sliding. Covers hard additives to protect them from oil seal damage and maintains long-lasting low friction and wear-resistant properties.

A metal compound of P or P having a weight ratio of 1 to 10 and/or a phosphate having a diameter of 1 to 10 may be further added and mixed to the above-mentioned mixture, and graphite and MC82 may be further added as a solid lubricant. The strip may contain up to 20% of its weight.

In the present invention, if the labyrinth groove formed on the insert surface is formed in a spiral shape, it is possible to perform a pumping action during relative rotation and reduce the intrusion of oil.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a part of FIG. 1. In the figure, 1 is the rotating shaft, 2 is the sleeve, 3 is the oil seal,
6 is the lip of the oil seal, 1 is the insert, 8 is a thin layer of fluororesin, etc., 9 is a smooth surface formed by polishing the surface of the thin layer, 10 is a garme spring, 11 is a felt sealing material, 14 indicate the labyrinth grooves.

Claims (3)

[Scope of utility model registration request] (1) In a shaft sealing device in which an oil seal is provided on opposing surfaces of a rotating member and a support member that supports the rotating member, a lip and an annular seal are provided on the opposing surface of either the rotating member housing or the supporting member. the lip button of the oil seal and the sealing material are in sliding contact with the other opposing surface, and the lip button and the sealing material are in sliding contact with each other; An insert with a flat surface is fixed to the surface, a thin layer made of a low-friction, wear-resistant material such as a fluororesin is formed on the surface of the insert that makes sliding contact with the lip and the sealing material, and the surface of the thin layer is A shaft sealing device characterized in that a labyrinth groove is formed on the surface of the contacting surface of the sealing material and reaching the insert from the surface thereof. (2) The shaft sealing device according to claim (1) of the utility model registration claim, wherein the thin layer is a fluororesin layer, and the surface of the layer is a surface smoothed by polishing. . (3) The thin layer is made of 50-90% tetrafluoroethylene resin by weight and a total of 9-40 strips of PB and/or Zn.
and a total of 1-20% At202゜5i02, TiC
Utility model registration claim No.
The shaft sealing device according to item 1).