JPH0710037Y2 - Supercharger bearing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a supercharger mounted on an internal combustion engine for automobiles, and more particularly to a bearing device for a turbine shaft.

<Prior Art> Conventionally, as a bearing device for a supercharger, for example, there is one as shown in Fig. 3 (see Japanese Patent Application No. 61-298370).

In the figure, a pair of angular ball bearings 3 and 4 are provided separately from each other on the outer circumference of a turbine shaft 2 that coaxially connects a turbine wheel 1A and a compressor wheel 1B of a supercharger. The ball bearings 3 and 4 respectively include inner rings (inner races) 3A and 4A, outer rings (outer races) 3B and 4B, and balls 3C and 4C as rolling elements. Each inner ring 3A, 4A has a turbine shaft 2
The inner ring raceways 3D and 4D of the inner rings 3A and 4A, which are fixed by press-fitting to the outer periphery, are arranged symmetrically opposite to each other in the figure.
A slight gap is formed between the outer peripheral surface of each of the outer rings 3B and 4B and the inner peripheral surface of the bearing housing 8, and the supply holes 9A and 9A are formed in this gap.
Lubricating oil pressurized by an oil pump synchronized with the engine rotation is supplied via B to form an oil film damper. One inner ring 3A is sandwiched between the inner spacer 10 and the stepped portion 2A formed on the turbine shaft 2, and the other inner ring 4A is sandwiched between the inner spacer 10 and the thrust collar 15 for positioning in the turbine shaft 2 direction. Is done. These bearings 3,4
A thrust receiving portion 8A protruding from the bearing housing 8 toward the turbine shaft 2 is formed in the middle of.

Reference numerals 5 and 6 denote outer spacers interposed between the thrust receiving portion 8A and the outer rings 3B and 4B, respectively.
The relative positions of B and B in the turbine axis 2 direction are restricted.

A slight gap is formed between the outer peripheral surface of each of the outer spacers 5 and 6 and the inner peripheral surface of the bearing housing 8.

Between the outer spacers 5 and 6, the outer ring 3
The spring 7 biasing toward B and 4B is arranged in a compressed state, whereby the rolling elements 3C and 4C settle on the curved surfaces of the inner ring raceways 3D and 4D, and the initial positions of the outer rings 3B and 4B are determined.

<Problems to be solved by the invention> By the way, in the bearing device of the supercharger as described above,
Since the means for restricting the rotation of the outer rings 3B, 4B and the outer spacers 5, 6 are not provided and they are configured to be freely rotatable, there are the following problems.

That is, when the supercharger is rotating at a low speed in the low speed range of the engine, the ball bearing
The thrust load applied to 3 and 4 is small, and the bearing housing 8
Also, the oil film layer formed between the outer rings 3B and 4B of the ball bearings 3 and 4 is not perfect. Therefore, since the rolling friction is relatively smaller than the fluid friction caused by the oil film layer, the outer rings 3B and 4B do not rotate, and the outer spacers 5 and 6 also do not rotate. On the other hand, during acceleration operation, the rotation of the turbine shaft 2 increases and the thrust load applied to the ball bearings 3 and 4 also increases, and the bearing housing 8 and the outer ring
The hydraulic pressure supplied to the gap between 3B and 4B also increases. Therefore, a sufficient oil film layer is formed in the gap, the fluid friction due to this oil film layer is relatively smaller than the rolling friction, and the outer rings 3B, 4B rotate integrally with the turbine shaft 2 at high speed, and at the same time The spacers 5 and 6 also rotate at high speed integrally with the turbine shaft 2, and the weight of the outer spacers 5 and 6 is added to the rotating body in the supercharger. For this reason, there is a problem that the weight of the rotating body increases, and the oil around the rotor is agitated by the rotation of the outer spacers 5 and 6, thereby increasing the stirring resistance of the oil, increasing the bearing loss, and deteriorating the acceleration performance. there were.

In view of the above-mentioned conventional problems, the present invention solves the above-mentioned conventional problems by adopting a configuration in which the rotation of the outer ring of the bearing is restricted, and yet while sufficiently obtaining the oil film damper effect. The purpose is to efficiently discharge lubricating oil after bearing lubrication.

<Means for Solving the Problems> Therefore, the bearing device of the supercharger of the present invention is mounted on the bearing housing, the turbine shaft penetrating through the bearing housing, and the turbine shaft which are spaced apart from each other. In a bearing device of a supercharger, comprising a pair of ball bearings supported in the bearing housing, in the bearing housing, respectively supported in a floating state via an oil film layer in an oil film forming portion,
A pair of cylindrical damper sleeves that respectively support the outer races of the ball bearings are arranged, and a substantially cylindrical outer member that allows the damper sleeves to selectively abut between the pair of damper sleeves in the bearing housing. The spacer is non-rotatably supported by the bearing housing, and an oil discharge port communicating with a space around the turbine shaft is provided in a part of a peripheral wall of the outer spacer, while a pair of ends are formed with the outer spacer. The inner end portions of the damper sleeves are provided with engaging portions that engage with each other to prevent rotation of the outer ring of the ball bearing through the damper sleeves. The joint portion is formed by a convex portion formed by projecting at both ends of the outer spacer by cutting out a peripheral portion of each end portion by a predetermined angle. Is formed by recessing the peripheral portions of the inner end portions of the damper sleeves by a predetermined angle smaller than the predetermined angle so as to be recessed in the both end portions and to be engaged with the convex portions. .

<Operation> In this mechanism, the thrust load acting on the turbine shaft is supported by the thrust receiving portion. Then, the engaging portions provided on the mating abutting portions between the both ends of the outer spacer and the inner ends of the pair of damper sleeves engage with each other to prevent rotation of the outer ring of the ball bearing through the damper sleeve. As a result, the outer ring of the bearing, the member fixing the outer ring of the bearing, and the like do not rotate even if the rotation of the turbine shaft increases during the acceleration operation. As a result, the weight of the outer spacer is not added to the rotating body in the supercharger, and the weight of the rotating body in the supercharger does not increase. Since the bearing is not agitated and there is no increase in bearing loss due to an increase in stirring resistance of oil, good acceleration performance can be maintained.

In particular, since the outer spacer side convex portion and the damper sleeve side concave portion are engaged with each other to prevent rotation of the outer ring of the ball bearing, the rotation restricting portion that is the engaging portion between the convex portion and the concave portion is No surface wear or stress concentration occurs due to surface contact or line contact.

By the way, in order to obtain a sufficient oil film damper effect, it is desirable for the damper sleeve to have a large axial width and a large outer peripheral area. On the other hand, in order to efficiently discharge the lubricating oil after bearing lubrication from the space around the turbine shaft, it is desirable to increase the opening area of the oil discharge port.

As described above, a concave portion is formed by cutting a predetermined angle range smaller than the angle range of the portion to be cut to form the convex portion on the outer spacer side on the peripheral portion of each inner end portion of each damper sleeve. As a result, the circumferential length of the convex portion formed after forming the concave portion on the damper sleeve side can be made longer than the circumferential length of the convex portion on the outer spacer side. That is, the damper sleeve can secure a large outer peripheral area by forming only the concave portion in the small angle range, and the outer spacer can secure at least the convex portion in the small angle range, so that the opening forming portion of the oil drain port is also formed. It is possible to secure a large amount, and thereby it is possible to improve both the oil film damper efficiency and the oil drainage efficiency.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a bearing housing 21 is provided in the bearing casing 20. A turbine shaft 22 penetrates through the bearing housing 21, and the turbine shaft 22 is supported by a turbine side ball bearing 23 and a compressor side ball bearing 24. In the bearing housing 21, the oil film forming part 2
A substantially cylindrical turbine that supports the turbine side ball bearing 23 by being supported in a floating state via the oil film layers in 5, 26 and a damper sleeve 27 is also supported to support the compressor side ball bearing 24. A cylindrical compressor-side damper sleeve 28 is provided.

Here, the axial width of the damper sleeves 27, 28 is formed to be larger than the axial width of each of the ball bearings 23, 24. The damper sleeves 27, 28 are arranged so that a slight gap is formed between the outer peripheral surface of the damper sleeve 27, 28 and the inner peripheral surface of the bearing housing 21 to form the oil film forming portions 25, 26. Can be freely moved in the radial direction.

The stepped portions 27a, 28a formed at the outer ends of the damper sleeves 27, 28 have inner circumferences on the outer rings 23a, 24a of the ball bearings 23, 24.
Is press-fitted and fixed. A coil spring 29 is provided between the damper sleeves 27 and 28 for applying a preload in a direction to move the outer rings 23a and 24a of the ball bearings 23 and 24 away from each other. The sleeves 27 and 28 are locked to the end surfaces of the stepped portions 27b and 28b at the inner ends thereof. The inner diameters between the stepped portions 27a, 27b and 28a, 28b of both ends of the damper sleeves 27, 28 are formed to be substantially the same as or larger than the inner diameters of the outer rings 23a, 24a of the ball bearings 23, 24. It

Further, the damper sleeves 27, 28 are communicated with the annular chambers 30, 31 provided on the outer peripheral sides of the damper sleeves 27, 28, and a small hole for lubricating oil supply for guiding the lubricating oil near the rolling parts of the ball bearings 23, 24. 30a and 31a are provided respectively. Around the coil spring 29 between the damper sleeves 27, 28, a substantially cylindrical outer spacer 32 is disposed as a thrust receiving portion with which the damper sleeves 27, 28 can selectively abut. The outer spacer 32 is non-rotatably positioned and fixed to the inner wall of the bearing housing 21 by a positioning pin 33.

In this case, the pin 33 has a circular cross section including a groove 32a having a semicircular cross section formed tangentially on the outer peripheral surface of the outer spacer 32 and a groove 21a having a semicircular cross section formed on the inner peripheral surface of the bearing housing 21. Is inserted into the hole.

Here, the outer ring 23a and 24a of the ball bearings 23 and 24 are engaged with each other at the abutting portions between the opposite ends of the outer spacer 32 and the opposite ends of the inner ends of the pair of damper sleeves 27 and 28, respectively. An engaging portion is provided to prevent the rotation of the via the damper sleeves 27 and 28.

That is, as shown in FIG. 2, the engaging portion on the outer spacer 32 side is a convex portion formed by projecting on both end portions of the outer spacer 32 by cutting off the peripheral portions of both end portions by a predetermined angle. Formed by 34.

Further, the engagement portion on the damper sleeve 27, 28 side is formed by denting both end portions of the damper sleeve 27, 28 by cutting the peripheral portions of the inner end portions of the damper sleeve 27, 28 by a predetermined angle smaller than the predetermined angle. And is formed by the concave portion 35 engaged with the convex portion 34.

A part of the peripheral wall of the outer spacer 32, that is, a portion between the protrusions 34 at both ends, is provided with an oil drain port 32b communicating with a space around the inner spacer 38 fitted around the turbine shaft 22. .

In FIG. 1, 36 is an oil supply port and 37 is an oil discharge port.

Next, the operation of the bearing device having such a configuration will be described.

The radial load acting on the turbine shaft 22 is
It is supported by 4, and is damped by the oil film of the oil film forming portions 25, 26 in the gap between the damper sleeves 27, 28 and the bearing housing 21, that is, the oil film damper.

That is, the vibration damping effect can be obtained.

In this case, the lubricating oil is supplied from the oil supply port 36 to the outer circumferences of the damper sleeves 27, 28.
Since the oil is uniformly supplied from 0, 31 to the outer circumferences of the damper sleeves 27, 28, the oil pressure as an oil film damper can be secured over the entire circumferences of the damper sleeves 27, 28, and the damping effect is stable.

On the other hand, the thrust load used together with the turbine shaft 22 is supported by the outer spacer 32.

That is, the outer spacer 32 receives the thrust force acting from the turbine in the direction of the compressor (direction of arrow A) via the turbine shaft ball bearing 23 and the turbine-side damper sleeve 27, and from the compressor to direction of the turbine (direction of arrow B). The thrust force acting on the compressor side ball bearing 24 and the compressor side damper sleeve 28 are received.

The elastic force of the coil spring 29 is applied to the outer rings 23a, 24a of the two ball bearings 23, 24 via the damper sleeves 27, 28, and the balls 23b, 24b as rolling elements settle on the curved surfaces of the inner ring raceways 23c, 24c. The precision of the bearings 23, 24 is maintained.

On the other hand, describing the lubricating oil system, the lubricating oil supplied from the oil supply port 36 is supplied to the oil film forming portions 25 and 26 in the gap between the damper sleeves 27 and 28 and the bearing housing 21,
The ball bearings 23, 24 are supplied to the rolling parts of the ball bearings 23, 24 through the annular chambers 30, 31 and the small holes 30a, 31a to lubricate and cool the ball bearings 23, 24.

Then, according to such a configuration, the outer rings 23a, 2 of the ball bearings 23, 24 are
While press-fitting and fixing to the damper sleeves 27, 28 of 4a,
The ball bearings 23, 24 are engaged with each other at the contact portions between the opposite ends of the outer spacer 32 rotatably supported by the bearing housing 21 and the respective inner ends of the pair of damper sleeves 27, 28. Rotation of the outer rings 23a, 24a of the damper sleeves 27, 2
Since the convex portion 34 and the concave portion 35 that are restrained via the 8 are provided, the outer rings of the damper sleeves 27 and 28 and the ball bearings 23 and 24 are provided.
Both 23a and 24a do not rotate even if the rotation of the turbine shaft 22 increases during acceleration operation. As a result, the weight of the outer spacer 32 is not added to the rotating body in the supercharger, and the rotating body weight in the supercharger does not increase. Also, the rotation of the outer spacer 32 does not scratch the surrounding oil,
Since there is no increase in bearing loss due to an increase in oil stirring resistance, good acceleration performance can be maintained.

Further, in the conventional device, since the oil film damper was formed on the outer circumference of the ball bearing, it was impossible to obtain the width of the oil film damper larger than the width of the outer ring of the ball bearing, but in the present embodiment, Since a pair of damper sleeves 27, 28 that are supported in a floating state in the bearing housing 22 and respectively support the ball bearings 23, 24 are provided, by changing the axial width of the damper sleeves 27, 28, The width of the oil film damper can be changed and the optimum width of the oil film damper can be selected.
Further, by using the pair of damper sleeves 27 and 28, the respective oil film dampers can move relative to each other (have different movements), and a more excellent damping effect can be obtained.

Further, in the conventional device, the inner diameter of the coil spring locking portion of the damper sleeve becomes smaller than the inner diameter of the outer ring of the ball bearing, and the outer diameter of the coil spring also becomes smaller, so that the vicinity of the ball bearing rolling portion inside the damper sleeve. Lubricant oil is likely to accumulate in the inner part of the damper sleeve, and the stirring resistance is increased, resulting in an increase in bearing loss.
Since the 7, 28 are arranged outside the outer rings 23a, 24a, the stepped portions 27b, 28b which are the locking portions of the coil spring 29.
The inner diameter of the ball bearings 23, 24 can be made substantially the same as or smaller than the inner diameters of the outer rings 23a, 24a, and the outer diameter of the coil spring 29 can be increased.
Lubricating oil is less likely to be accumulated in the vicinity of the rolling portion, stirring resistance can be reduced, and an increase in bearing loss can be prevented.

Particularly, according to the above configuration, the protrusion 34 on the outer spacer 32 side and the recess 35 on the damper sleeve 27, 28 side are engaged with each other to prevent rotation of the outer rings 23a, 24a of the ball bearings 23, 24. Therefore, the rotation restricting portion C, which is the engaging portion between the convex portion 34 and the concave portion 35, is in a surface contact or a line contact state, and local wear and stress concentration do not occur.

The advantage of the unique formation positions of the convex portion 34 and the concave portion 35 will be described with reference to FIG.

That is, it is desirable that the damper sleeves 27, 28 have a large axial width L and a large outer peripheral area in order to obtain a sufficient oil film damper effect.

On the other hand, in order to efficiently discharge the lubricating oil after bearing lubrication from the space around the turbine shaft 22, it is desirable to take a large opening area M of the oil discharge port 32b.

As described above, by cutting a predetermined angle range smaller than the angle range of the part to be cut to form the convex portion 34 on the outer spacer 32 side on the peripheral portion of each inner end portion of each of the damper sleeves 27, 28. By forming the concave portion 35, the circumferential length A of the convex portion formed after the concave portion 35 is formed on the damper sleeve 27, 28 side is equal to the circumferential length B of the convex portion 34 on the outer spacer 32 side.
Can be longer than.

That is, the damper sleeves 27, 28 can secure a large outer peripheral area by the shape of only the concave portion 35 in the small angle range, and the outer spacer 32 can secure at least the convex portion 34 in the small angle range, and thus the oil drain port. It is possible to sufficiently secure the opening forming portion of 32b, and thereby it is possible to improve the efficiency of the oil film damper at the same time.

<Effects of the Invention> As described above, according to the present invention, a pair of cylinders that are respectively supported in a floating state in the bearing housing via the oil film layer in the oil film forming portion and that respectively support the outer rings of the ball bearings. -Shaped damper sleeve is disposed, and a substantially cylindrical outer spacer that allows the damper sleeve to selectively abut between a pair of damper sleeves in the bearing housing is non-rotatably supported on the bearing housing. A drain oil port communicating with the space around the turbine shaft is provided on a part of the peripheral wall of the outer spacer, while both end portions of the outer spacer and the inner end portions of the pair of damper sleeves are mated with each other. Since the engaging portion for engaging with each other to prevent rotation of the outer ring of the ball bearing via the damper sleeve is provided at the contact portion of the turbine shaft rotation of the turbine shaft during acceleration operation. The outer ring of the ball bearing does not rotate even when the oil pressure rises, the weight of the rotating body in the supercharger can be prevented from increasing, and the bearing loss does not increase due to the increase in oil stirring resistance. To be kept.

In particular, the damper sleeve is formed by cutting a predetermined angle range smaller than the angle range of the part to be cut to form the protrusion forming the engaging portion on the outer spacer side at the peripheral portion of each inner end of each damper sleeve. By forming the recessed portion that constitutes the engagement portion on the sleeve side, the damper sleeve can secure a large outer peripheral area, and the outer spacer can secure a large opening forming portion of the oil drain port. This is a great practical effect that can improve both the film damper efficiency and the oil drainage efficiency.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a bearing device for a supercharger according to the present invention, FIG. 2 is a perspective view showing a structure of a damper sleeve and an outer spacer in the same embodiment, and FIG. .. is a sectional view, FIG. 4 is a view for explaining the effect of the above-mentioned embodiment, (A) is a front view, and (B) is a sectional view taken along the line AA in (A). 21 ... Bearing housing, 22 ... Turbine shaft, 23 ... Turbine side ball bearing, 24 ... Compressor side ball bearing, 23a, 24a ... Outer ring, 2
7 ... Turbine side damper sleeve, 28 ... Compressor side damper sleeve, 32 ... Outer spacer, 32b ... Oil drain port, 3
3 ... pin, 34 ... convex, 35 ... concave

Claims (1)

[Scope of utility model registration request] 1. A bearing housing, a turbine shaft that penetrates the bearing housing, and a pair of ball bearings that are mounted on the turbine shaft so as to be spaced apart from each other and supported in the bearing housing. In a bearing device of a feeder, a pair of cylindrical damper sleeves, which are respectively supported in a floating state via an oil film layer in an oil film forming portion and respectively support an outer ring of the ball bearing, are provided in the bearing housing. ,
A substantially cylindrical outer spacer capable of selectively abutting the damper sleeve is provided between the pair of damper sleeves in the bearing housing so as to be non-rotatably supported on the bearing housing, and one outer wall of the outer spacer is provided. The portion is provided with an oil discharge port that communicates with the space around the turbine shaft, while engaging with the abutting portions between the opposite ends of the outer spacer and the inner ends of the pair of damper sleeves. By providing an engaging portion for inhibiting the rotation of the outer ring of the ball bearing via the damper sleeve, and the outer spacer side engaging portion is formed by cutting the peripheral portions of both end portions of the outer spacer by a predetermined angle. , Each of the damper sleeve side engaging portions has a peripheral portion of each inner end portion of each of the damper sleeves at a predetermined angle smaller than the predetermined angle. By partial resection, is formed recessed the both ends, the bearing apparatus of supercharger, characterized by being configured by the recess which is engaged with the convex portion.