JP2004019819A - Rolling bearing and transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing and a transmission, preventing entering of foreign matter, an adsorbing phenomenon, and outflow of oil together without an increase in manufacturing cost due to complicated design, and enabling long-time continuous use. <P>SOLUTION: This rolling bearing 1 includes: an outer ring 2 where an outer ring raceway surface 3a is formed on the inner peripheral surface 3; an inner ring 5 where an inner ring raceway surface 6a is formed on the outer peripheral surface 6; a plurality of balls 8 disposed to freely roll in a raceway formed between the outer ring raceway surface 3a and the inner ring raceway surface 6a, and contact seals 9 mounted at both end sides in the axial direction in the inner peripheral surface 3 of the outer ring 2. A wall part 13 of the contact seals 9 that does not come into contact with the outer ring 2 or the inner ring 5 is provided with at least one air hole 12 penetrating through the contact seal 9, and an open area per air hole 12 is 0.01 to 10% of a projection area obtained by projecting the balls 8 in the rolling direction. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rolling bearing, and more particularly, to a rolling bearing suitable for supporting a gear of an automatic transmission or a manual transmission mounted on an automobile or a pulley of a belt-type continuously variable transmission.
[0002]
[Prior art]
2. Description of the Related Art Transmissions such as automatic transmissions, manual transmissions, and belt-type continuously variable transmissions mounted on automobiles are provided with a plurality of rotating shafts that support gears, pulleys, and the like. Rolling bearings supporting these rotary shafts are provided with a contact seal between the inner and outer rings to prevent the entry of foreign matter mixed in the oil, thereby improving the sealing performance. The contact seal is mounted in one seal groove of the outer ring or the inner ring, and the other seal groove slides on the lip portion of the contact seal.
[0003]
The bearing provided with the contact seal is in a state where the inside of the bearing is sealed by the contact seal. Therefore, when frictional heat is generated due to the operation of the bearing, or when the temperature of the bearing increases due to heat conduction from the outside, the pressure inside the bearing becomes a negative pressure compared to the outside by cooling the bearing thereafter. . At this time, a force is generated by the lip of the contact seal to press the seal groove toward the inside of the bearing, and the frictional resistance between the lip and the seal groove increases. When the bearing is operated in this state, a phenomenon that the rotational torque of the bearing becomes extremely heavy (a so-called adsorption phenomenon) occurs. Such an increase in the rotational torque leads to a loss of rotational energy, which undesirably deteriorates the fuel efficiency of the vehicle.
[0004]
In order to suppress the pressure fluctuation caused by the contact seal as described above, for example, as shown in FIG. No. 65074).
[0005]
In addition, in the above-described rolling bearing used for a transmission of an automobile or the like, grease is usually sealed inside the bearing for initial lubrication. As the grease is continuously operated, the oil scattered by splashing of gears or the like gradually enters the inside of the bearing from the outside and is replaced with the grease. Therefore, the lubrication of the bearing is finally oil lubrication.
When the operation of the bearing is stopped, the oil inside the bearing collects below the bearing and is used for initial lubrication in the next operation.
[0006]
[Problems to be solved by the invention]
By the way, oils used for transmissions and the like generally have lower viscosity and better fluidity than grease. Therefore, as shown in FIG. 7, when the air hole 102 of the contact seal 101 is located below the rolling bearing 100, the oil 103 inside the bearing may flow out from the air hole 102. Further, depending on the location and conditions under which the rolling bearing 100 is used, the oil supplied from outside the bearing may be cut off or the supply amount may be insufficient. Further, since the rolling bearing 100 is provided with the contact seal 101, it is difficult for oil to enter the inside of the bearing from outside.
When the rolling bearing 100 is operated in such a state, poor lubrication may occur and seizure or early peeling may occur.
[0007]
Further, even when the position of the air hole is set so as not to be downward when the bearing is assembled, creep may occur during operation of the bearing and the contact seal may rotate with the outer ring or the inner ring. Therefore, it has been difficult to prevent oil from flowing out of the bearing.
[0008]
In addition, the size of the air hole provided in the contact seal must be reduced in order to prevent the intrusion of foreign matter, and the air hole must be designed in consideration of variations due to manufacturing errors. Therefore, in the case where air holes are provided on the outer diameter side or the inner diameter side, there has been a situation in which the manufacturing cost increases.
[0009]
An object of the present invention is to provide a rolling bearing and a transmission that can be used for a long time by preventing invasion of foreign matter, adsorption phenomenon, and outflow of oil, without increasing manufacturing costs due to a complicated design. Is to do.
[0010]
[Means for Solving the Problems]
To achieve the above object, a rolling bearing according to claim 1 of the present invention has an outer race having an outer raceway surface formed on an inner peripheral surface, an inner race having an inner raceway surface formed on an outer peripheral surface, and an outer raceway surface. A plurality of rolling elements rotatably arranged in a raceway formed between the inner raceway surface and the inner raceway surface, and a contact mounted on both ends in the axial direction on the inner peripheral surface of the outer race or the outer peripheral surface of the inner race. In a rolling bearing provided with a seal, at least one air hole penetrating the contact seal is provided on a wall portion of the contact seal that does not contact the outer ring or the inner ring, and an opening area per air hole is: It is characterized in that the rolling element is 0.01% to 10% of the projected area projected in the rolling axis direction.
[0011]
According to the rolling bearing having the configuration according to the first aspect, the structure of the air hole can be simplified, and the cost of forming the air hole can be reduced. Further, since the size of the air holes is set as described above, it is possible to effectively prevent intrusion of foreign matter and adsorption. In addition, since the air holes are provided not on the outer diameter side or the inner diameter side but on the wall portion, oil inside the bearing hardly leaks. Therefore, long-term continuous use is possible.
[0012]
According to a second aspect of the present invention, there is provided a rolling bearing comprising: an outer ring having an inner raceway surface formed on an inner peripheral surface; an inner race having an inner raceway surface formed on an outer peripheral surface; A plurality of rolling elements rotatably disposed in a raceway formed between the raceway surface and the inner raceway surface, and mounted on both ends in the axial direction of the inner peripheral surface of the outer race or the outer peripheral surface of the inner race. In the rolling bearing provided with the contact seal, at least one notch penetrating the contact seal is provided in a wall portion of the contact seal that does not contact the outer ring or the inner ring, and the notch is a pressure between both surfaces of the contact seal. It is characterized in that it is configured to allow air to pass through by opening due to the difference.
[0013]
According to the rolling bearing having the configuration according to the second aspect, by providing a notch having a simple structure, even if a pressure difference occurs between the inside and the outside of the bearing, it is possible to prevent the adsorption phenomenon. it can. Further, since the cuts are not usually opened, it is possible to prevent foreign substances from entering and oil from leaking. Therefore, long-term continuous use is possible.
[0014]
Further, a transmission according to a third aspect of the present invention for achieving the above object uses the rolling bearing according to the first or second aspect.
[0015]
According to the transmission having the configuration according to the third aspect, a stable operation state can be obtained even during long-time continuous use. The transmission may be an automatic transmission, a manual transmission, a belt-type continuously variable transmission, or the like.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a rolling bearing according to the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view of a principal part showing an embodiment of a rolling bearing according to the present invention, FIG. 2 is a front view of a contact seal shown in FIG. 1, and FIG. 3 is a cross-sectional view of the contact seal shown in FIG. It is.
In the present embodiment, a ball bearing using a ball as a rolling element will be described, but the present invention is also applicable to a roller bearing.
[0017]
As shown in FIG. 1, the ball bearing 1 of the present embodiment is a sealed ball bearing provided with a contact seal 9.
The ball bearing 1 includes an outer ring 2, an inner ring 5, a plurality of balls 8 as rolling elements, a retainer 14, and a contact seal 9. An outer raceway surface 3 a having an arc-shaped cross section having a radius of curvature slightly larger than the radius of the ball 8 is formed on the inner peripheral surface 3 of the outer race 2.
Similarly to the outer raceway surface 3a, an inner raceway surface 6a having an arc-shaped cross section having a radius of curvature slightly larger than the radius of the ball 8 is formed on the outer peripheral surface 6 of the inner race 5.
[0018]
In the raceway formed between the outer raceway surface 3a and the inner raceway surface 6a, a plurality of balls 8 which are aligned and held at predetermined intervals in the circumferential direction by a retainer 14 are rollably arranged. Is established.
In addition, hermetic contact seals 9 are fixed to outer ring seal grooves 4 provided at both ends of the inner peripheral surface 3 of the outer ring 2. In addition, inner ring seal grooves 7 are provided at both ends of the outer peripheral surface 6 of the inner ring 5, and the contact seal 9 is mounted so as to seal between the outer ring seal groove 4 and the inner ring seal groove 7. .
[0019]
As shown in FIGS. 1 to 3, the contact seal 9 is formed in a ring shape by covering a core metal part 9 a with a rubber seal part 9 b. In addition, it is also possible to adopt a mode in which only the rubber seal portion is provided without providing the cored bar portion 9a. The contact seal 9 has an outer peripheral portion 10 on the outer diameter side and a lip portion 11 on the inner diameter side. The outer peripheral portion 10 is fixed to the outer ring seal groove 4, and the lip portion 11 contacts the inner ring seal portion 7 and slides during operation. This prevents entry of foreign matter from outside the bearing and leakage of grease or oil from inside the bearing.
[0020]
The contact seal 9 has at least one air hole 12 penetrating both sides of the contact seal 9 in the wall portion 13. The wall portion 13 is formed in a substantially flat plate shape, and is arranged at a height between the inner peripheral surface 3 of the outer ring 2 and the outer peripheral surface 6 of the inner ring 5 so as not to contact the outer ring 2 and the inner ring 5. .
In the present embodiment, the air hole 12 is provided in the wall portion 13 at a substantially intermediate position between the inner peripheral surface 3 of the outer ring 2 and the outer peripheral surface 6 of the inner ring 5. In addition, the air holes 12 are formed at four locations at substantially equal intervals in the circumferential direction.
Since the wall portion 13 has a simple flat plate structure as compared with the outer peripheral portion 10 and the lip portion 11, the structure of the air hole 12 can be a simple round hole, and processing is easy. Therefore, the cost for forming the air holes 12 can be reduced.
[0021]
The opening area of the air hole 12 is set based on the projected area of the ball 8 projected in the rolling axis direction. The opening area of one air hole 12 is 0.01% to 10% of the projected area of ball 8. Since the ball 8 is spherical, the projected area in the rolling axis direction is equivalent to the cross-sectional area of the diameter portion. By setting the opening area of the air hole 12 in this way, it is possible to effectively prevent the adsorption phenomenon from occurring without causing intrusion of foreign matter and oil leakage.
[0022]
If the opening area of the air hole 12 exceeds 10% of the projected area of the ball 8, foreign matter easily enters the inside of the bearing from the air hole 12, or if the oil rebounds inside the bearing during operation, the oil may be removed. It is not preferable because it may leak.
[0023]
As shown in FIG. 1, even when the oil 15 inside the bearing is accumulated below the bearing when the operation is stopped, the air hole 12 is formed in the wall portion 13 at a position higher than the inner peripheral surface 3 where the oil 15 is accumulated. The oil 15 does not leak from the air hole 12. Even if the position of the air hole 12 is lower than that shown in FIG. 1, since the wall portion 13 is at a position higher than the inner peripheral surface 3, all the oil 15 leaks out and is completely lost. There is no.
[0024]
Next, another embodiment of the above-described air hole will be described with reference to FIGS.
FIG. 4 is an enlarged cross-sectional view of a main part when an air hole is formed in a direction perpendicular to the wall, and FIG. 5 is an enlarged cross-sectional view of a main part when an air hole is formed in a direction oblique to the wall. It is.
[0025]
As shown in FIG. 4A, the air hole 12 of the contact seal 9 described above is formed such that the air hole 12 having the same diameter is perpendicular to the cored bar 9a and the rubber seal 9b. In addition, the thickness of the core metal part 9a and the thickness of the rubber seal part 9b are substantially equal.
As a modification, as shown in FIGS. 4B to 4D, the inner diameter of the air hole may be changed.
[0026]
For example, like the air hole 21 of the contact seal 20 shown in FIG. 4B, the diameter of the rubber seal portion 20b can be smaller than that of the core metal portion 20a. It is not preferable to simply fluctuate the entire inner diameter of the air hole because there is a trade-off between preventing intrusion of foreign matter and leakage of oil and maintaining good air passage. However, by reducing the diameter of only the rubber seal portion 20b facing the outside of the bearing, it is possible to satisfy the prevention of intrusion of foreign matters and leakage of oil and the maintenance of the passage of air.
[0027]
Also, as in the air hole 26 of the contact seal 25 shown in FIG. 4C, the length of the small-diameter portion may be shortened by making the rubber seal portion 25b thinner than the cored bar portion 25a. With such a configuration, it is possible to more effectively satisfy the respective operations having the above trade-off relationship as compared with FIG. 4B. When the thickness of the rubber seal portion 30b is large, as in the case of the contact seal 30 shown in FIG. 4D, a step is provided in the rubber seal portion 30b to open the portion where the air hole 31 faces the outside. The area can be reduced.
[0028]
The air holes 12, 21, 26, and 31 shown in FIGS. 4A to 4D are similar to the air holes 36, 41, 46, and 51 shown in FIGS. It may be formed in a direction inclined with respect to the part. According to these contact seals 35, 40, 45, and 50, it is possible to more effectively prevent leakage of grease or oil due to rebound during operation of the bearing.
[0029]
The air holes shown in FIGS. 4 and 5 have an opening area of 0.01% of the projected area of the rolling element at both the opening facing the inside of the bearing and the opening facing the outside. % To 10%.
[0030]
Next, a contact seal provided with a cut in place of the above-described air hole in the rolling bearing according to the present invention will be described with reference to FIG.
FIG. 6 is a sectional view of a main part showing a contact seal provided with a cut.
[0031]
As shown in FIG. 6, the contact seal 60 includes a cored bar 60a and a rubber seal 60b. The contact seal 60 is formed in an annular shape by covering a metal core 60a with a rubber seal 60b, similarly to the contact seal 9 described above (see FIGS. 2 and 3). The contact seal 60 is suitably used as a seal for the above-described ball bearing 1, but can also be applied to other rolling bearings.
[0032]
The core 60 a has an air hole 61 penetrating the core 60 a in the wall of the contact seal 60. In the rubber seal portion 60b, a cut 62 penetrating the rubber seal portion 60b is formed at a position facing the air hole 61. The cut 62 is formed by, for example, a needle or the like in a direction along the circumferential direction of the rubber seal portion 60b. The air holes 61 and the cuts 62 are formed at a plurality of locations at substantially equal intervals in the circumferential direction of the contact seal 60.
[0033]
FIG. 6A shows an embodiment of the contact seal 60 in a state where there is no or almost no pressure difference between the inside and the outside of the bearing. At this time, the cut 62 is in a closed state, and interrupts the flow of air between the inside (the core metal part 60a side) and the outside (the rubber seal part 60b side) of the contact seal 60. At this time, intrusion of foreign matter and leakage of oil are reliably prevented.
[0034]
FIG. 6B shows an aspect of the contact seal 60 in a state where the pressure inside the bearing is a negative pressure as compared with the outside. At this time, a force that presses the contact seal 60 from the outside (the right side in the figure) to the inside (the left side in the figure) acts due to the pressure difference between both surfaces of the contact seal 60. Since the rubber seal portion 60b facing the air hole 61 does not have the support of the metal core portion 60a, a portion near the cut 62 is elastically deformed inward, and the cut 62 is opened. When the cut 62 opens, air passes through the inside and the outside of the bearing, so that air flows from the outside of the bearing toward the inside, and the inside pressure becomes equal to that of the outside.
Therefore, even if a temperature change occurs in the bearing or the like, the negative pressure state inside the bearing can be immediately eliminated and the occurrence of the adsorption phenomenon can be prevented.
[0035]
Further, the above-described rolling bearing according to the present invention is used as a bearing for supporting a rotating shaft used for a gear or a pulley of a transmission (automatic transmission, manual transmission, belt-type continuously variable transmission, etc.) for an automobile, for example. Good. For example, it can be used for a belt-type continuously variable transmission described in JP-A-2000-161455.
According to such a transmission, even when the rolling bearing is continuously used for a long time, a stable operating state can be obtained without causing seizure or early peeling of the rolling bearing.
[0036]
【The invention's effect】
As described above, according to the rolling bearing according to the present invention, the invasion of foreign matter, the adsorption phenomenon, and the outflow of oil are prevented at the same time without increasing the manufacturing cost due to the complicated design, and continuous use for a long time is possible. It is possible. In addition, according to the transmission using the rolling bearing, a stable operation state can be obtained even during long-time continuous use.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part showing an embodiment of a rolling bearing according to the present invention.
FIG. 2 is a front view of the contact seal shown in FIG.
FIG. 3 is a sectional view of the contact seal shown in FIG. 2 taken along line AA.
FIG. 4 is an enlarged sectional view of a main part showing a modified example of the air hole shown in FIG. 1;
FIG. 5 is an enlarged cross-sectional view of a main part showing a modification in which the air holes shown in FIG. 4 are formed in a direction oblique to a wall.
FIG. 6 is a sectional view of a main part showing a cut of a contact seal in the rolling bearing according to the present invention.
FIG. 7 is a cross-sectional view of a main part showing an example of a conventional rolling bearing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rolling bearing 2 Outer ring 3 Inner ring 3a Outer ring raceway surface 4 Outer ring seal groove 5 Inner ring 6 Outer peripheral surface 6a Inner ring outer peripheral surface 7 Inner ring seal groove 8 Ball (rolling element)
9 Contact seal 9a Core part 9b Rubber seal part 10 Outer peripheral part 11 Lip part 12 Air hole 13 Wall part 14 Cage 15 Oil 62 Cut

Claims (3)

An outer ring having an outer raceway surface formed on an inner peripheral surface, an inner ring having an inner raceway surface formed on an outer peripheral surface, and a rolling freely formed in a raceway formed between the outer raceway surface and the inner raceway surface. A plurality of rolling elements provided, and a rolling bearing comprising contact seals mounted on both ends in the axial direction of the inner peripheral surface of the outer ring or the outer peripheral surface of the inner ring,
At least one air hole penetrating the contact seal is provided on a wall portion of the contact seal that does not contact the outer ring or the inner ring,
A rolling bearing, wherein an opening area per one of the air holes is 0.01% to 10% of a projection area of the rolling element projected in a rolling axis direction. An outer ring having an outer raceway surface formed on an inner peripheral surface, an inner ring having an inner raceway surface formed on an outer peripheral surface, and a rolling freely formed in a raceway formed between the outer raceway surface and the inner raceway surface. A plurality of rolling elements provided, and a rolling bearing comprising contact seals mounted on both ends in the axial direction of the inner peripheral surface of the outer ring or the outer peripheral surface of the inner ring,
At least one cut through the contact seal is provided on a wall portion of the contact seal that does not contact the outer ring or the inner ring,
The rolling bearing is characterized in that the cut is opened by a pressure difference between both surfaces of the contact seal so that air can pass therethrough. A transmission using the rolling bearing according to claim 1 or 2.

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