JP2501577Y2 - Supercharger bearing structure - Google Patents

Description

[Detailed Description of the Invention] [Industrial application] The present invention relates to a bearing structure of a supercharger, which prevents mistaken mounting directions of two angular ball bearings that support a turbine shaft, and the turbine side and the compressor. This is designed to prevent mistakes in assembling when the specifications of the angular contact ball bearing are changed on the side, and is particularly suitable as a bearing structure for a supercharger for automobiles.

[Prior Art] There are various types of bearing structures for superchargers.
For example, in a small supercharger for automobiles, as shown in FIG. 3, the supercharger 1 itself is composed of three vehicle compartments 2, 3, 4 and a turbine vehicle compartment 2 of a turbine shaft 5 is provided. An overhang structure in which a turbine impeller 6 is arranged at one end inside thereof, a compressor impeller 7 is arranged at the other end inside the compressor casing 4 of the turbine shaft 5, and a bearing portion 8 is provided at the bearing casing 3 in the central portion. I am trying.

Then, as the bearing portion 8 of the bearing casing 3, the two angular ball bearings 9 and 10 are arranged so as to face each other, and the inner rings 9a and 10a are fitted to the turbine shaft 5, while the outer rings 9b and 10b are respectively fitted. It has a structure that fits into a cylindrical sleeve (oil film damper) 11 inserted into the bearing casing 3, and a preload is applied to the angular ball bearing 10 on the compressor side by a spring 12 provided inside the sleeve 11, It is configured for positioning.

The sleeve 11 is supported in a floating state in the bearing casing 3 through an oil film, supports the two angular ball bearings 9 and 10, and functions as an oil film damper for damping axial vibration and external vibration. ing.

By adopting the bearing structure using the angular ball bearings 9 and 10 as described above, the friction loss is reduced as compared with the case where the sliding bearing in which the journal bearing and the thrust bearing are combined is used for the bearing portion 8 of the supercharger 1. It can be made extremely small, and the efficiency of the supercharger 1 can be improved.

[Problems to be solved by the invention] As described above, the angular contact ball bearing is used as the bearing structure of the supercharger.
When 9, 10 are adopted, it is necessary to support the thrust load acting in both directions of the turbine shaft 5 together with the radial load, so that the two angular ball bearings 9, 10 are arranged in a certain direction, for example, the turbine impeller 6 on the turbine shaft 5. When a thrust load is applied to the compressor impeller 7, the angular ball bearing 10 to the compressor impeller 7 side is applied. On the contrary, when a thrust load is applied to the compressor impeller 7 side, the angular ball bearing 9 is applied to the turbine impeller 6 side. They must be placed face-to-face to support the load.

However, in the structure of conventional angular contact ball bearings 9 and 10,
Since it can be installed in either direction, it may be installed by mistake, and there is a problem that the thrust load in both directions of the turbine shaft 5 cannot be supported.

Further, in the case of the supercharger 1 for automobiles, the inlet gas temperature to the turbine impeller 6 may exceed 900 ° C. If the engine is stopped in such a state, the supply of lubricating oil is stopped and the turbine impeller is stopped. Since there is a heat soak back phenomenon in which the residual heat of No. 6 flows into the angular ball bearing 9 and causes a rapid temperature rise, the water-cooled bearing casing 3 is adopted, but at least for the angular ball bearing 9 on the turbine side. Need to adopt high-grade special material.

However, the temperature condition of the angular contact ball bearing 10 on the compressor side is relaxed, so it is not necessary to have high-grade specifications as on the turbine side. When the low-grade angular contact ball bearing 9 is incorporated in the side, there is a problem that the life of the supercharger 1 is significantly shortened.

Therefore, conventionally, a high-grade specification angular contact ball bearing 10 is also used on the compressor side, and there is a problem that the quality is excessive and the cost is increased.

The present invention has been made in view of the above problems of the prior art. When the specifications of the two angular ball bearings are changed, the ones having the predetermined specifications can be assembled in the predetermined positions and the thrust load is received. It is an object of the present invention to provide a bearing structure for a supercharger, which can prevent a mistake in assembling in the mounting direction of.

Further, it is an object of the present invention to provide a bearing structure for a supercharger in which, when the specifications of two angular contact ball bearings are changed, those having predetermined specifications can be installed in predetermined positions.

[Means for Solving the Problems] In order to solve the above problems, a bearing structure of a supercharger of the present invention is a bearing structure of a supercharger in which two angular ball bearings are arranged in a middle portion of a turbine shaft at regular intervals. In the above, at least a part of the opposing end portions of the inner rings of the two angular ball bearings is formed with a protrusion capable of specifying the mounting direction of the angular ball bearing, while the specifications of the two angular ball bearings are specified on the turbine side and the compressor side. In addition, the axial width of the outer ring of the ball bearing on the turbine side is made smaller than that of the ball bearing on the compressor side.

Further, the bearing structure of the supercharger of the present invention is a bearing structure of a supercharger in which two angular ball bearings are arranged at a constant interval in an intermediate portion of a turbine shaft. The specifications of the two angular ball bearings are turbine side. And the compressor side, and the axial width of the outer ring of the turbine side ball bearing is made smaller than that of the compressor side ball bearing.

[Operation] According to the bearing structure of the supercharger as described above, the protruding portions are formed on at least a part of the facing end portions of the inner rings of the two angular ball bearings arranged so as to face each other at a constant interval, and When changing the specifications of the angular contact ball bearings on the turbine side and the compressor side, the axial width of the outer ring of the turbine side is made smaller than that of the compressor side, so that the assembly direction in the thrust receiving direction may be incorrect. In addition to the prevention by the protruding part of the inner ring, if at least low-grade specification (compressor side) angular contact ball bearings are installed in both, this will be known because the bearing spacing will be large, and it is possible to prevent incorrect specification combinations. I have to.

Further, when the specifications of the two angular ball bearings arranged to face each other at a constant interval are changed between the turbine side and the compressor side, the axial width of the outer ring of the turbine side is made shorter than that of the compressor side. If at least low specification (compressor side) angular contact ball bearings are installed in both, the bearing spacing will increase, so be aware of this and make a mistake in assembly that affects the life of the turbocharger. I try to prevent it.

[Embodiment] An embodiment of the present invention will be described below in detail with reference to the drawings.

1 and 2 are sectional views of an embodiment of the bearing structure of the supercharger according to the present invention. The same parts as those of the bearing structure of the supercharger described in FIG. 3 are designated by the same reference numerals. is there.

In this bearing structure 20 of the supercharger, the structure of two angular ball bearings 21 and 22 provided in the middle portion of the turbine shaft 5 for supporting a radial load and a thrust load in both directions is changed, and each angular ball bearing is changed. Inner ring 21 of bearing 21,22
The protruding portions 23 are formed on at least a part (for example, a part or the entire circumference, which is a part in the illustrated example) of the inner side ends of the a and 22a facing each other, that is, the opposite ends.

As shown in FIG. 1, these two angular ball bearings 21 and 22 are mounted on the bearing portion 24 of the bearing casing 3 at the center of the supercharger 1.

In this bearing portion 24, a cylindrical sleeve (oil film damper) 11 is inserted into the bearing casing 3 and is rotated by a detent pin 13 which is loosely inserted between the bearing casing 3 and the sleeve 11. It is supposed not to.

An oil groove is formed on the outer circumference of the sleeve 11, oil holes 14 are formed so as to penetrate the inner and outer circumferences, and step portions 15 and 16 serving as bearing stoppers are formed on both ends of the inner circumference. .

Of these step portions 15 and 16, the step portion 15 on the turbine 6 side
Are formed in correspondence with the axial width of the outer ring 21b of the angular ball bearing 21 and the axial width of the turbine side spring bearing 17, and the step portion 16 on the compressor 7 side is formed by the angular ball bearing.
It is formed so as to correspond to the axial width of the outer ring 21b of 21, and these step portions 15 and 16 enable the inner space between the two angular ball bearings 21 and 22 to be arranged at a constant interval. .

On the other hand, the turbine shaft 5 supported by such a bearing portion 24
Has a step portion 18 having a one-step smaller diameter on the turbine impeller 6 side of the bearing portion 24 and a step portion 19 having a further one-step smaller diameter on the compressor impeller 7 side. An outer space between the two angular ball bearings 21, 22 can be fixedly arranged.

On the turbine side of such bearing 24, the turbine shaft 5
The flat inner ring 21a of the turbine-side angular contact ball bearing 21 abuts on the stepped portion 18 on the turbine 6 side of the turbine 6 and the protrusion 23 of the inner ring 21a is mounted inside, and the outer ring 21b of the turbine-side angular contact ball bearing 21 is attached. Is mounted so as to contact the turbine side spring receiver 17 applied to the step portion 15 of the sleeve 11. Further, on the compressor side of the bearing portion 24, the outer ring 22b of the compressor side angular contact ball bearing 22 is connected to the sleeve 11
The inner ring 22a is mounted so that the projection 23 of the inner ring 22a is located inside.

Then, the oil scraper 25 is mounted so as to abut on the compressor-side stepped portion 19 of the turbine shaft 5, and the flat inner ring 22a of the compressor-side angular contact ball bearing 22 is inserted through the compressor 7 as shown in FIG. It can be pressed by the shaft end nut 26.

In addition, the outer ring 22 of the compressor side angular contact ball bearing 22
The compressor side spring holder 27 is installed inside b and the spring 12
Is inserted to urge the outer rings 21b and 22b of both angular ball bearings 21 and 22 away from each other to apply a preload.

Further, in the bearing structure 20 of this supercharger, the sleeve 11 is made to function as an oil film damper, and in order to lubricate the two angular ball bearings 21 and 22, a lubrication port 28 is formed in the upper portion of the bearing casing 3. An oil drainage port 29 is formed in the lower part, and the oil hole of the sleeve 11 is formed in the turbine side spring receiver 17.
An oil hole 30 communicating with 14 is formed so as to face the turbine side angular contact ball bearing 21. Further, a central oil drain hole 31 communicating with the oil drain port 29 is formed in the lower center of the sleeve 11.

In the bearing structure 20 of such a supercharger, since the distance between the outer sides of the inner rings 21a, 22a of the two angular ball bearings 21, 22 is constant, at least one of the inner rings 21a, 22a is reversed. When it is mounted in the facing direction and the protruding portion 23 projects outward, a gap is formed in at least one of the two step portions 18 and 19 of the turbine shaft 5, and the shaft end nut 26
Will be difficult to tighten.

Therefore, the inner ring 21 of the two angular contact ball bearings 21,22
By mounting the protrusions 23 of the a and 22a inward, it is possible to prevent the mounting direction from being mistaken and to support the thrust load acting in both directions of the turbine shaft 5.

However, in such a bearing structure 20, the two angular ball bearings 21 and 22 need to have the same specifications, and the angular contact ball bearing 22 on the compressor side must also have the high-grade specifications.

Therefore, in the bearing structure 20 of the supercharger of the present invention, as shown in FIG. 2, the two angular ball bearings 41, 42 that support the radial load and the thrust load of the turbine shaft 5 can be used depending on the operating conditions. It has been changed, and the turbine side angular contact ball bearing 41, which is in a high temperature state due to the heat soak back phenomenon, has a high-grade specification, and the compressor side angular contact ball bearing 42, which has a relatively mild temperature condition, has a low-grade specification.

If the specifications of the two angular ball bearings 41, 42 are changed in this way, if a low-grade angular contact ball bearing is installed on the turbine side, if the temperature becomes high due to the heat soak back phenomenon, the bearing life will be significantly shortened. turn into.

Therefore, at least the outer ring 41 of the inner ring 41a and the outer ring 41b of the high-grade angular contact ball bearing 41 used on the turbine side is used.
The axial width L1 of b is smaller than the axial width L2 of the outer ring 42b of the low specification angular ball bearing 42 used on the compressor side (L1 <L2).

The lengths of the step portions 15 and 16 of the sleeve 11 are changed corresponding to the axial widths L1 and L2 of the outer rings 41b and 42b of the two angular ball bearings 41 and 42.

The other structure is the same as that of the bearing structure 20 of the supercharger of FIG. 1 which has already been described. Therefore, the same parts are designated by the same reference numerals and the description thereof will be omitted.

In the bearing structure 20 of the supercharger configured as described above, the high-angle specification angular contact ball bearing 41 having a small axial width L1 of the outer ring 41b is mounted on the turbine side, and the compressor side is the low-grade specification of the angular width of the outer ring 42b. An angular ball bearing 42 having a large L2 is mounted.

These angular contact ball bearings 41 and 42 having different specifications face each other with an angular angle determined so as to support the thrust load acting in both directions of the turbine shaft 5 as described in FIG. It goes without saying that it will be installed like this.

In such a supercharger bearing structure 40, when the low-grade angular contact ball bearing 42 is installed on the turbine side, the axial width L2 of the outer ring 42b of the low-grade angular contact ball bearing 42 is increased, so that the step portion 15 of the sleeve 11 is increased. When the inner side of the outer ring 42b is in contact with the compressor, the other end of the sleeve 11 is connected to the compressor 7 of the bearing casing 3.
Since it will protrude to the side by the amount corresponding to the axial width difference (L2-L1), you can easily know the mistake in installing the low-grade angular contact ball bearing 42 on the turbine side, and be sure to use the high-grade angular contact ball. The bearing 41 can be incorporated.

On the other hand, on the compressor side, a low-grade angular ball bearing 42 having a large axial width L2 of the outer ring 42b may be mounted, but a high-grade angular ball bearing 41 having a small axial width L1 of the outer ring 41b may be mounted. It is also possible to assemble it, and even if the high-grade angular contact ball bearing 41 is installed by mistake, there is no problem in terms of bearing life.

Therefore, the axial width L1 of at least the outer rings 41b, 42b of the two angular contact ball bearings 41, 42 having different specifications in this way is
By changing L2, it is possible to prevent the lower specification angular contact ball bearing 42 from being installed on the turbine side that requires the higher specification.

Further, as shown in FIG. 2, since the protruding portions 43 are formed at the inner side end portions of the inner rings 41a, 42a of the respective angular ball bearings 41, 42 facing each other, that is, at the opposite end portions,
Angular contact ball bearings with the protrusion 43 inside
By mounting the 41 and 42, it is possible to prevent the specifications of the angular ball bearings 41 and 42 with different specifications from being mistakenly incorporated and also to support the thrust load.
It is also possible to prevent incorrect installation of the 1,42 mounting direction.

In the above embodiments, the supercharger for automobiles has been described as an example, but the present invention is not limited to this, and can be widely applied as a bearing structure of a supercharger using an angular ball bearing.

[Effect of the Invention] As described above in detail with the embodiments, according to the bearing structure of the supercharger of the present invention, the opposite ends of the inner rings of the two angular ball bearings arranged so as to face each other at regular intervals. When forming the protrusion on at least a part of the part and changing the specifications of each angular ball bearing according to the operating conditions, make the axial width of the outer ring of the turbine side smaller than that of the compressor side. As a result, misalignment in the direction of receiving thrust can be prevented by the protruding part of the inner ring, and at least when low-grade specification (compressor side) angular contact ball bearings are installed in both, the bearing spacing is By increasing the size, it is possible to know this and prevent incorrect specifications.

Further, according to the bearing structure of the supercharger of the present invention, when the specifications of the two angular ball bearings arranged to face each other at a constant interval are changed between the turbine side and the compressor side, the outer ring of the turbine side Since the axial width of is set to be shorter than that of the compressor side, if at least low specification (compressor side) angular contact ball bearings are installed in both, the bearing spacing will be large. Therefore, it is possible to prevent an assembly error that affects the life of the supercharger.

[Brief description of drawings]

1 and 2 are sectional views showing an embodiment of the bearing structure of the supercharger of the present invention, and FIG. 3 is a sectional view of the bearing structure of the conventional supercharger. 1: Supercharger, 2: Turbine casing, 3: Bearing casing, 4: Compressor casing, 5: Turbine shaft, 6: Turbine impeller, 7: Compressor impeller, 11: Sleeve (oil film damper), 12: Spring, 13: Non-rotating pin, 14: Oil hole, 15,
15: Stepped part of sleeve, 17: Turbine side spring receiver,
18, 19: Step portion of turbine shaft, 20: Bearing structure of turbocharger, 21,
22: Angular contact ball bearings, 21a, 22a: Inner ring, 21b, 22b: Outer ring, 2
3: Projection part, 24: Bearing part, 25: Oil remover, 26: Shaft end nut, 27:
Compressor side spring receiver, 28: oil supply port, 29: oil discharge port, 30: oil hole, 31: central oil discharge hole, 41, 42: angular contact ball bearings, 41a, 42a: inner ring, 41b, 2b: outer ring, 43: Projection, L1, L2:
Axial width of outer ring.

Claims (2)

(57) [Scope of utility model registration request] 1. A bearing structure of a supercharger in which two angular ball bearings are arranged at regular intervals in an intermediate portion of a turbine shaft,
At least a part of the opposite ends of the inner races of the two angular ball bearings is formed with a protrusion capable of specifying the mounting direction of the angular ball bearing, and the specifications of the two angular ball bearings are changed between the turbine side and the compressor side. ,
A bearing structure for a supercharger, characterized in that the axial width of the outer ring of the ball bearing on the turbine side is smaller than that of the ball bearing on the compressor side. 2. A bearing structure of a supercharger in which two angular ball bearings are arranged at regular intervals in an intermediate portion of a turbine shaft,
The specifications of the two angular contact ball bearings are changed between the turbine side and the compressor side, and the axial width of the outer ring of the turbine side ball bearing is made smaller than that of the compressor side ball bearing. Bearing structure.