JPH01310195A - Fan motor and electric cleaner using it - Google Patents

Abstract

PURPOSE:To prevent the occurrence of vibration and noise, by using an air bearing means which generates thrust coping with thrust generated by the revolution of a fan and also, conducts support against a radial direction without coming into contact. CONSTITUTION:A fixed shaft 3 supporting rotationally a fan 5 and a rotary bearing portion 8 is fixingly supported at the front end axis center position of a front portion casing 2a, and forms, together with the bottomed cylindrical rotary bearing portion 8 whose rear end surface is closed, an air bearing. This air bearing generates thrust which copes with thrust generated by the revolution of the fan 5, and also, conducts support against a radial direction without coming into contact.

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.

2. Description of the Related Art Conventional vacuum cleaners have used fan motors in which both ends of a rotor shaft with a fan fixed to one end are rotatably supported by Beaufret bearings.

An example of the structure of the fan motor 20 will be described based on FIG. A fan 26 is fixed to one end of the rotor shaft 25. The rotor shaft 26
is supported by a first ball bearing 27 between the fan 26 and the rotor 22 and by a second pole bearing 28 at the other end. 26a is an intake port of the fan 26, and 29 is a differential user.

To explain the operation, the rotor 22 is rotated at high speed by energizing the rotor 22 through the brush 23 or the commutator 24, and the fan 2e fixed to one end of the rotor shaft 26 is rotated to draw air from the intake port 26a. inhale,
The air is exhausted through a differential user 29.

Problems to be Solved by the Invention Incidentally, in current vacuum cleaners, the fan 26 is normally rotated at 20,000 to 30,000 r, p, m, but in order to achieve miniaturization and high efficiency, the fan 26 is rotated at 5 to 60,000 rpm. Million r, p, m.

If you try to increase the rotational speed to Furthermore, there was a problem in that the torsion loss also increased and the efficiency deteriorated.

On the other hand, the above-mentioned problems caused by contact between the brush 23 and commutator 24 can now be solved by adopting a brushless motor, but ball bearings can generate noise and vibration, shorten the bearing life, and worsen 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, long life, 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-mentioned object, the present invention has a rotary bearing section to which a fan is fixed, which generates a thrust force that counters the thrust force generated by the rotation of the fan, and also in the radial direction. To provide a fan motor supported by air bearing means that is supported in a non-contact manner.

Further, the air bearing means preferably includes a bottomed cylindrical rotary bearing portion to which the fan is fixed, which is externally fitted onto a shaft fixed to the fan motor body, and the share is transferred by rotation of the rotary bearing portion to the inside of the rotary bearing portion. It is constructed by forming a spiral groove that feeds pressure toward the bottom surface.

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 large noise or vibration, and the life of the bearing can be extended.Also, since air with low viscosity is used as the lubricating fluid, torsion loss at high speed rotation is small, resulting in high You can improve efficiency. Further, the thrust load generated by the rotation of the fan can be supported by air that is force-fed to the inner bottom surface of the rotary bearing portion along the spiral groove.

Furthermore, the air bearing having the spiral groove does not need to be supplied with air from the outside, and can support the load in the radial direction with a simple structure, as well as the thrust force generated by the rotation of the fan.

Moreover, by mounting a fan motor capable of rotating at such a high speed on 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 dust collection filter (not shown) is arranged in front of the air intake port 11 at the front end, and the fan motor 1 is connected through a suction hose (not shown). It communicates with a suction port (not shown).

A casing 2 is divided into a front casing 2a and a rear casing 2b. A fixed shaft 3 that rotatably supports a fan 5 and a rotary bearing part 8 is fixedly supported at the front end axis position of the front casing 2a, and together with a rotary bearing part 8 having a closed bottom cylindrical shape at the rear end surface. , forming an air bearing.

The front end of the oral bearing part 8 has a labyrinth structure that prevents dust and dirt from entering, and a fan intake port 11 is formed around the labyrinth structure.

A fan 6 and a differential user 6 are disposed within the i1 section casing 2a, and a brushless motor 7 is disposed within the rear casing 2b.

The fan 6 is fixed to the front part of the rotation bearing part 8, and the rotor 9 of the brushless motor 7 is fixed to the rear part. A stator 1o is fitted around the outer periphery of the rotor 9 with an appropriate gap, and is fixed to the rear casing 2b. The differential user 6 is located at the back of the fan 6 and fitted into the front casing 2a. A narrow passage is formed between the outer circumference of the differential user e and the inner circumference of the front casing 2a, and a large number of guide fins 6a are provided. θb is a rib formed on the differential user 6.

A plurality of spiral grooves 13 are formed on the outer periphery of the fixed shaft 3 that is fitted into the rotary bearing portion 8 .

This null spiral groove 13 allows lubricating air between the rotary bearing part 8 and the fixed shaft 3 to be transferred to the rotary bearing part 8 by the rotation of the rotary bearing part 8.
The air bearing is formed to force feed toward the inner bottom 8a of the fan 6, and constitutes an air bearing that generates a thrust force that counteracts the thrust force generated by the rotation of the fan 6. Further, one end surface 3a of the fixed shaft 3 is formed into a spherical surface so as to make point contact with the axial center position of the inner bottom surface 8a of the rotary bearing portion 8. Furthermore, the support base 4 that fixes the fixed shaft 3 to the fan motor main body 1 forms a labyrinth 4a together with the rotary bearing part 8 to prevent dust from entering between the bearing part 8 and the fixed shaft 3. ing.

Reference numeral 14 denotes an exhaust port formed at the axial center position of the bottom surface 8a of the rotary bearing portion 8. By exhausting an appropriate amount of air forced into the inner bottom surface 8a, the axial position of the fan 6 and the rotor 9 can be adjusted. It is secured. Reference numeral 15 denotes a control board including a Hall element 16 for detecting the rotational position of the brush reflex motor 7. 17a.

Reference numeral 17b denotes a belling bone groove formed on the outer periphery of both ends of the fixed shaft 3.

Next, the operation will be explained.

When the nutator 10 of the motor 7 is energized, the rotor 9, the rotary bearing 8, and the fan 6 start rotating.

After that, when the rotational speed increases, lubricating air is pumped toward the inner bottom of the rotary bearing 8 by the pumping action of the Nuvira ρ shaft 13, and its pressure increases. A radial bearing action is produced between the surface and the outer circumference of the fixed shaft 3 due to the wedge effect of the lubricating air, and the pressure acting on the inner bottom surface 8a of the rotation bearing part 8 causes a rearward movement with respect to the rotation bearing part 8. A thrust force toward . This thrust force supports the thrust force directed toward fqiT that acts on the rotary bearing portion 8 as the fan 6 rotates. In this way, the bearing part 8 rotatably supports the fixed shaft 3 without contacting it.
Even if it is rotated at a high speed of 60,000 to 60,000 r, p, m, it does not produce noise or vibration, and can operate with long life and high efficiency.

Air sucked in from the intake port 11 by the rotation of the fan 6 is subjected to centrifugal force by the fan 6 and is forced toward its outer periphery, and passes through a narrow passage on the outer periphery of the differential user 6 while being guided by guide fins 6a. It diffuses at the rear of the rear casing 2b 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 attached in which a separate pressure generating means is provided on the rotor shaft and the entire pressure is introduced. It is also possible to use other air bearings.

According to the fan motor developed in this investigation, as described above, the entire rotor is rotatably supported by air bearings, so even when rotating at high speed, the bearing does not generate large noise or vibration, and the bearing life is extended. Furthermore, since air with low viscosity is used as the lubricating fluid, torsion 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 Nulast Air Bearing.

Furthermore, a dynamic pressure type air bearing having a spiral groove can rotatably support a rotor with a simple structure without receiving air supply from an external force. Furthermore, since it does not have two bearing portions as in the conventional case, there is no need for concentric adjustment of both bearings, which is difficult with air bearings, and it is easy to assemble. In addition, the labyrinth structure on the end face of the air intake port of the bearing portion makes it difficult for dirt and dust to get in, thereby extending the life of the bearing.

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...Fixed shaft,
5...Fan, 7...Brushless motor, 8...Bearing section, 13...Nuspiral groove. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (3)

[Claims] (1) The rotary bearing section to which the fan is fixed is supported by an air bearing means that generates a thrust force that counters the thrust force generated by the rotation of the fan, and also supports it in the radial direction without contact. Features a fan motor. (2) A bottomed cylindrical rotary bearing portion to which the fan is fixed is fitted onto the shaft fixedly supported by the motor body, and the inner peripheral surface of the rotary bearing portion or the outer peripheral surface of the fixed shaft is A fan motor characterized in that a spiral groove is formed for pumping air toward an inner bottom surface of a rotary bearing part by rotation of the rotary bearing part. (3) A vacuum cleaner equipped with the fan motor according to claim 1 or 2.