JP4479375B2 - Rolling bearing and fan coupling device using the same - Google Patents

Description

  The present invention relates to a rolling bearing and a fan coupling device using the same.

A fan for cooling an automobile engine is provided with a fan coupling that transmits a driving torque of a rotating shaft to a cooling fan by using the viscosity of a viscous fluid. In a fan coupling device including this fan coupling, A rolling bearing that supports a rotating shaft in a housing integral with a fan is used. The viscous fluid is stored inside the fan coupling, and the driving torque from the engine is transmitted to the fan using the viscous resistance of the viscous fluid. In the fan coupling, the torque transmission amount by the viscous fluid is controlled with respect to the ambient temperature, and the fan is rotated at a low speed when the temperature is low, and is rotated at a high speed when the temperature is high. Grease is sealed in the rolling bearing, and a sealing member is provided at the viscous fluid side end and the anti-viscous fluid side end of the rolling bearing so as to be symmetric with respect to the center line of the bearing (Patent Document 1). ).
Japanese Patent Publication No.63-64608

  The rolling bearing in the above conventional fan coupling device has a seal surface that receives the seal lip portion, for example, a tapered surface, and is used in a state where the outer ring is pressed against the engine side by the thrust of the fan during fan rotation. ing. Therefore, when the fan rotates, there is a concern that the interference margin of the viscous fluid side seal member becomes small (loose), the sealing performance is lowered, and the viscous fluid easily enters the bearing. On the contrary, the lip claw allowance of the anti-viscous fluid side seal member becomes large (tight), and there is a concern of causing large heat generation and abnormal wear.

  An object of the present invention is to provide a rolling bearing and a fan coupling device using the same, in which a balance between the left and right sealing properties is ensured when the outer ring is used while being pressed against one of the axial directions. is there.

A rolling bearing according to the present invention includes an inner ring, an outer ring, a rolling element disposed between the center portions of both wheels, and a seal member disposed between end portions of both wheels, and the outer ring is disposed in one of the axial directions. In a rolling bearing used in a pressed state , each seal member has a seal lip portion that comes into contact with the inner ring, and a seal surface that receives the seal lip portion is formed on the inner ring. The interference margin between the inner ring and the inner ring has a different value between one and the other in the axial direction, and the axial component (sx1) of the interference of one seal member is the axial component (sx2) of the interference of the other seal member. ) And the bearing axial clearance (AS) after assembly .

  The rolling bearing according to the present invention is a device that is used in a state where the outer ring is pressed against one side in the axial direction (for example, a fan coupling device that is used while the outer ring is pressed against the engine side during fan rotation). It is suitable for being used in.

  The sealing surface is a tapered surface, R surface, etc., and the interference between the sealing lip and the sealing surface is directed in a direction inclined with respect to the radial direction, that is, has not only a radial component but also an axial component. It is supposed to be.

  In order to change the interference margin on the left and right, the diameter of the seal surface of the inner ring that receives the seal lip portion may be changed, or the inner diameter of the seal member may be changed.

  The axial component (sx1) of the interference margin of one seal member is a value obtained by adding the axial clearance (AS) after assembly to the axial component (sx2) of the interference margin of the other seal member (ie, sx1 = sx2 + AS). In this way, when the outer ring moves by half of the bearing axial clearance (AS) with respect to the inner ring due to the pressing force on one side in the axial direction, the interference of each sealing member after the movement is sx1 ′. And sx2 ′, sx1 ′ = sx1−AS / 2 and sx2 ′ = sx2 + AS / 2. Therefore, | sx1'-sx2 '| = | sx1-sx2-AS | = 0, and the right and left interference margins during fan rotation are well balanced.

  According to the rolling bearing of the present invention, each seal member has a seal lip portion that comes into contact with the inner ring, and the inner ring is formed with a seal surface that receives the seal lip portion. Since the seal member has a different tightening allowance, when a force from one side to the other in the axial direction is applied to the outer ring, the loose end of the tightening allowance is on the one side and the tight end of the tightening allowance is on the other side. By arranging on the side, the balance of the sealing performance of the sealing member is ensured.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2 show an embodiment of a rolling bearing and a fan coupling device using the same according to the present invention. In the following description, the left and right refer to the left and right in the figure. In the figure, the right side is the engine side and the left side is the anti-engine side.

  As shown in FIG. 2, the fan coupling device (1) includes a fan coupling (3) for transmitting the driving torque of the rotating shaft (2) to the cooling fan (5) using the viscosity of the viscous fluid, A rolling bearing (6) for supporting the rotating shaft (2) in a housing (4) integrated with (5) is provided.

  The rolling bearing (6) consists of an inner ring (11), an outer ring (12), a ball (rolling element) (13) disposed between the central portions of both wheels (11) and (12), and both wheels (11) and (12). Left and right seal members (14) and (15) are disposed between the left and right end portions.

  The left and right sealing members (14) and (15) are made of a core metal and an elastic seal, and the elastic seal is provided with seal lip portions (16) and (17) that contact the inner ring (11).

  As shown in FIG. 1 in an enlarged manner, the left and right end portions of the inner ring (11) are sealed surfaces (11a) and (11b) that receive the seal lip portions (16) and (17) of the left and right seal members (14) and (15). Is formed. In FIG. 1, the left and right sealing members (14) and (15) are shown in the shape before being mounted on the rolling bearing (6). The left and right sealing surfaces (11a) and (11b) are tapered surfaces whose diameters decrease toward the outside in the axial direction, and the axial length and taper angle thereof are equal on the left and right, and the diameter (for example, Regarding the diameter at the end face, the diameter of the left sealing surface (11a) is larger than the diameter of the right sealing surface (11b).

  The left and right seal members (14) and (15) have the same shape on the left and right, and therefore the inner diameter is the same, so that the interference between the seal lip portions (16) and (17) and the inner ring (11) is left. The value of is harder and different on the left and right.

  Specifically, the axial component (sx1) of the interference margin of the left seal member (14) is the bearing axial after being incorporated into the axial component (sx2) of the interference margin of the right seal member (15). A value obtained by adding the clearance (AS), that is, sx1 = sx2 + AS. When the fan (5) rotates, the outer ring (12) of the rolling bearing (6) is pressed against the non-engine side (left side) by the thrust of the fan (5). As a result, the outer ring (12) moves 1/2 of the bearing axial clearance (AS) from both reference positions with respect to the inner ring (11) (although there are variations depending on the individual bearings, the average axial movement amount is AS / 2). Accordingly, if the interference after moving is sx1 'and sx2', respectively, sx1 '= sx1-AS / 2, sx2' = sx2 + AS / 2. As a result, during fan rotation, the difference between the left and right interference margins | sx1'-sx2 '|

  In rolling bearings used in conventional fan coupling devices, the interference is designed considering only when the fan is not rotating, and at this time, it is determined to be equal on the left and right. If the left and right interference margins are sx0 and the left and right interference margins after movement are sx1 ″ and sx2 ″, respectively, sx1 ″ = sx0−AS / 2, sx2 ″ = sx0 + AS / 2, | sx1 ″ −sx2 ″ | = AS. For this reason, in the fan rotation state in which a load is applied to the rolling bearing, the interference of the left side (viscous fluid side) sealing member is small (loosened), the sealing performance is lowered, and the viscous fluid may easily enter the bearing. On the contrary, the lip claw allowance of the right side (anti-viscous fluid side) seal member becomes large (tight), and the possibility of causing large heat generation and abnormal wear increases. On the other hand, according to the rolling bearing (6) of the present invention, the interference allowance is designed to be appropriate when the fan (5) rotates, and the left and right interference allowances (sx1 'and sx2' when the fan (5) rotates. ) Is well balanced (| sx1′−sx2 ′ | = 0).

  In this way, considering the difference between the sealing targets of the left and right sealing members (14) and (15) (viscous fluid entry prevention on the left and foreign material entry prevention on the right) and the axial force that always acts, By making it asymmetric, the sealing performance of the rolling bearing (6) is improved.

  The sealing surface is not limited to a tapered surface, and may be various shapes such as an R surface. In the case of the R plane, the left and right interference margins can be adjusted by changing the curvature radius and / or the center of curvature of the R plane on the right and left sides.

  To change the interference allowance on the left and right, instead of changing the diameter of the seal surface (11a) (11b) of the inner ring (11) that receives the seal lip (16) (17), the seal surface of the inner ring (11) The diameters of (11a) and (11b) may be the same on the left and right, and the inner diameters of the seal lip portions (16) and (17) of the seal members (14) and (15) may be different on the left and right. In either case, the diameters of the seal surfaces (11a) and (11b) of the inner ring (11) or the inner diameters of the seal lips (16) and (17) are different, and the taper angle (R surface) of the seal surfaces (11a) and (11b) is different. In this case, the radius of curvature and / or the center of curvature may be different on the left and right.

  The rolling bearing (6) is a fan coupling device (1) in which the seals of the left and right seal members (14) and (15) are different and an axial force acts between the inner ring (11) and the outer ring (12). However, it can also be applied to rolling bearings of other devices used in a state where an axial force acts between the inner ring (11) and the outer ring (12).

It is an expanded vertical sectional view of the principal part of the rolling bearing by this invention. 1 is a longitudinal sectional view showing a rolling bearing and a fan coupling device using the same according to the present invention.

Explanation of symbols

(1)
(2) Rotating shaft
(3) Fan coupling
(4) Housing
(5) Fan
(6) Rolling bearing
(11) Inner ring
(11a) (11b) Tapered surface
(12) Outer ring
(13) Ball (rolling element)
(14) Seal member (viscous fluid side seal member)
(15) Seal member (Anti-viscous fluid side seal member)
(16) Seal lip (viscous fluid side seal lip)
(17) Seal lip (anti-viscous fluid side seal lip)

Claims (2)

It has an inner ring, an outer ring, a rolling element disposed between the center portions of both wheels, and a seal member disposed between the end portions of both wheels, and is used in a state where the outer ring is pressed against one of the axial directions. in the rolling bearing that,
Each seal member has a seal lip portion that comes into contact with the inner ring, and a seal surface that receives the seal lip portion is formed on the inner ring, and the interference between the seal lip portion of the seal member and the inner ring is one of the axial directions. and it is different from the value in the other axial component of the tightening margin of one of the sealing member (sx1) the bearing axial clearance after incorporation in the axial component of the interference of the other seal member (sx2) (aS) A rolling bearing characterized by having a value obtained by adding A rolling bearing in a fan coupling device comprising: a fan coupling that transmits a driving torque of a rotating shaft to a cooling fan using viscosity of a viscous fluid; and a rolling bearing that supports the rotating shaft in a housing integrated with the fan. Is a rolling bearing according to claim 1, and is mounted so that the tightness of the interference is on the viscous fluid side.

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