JPH10225045A - Bearing press-in preventive structure of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix a bearing with a loose fit, and to increase the durability of the bearing by arranging a core to a housing for a motor, without compressing and distorting the disposing section of the bearing disposed as the bearing. SOLUTION: In a bearing press-in preventive structure of a motor, a core 20 is disposed on the outside diameter side of a cylinder section 12 for passing a shaft formed to a housing, and a bearing is arranged on the inside diameter side of the cylinder section 12 and used as the bearing. The core 20 has a hole for insertion into the cylinder section 12 at a center in this case, a plurality of grooves are formed on the hole, a plurality of projections 14 are formed on sections except a section, to which the bearing is arranged. On the outside diameter side of the cylinder section 12, the projections 14 shaped on the outside diameter side of the cylinder section 12 are brought into press-contact with the grooves formed on the hole of the core 20, and the core 20 is fixed on the outside diameter side of the cylinder section 12 of the housing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing bearing press-fitting of a motor, and more particularly to a structure for preventing bearing press-fitting of a motor in which a core having a hole is disposed on an outer diameter side of a cylindrical portion of a housing.

[0002]

2. Description of the Related Art A laser cruise system, which is a drive control device for an automobile, is a system in which an automatic deceleration function is added to a conventional constant speed cruise function, and emits pulse laser light and then receives reflected light of a preceding vehicle. This is a system that measures the distance to the vehicle in front by measuring the time until the automatic deceleration function works according to the distance. In the laser radar sensor section of this system, a polygon mirror for diffusing laser light is rotated by a driving motor. This polygon mirror driving motor is required to have high precision, high-speed rotation, high rotation stability, and a long life of the bearing portion.

[0003] As a configuration of the driving motor as described above,
An outer rotor type brushless motor is used in which a core having a hole formed in the center is press-fitted into a cylindrical portion formed in a housing, and an inverted bowl-shaped rotor is disposed outside the core so as to surround the core. .

[0004]

A pair of bearings are housed in the housing of the motor as bearings, and a shaft integrally formed with the rotor is rotatably supported by these bearings. At this time, the inner diameter of the cylindrical portion of the housing and the outer ring of the bearing must be fixed with a clearance fit in order to maintain rotational stability.

However, in assembling the motor as described above, first, the core is press-fitted into the cylindrical portion of the housing, and then the inner diameter of the housing is compressed and distorted, so that the bearing may be press-fitted to the outer ring. For this reason, there has been a problem that the radial gap inside the bearing decreases and becomes a minus gap, which causes a reduction in the life of the bearing.

Further, a spring is disposed in the cylindrical portion of the housing, and the spring is configured to eliminate the backlash in the thrust direction and stabilize the rotor. There is a problem that the effect is lost, which causes uneven rotation and causes deterioration of rotation stability.

[0007] A circuit board is provided below the core, and energization of the winding wound on the core is performed by a detection signal of a position detecting element comprising a Hall element provided on the circuit board. It is controlled through the control circuit of the board. Therefore, the relationship between the position of the core and the position detecting element on the circuit board is important, and it is necessary to perform positioning when disposing the core.

In order to improve the bearing life and rotational stability of the bearing, the core hole is formed larger than the outer diameter of the cylindrical portion of the housing, and the core is disposed on the outer diameter side of the cylindrical portion of the housing. There is a technique of fixing the core with an adhesive when installing. However, this technique has disadvantages that the man-hour and cost are increased, and a gap for the adhesive is required, so that the core misalignment is increased. Further, the fixing technique using an adhesive has a problem in that the reliability is improved.

Alternatively, as shown in FIG.
At 244, the engagement groove 1 is inserted into the cylindrical portion 1a of the housing 1.
b, and the concave groove 1 is formed on the inner peripheral surface of the fitting hole of one insulator 3 covered with the stator core 2.
b is provided with a retaining ridge 3a which is elastically deformed and engages, and the stator core 2 is pushed into the cylindrical portion 1a of the housing 1 so that the retaining ridge 3a formed on the insulator 3 is formed.
a is fitted while being elastically deformed, and the engagement groove 1 of the cylindrical portion 1a is
A technique for elastically restoring and locking at a position b is disclosed. A pair of ridges 1c is provided on the inner peripheral side of the cylindrical portion 1a, and a pair of small grooves 3b and a small groove 2a are provided in the insulator 3 and the stator core 2, respectively.
The stator core 2 is positioned by the engagement of the ridge 1c, the small groove 3b of the insulator 3, and the small groove 2a of the stator core 2 in the area a.

However, the above-mentioned technique is a technique of disposing the stator core 2 in the cylindrical portion 1a of the housing 1 and positioning the stator core 2, and compressing the bearing arrangement portion of the housing by fitting the core, which is an object of the present invention. There is no disclosure or suggestion of disposing the core without distortion.

An object of the present invention is to provide a motor housing,
By arranging the core without compressing and distorting the bearing arrangement part that is arranged as a bearing, the bearing is press-fitted to fix the bearing with a clearance fit and improve the durability of the bearing. It is to provide a prevention structure.

Another object of the present invention is to provide a structure for preventing bearing press-fitting of a motor which can always maintain stable rotation.

It is still another object of the present invention to provide a motor bearing press-in preventing structure capable of positioning a core.

[0014]

According to a first aspect of the present invention, there is provided a motor bearing press-in preventing structure, wherein a core is disposed on an outer diameter side of a cylindrical portion through which a shaft formed in a housing passes.
In a motor provided with a bearing on the inner diameter side of a cylindrical portion, the core has a hole at the center for fitting into the cylindrical portion, and a plurality of grooves are formed in the hole, A plurality of protrusions are formed on the outer diameter side of the cylindrical portion other than where the bearing is arranged, and the protrusions formed on the outer diameter side of the cylindrical portion are pressed against grooves formed in the holes of the core. The core is fixed on the outer diameter side of the cylindrical portion of the housing.

The core is fitted into the cylindrical portion by a plurality of grooves formed in the hole of the core and a plurality of protrusions formed on the outer diameter side of the cylindrical portion other than where the bearing is arranged. Suitably, the core is positioned in the housing when inserted.

According to a third aspect of the present invention, in the motor bearing press-in preventing structure, a core is provided on an outer diameter side of a cylindrical portion through which a shaft formed in a housing passes, and a bearing is provided on an inner diameter side of the cylindrical portion. In the motor provided as a bearing, the core has a hole at the center for fitting into the cylindrical portion, and a knurl is formed at a portion other than the outer diameter side of the cylindrical portion where the bearing is arranged. The knurl formed on the outer diameter side of the cylindrical portion presses against the hole of the core, and the core is fixed on the outer diameter side of the housing cylindrical portion.

Preferably, a plurality of grooves are formed in the hole of the core, and a plurality of projections are formed in a portion of the outer diameter side of the cylindrical portion other than where the bearing is arranged.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the motor bearing press-in prevention structure of the present invention, a cylindrical portion 12 for passing a shaft 40 through a housing 10 is formed, and a core 20 is arranged on the outer diameter side of the cylindrical portion 12. Has been established. A bearing 30 is provided on the inner diameter side of the cylindrical portion 12 as a bearing. The core 20 has a hole 24 in the center for fitting into the cylindrical portion 12.
have. A plurality of grooves 26 are formed in the hole 24. On the other hand, on the outer diameter side of the cylindrical portion 12, a plurality of projections 14 are formed in a portion other than where the bearing 30 is arranged in the housing 10.

In the above-described configuration, the projection 14 formed on the outer diameter side of the cylindrical portion 12 is pressed against the groove 26 formed in the hole 24 of the core 20, and the core 20 is brought into contact with the cylindrical portion 12 of the housing 10. Fixed on the outer diameter side.

As described above, according to the present invention, the core 20
In the cylindrical portion 12 of the housing 10, the bearing 30 in the housing 10 is fitted without compressing and distorting the arrangement position of the bearing 30, and is pressed and fixed at a predetermined position of the housing 10. It can be fixed by a clearance fit, and the life of the bearing can be improved. Further, since the bearing 30 is fixed by the clearance fit, the spring 70 provided in the housing 10 pushes back the vibration in the thrust direction, whereby the rotational stability of the motor M can be secured. Furthermore, the projection 14 and the core 2
A groove 26 is formed in the groove 20 and the core 20 can be easily positioned by assembling the protrusion 14 and the groove 26 together.

[0021]

An embodiment of the present invention will be described below with reference to the drawings. The members, arrangements, and the like described below do not limit the present invention, and can be variously modified within the scope of the present invention.

FIGS. 1 to 4 show a first embodiment according to the present invention. FIG. 1 is a partial plan view for explaining a press-fit state portion of a motor having a bearing press-fit prevention structure of this embodiment, and FIGS. FIG. 2A is an explanatory view showing the assembling of the motor having the bearing press-in prevention structure of the present embodiment. FIG. 2A is a cross-sectional view showing the temporary assembling of the bearing and the rotor, and FIG. 2B is a front view of the core. FIG. 2C is an explanatory cross-sectional view showing the housing of the present embodiment, and is a cross-sectional view taken along line AA in the housing of FIG.
FIG. 3 is a plan view of the core, and FIG. 4 is an explanatory sectional view of the motor.

In this embodiment, the motor M has a housing 10
, A core 20, a bearing 30, a shaft 40,
It includes a rotor 50, a circuit board 60, a spring 70, and a polygon mirror 80.

The housing 10 of this embodiment is made of a metal such as aluminum, and has a disc-shaped base 11 and a base 1.
A tubular portion 12 is formed at the center of the first portion. And the cylindrical part 12
A circuit board 60 is disposed on the base 11 of the housing 10 at an outer peripheral position of the housing 10, and a predetermined circuit (not shown) is printed and printed on the circuit board 60. The board 11 is provided with a mounting portion 11a having a hole, and the circuit board 60 is mounted via screws or the like.

FIG. 2C is an explanatory view showing a cross section of the housing 10. As shown in FIG. 2C, the inside of the housing 10 has a hollow portion. A spring 70 is provided in this hollow portion.

Also, as shown in FIG.
A protrusion 14 is formed on the outer diameter side of the 0 cylindrical portion 12 at a position where a core 20 described later is disposed. This projection 1
Reference numeral 4 denotes a plurality of portions at equal intervals in the circumferential direction on the outer diameter side of the cylindrical portion 12 of the housing 10 (in this example, 3 at every 120 ° in the circumferential direction).
Location) is formed.

As shown in FIG. 2B, the core 20 of the present embodiment includes a laminated body 22 in which a plurality of steel plates 21 are laminated, and a winding 23 wound in a space inside the laminated body 22. Each of the steel plates 21 constituting the laminated body 22 has a hole 24 in the center as shown in FIG. 3, and the hole 24 is provided with the bearing 30 in the cylindrical portion 12 of the housing 10. It is formed slightly larger than the outer diameter of the position.

Further, as shown in FIG. 3, each steel plate 21 has a concave portion 25 which can be engaged with the projection 14 formed on the cylindrical portion 12 of the housing 10. The grooves 26 are formed in the core 20 by stacking the concave portions 25 of the steel plates 21 in alignment. The groove 26 is formed so as to engage with the protrusion 14 and be pressed against when the core 20 is disposed on the outer diameter side of the cylindrical portion 12 of the housing 10.

As shown in FIG. 2A, the rotor 50 of this embodiment comprises a rotor main body 51 having an inverted arm shape and a shaft 40 erected from the center thereof.
The rotor main body 51 and the shaft 40 are integrally fixed, and the shaft 40 has a bearing 3 as a bearing.
It is pivoted through 0. Further, the magnets 52 constituting the rotor 50 are arranged at a slight interval at the end of the rotor main body 51.

On the rotating board 60, together with various electronic parts,
A position detecting element for detecting the position of the magnet 52 of the rotor 50 is provided, and energization of the winding 23 of the core 20 is controlled by a control circuit of the control circuit board 60 based on a detection signal of the position detecting element. The rotor 50 is configured to rotate integrally with the shaft 40 by such control.

Next, the assembly of the motor M having the bearing press-in prevention structure will be described. As shown in FIG. 4, a circuit board 60 is placed on the housing 10. As shown in FIG. 2, the housing 10 is assembled as shown in the order of the arrows in the figure, and the core 20 is first fitted into the outer diameter side of the cylindrical portion 12 of the housing 10.

At this time, as described above, the hole 24 of the core 20 is formed slightly larger than the outer diameter of the cylindrical portion 12 at the bearing arrangement position, and the groove 26 of the core 20 is formed with the protrusion 14 formed in the cylindrical portion 12. The core 20 is fitted into the cylindrical portion 12 of the housing 10 while the projection 14 of the cylindrical portion 12 and the groove 26 of the core 20 are aligned with each other. The core 20 is press-fitted at the position 14.

Next, the bearing 30 and the rotor 50 are temporarily assembled, and the bearing 30 is fixed to the housing cylindrical portion 12 by being fitted in a gap. Reference numeral 80 in FIG. 4 denotes a polygon mirror, which is disposed on the rotor 50 and has a configuration such that it rotates as a rotating body integrated with the rotor 50.

As described above, the projection 14 is formed on the outer diameter side of the cylindrical portion 12 of the housing 10, and the groove 26 is formed in the core 20 so as to engage and press the projection 14.
When disposing the core 20 in the housing 10, the core 20 is inserted without being pressed into a portion of the cylindrical portion 12 of the housing 10 where the bearing 30 is disposed, and the core 20 on which the protrusion 14 is formed is disposed. It is press-fitted and fixed at the position.

Therefore, according to the bearing press-in prevention structure for a motor of the present invention, the housing 10 is compressed and distorted by fitting the core 20, and the bearing 30 is not deformed.
The core 20 can be fixed at a predetermined position of the housing 10 while preventing the outer ring from being press-fitted.

Further, when the core 20 is inserted, the projection 20 of the cylindrical portion 12 of the housing 10 and the groove 26 of the core 20 are assembled while being aligned, so that the core 20 can be easily disposed at a predetermined position. it can.

As described above, the spring 70 is provided inside the housing 10 and has a function of immediately pushing back minute vibrations in the thrust direction. It has a structure that can be held. In this example, since the housing 10 and the bearing 30 are fixed by a clearance fit, the spring 7
The effect by 0 can be obtained.

FIGS. 5 and 6 show another embodiment of the present invention. FIG. 5 is a partial plan view for explaining a press-fit state portion of a motor having a bearing press-fit prevention structure of this embodiment.
FIG. 6 is an explanatory sectional view showing the housing of the present example, and is a sectional view taken along the line BB in the housing of FIG. 5. In this embodiment, the same members and the like as those in the above embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the above embodiment, the cylindrical portion 12 of the housing 10
A protrusion 14 is formed on the cylindrical portion 12 of the housing 10.
Although the example in which the upper protrusion 14 is pressed against is shown, in this example, the knurl 15 is formed in the housing 10. With such a configuration, the hole 24 of the core 20 is formed.
Since the knurl 15 is pressed into contact with the entire inner diameter portion, a large press-in allowance can be taken, so that the strength against the thrust-direction pull-out force increases, and the core 20 can be more firmly fixed to the housing 10.

FIG. 7 is an explanatory view showing still another embodiment. This embodiment is a combination of the above two embodiments. In the present embodiment, a projection 14 is formed on the cylindrical portion 12 of the housing 10 and a knurl 15 is formed. A groove 26 is formed on the core 20 side. In this example, when the core 20 is disposed on the cylindrical portion 12 of the housing 10, the cylindrical portion 12 of the housing 10 and the core 20 can be firmly pressed by the projections 14 and the knurls 15, and the core is formed by the projections 14 and the grooves 26. Positioning of 20 is also possible.

[0041]

As described above, according to the present invention, a projection is formed on a cylindrical portion of a housing, a groove is formed on a core provided on the housing, and the core is pressed and fixed at the projection on the cylindrical portion of the housing. With this configuration, the core can be arranged without compressing and distorting the bearing arrangement portion of the housing by fitting the core, and press-fitting of the outer ring of the bearing can be prevented, and the life of the bearing can be improved.

Further, since the bearing is fixed to the cylindrical portion of the housing by a clearance fit, the spring disposed in the housing can obtain the effect of pushing back the vibration in the thrust direction, thereby improving the rotational stability of the motor. Can be done. Further, the positioning between the housing and the core can be easily performed.

[Brief description of the drawings]

FIG. 1 is a partial plan view of a motor according to the present invention.

FIG. 2 (a) is an explanatory view showing assembly of a motor according to the present invention, and is a cross-sectional view showing temporary assembly of a bearing and a rotor. (B) is explanatory drawing which shows the assembly of the motor which concerns on this invention, and is a front view of a core. (C) is an explanatory view showing the assembly of the motor according to the present invention, is an explanatory sectional view showing the housing, and is an AA sectional view of the housing in FIG. 1.

FIG. 3 is a plan view of a core according to the present invention.

FIG. 4 is an explanatory sectional view of a motor according to the present invention.

FIG. 5 is an explanatory view showing another embodiment of the present invention.

FIG. 6 is an explanatory view showing another embodiment of the present invention.

FIG. 7 is an explanatory view showing another embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Housing 11 Base 12 Tube part 13 Bearing part 14 Projection 15 Knurl 20 Core 21 Steel plate 22 Laminated body 23 Winding 24 Hole 25 Depression 26 Slot 30 Bearing 40 Shaft 50 Rotor 51 Rotor body 52 Magnet 60 Circuit board 70 Spring 80 Polygon Mirror M motor

Claims (4)

[Claims] 1. A motor in which a core is disposed on an outer diameter side of a cylindrical portion through which a shaft formed in a housing is passed, and a bearing is disposed on an inner diameter side of the cylindrical portion to provide a bearing. At the center, there is a hole for insertion into the cylindrical portion, a plurality of grooves are formed in the hole, and a plurality of projections are formed on the outer diameter side of the cylindrical portion other than where the bearing is arranged. The protrusion formed on the outer diameter side of the cylindrical portion is pressed against the groove formed in the hole of the core, and the core is fixed on the outer diameter side of the cylindrical portion of the housing. Motor bearing press-fit prevention structure. 2. The core is fitted into the cylindrical portion by a plurality of grooves formed in the hole of the core and a plurality of protrusions formed on a portion other than the bearing on the outer diameter side of the cylindrical portion. The bearing press-in prevention structure for a motor according to claim 1, wherein the core is positioned in the housing when the core is inserted. 3. A motor in which a core is disposed on an outer diameter side of a cylindrical portion through which a shaft formed in a housing is passed, and a bearing is disposed on an inner diameter side of the cylindrical portion. At the center, there is a hole for insertion into the cylindrical portion, and a knurl is formed in a portion other than the outer diameter side of the cylindrical portion where the bearing is arranged, and an outer diameter of the cylindrical portion is formed in a hole of the core. A knurl formed on the side of the housing is pressed against the core, and the core is fixed on the outer diameter side of the housing cylindrical portion. 4. A plurality of grooves are formed in the hole of the core,
4. The motor bearing press-in prevention structure according to claim 3, wherein a plurality of protrusions are formed on a portion of the outer diameter side of the cylindrical portion other than where the bearing is arranged.