JPH01244195A - Fan motor and vacuum cleaner therewith - Google Patents

Abstract

PURPOSE:To keep off a large noise and vibration in a bearing part at the time of high speed rotation by supporting a rotor shaft with a thrust air bearing and a radial air bearing free of rotation. CONSTITUTION:Plural line of spiral grooves 13 are formed on the circumference of one end of a rotor shaft 8, while lubricating air between a first bearing part 3 and the rotor shaft 8 is fed, with pressure, toward an inner bottom surface 3a of the first bearing part 3, thereby constituting an air bearing which generates thrust force. A pair of spiral grooves 14a, 14b consisting of plural lines of grooves are formed on the circumference of the other end of the rotor shaft 8 being fitted in the inner part of a second bearing part 4, and lubricating air between the second bearing part 4 and the rotor shaft 8 is fed, with pressure, to an intermediate part between these spiral grooves 14a and 14b, thereby constituting a radial air bearing.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fan motor suitable for high-speed rotation and a vacuum cleaner equipped with the fan motor.

BACKGROUND OF THE INVENTION Conventional vacuum cleaners have used a fan motor in which the end of a rotor shaft with a fan fixed to one end is rotatably supported by a ball bearing.

Based on FIG. 2, a specific example of the configuration of the fan motor 2o will be described. 21 is a stator, 22 is a rotor, 23 is a brush, and 24 is a commutator. fixed to the rotor shaft 25 of the brackets
A 77 pin 26 is fixed to one end of the . The rotor shaft 2
5 is rotatably supported by a first ball bearing 27 between the fan 26 and D-422, and by a ball bearing 28 of m2 at the other end. 26a is an intake port of the fan 2G, and 29 is a differential user.

To explain the operation, the rotor 22 is rotated at high speed by applying current to the rotor 22 from the brush 23 through the commutator 24, and the fan 26 fixed to one end of the rotor shaft 25 is rotated to draw air from the intake port 26a. inhale,
The air is exhausted through a differential user 29.

Problem to be Solved by the Invention Incidentally, in current vacuum cleaners, the 7T ton 26 is normally rotated at 20,000 to 30,000 r, p, m, but in order to reduce the size, it is rotated at 50,000 to 60,000 r. , pom, the contact portion between the brush 23 and the commutator 24, and the ball bearing 27 that supports the rotor shaft 25.
．． There has been a problem in that the noise and vibration generated in the 28 are increased, their lifespan is shortened, and the torque loss is also increased, resulting in poor efficiency.

On the other hand, the above-mentioned problem caused by contact between the brush 23 and commutator 24 can be solved by adopting a brushless smoke, but it also causes noise and vibration caused by ball bearings, shortens bearing life, and worsens torque loss. This then emerged as a major problem that needed to be resolved.

In view of the above-mentioned problems, an object of the present invention is to provide a fan motor that can achieve low noise, high efficiency, and high efficiency even at high speed rotation, and can be made compact, and a vacuum cleaner using the fan motor.

Means for Solving the Problems In order to achieve the above object, the present invention has a rotor shaft to which a fan is fixed, which is connected to a thrust air bearing that generates a thrust force that counters the thrust force generated by the rotation of the fan, and a radial air bearing. To provide a fan motor that is rotatably supported.

Preferably, one end of the rotor shaft is fitted into a bottomed cylindrical first bearing part, and one of the mutually opposing cylindrical surfaces is provided with a spiral groove for pumping air toward the inner bottom surface by rotation of the rotor shaft. The formed first air bearing is fitted into the cylindrical second air bearing at the other end of the rotor shaft, and the rotation of the rotor shaft causes one of the mutually opposing cylindrical surfaces to move toward the intermediate portion thereof. The rotor shaft is rotatably supported by a second air bearing formed with one or more pairs of spiral grooves for pumping air.

The present invention also provides a vacuum cleaner equipped with such a fan motor.

Function According to the fan motor of the present invention, since the rotor is rotatably supported by an air bearing,
Even when rotating at high speeds, the bearing does not generate much noise or vibration, and the bearing life can be extended. Also, since air with low viscosity is used as the lubricating fluid, torque loss at high speeds is small, and You can improve efficiency. Further, the thrust load generated by the rotation of the fan can be supported by the thrust air bearing.

The first air bearing is composed of one end of the rotor shaft and a bottomed cylindrical first bearing and has a spiral groove, and the other end of the rotor shaft is composed of a cylindrical second bearing. By using two air bearings in the second air wheel bearing having one or more pairs of spiral grooves, the rotor can be rotatably supported with a simple configuration without receiving air supply from the outside, and thrust force can be generated. I can support it.

Furthermore, by installing such a high-speed rotation fan motor in a vacuum cleaner, it is possible to reduce the size, reduce noise, and increase efficiency.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIG.

Reference numeral 1 denotes a fan motor installed in the main body of the vacuum cleaner (not shown). A collecting M filter (not shown) is arranged in front of the air intake port 11 at the front end, and a suction hose (not shown) is used to collect suction. It communicates with the mouth (not shown).

A casing 2 is divided into a front casing 2a and a rear casing 2b. At the front wheel center position of the front casing 2a, there is a first bearing part 3 in the shape of a cylindrical bottom with an open front end.
is formed, and the intake port 11 is formed around it, and a cylindrical second bearing portion 4 is formed at the rear end axis position of the rear casing 2b. Front casing 2
A 7-an 5 and a day 7jL-za 6 are arranged inside the rear casing 2b, and a brushless motor 7 is arranged inside the rear casing 2b.

8 is a rotor shaft rotatably supported by a first bearing 3 at one end and a second bearing 4 at a rear end. The 7T ton 5 is fixed to the front part of this rotor shaft 8, and the rotor 9 of the brushless motor is fixed to the rear part. A suitable gap is provided on the outer periphery of the rotor 9, and the stator 10
is fitted onto the outside and fixed to the rear casing 2b with fixing bolts 12. The Day 7 User 6 is the 7 An 5
The front casing 2a is located at the back of the front casing 2a. A narrow passage is formed between the outer circumference of the day 7 user 6 and the inner circumference of the front casing 2a, and a large number of guide fins 6a are provided. 61I is a reply created by Day 7 User 6.

A plurality of spiral grooves 13 are formed on the outer periphery of one end of the rotor shaft 8 that is fitted into the first bearing portion 3 . This spiral groove 13 is formed so that the rotation of the rotor shaft 8 forces the lubricating air between the #1 bearing part 3 and the rotor shaft 8 toward the inner bottom surface 3a of the first bearing part 3. It constitutes an air bearing that generates a thrust force opposite to the thrust force generated by the ring 5. Further, one end surface 8a of the rotor shaft 8 is formed into a spherical surface so as to make point contact with the axial center position of the inner bottom surface 3a of the first bearing part 3, and at the beginning of rotation immediately after the brushless motor 7 is energized, The rotor 9 and stator 10 are slightly eccentric in the axial direction in order to urge the rotor shaft 8 so as to bring them into point contact.

A pair of spiral grooves 14a114b each consisting of a plurality of grooves are formed on the outer periphery of the other end of the rotor shaft 8 that is fitted into the second bearing part 4. These spiral grooves 14a and 114b are formed in a so-called herringbone shape, and the rotation of the rotor shaft 8 forces the lubricating air between the second bearing part 4 and the rotor shaft 8 to the intermediate part between these spiral grooves 14a and 14b. It is formed like this, and constitutes the Lanoarue 7 Tsumugi Uke.

15 is a position detection plate for detecting the rotational position of the brushless motor and controlling the energization.

Next, the operation will be explained.

When the stator 10 of the motor is energized, the rotor 9, rotor shaft 8, and shaft 5 start rotating, and the rotor shaft 8 is biased forward due to the eccentricity of the rotor 9 and stator 10 in the axial direction. The end surface 8a is positioned by abutting against the inner bottom surface 3a of the #&1 bearing portion 3. After that, when the rotational speed increases, the first bearing part 3 receives a spiral rf!
The lubricating air is pumped toward the inner bottom of the first bearing 3 by the pumping action at t13, increasing its pressure, and the air is pumped between the inner circumferential surface of the first bearing 3 and the outer circumferential surface of the rotor shaft 8. The wedge action of the lubricating air produces a bearing action in the radial direction, and the pressure acting on one end surface 8a of the rotor shaft 8 causes a rearward thrust force to act on the rotor shaft 8. This thrust force supports the forward thrust force that acts on the rotor shaft 8 as the 7γ rotation 5 rotates.

Further, in the second bearing portion 4, the spiral grooves 14a, 14
The lubricating air flows into these spiral grooves 1 by the pumping action of b.
4a and 14b, the pressure increases, and the lubricating air (rust action) causes a bearing action in the radial direction between the inner circumferential surface of the bearing portion 4 of @2 and the outer circumferential surface of the rotor shaft 8. Since both ends of the rotor shaft 8 are supported by air bearings in a non-contact manner so that they can rotate freely, noise and vibrations are generated even when the rotor shaft is rotated at high speeds of 50,000 to 60,000 J, p, and 1 m. First, it is a matter of safety, and there is less torque loss.

The air sucked in from the intake port 11 by the rotation of the 77n 5 is subjected to centrifugal force at the 77n 5 and is forced toward its outer periphery, and is passed through a narrow passage on the outer periphery of the day 7 user 6 by the guide fins 6a. It is guided and diffused at the rear portion where it passes, passes through the space around the outer periphery of the stator 10, and is discharged from the rear surface of the rear casing 2b.

In the above embodiments, the air bearing has a spiral groove in the bearing portion, but for example, a static pressure air bearing may be provided in which a separate pressure generating means is provided on the rotor shaft and the pressure is introduced. , other air bearings can also be used.

Effects of the Invention According to the fan motor of the present invention, since the rotor pongee is rotatably supported by the air bearing as described above, the bearing part does not generate large noise or vibration even when rotated at high speed. The service life can be extended, and since air with low viscosity is used as the lubricating fluid, torque loss at high speed rotation is small, and high efficiency can be achieved.

Additionally, the thrust load generated by the rotation of the fan can be supported by the thrust air bearing.

The first air bearing is made up of one end of the rotor pongee and a first bearing part in the shape of a cylinder with a bottom and has a spiral groove, and the second end part of the rotor pongee is made up of a second bearing part in the shape of a cylinder with a spiral groove. By using two air bearings, the second air bearing having one or more pairs of spiral grooves, there is no external air supply, etc., making it easy! The shaft supports the rotor rotatably and can also support the thrust force.

Further, by installing such a high-speed rotation fan motor in a vacuum cleaner, it is possible to reduce the size, reduce noise, and increase efficiency.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of an embodiment of the present invention, and FIG. 2 is a longitudinal sectional front view of a conventional example. １・・・・・・・・・・・・・・・・・・・・・Fan motor 3・・・・・・・・・・・・・・・・・・・・・
First bearing part 4・・・・・・・・・・・・・・・・・・
・・・Second bearing part 5・・・・・・・・・・・・・・・
・・・・・・Fan 8・・・・・・・・・・・・・・・
・・・・・・Rota Tsumugi 13・・・・・・・・・・・・・・・
......Spiral grooves 14a, 14b...
...Spiral groove. Acting patent attorney Toshio Nakao 16 people Figure 1 Figure 2

Claims (3)

[Claims] (1) A fan motor characterized in that a rotor shaft to which a fan is fixed is rotatably supported by a thrust air bearing that generates a thrust force that counteracts the thrust force generated by rotation of the fan, and a radial air bearing. (2) One end of the rotor shaft to which the fan is fixed is fitted into the first cylindrical bearing with a bottom, and air is forcedly sent toward the inner bottom surface by rotation of the rotor shaft to one of the mutually opposing cylindrical surfaces. A spiral groove is formed, and the other end of the rotor shaft is fitted into a cylindrical second bearing part, and air is forcedly sent to one of the mutually opposing cylindrical surfaces toward the middle part by rotation of the rotor shaft. A fan motor characterized by forming one or more pairs of spiral grooves. (3) A vacuum cleaner equipped with the fan motor according to claim 1 or 2.