JPH08210370A - Bearing fitting structure - Google Patents

Abstract

PURPOSE: To provide a bearing fitting structure capable of preventing the wear of a bearing fitting surface of a housing in an inexpensive manner with a simple structure, and facilitating the assembly work. CONSTITUTION: A sleeve 9 consisting of a pressed steel plate with a hardened surface is interposed between an outer diameter part of an outer ring 6 of a bearing and a housing 1. The sleeve 9 is fitted to both the outer ring 6 of the bearing and the housing 1, and the press-fitting to the housing 1 is stronger than that to the outer ring 6 of the bearing. The surface hardness of the pressed steel plate to constitute the sleeve 9 is as large as that of the outer ring 6 of the bearing, e.g. about HRC58.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing mounting structure for fitting a bearing outer ring to an aluminum housing or the like of an automobile transmission.

[0002]

2. Description of the Related Art Conventionally, when the housing of an automobile transmission is made of aluminum, the outer diameter surface of the bearing outer ring 31 and the bearing fitting surface of the housing 32 are loose as shown in FIG. It is used by being fitted by fitting. This is because of an assembly problem, and the housing 32 cannot be mounted with a strong interference fit.

Normally, when the transmission is in use, the temperature of the oil rises, and the fit between the outer diameter of the outer ring and the housing 32 becomes even looser. When vibration or gear shifting operation occurs in such a state, the bearing outer ring 31 may rotate in the opposite direction to the rotation of the shaft 33, or may rotate in the same direction. Due to relative sliding with the housing 32 at this time,
The wear of the aluminum housing 32, which is a soft material, may adversely affect the bearing 30.

As conventional techniques for stopping this rotation, for example, the following three configurations have been considered or put into practical use. a. The housing 3 is formed by setting pins on the outer diameter surface of the outer ring 31.
Prevent rotation of 2. b. A resin having a large linear expansion coefficient is interposed between the outer diameter surface of the outer ring 31 and the housing 32, and the outer ring 3 is heated by the thermal expansion of the resin.
Fix 2 to prevent rotation. c. The outer diameter of the outer ring 31 or the bearing fitting surface of the housing 32 is subjected to surface treatment with high lubricity so as to prevent abrasion even when rotated.

However, the configurations a to c have the following problems. That is, in the configuration of the above a, the housing needs a notch groove for pin engagement, and the notch and the pin must be positioned when the bearing is incorporated in the housing. Moreover, this positioning cannot be performed because the bearing outer ring is in a free state. In the case of the configuration of the above b, the operating temperature of the transmission is usually in a wide range of about −40 ° C. to 150 ° C., and expansion of the resin causes rotation due to loosening at high temperature,
Conversely, it abrades the resin. The structure of c is excellent in function, but it is expensive due to the surface treatment with high lubricity.

An object of the present invention is to provide a bearing mounting structure in which abrasion of the bearing fitting surface of the housing can be prevented at a low cost with a simple structure and the assembling work can be simple.

[0007]

According to the bearing mounting structure of the present invention, a sleeve made of a pressed steel plate whose surface is hardened is interposed between the outer diameter surface of the outer ring of the rolling bearing and the housing. The bearing is fitted to both the outer ring and the housing. The above fitting makes the press-fitting fitting to the housing stronger than the fitting to the bearing outer ring. The surface hardness of the pressed steel plate should be equal to or higher than the surface hardness of the bearing outer ring.

The surface hardness of the sleeve is H _R C58-65
It is preferable that it is above. The surface of the sleeve may be induction hardened or may be soft nitrided. The surface roughness of the sleeve fitting part of the housing is 3 to
It may be 25 μm or more.

[0009]

According to this structure, the sleeve made of a pressed steel plate is press-fitted into the housing, and the bearing outer ring is fitted to this. However, since the press-fitted fitting to the housing side is strong, the bearing outer ring is When the shaft is rotated by the rotation of the shaft, it slides between the sleeve made of a pressed steel plate and the bearing outer ring, and no slip occurs between the housing and the sleeve. The sleeve is a surface-hardened pressed steel plate, and has a surface hardness equal to or higher than that of the bearing outer ring, so that no wear occurs. Therefore, the fitting between the pressed steel plate sleeve press-fitted into the housing and the outer diameter surface of the bearing outer ring does not change over time due to wear. In addition, since the press-hardened steel plate having the surface hardened to strengthen the fitting, the tightening margin with the housing is not lost even at a high temperature. Further, the pressed steel plate is easy to cost. If the sleeve is preliminarily press-fitted into the housing for preparation, it is only necessary to loosely press-fit the bearing into the housing when assembling the bearing-using device. Since the press-fitting is loose, the assembly work is the same as the conventional loose fitting.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG. The housing 1 is an aluminum housing for a transmission such as an automobile transmission, and a shaft 3 is provided via a bearing 2.
I support. The bearing 2 is a deep groove ball bearing, and a rolling element 8 held by a cage 7 is interposed between an inner ring 5 and an outer ring 6. The shaft 3 serves as a main shaft, and the gear 4 is integrally formed. The shaft 3 is formed with a small diameter portion 3a into which the bearing inner ring 5 is fitted, and a step surface 3b following the small diameter portion 3a is engaged with the width surface of the bearing inner ring 5. The housing 1 is formed with a bearing fitting surface 10 which is an inner diameter surface of a round hole.
A step surface 11 continuing from 0 is formed as an engaging surface for engaging the width surface of the outer ring 6.

Between the outer diameter surface of the bearing outer ring 6 and the inner diameter surface of the bearing fitting surface 10 of the housing 1, a sleeve 9 made of a pressed steel plate, the surface of which is hardened by quenching or the like, is interposed so that the bearing outer ring 6 and It is fitted to both the housing 1. That is, both are tightly fitted or only the bearing outer ring 6 and the sleeve 9 are loosely fitted. This fitting makes the press-fitting fitting to the housing 1 stronger than the fitting to the bearing outer ring 6. That is, the tightening margin for the housing 1 is made larger than the tightening margin for the bearing outer ring 6. The sleeve 9 has a peripheral wall portion 9a.
Has a flange 9b at one end of
b is engaged with the step surface 10 a of the housing 1. The sleeve 9 is press-fitted into the housing 1 in advance before assembling the transmission, and only the bearing 2 is press-fitted or pushed in when the transmission is assembled. The pressed steel plate of the sleeve 9 is made of a material used for, for example, a shell type needle bearing, and has a surface hardness equal to or higher than the hardness of the bearing outer ring 6. Bearing outer ring 6, the surface hardness is from bearing steel heat treated to a predetermined hardness (e.g. about H _R C58~65), thus also the press steel plates constituting the sleeve 9, the surface hardness of about H _R C58~65 More than about

In this case, the surface hardness of the bearing outer ring 6 may be equal to the surface hardness of the inner surface of the sleeve 9. Further, for example, about the surface hardness of the bearing outer ring 6 H _R C58~6
And about 3 equivalent or more surface hardness of the sleeve 9, or a value exceeding this, also, the surface hardness of the inner surface of the sleeve 9 to about H _R about C60～65, the surface hardness of the bearing outer ring 6 The surface hardness of the inner surface of the sleeve 9 may be made higher than the surface hardness of the bearing outer ring 6 as a value equal to or less than or equal to or less than this value. In addition, about H _R C62,
The surface hardness of the bearing outer ring 6 is less than H _R C62 or less, and the surface hardness of the sleeve 9 is more than H _R C62 or more,
Alternatively, it may be set to a value exceeding this value.
It may be applied within the above range such as _{R C} 58 to 65. When the hardness of the sleeve 9 is set as described above, even if the inner surface of the sleeve 9 and the outer ring 6 of the bearing are loosely fitted to each other to cause slight sliding, the surface hardness of the other side is relatively equal. In addition, it is expected that either one of the members will not wear out. Further, by setting the hardness such as the surface hardness of the sleeve 9 in an appropriate range, it is possible to obtain a sufficient rigidity that can withstand a load applied to the bearing 2. If the hardness of the sleeve 9 or the bearing outer ring is too low, wear resistance and rigidity as a shaft support member cannot be expected, and if the hardness is too high, impact resistance and the like cannot be expected. Further, if the surface hardness of the sleeve 9 is too high, when the sleeve 9 is fitted into the housing 1, a stop fit,
Particularly, in the case of press-fitting such as interference fit, the sleeve 9 is fitted while being slightly contracted. Therefore, unless the sleeve 9 has appropriate hardness and elasticity, the press-fitting into the housing 1 is difficult. The efficiency of assembly work cannot be expected. If a chamfered portion of, for example, about C0.5 to 1 is provided at the end of the bearing fitting surface 10 of the housing 1, the sleeve 9 is provided.
Can be fitted relatively efficiently, but if the corner surface R at the base of the flange of the sleeve 9 is sufficiently large, the chamfered portion is omitted, and the chamfering work and the time are reduced without lowering the assembly work efficiency of the transmission. It is considered that the machining efficiency of the housing 1 can be increased and the cost of the entire transmission can be reduced.

The material of the sleeve 9 is a metal strip 1 such as strip steel.
There are, for example, cold-rolled steel strip, special cold-rolled steel strip, and cold-rolled steel sheets and steel strips such as SPCC, SPCD, SPCE.
Etc. These tempers can be selected from standard temper, 1/8 hard, 1/4 hard, 1/2 hard, hard, etc. as they are annealed, and the surface finish of these can be dull finish or bright finish. Etc. can be selected. The dull finish is a matte finish with a roll whose surface is mechanically or chemically roughened, and the bright finish is a smooth finish with a roll with a smooth surface. When forming the surface 6b, the shot amount may be reduced in a surface treatment step such as shot blasting, or the surface treatment step may be omitted in some cases. When shot blasting is performed, fine recesses of about 0.3 mm to 0.4 mm or less can be formed on the surface, so a wedge effect can be expected and the adhesion with the housing 1 can be enhanced. Alternatively, the same effect can be expected by roughening the surface by chemical treatment. Their bendability is relatively good. Also, as hot rolled mild steel plate and strip steel, SPHC, SPHD, SP
HE, etc., and the bendability is relatively good. In addition, SPB as rolled steel for rolling bearings and cold rolled steel sheet
There are 1, SPB2, SPB3, etc.
There are B1T and the like. These have an elongation of at least 28% or more and are good. These plate materials have good bendability and have a bending test of 180 ° and a tensile strength of 270 N /
Since it has a size of mm ² or more, it is suitable for bending and deep drawing.

In the bending test, the bending angle is 180 degrees, and the bending workability is excellent. The elongation varies depending on the material and plate thickness, but at least 32% for SPCC and 37% for plate thickness of 1 mm or more,
SPCD at least 34% or more, plate thickness 1mm or more 39
% Or more, SPCE at least 36% or more, plate thickness 1 mm
The above results are 41% or more, SPHC is at least 27% or more, SPHD is at least 30% or more, and SPHE is at least 31% or more. In particular, SPCE has good elongation and excellent bending drawability. These steel sheets include
To prevent rust, a surface protective layer may be formed by plating such as nickel plating such as Kanigen plating (registered trademark), chrome plating, hard chrome plating, zinc plating, tin plating and the like. Further, the surface may be further buffed. In addition, black dye, Parker Rising (registered trademark)
Etc. may be given. This surface treatment may be performed on both sides or one side of the steel sheet. Further, a protective layer may be provided only on the inner peripheral surface of the sleeve 9, the protective layer may be omitted on the surface of the outer peripheral surface due to the wedge effect, and after the protective layers are provided on both surfaces, the outer peripheral surface may be covered. You may perform the said surface treatment for roughening a surface.

In addition, as rolled stainless steel plates and strips, SUS403, SUS410, SUS410S, S
US410J1, SUS416, SUS420F, SU
S420J1, SUS420J2, SUS429J1,
SUS431, SUS440A, SUS440B, SU
Examples include martensite-based materials such as S440C, and in addition to martensite-based materials, there are austenite-based, austenite-ferrite-based, ferrite-based, precipitation hardening-based, and the like. These steel sheets have a yield strength of at least 155 N / mm ²
The tensile strength is at least 360 N / mm ² and the elongation is at least 15%. In particular, among martensitic stainless steel plates and steel strips, SUS420
The carbon content of J type is about 0.16 to 0.4%, SUS4
In the 40 type, about 0.7 to 1.1% of carbon is contained, and it is suitable because it has quench-hardenability, and is also excellent in corrosion resistance such as rust.

Further, SUS301L, SUS301JI
Has an elongation of 45% or more and is particularly excellent in bending workability. With such a steel plate having excellent bending workability, at least one end portion of the sleeve 9 is formed at a substantially right angle so that the sleeve 9 also receives the thrust direction of the bearing 2 like the sleeve 9 in FIG. Even with a flanged shape that bends, it has excellent deep drawing workability such as bending at a substantially right angle, and cracks in the bent portion are less likely to occur. Further, if the bent portion is set to about R0.5 to R1 or more so that the bent portion does not interfere with the end surface R of the bearing 2, a large stress is not generated in the plate material, and the end portion of the housing 1 also interferes. Without this, the sleeve 9 can be easily fitted when it is assembled to the housing 1. These are 1 / 4H, 1 / 2H, 3 / 4H, H
You may heat-treat like. Further, as the surface finish, heat treatment, pickling or acid treatment, light cold rolling at the final stage with a matte roll, or shot blasting may be performed. Since the stainless steel sheet has excellent corrosion resistance, even if the surface protection layer such as plating is omitted, rust unlike the steel sheet does not occur. It is also relatively corrosion resistant when exposed to transmission oil. The material of the sleeve 9 is not limited to those exemplified above.

In addition to these, brass plates 1 to 3 (BSP1 to BSP3) and phosphor bronze plate (PB) are used for special environments.
P), PBP2, etc., and can be selected depending on the environment in which the transmission oil or the like is used. These metal strips are
Thickness is about 0.3 mm to about 4 mm, about 0.3 mm to about 1.0 mm
In between, plate materials of each thickness can be selected in 0.1 mm increments,
Every 0.2mm from 1.0mm to 2.0mm,
In addition, 2.3mm, 2.5mm, 2.8mm, 3.
There is no particular limitation on the plate thickness, but it is about 2 mm.
Bending, if the plate thickness is less than or equal to mm, especially about 0.8 to 2 mm, preferably about 1 to 1.5 mm.
Easy to draw. If the plate is too thin, bearing 2
Can not be expected to support rigidity, and if it is too thick, bending and deep drawing are difficult to perform. Further, the material is not limited to the above materials.

When bending a metal strip material such as a steel strip into a substantially cylindrical shape and performing deep drawing, it may be at room temperature, but it may be heated depending on the sheet thickness and material to make it easier to bend. It is also possible to prevent cracks such as cracks from occurring in the sleeve 9 having a small end surface R bent at a substantially right angle, which corresponds to the root portion of the flange of the sleeve 9. This heating temperature is about 1
The temperature may be from 00 ° C to about 500 ° C, and rapid heating may be performed in high frequency for about 1 to 3 minutes. With high-frequency heating, heating work is quick and efficient. Also, depending on the curvature, thickness, and material of the sleeve 9, approximately 100 ° C to 200 ° C to 300 ° C to 400 ° C.
The temperature may be gradually raised and cooled in several steps of up to about 500 ° C., or the optimum temperature range may be selected from these temperature ranges depending on the material. Induction hardening gives a hardness that is about 5 in terms of H _R C hardness as compared with heating and hardening in a furnace.

The material has a carbon content of about 0.1 to 1.5% or more, preferably about 0.3% or more, so that the hardness can be increased by quenching, soft nitriding or the like.
More preferably, the steel contains about 0.5% or more. If the amount of carbon is less than the above, sufficient quenching hardness cannot be obtained. If the carbon content is too large, impact resistance and the like cannot be expected, and the carbon content may be, for example, about 0.5 to 0.8%. A soft nitriding method may be adopted as a surface treatment method having a relatively small internal strain. Examples of the soft nitriding method include soft nitriding with a gas or a liquid, and the temperature may be raised or cooled under the temperature conditions as described above.
Internal distortion is less likely to remain, resulting in excellent dimensional accuracy. Depending on the material, specifications, conditions, etc., this may be done by soft nitriding after carburizing and quenching, or by induction hardening after soft nitriding.
It is also possible to adopt a method in which a composite surface treatment is performed and the strain is relatively small and the surface hardness becomes harder. The above heat treatments are performed after bending and drawing.

According to this structure, the sleeve 9 made of a pressed steel plate is press-fitted into the housing 1 and the bearing outer ring 6 is fitted thereto, but the press-fitted fitting to the housing 1 side is strong. When the bearing outer ring 6 is rotated by the rotation of the shaft 3, the sleeve 9 made of pressed steel plate and the bearing outer ring 6
Therefore, no slippage occurs between the housing 1 and the sleeve 9. Therefore, the soft housing 1 made of aluminum is not worn. Also, the sleeve 9
Is a surface-hardened pressed steel plate, which has a surface hardness equal to or higher than that of the bearing outer ring 6, so that no wear occurs. Therefore, the fitting between the pressed steel plate sleeve press-fitted into the housing and the outer diameter surface of the bearing outer ring does not change over time due to wear. Moreover, since the press-hardened steel plate having the surface hardened to strengthen the fitting, the tightening margin with the housing is not lost even at a high temperature. In this way, since the wear is eliminated, the bearing 2
Does not change, the misalignment with respect to the bearing 2 does not increase, an abnormal eccentric load does not occur inside the bearing, and the bearing 2 is not adversely affected. Further, there is no increase in the gap due to wear of the housing 1, and abnormal noise or vibration does not occur. Moreover, since a pressed steel plate is used, it is inexpensive, wear can be prevented, and the cost advantage is great. Also,
Since the assembly work of the transmission, which is a bearing-using device, is loosely press-fitted, the same assembly work as the conventional loose fitting can be performed.

In order to fix the inner diameter surface of the housing 1 and the outer diameter surface of the sleeve 9 relatively strongly, at least the inner diameter surface of the portion of the housing 1 to which the sleeve 9 is attached, or the outer diameter surface of the sleeve 9. The surface roughness is Rmax, Ra
, Rz, etc., may be about 3 μm or more, preferably 8 μm or more, and more preferably 25 μm or more. Particularly, the housing 1 of the transmission can reduce the amount of finishing processing in the processing process, improve the processing efficiency, and lead to the overall cost reduction. It is considered to be effective for a bearing assembly mechanism in which

In the above embodiment, the bearing 2 is a deep groove ball bearing, but the present invention can be applied to a case where the bearing 2 is another type of ball bearing or a roller bearing.

[0023]

According to the bearing mounting structure of the present invention, a sleeve made of a pressed steel plate having a hardened surface is interposed between the outer diameter surface of the outer ring of the rolling bearing and the housing. And fit both,
The press-fitting fitting to the housing is made stronger than the fitting to the bearing outer ring, and the surface hardness of the pressed steel plate is equal to or more than the surface hardness of the bearing outer ring, so that the housing and the like at the bearing press-fitting portion do not wear, No change over time due to wear. Since the wear is eliminated in this way, the position of the bearing center does not change, misalignment with the bearing does not increase, an abnormal offset load does not occur inside the bearing, and the bearing is not adversely affected. Also, there is no increase in the gap due to wear of the housing,
No abnormal noise or vibration is generated. Moreover, since a pressed steel plate is used, it is inexpensive, wear can be prevented, and the cost advantage is great. Also, since the assembly work of the bearing-using device is a loose press-fitting, a simple assembly work similar to loose fitting can be performed.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional example.

[Explanation of symbols]

1 ... Housing, 2 ... Bearing, 3 ... Shaft, 6 ... Bearing outer ring, 9
… Sleeve, 9b… Flange, 10… Bearing mating surface

Claims (5)

[Claims] 1. A sleeve made of a pressed steel plate having a hardened surface is interposed between the outer diameter surface of the outer ring of the rolling bearing and the housing, and the sleeve is fitted to both the outer ring of the bearing and the housing. A bearing mounting structure in which the fitting to the housing is stronger than the fitting to the bearing outer ring, and the surface hardness of the pressed steel plate is equal to or more than the surface hardness of the bearing outer ring. 2. The surface hardness of the sleeve is H _R C58-6.
The bearing mounting structure according to claim 1, wherein the number is 5 or more. 3. The bearing mounting structure according to claim 1, wherein the surface of the sleeve is induction hardened. 4. The bearing mounting structure according to claim 1, wherein the surface of the sleeve is soft-nitrided. 5. The bearing mounting structure according to claim 1, wherein the surface roughness of the fitting portion of the sleeve of the housing is 3 to 25 μm or more.