JP5262139B2 - Electric motor and ventilator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a very silent electric motor by preventing generation of abnormal noise from a bearing due to a foreign matter entering the bearing. <P>SOLUTION: A stop ring 17 to be press fitted in a ring groove which is provided in a rotating shaft 4 in the radial direction in order to specify the axial position of bearings 14 and 16 for supporting the rotating shaft 4 of a rotor 7 with respect to the rotating shaft 4, is made of a metal not containing a thin layer of a different metal on the surface. The metal material has a strength equal to or larger than the strength at the groove portion of the rotating shaft 4. The bearings 14 and 16 are ball bearings having an inside diameter of &phiv;3-&phiv;10 mm. Furthermore, the stop ring 17 is made of stainless steel. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an electric motor in which the position of a bearing that receives a rotating shaft is defined by a retaining ring, and a ventilation device using the electric motor.

  The electric motor that rotates the impeller of the ventilation device is particularly required to be quiet when it is ventilated for 24 hours. The quietness of electric motors has progressed considerably due to the reduction of magnetic noise and the improvement of accuracy of rotating parts. In addition to these measures, noise may be generated in the bearings in the motors that define the position of the bearing that receives the rotating shaft of the motor with a retaining ring. In addition, there exists what was disclosed by patent document 1 as a prior art of the motor which prescribed | regulated the position of the bearing which receives a rotating shaft with the retaining ring.

JP-A-9-19088

  The generation of abnormal noise in a motor bearing in which the position of the bearing that receives the rotating shaft is defined by a retaining ring has been regarded as an inexplicable phenomenon. The original sound level of the bearing is very small, and it is easy to confirm the occurrence of abnormal noise from the bearing when it is incorporated in the electric motor. It was found that abnormal noise was caused by small foreign matter entering the bearing. This small foreign matter is from a retaining ring that is press-fitted into a groove provided on the rotating shaft. It is a shape. In a small electric motor having an inner diameter of a bearing of φ8 mm or less, a chip-like foreign matter causes abnormal noise. Further, depending on the material, problems such as the progress of rust due to corrosion of the retaining ring or the intrusion of rust powder into the bearing have also surfaced.

  The present invention has been made in order to solve the above-described conventional problems, and is to obtain an electric motor having high quietness by avoiding occurrence of bearing noise due to foreign matter intrusion into the bearing. It is to obtain a highly quiet ventilation device.

In order to achieve the above object, the present invention provides, on the surface, a retaining ring that press-fits a bearing that supports a rotating shaft of a rotor into a groove provided in a radial direction of the rotating shaft in order to define an axial position with respect to the rotating shaft. A metal material that does not include a thin layer of a dissimilar metal is used , and the metal material has a strength exceeding the groove portion of the rotating shaft.
Another invention employs means for configuring a ventilation device using the electric motor having the above-described configuration as a drive source for rotating the impeller.

  According to the present invention, the strength of the retaining ring press-fitted into the groove provided on the rotating shaft is higher than that of the groove part. There is no intrusion and the generation of bearing noise can be avoided. That is, an electric motor with high silence is obtained, and by applying it to a ventilation device as an electric motor that rotates an impeller, a ventilation device with high silence is obtained as a ventilation device that performs 24-hour ventilation.

  In the electric motor of the present invention, the axial position with respect to the rotating shaft is defined by the retaining ring of the bearing that supports the rotating shaft of the rotor. The retaining ring is attached to the rotating shaft in the usual manner regardless of the shaft processing such as bonding or stepped portion. That is, it is press fitted into a ring groove provided in the radial direction of the rotating shaft. The bearing is a ball bearing, and the inner ring side portion hits this retaining ring, and the axial position is defined. The retaining ring is a metal that does not have a thin layer of dissimilar metal on the surface, such as plating, and is a versatile E-shaped ring. The metal material of the retaining ring has strength (total strength such as peel strength, bending strength, tensile strength, etc.) at least equal to or exceeding the groove portion of the rotating shaft. Specifically, the rotating shaft is steel and the retaining ring is stainless steel.

  According to the present invention, since the strength of the retaining ring press-fitted into the ring groove provided on the rotating shaft is higher than the groove part, the contact part is peeled off or scraped by mechanical sliding, scraping, etc. when press-fitting into the ring groove. No swarf-like fine foreign matter is produced. Therefore, there is no foreign matter intrusion into the bearing, and the occurrence of abnormal bearing noise can be easily avoided without increasing the cost. That is, both the electric motor and the ventilator configured as a drive machine have high silence.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view of a ventilator according to the present embodiment, FIG. 2 is a cross-sectional view showing an electric motor that moves an impeller of the ventilator, FIG. 3 is a plan view showing a rotor, and FIG. FIG. 5 is an enlarged front view of a main part showing a ring groove provided on the rotating shaft, FIG. 5 is an enlarged front view showing a retaining ring, and FIG. 6 is a perspective view showing a cover.

  In the ventilation device 1 according to the present embodiment, a propeller impeller 5 is mounted on a rotating shaft 4 of an electric motor 3 mounted on a center line of a wind tunnel 2, and the impeller 5 rotates in the wind tunnel 2 so that a ventilation flow is generated. Is formed. As shown in FIG. 2, the electric motor 3 is an inner rotary type in which a rotor 7 rotates inside a stator 6, and an outer shell is constituted by a frame 8 and a bracket 9 which are flange-joined. A housing 10 is formed so as to penetrate inward in the axial direction of the bracket 9, and a terminal block 11 having a size substantially equal to the diameter of the bracket 9 is attached to the end surface of the bracket 9 (see FIG. 2). The terminal block 11 is formed of a synthetic resin in a circular shallow container shape, and a phase advance capacitor 12 is accommodated in the center thereof. The terminal block 11 is covered with a cover 13 as shown in FIG. The rotor 7 is supported at both ends by a bearing 14 fixed to a housing 10 provided on the bracket 9 and a bearing 16 fixed to a housing 15 provided on the frame 8, and the rotor 7 extends from the frame 8. The impeller 5 is attached to the end of the rotating shaft 4.

  The two bearings 14 and 16 for both-supporting the rotating shaft 4 of the rotor 7 have an inner diameter of about φ3 to φ10 mm, for example, φ5 mm in consideration of being used for ventilation for 24 hours in a bedroom or a living room. As shown in FIG. 3, the axial position with respect to the rotating shaft 4 is defined by the retaining ring 17 as shown in FIG. 3. The retaining ring 17 is attached to the rotating shaft 4 in a manner that is normally performed, regardless of the shaft processing such as bonding or stepped portions. That is, as shown in FIG. 4, it is press-fitted and attached to the ring groove 18 provided in the radial direction of the rotating shaft 4. The bearings 14 and 16 are ball bearings, and the side ends of the inner ring portions of the bearings 14 and 16 are in contact with the retaining rings 17, the positions in the axial direction are defined, and the outer ring portions are fitted to the inner walls of the housings 10 and 15.

  The retaining ring 17 is a metal that does not have a thin layer of dissimilar metal on the surface, such as plating, and is configured as a highly versatile E-shaped ring as shown in FIG. 5 to reduce the price. Of course, the form of the retaining ring 17 may be a C-shaped ring or a K-shaped ring. The metal material of the retaining ring 17 has an overall strength such as a strength at least equal to or exceeding the groove portion 19 of the rotating shaft 4, specifically, a peel strength, a bending strength, a tensile strength, and the like. Specifically, when the rotating shaft 4 is mostly steel, the retaining ring 17 is made of stainless steel. If the retaining ring 17 is made of metal that does not include a thin layer of a different kind of metal on the surface, such as plating, the same effect can be obtained even if a surface treatment such as chemical conversion coating or passivation is performed.

  The bearings 14 and 16 include steel plate shielded ball bearings, ones on the counter ring 17 side and the retaining ring 17 side, or one sealed with contact type rubber, and one sealed with non-contact type rubber. By adopting a combination of both, or a combination of these and a steel plate shield type, depending on the material, the progress of rust due to corrosion of the retaining ring 17 or the penetration of rust powder into the bearings 14 and 16 The problem of foreign matter intrusion from the outside can also be solved.

  According to the electric motor 3 of the present embodiment, the strength of the retaining ring 17 that is press-fitted into the ring groove 18 provided on the rotating shaft 4 is higher than that of the groove portion 19, so that mechanical slipping and scraping are caused when the ring ring 18 is pressed. The contact portion (such as the locking portion 20 having a bulge on the inner surface of the E-ring shape) is not peeled off or scraped off, and fine chips like foreign matter are not generated. Accordingly, there is no foreign matter intrusion into the bearings 14 and 16, and the occurrence of abnormal bearing noise can be avoided easily without increasing the cost. That is, both the electric motor 3 and the ventilator 1 configured as a drive machine have high performance with high silence.

It is sectional drawing of a ventilation apparatus. (Embodiment 1) It is sectional drawing which shows the electric motor which moves the impeller of a ventilation apparatus. (Embodiment 1) It is a top view which shows a rotor. (Embodiment 1) It is an expanded sectional view of the principal part which shows the ring groove provided in the rotating shaft of a rotor. (Embodiment 1) It is an enlarged front view which shows a retaining ring. (Embodiment 1) It is a perspective view which shows a cover. (Embodiment 1)

  DESCRIPTION OF SYMBOLS 1 Ventilator, 3 Electric motor, 4 Rotating shaft, 5 Impeller, 7 Rotor, 14,16 Bearing, 17 Retaining ring, 18 Ring groove.

Claims (7)

A metal material that does not include a thin layer of dissimilar metal on the surface of a retaining ring that press-fits a bearing that supports the rotating shaft of the rotor into a groove provided in a radial direction of the rotating shaft in order to define an axial position with respect to the rotating shaft. The metal material is an electric motor having strength exceeding the groove portion of the rotating shaft. The electric motor according to claim 1, wherein the rotating shaft is made of steel and the retaining ring is made of stainless steel. 3. The electric motor according to claim 2 , wherein the retaining ring is an E-shaped ring. The electric motor according to any one of claims 1 to 3 , wherein the bearing is a steel plate shield type. The electric motor according to any one of claims 1 to 3 , wherein the bearing is sealed at least on the side of the retaining ring with a contact-type rubber. The electric motor according to any one of claims 1 to 3 , wherein the bearing is sealed at least on the side of the retaining ring with a non-contact type rubber. The ventilation apparatus provided with the impeller rotated by the electric motor in any one of Claims 1-6 .

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