JPH044314A - Vibrationproof supporting device for high speed rotary body - Google Patents

Abstract

PURPOSE:To obtain the sufficient vibration suppressing function even in the high speed revolution by a vibration suppressing member and an oil film layer by forming an oil film layer by introducing the lubricating oil into an annular gap formed between the outer peripheral surface of an outer race and the inner peripheral surface of a supporting body. CONSTITUTION:A prescribed gap is formed between the inner peripheral surface of a bearing casing 37 as a supporting body and the outer peripheral surface of a resin damper 41 as a vibration suppressing member, and oil is supplied into annular grooves 20B and 20C through the through holes 20D and 20E from an oil passage 25, and in the high speed revolution of a rotary shaft 2, an oil film layer (squeeze film damper) OD is formed in the gap. When a rotary shaft 2 vibrates, the vibration is transmitted to a resin damper 41 and attenuated, and after attenuated furthermore on the oil film layer OD, the vibration is transmitted to a bearing casing 37, and the vibration characteristic value, viewed from a bearing casing 37 side, becomes a drastically small value, and an extremely quiet turbocharger as the turbocharger for automobile engine can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an improvement of a device for supporting a high-speed rotating body having a rolling bearing with good vibration damping performance.

<Prior Art> Conventionally, for example, in a turbocharger of an internal combustion engine, there is a vibration damping support device that supports a high-speed rotating body together with a rolling bearing via a squeeze oil film layer (Japanese Patent Laid-Open No. 152716/1983).
(see publication).

To explain this based on FIG. 3, an angular contact rolling bearing 3.4 is interposed on the outer periphery of a rotating shaft 2 coaxially connecting a turbine wheel IA of a turbocharger and a compressor wheel IB. This rolling bearing 3,
4 is the inner ring 3A respectively.

4A, outer rings 3B, 4B and balls 3C, 4C,
Inner raceways 3D and 4D of inner races 3A and 4A are arranged symmetrically opposite each other in the figure.

A hair ring housing 20 located on the outer periphery of each of the rolling bearings 3 and 4 is integrally formed with a thrust bearing portion 20A that projects toward the rotating shaft.

Outer spacers 22 and 23 are interposed between the thrust receiver section 2OA and the outer rings 3B and 4B, respectively, and are biased toward the outer rings 3A and 4A by a compression spring 10. The relative position of the axis of rotation is regulated.

Further, the inner ring 3A is held between the stepped portion 2A formed on the rotating shaft 2 and the inner spacer 11, and the inner ring 4A is held between the inner spacer 11 and the thrust collar 21, so that positioning in the rotating shaft direction is performed.

A predetermined gap is formed between the bearing housing 20 and each of the outer rings 3B, 4B and the outer spacer 22, 23, and the pressure oil guided through the oil passage 25 into this gap flows through the through hole 2.
It is supplied through the annular holes 0D, 20E and the annular holes 20B and 20C, respectively.

In this configuration, in the low speed range, the rolling bearings 34 roll, while in the high speed range, a squeeze oil film layer having a thickness sufficient to support the rotating shaft 2 is formed in the gap, and the outer rings 3B, 4B and the outer The spacers 22 and 23 rotate together with the rotating shaft 2 at high speed.

Incidentally, in order to improve the damping performance of such a high-speed rotating body, if the bearing housing 2o is made of a resin or the like having damping properties, the damping performance can be significantly improved.

(Problems to be Solved by the Invention) However, in such a conventional vibration damping device for a high-speed rotating body, the hair ring housing 20 has a flanged cylindrical strip shape and forms a squeeze oil film layer. The annular groove 20B, 20C1 through hole 20D20E and the thrust receiver have a complex structure such as having a section 2OA, so the annular groove has a shape where stress is concentrated, the thrust where impact and repeated loads are applied], and the receiver is prone to cracks from the section. In addition, there are problems in that high-precision alignment is required, the shape is complex, so the machining costs are high due to the large number of machined parts, and the unit cost of materials is high, which increases costs. Ta. In particular, when the bearing housing 20 is made of resin in order to improve vibration damping performance, the above-mentioned tendency becomes remarkable because the bearing housing 20 is weak in strength.

The present invention was made in view of these conventional problems, and is a vibration damping device for high-speed rotating bodies that solves the above problems by improving the support structure of rolling bearings and simplifying machining. The purpose is to provide

<Means for Solving the Problems> For this reason, the present invention provides a method of interposing a pair of rolling bearings at a predetermined distance in the direction of the rotational axis of the rotating body between a rotating body and a support body located on the outer periphery of the rotating body. At the same time, lubricating oil is introduced into the annular gap formed between the outer ring and the support to form an oil film layer when the rotating body rotates at high speed, and the oil film layer is formed while each rolling bearing rotates integrally with the rotating body. In a vibration damping support device for a high-speed rotating body supported on a support body through a support body, a cylindrical vibration damping member is interposed between the outer ring outer peripheral surface of each rolling bearing and the support inner peripheral surface, and A passage for guiding lubricating oil is formed between the peripheral surface of the support body and the outer peripheral surface of the outer ring or between the inner peripheral surface of the damping member and the outer peripheral surface of the outer ring, and an oil film layer is interposed therebetween.

<Function> When the rotating body rotates at high speed, an oil film layer is formed between the inner circumferential surface of the support and the outer circumferential surface of the outer ring, or between the inner circumferential surface of the vibration damping member and the outer circumferential surface of the outer ring. The damping member, the rolling bearing, and the rotating body are integrally supported on the inner circumferential side of the vibration damping member, or the vibration damping member, the rolling bearing, and the rotating body are integrally supported on the inner circumferential side of the support body. At this time, the vibration of the rotating body can be sufficiently damped by the cylindrical damping member having high damping properties made of resin or the like and the damping function of the oil film layer.

In addition, instead of the conventional complex-shaped bearing housing, a simple cylindrical damping member only needs to be installed between the outer ring outer circumferential surface of the rolling bearing and the support inner circumferential surface, thereby avoiding stress concentration. In addition to ensuring strength, machining is also easy and costs can be reduced.

<Example> Examples of the present invention will be described below based on the drawings. still,
Components similar to those of the conventional example are given the same reference numerals, and explanations thereof will be omitted.

In FIG. 1 showing the first embodiment, the cylindrical hair ring housing with a resin flange in the conventional example is abolished, and a cylindrical housing as a vibration damping member is installed on the outer periphery of the outer rings 3B and 4B of the rolling bearing 3.4. A resin damper 41 having a shape is provided. The resin damper 41 is fixed to the bearing casing with a snap pin 40. Snap pin 40 and resin damper 41
and have a clearance in the axial direction, so that stress does not act on the resin damper 41 due to fixation.

A predetermined gap is formed between the inner circumferential surface of the bearing casing 37, which is a support, and the outer circumferential surface of the resin damper 41, which is a vibration damping member.
The oil is supplied to the annular grooves 20B, 20C through the grooves, and when the rotating shaft 2 rotates at high speed, an oil film layer (squeeze film damper) oD is formed in the gap.

A metal thrust receiver 38 is fixed to the bearing casing 37 by a pin (not shown) on the outer side of the central portion of the rotating shaft 2, and outer spacers 35, 36 are installed between both sides of the thrust receiver 38 and each outer ring 3B, 4B.

Then, the oil film layer 0. The oil that has passed through the gap where is formed flows into the space formed between the outer spacer 35. Jet lubrication is applied to the bearing portions of the pawls 3C and 4C of the rolling bearings 3 and 4 via 35A and 36A.

Further, the thrust force generated on the rotating shaft 2 is transmitted to the thrust portions 1 to 38 via the outer spacers 35 and 36.

The resin damper 41 and the outer spacers 35 and 36 are dimensioned so that they do not interfere with each other in both the axial and radial directions.

Next, the vibration damping effect of this embodiment will be explained.

When the rotating shaft 2 vibrates, it is transmitted to the resin damper 41 and damped, and then further damped by the oil film layer O9 before being transmitted to the bearing casing 37, so the vibration characteristic value seen from the bearing casing 37 side becomes a significantly small value. , it is possible to realize an extremely quiet turbocharger for a passenger car engine.

On the other hand, in terms of strength, the resin damper 41 can be a simple cylindrical part, and has no cutouts or cutouts that tend to cause stress concentration.
Sudden changes in grooves and wall thickness are eliminated, and stress generated can be kept low, ensuring sufficient durability and strength.

In addition, in terms of cost, as mentioned above, the resin damper 41 has a simple cylindrical shape, and the resin damper 41 is provided only on the outer periphery of the rolling bearing 3°4, which reduces machining and significantly reduces material costs. As a result, manufacturing costs can be significantly reduced.

FIG. 2 shows a second embodiment of the invention. In this example, the oil film layer is 0. is provided between the outer periphery of the rolling bearing and the resin damper. Note that although only the 4 rolling bearing portions are shown in the figure, the 3 rolling bearing portions are also formed symmetrically.

Here, a through hole 41A is formed in the resin damper 41, communicating with the annular groove 20C and penetrating the outer circumferential surface and the inner circumferential surface,
An annular groove 4E communicating with the through hole 41A is formed on the outer peripheral surface of the outer ring 4B.

To explain the operation, oil flows from the oil passage 25 to the through hole 2.
It enters the annular groove 20C through 0E, reaches the gap between the inner circumferential surface of the resin damper 41 and the outer circumferential surface of the outer ring 4B via the through hole 41A, and forms an oil film layer OD over the entire circumference of the gap through the annular groove 4E. .

In this embodiment, since there is an oil film layer OD on the outside of the rolling bearings 3 and 4, the vibration of the rotating shaft 2 is first attenuated there, and then transmitted to the resin damper 41, so that the vibration is applied to the resin damper 41 (force is applied to the resin damper 41). It can be made smaller than the example.

Furthermore, by providing the annular grooves (3E) and 4E in the bearing casing 37 and the outer rings (3B) and 4B, only alignment with the through hole 41A of the resin damper 41 is required, which significantly improves assembly efficiency and reduces cost. It can be suppressed. still,
These annular grooves may be formed on the outer circumferential surface and the inner circumferential surface of the resin damper 41, which is easy to process and allows the use of a common bearing.

be.

<Effects of the Invention> As explained above, according to the present invention, a simple cylindrical damping member is mounted between the outer ring outer circumferential surface and the support inner circumferential surface of a rolling bearing, and the outer ring outer circumferential surface and the support inner circumference are Since the lubricating oil is guided into the annular gap formed between the surface and the oil film layer to form an oil film layer, the vibration damping member and the oil film layer can provide sufficient vibration damping function even during high speed rotation, and the shape This simplification provides various advantages, such as avoiding stress concentration and securing strength, and facilitating machining to reduce costs.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing the configuration of an embodiment of the present invention, and FIG.
The figure is a sectional view showing the main part configuration of another embodiment of the present invention.
The figure is a longitudinal sectional view showing the configuration of a conventional example. IA... Turbine wheel IB... Compressor wheel 2... Rotating shaft 3, 4... Rolling bearing 3B, 4B... Outer ring 4E... Annular groove
20B, 20C... annular groove 20D, 20E.
...Through hole 25...Oil passage 37...Bearing casing 41...Resin damper 41A...
・Through hole ○, ...Oil slick layer patent applicant Nissan Motor Co., Ltd. agent Patent attorney Fujio Sasashima■

Claims (1)

[Claims] A pair of rolling bearings are interposed between the rotating body and a support body located on its outer periphery at a predetermined distance in the direction of the rotational axis of the rotating body, and an annular bearing formed between the outer ring and the support body. A high-speed rotating body in which lubricating oil is introduced into the gap to form an oil film layer when the rotating body rotates at high speed, and each rolling bearing is supported on a support body through the oil film layer while rotating integrally with the rotating body. In the vibration damping support device, a cylindrical damping member is interposed between the outer circumferential surface of the outer ring of each rolling bearing and the inner circumferential surface of the support body, and the vibration damping member is interposed between the inner circumferential surface of the support body and the outer circumferential surface of the outer ring, or A vibration damping support device for a high-speed rotating body, characterized in that a passage for introducing lubricating oil is formed between the inner circumferential surface of a member and the outer circumferential surface of an outer ring, and an oil film layer is interposed therebetween.