JPH0525026U - Rolling bearing device - Google Patents

Abstract

(57) [Summary] [Purpose] Mainly to prevent heat buildup inside the housing. An inner cylinder portion 12 of a heat conducting ring 11 having a substantially U-shaped cross section is externally fitted on the outer peripheral surface of a long extending portion of an inner ring 6. The outer tube portion 13 and the annular plate portion 14 of the heat conduction ring 11
The outer peripheral surface of is close to the projecting portion 15 of the housing 1 so as to form a slight gap. The gap is filled with a heat conduction medium 16 in which grease is mixed with carbon powder or copper powder. As a result, the heat of the armature shaft 3 is transferred to the inner ring 6
And since it is efficiently conducted from the heat conduction ring 11 to the outer ring 7 and the housing 1 side via the heat conduction medium 16,
The temperature rise of the armature shaft 3 is suppressed.
Dynamic pressure groove portions 17 and 18 are formed on the outer surface of the heat conduction ring 11, and prevent the heat conductive medium 16 from flowing out of the gap due to the dynamic pressure generated by the dynamic pressure groove portions 17 and 18.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rolling bearing device suitable for conducting heat of a rotary shaft to the housing side.

[0002]

[Prior Art]

 In vehicle wiper drive systems, the armature shaft was supported on the housing via sliding bearings.However, in order to improve the transmission efficiency of armature power, the armature shaft may be supported on the housing via rolling bearings. It is known.

[0003]

[Problems to be solved by the device]

 In this type of wiper drive, when the armature generates heat under high load, heat can be efficiently transferred from the armature shaft to the housing when using a sliding bearing, but when a rolling bearing is used, the heat can be transferred from the armature shaft to the housing. Heat conduction in the housing deteriorates, and heat is trapped inside the housing. In such a situation, if the worm wheel is made of synthetic resin, heat transfer from the armature shaft may cause thermal deformation of the worm wheel.

On the other hand, the inventor of the present application extends a part of the inner wall of the housing so as to be close to the peripheral surface of the armature shaft, and allows the heat of the armature shaft to pass through the protruding portion that is close to the inner side wall of the housing side. I am thinking of making it conductive to.

However, in this case, in order to improve the heat transfer efficiency, it is necessary to set the size of the gap formed between the overhang portion and the armature shaft as small as possible. The manufacturing cost will increase because the inner diameter of the overhanging part will have to be controlled with high accuracy by polishing the inner peripheral surface of the part.

The present invention has been made in view of such circumstances, and an object thereof is to reduce the cost required for the countermeasure while preventing the heat buildup inside the housing.

[0007]

[Means for Solving the Problems]

 In order to achieve such a subject, the present invention has the following configurations.

A rolling bearing device of the present invention rotatably supports a rotating shaft with respect to a housing, and a heat conducting member provided on an inner ring so as to be close to an outer ring or an inner peripheral surface of the housing, A heat conducting medium interposed in a gap between the heat conducting member and its adjacent partner, and obliquely to the rotation axis on a surface of the heat conducting member facing the inner peripheral surface of the housing. It is characterized in that a dynamic pressure groove or a dynamic pressure protrusion is formed.

[0009]

[Action]

 The heat of the rotating shaft is efficiently transferred from the inner ring to the outer ring side through the heat conducting member and the heat conducting medium, and the temperature rise of the rotating shaft is suppressed. During the rotation of the heat conduction member, the heat conduction medium in the gap is held there by the dynamic pressure generated by the dynamic pressure groove or the dynamic pressure ridge, so that the heat conduction performance is maintained for a long time. You will be able to exert stability over time.

Since the heat conduction member is provided on the bearing ring which originally requires high surface accuracy, the labor required to form the overhanging portion with high precision as in the case where the overhanging portion is provided on the housing. Can be eliminated and the factor that increases the production cost can be eliminated.

[0011]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 3 show an embodiment of the present invention. In the wiper drive device shown in FIG. 2, 1 is a housing, 2 is an armature, 3 is an armature shaft, 4 is a worm wheel made of synthetic resin, and 5 is a rolling bearing device.

As shown in FIG. 1, the rolling bearing device 5 uses a deep groove ball bearing that rotatably supports the armature shaft 3 in the housing 1, and includes an inner ring 6, an outer ring 7, a ball 8, and a cage. 9, an oil seal 10, and a heat conduction ring 11. The inner ring 6 is different from a general one in that one side in the axial direction is formed to be extended, and the inner cylindrical portion 12 of the heat conducting ring 11 having a substantially U-shaped cross section is externally fitted to the outer peripheral surface of this elongated portion. The free end portion of the outer tube portion 13 of the heat conduction ring 11 is close to the end surface of the outer ring 7 so that a slight gap is formed, and the outer tube portion 13 and the annular plate portion of the heat conduction ring 11 are close to each other. The outer peripheral surface of 14 is close to the protruding portion 15 of the housing 1 so that a slight L-shaped gap S (for example, 0.5 mm) is formed. The space S here is filled with a heat conductive medium 16 made by mixing carbon powder and copper powder into grease.

The heat conducting ring 11 is made of a material having a high heat conductivity, such as copper or aluminum, and is designed to have a large surface area. Further, as shown in FIG. 3, dynamic pressure groove portions 17 and 18 oblique to the rotation axis are provided on the outer peripheral surface of the outer cylindrical portion 13 of the heat conduction ring 11 and the outer surface of the annular plate portion 14, respectively. ing. The dynamic pressure groove portions 17 and 18 generate dynamic pressure so as to collect the heat transfer medium 16 at the corner portions of the L-shaped gap S as the armature shaft 3 rotates.

When such a rolling bearing device 5 is used, the heat of the armature shaft 3 is efficiently conducted from the inner ring 6 and the heat conducting ring 11 to the outer ring 7 and the housing 1 side via the heat conducting medium 16. As a result, the temperature rise of the armature shaft 3 is suppressed. Therefore, even if the worm wheel 4 is made of synthetic resin, it is not thermally deformed by the heat of the armature shaft 3, and malfunction of the wiper can be prevented.

The heat conducting ring 11 is not limited to the one described in the above embodiment. A ridge portion may be provided instead of the dynamic pressure groove portions 17 and 18. Further, the present invention can be applied to various types of rolling bearings other than those applied to the deep groove ball bearing of the embodiment.

[0017]

[Effect of the device]

 As described above, according to the present invention, the heat of the rotating shaft (corresponding to the armature shaft) can be efficiently conducted from the inner ring to the outer ring and the housing side via the heat conducting member and the heat conducting medium. As a result, the temperature rise of the rotating shaft (corresponding to the armature shaft) can be suppressed, and the heat transfer medium is generated by the dynamic pressure generated by the dynamic pressure grooves or the dynamic pressure protrusions. Since the outflow is prevented, excellent heat transfer performance can be exhibited for a long period of time.

Therefore, when the rolling bearing device of the present invention is applied to, for example, a wiper drive device, a worm wheel made of synthetic resin meshed with the armature shaft is deformed by conduction heat from the armature shaft. Can be prevented. Moreover, since the heat conducting member is originally provided on the track ring of the rolling bearing, which is required to have high surface accuracy, the overhanging part is provided with high accuracy as in the conventional case where the overhanging part is provided on the housing and is close to the armature shaft. It eliminates the labor required for forming and eliminates the factor of increasing the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of the rolling bearing device shown in FIG.

FIG. 2 is a sectional view of a wiper driving device using the rolling bearing device according to the embodiment of the present invention.

FIG. 3 is a partial perspective view showing a heat conducting ring.

[Explanation of symbols]

 1 Housing 2 Armature 3 Armature Shaft 5 Rolling Bearing Device 6 Inner Ring 7 Outer Ring 11 Heat Conduction Ring 16 Heat Conduction Medium 17,18 Dynamic Pressure Groove

Continued Front Page (72) Inventor Noboru Kamiya 390 Umeda, Kosai City, Shizuoka Asmo Stock Association In-house

Claims (1)

[Scope of utility model registration request] 1. A rolling bearing device for rotatably supporting a rotary shaft with respect to a housing, wherein a heat conducting member is provided on an inner ring so as to be close to an outer ring or an inner peripheral surface of the housing, and a heat conducting member and the same. A heat-conducting medium intervening in a gap between the heat-conducting member and an inner peripheral surface of the housing of the heat-conducting member, and a dynamic pressure groove portion oblique to the rotation axis or A rolling bearing device, wherein a dynamic pressure ridge portion is provided.