JPH0724668Y2 - Bearing dust prevention device for viscous fluid coupling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a bearing dust preventer for a viscous fluid coupling which can be used in a viscous fluid coupling apparatus for controlling the rotation of an internal combustion engine cooling fan.

(Prior Art) For the conventional viscous fluid joint, Japanese Patent Publication No. 59-27452 and Japanese Patent Publication No. 60-5
A conventional general viscous fluid coupling, which is proposed in Japanese Patent Publication No. 74, will be described with reference to FIG. 1. Reference numeral 1 is a drive shaft to which a disk-shaped rotor 2 is fitted and fixed. 3 is a casing,
Under the condition that the rotor 2 is housed, the rotor 2 is rotatably supported by the drive shaft 1 via a bearing 4. Labyrinth grooves 5 are formed in the torque transmitting surfaces of the rotor 2 and the casing 3 which face each other, and the respective grooves 5 facing each other are loosely fitted. A cover 6 having a stepped recess is sealed by an O-ring 7 and integrally joined to the left end surface of the casing 3 so as to form an appropriate space with the rotor 2. The cover 6 constitutes the front part of the joint body.

A partition plate 8 is fixed to the shoulder portion of the inner peripheral step of the cover 6, and the partition plate 8 divides the space between the rotor 2 and the cover 6 into a working chamber 9 in which the rotor 2 is housed and a storage chamber 10 on the cover 6 side. Split into and. Further, a passage 8a is formed in the partition plate 8, and the passage 8a
This allows the viscous fluid in the storage chamber 10 to flow into the working chamber 9. A rod 11 is rotatably attached to the cover 6 at substantially the center thereof. Reference numeral 12 is a bimetal, which operates by detecting the air temperature behind the radiator, and the valve plate 13 controls the opening and closing of the passage 8a of the partition plate 8 according to the operation of the bimetal 12.

(Problems to be solved by the invention) The bearing of a viscous fluid coupling is designed with due consideration of its function and reliability, but especially when it comes on the market, dust,
There is a risk that foreign matter such as mud and sand will adhere to the periphery of the bearing and damage the seal device of the bearing, and also reduce the sealing function. Further, there is a problem that foreign matters enter the inside of the bearing to damage the transfer surface and deteriorate the lubricating oil, thereby impairing the original function and reliability of the bearing.

FIG. 6 is a detailed cross-sectional view of a conventional bearing portion corresponding to the portion A of FIG. It adheres to ′ and damages the sealing surface 4e ′, which deteriorates the sealing function. Further, it penetrates into the bearing 4'and damages the inside, or causes deterioration of the lubricating oil. As a result, there are drawbacks such as leakage of lubricating oil, abnormal noise of the bearing, seizure and the like. The sixth
In the figure, 1 is a drive shaft, 2 is a rotor, 3 is a casing, 3b 'is an inner diameter portion of the casing 3, and 4a' is an inner ring of the bearing 4.

The present invention protects the bearing from foreign matter such as dust and mud from the outside air,
An object of the present invention is to provide a bearing dustproof device for a viscous fluid coupling having the function and reliability of a bearing, and to solve the above-mentioned problems.

[Constitution of device]

(Means for Solving the Problem) For this reason, the present invention provides a viscous fluid coupling device in which a casing serving as an output member is disposed on a drive shaft via a bearing.
A weir is provided in the casing of the portion in contact with the atmosphere side of the bearing,
A labyrinth seal is formed by a minute gap between the weir and the drive shaft surface, and a foreign substance to the atmosphere side by relative rotation with the drive shaft or the casing on the inner diameter surface of the weir or the drive shaft surface facing the inner diameter surface. Is formed by forming a groove having a shape so as to extrude, and this is a means for solving the problem.

(Operation) When the drive shaft rotates, the rotor integrated with the drive shaft rotates, and the casing supported on the drive shaft via the labyrinth and the bearing rotates. By providing a weir on the casing and forming a labyrinth seal with a minute gap between the weir and the drive shaft surface, it is possible to prevent foreign matter from entering the bearing sealing device from the atmosphere side. Further, by forming a groove on the inner diameter surface or the drive shaft surface of the weir so as to push the foreign matter toward the atmosphere side, it is possible to positively push the foreign matter toward the atmosphere side.

(Embodiment) The present invention will be described below with reference to embodiments of the drawings. FIGS. 2 to 4 are sectional views showing embodiments of the present invention corresponding to the portion A in FIG. 1, respectively.

First, referring to the embodiment shown in FIG. 2, 1 is a drive shaft,
Reference numeral 2 is a rotor, 3 is a casing, and 4 is a bearing, which are the same as those in FIG. The bearing 4 is on the input rotation side (drive shaft 1
Side) and the output rotation side (casing 3 side), the inner ring 4a is locked to the input shaft 1 and the outer ring 4b is locked to the casing 3 so as to support relative rotation. Sealing devices 4c and 4d for the bearing 4 face the atmosphere side 14 and the viscous fluid coupling inside (bearing side) 15, respectively, and perform a sealing function against the outside air and the viscous fluid, respectively. This prevents foreign matter from entering the bearing side 15 and leakage of lubricating oil to the outside of the bearing (atmosphere side 14). 3a is a weir that extends from the casing 3 and is between the drive shaft 1 and the weir 3a.
A small gap is formed between the inner diameter surface 3b of the shaft and the drive shaft 1 to perform the function of a labyrinth seal and to seal the bearing 4c.
It prevents foreign matter from adhering to the. In FIG. 2, 3c is an oil sump (gap) and 5 is a labyrinth groove.

Furthermore, the inner diameter surface 3b of the weir 3 in FIG.
The function of the labyrinth seal is further improved by forming the slanted groove 16 shown in FIG. 4 or the saw tooth groove 16 'shown in FIG. The grooves 16 and 16 'are formed in such a direction that foreign matter is pushed out from the bearing side 15 to the atmosphere side 14 by the relative rotation between the drive shaft 1 and the casing 3. A groove for achieving the same function as the grooves 16 and 16 'may be provided not on the inner diameter surface 3b of the weir 3 but on the surface of the drive shaft 1 facing the inner diameter surface 3b.

FIG. 3 shows an embodiment different from that of FIG. 2, and further, in order to prevent foreign matter from entering the seal device 4c of the bearing 4 from the atmosphere side 14, a ridge 17 provided on the drive shaft 1 outside the weir 3a. Is provided.

FIG. 4 shows still another embodiment, in which a bevel 18 which inclines the drive shaft 1 outward and upward is formed from a portion of the bearing 4 which is in contact with the outer end of the inner ring 4a so that the bearing 4 is sealed to the seal device 4c. It is designed to reduce the intrusion of foreign matter. However, the embodiment of FIGS. 3 and 4 is not different from the embodiment of FIG. 2 in operational effect.

[Effect of device]

As described above, according to the present invention, since the labyrinth seal is formed by the minute gap between the weir provided in the casing and the drive shaft surface, foreign matter can be prevented from entering the seal device of the bearing from the atmosphere side through the minute gap. be able to. Further, since the groove for pushing out the foreign matter to the atmosphere side by the relative rotation of the drive shaft and the casing is formed on the inner diameter surface or the drive shaft surface of the weir, in addition to the effect of preventing the foreign matter from entering by providing the weir as described above
Since the effect of positively pushing the foreign matter to the atmosphere side is added, the dustproof effect on the bearing can be further enhanced.
If an oil sump is formed between the weir and the bearing, it is possible to store a small amount of leaked lubricating oil at a level where there is no problem in terms of function and reliability from the bearing, etc. Can be prevented from flowing out.

[Brief description of drawings]

FIG. 1 is a side sectional view of a general viscous fluid coupling device, FIG. 2 is a sectional view of a bearing dustproof device corresponding to part A of FIG. 1 in a viscous fluid coupling device showing an embodiment of the present invention, FIG. And the fourth
FIG. 5 is a sectional view of a bearing dustproof device showing an embodiment different from FIG. 2, FIGS. 5 (a) and 5 (b) are development views showing groove shapes of different shapes on the inner surface of the weir, and FIG. It is sectional drawing of the bearing part of the conventional viscous fluid coupling apparatus corresponding to the A section of FIG. Description of the main parts of the figure 1 …… Drive shaft, 2 …… Rotor 3 …… Casing, 3a …… Weir 3b …… Inner diameter surface, 3c …… Oil sump 4 …… Bearing, 4a …… Inner ring 4b …… Outer ring, 4c, 4d …… Seal device 5 …… Labyrinth groove, 14 …… Atmosphere side 15 …… Bearing side, 16,16 ′ …… Groove 17 …… Ridge, 18 …… Slope

Claims (2)

[Scope of utility model registration request] 1. A viscous fluid coupling device in which a casing serving as an output member is disposed on a drive shaft via a bearing, and a weir is provided in a casing in a portion in contact with the atmosphere side of the bearing, and the weir and the drive shaft surface are provided. A labyrinth seal is formed by the minute gap between the weirs, and a groove having a shape that pushes foreign matter toward the atmosphere side by relative rotation with the drive shaft is formed on the inner diameter surface of the weir. Bearing dust control device. 2. A viscous fluid coupling device in which a casing serving as an output member is disposed on a drive shaft via a bearing, and a weir is provided in a casing in a portion in contact with the atmosphere side of the bearing, and the weir and the drive shaft surface are provided. A labyrinth seal is formed by a minute gap between the weirs, and a groove is formed on the drive shaft surface facing the inner diameter surface of the weir so that foreign matter is pushed out to the atmosphere side by relative rotation with the casing. Bearing dust prevention device for viscous fluid couplings.