WO2001089059A2

WO2001089059A2 - Commutator fan coupling

Info

Publication number: WO2001089059A2
Application number: PCT/TR2000/000025
Authority: WO
Inventors: Ridvan Egin; Levent Akdag; Ahmet AÇIKGÖZ
Original assignee: Arçelik A.Ş
Priority date: 2000-05-18
Filing date: 2000-05-18
Publication date: 2001-11-22
Also published as: WO2001089059A3; AU2000251211A1

Abstract

The invention is related to a by-pass type electrical vacuum cleaner motor that lengthens the service life of the roller (9) at the commutator side by protecting it from the carbon dusts and that prevents the deterioration of the roller grease. A radial fan is mounted on the surface (2) of the commutator (1) facing the roller (9) in such a manner that it rotates together with the commutator, and it prevents the carbon dusts from penetrating into the roller (9) by providing an air flow to avoid the irregular air flow and turbulences generated when the cooling air is struck onto the commutator upper surface (2) and returns to the roller bearing (10), and directs the air and therefore the carbon dusts towards the lateral surface of the commutator with a smooth and regular flow.

Description

COMMUTATOR FAN COUPLING

The present invention is related to an electrical motor with a commutator fan coupling that protects the roller from penetration of dust, generated by the brush, into the roller at the commutator side, damaging the roller grease and the surface of the balls, particularly in by-pass type-electrical vacuum cleaners.

In the by-pass type motors, when the air, sucked in by the cooling fan, reaches the upper part of the commutator, a main air flow is formed around the commutator. At the same time, due to the difference between the size of the commutator and that of the roller bearing a certain amount of the air is struck onto the surface of the commutator, generates turbulence and returns to the roller bearing.

In the motors with brush, the carbon dust formed during the abrasion of the carbon, due to the contact of the brashes with the commutator, is directed towards and penetrates into the roller under the impact of the said air flow in the motor. The dust penetrated into the roller causes the deterioration due to the dust stick on the grease and increase the friction of the roller and abrades the balls and ball paths, whereas the dust accumulated on the roller causes an isolation effect and prevents the roller heat propagation and leads to excessive heating. All these problems shorten the service life of the roller.

For by-pass type electrical vacuum cleaner motors a bearing cap is used in order to prevent the penetration of the carbon dust, generated by the brush, into the roller and to protect the roller. One advantage of this implementation is the fact that the roller is assembled together with the bearing cap, and this is an efficient way to prevent dust penetration into the roller. However, the most significant disadvantage of the bearing cap is that it causes excessive heat by hindering any heat losses and that this additional piece increases the cost. In another embodiment, the protection of the roller is provided by a flat washer mounted on the shaft between the roller and the commutator. The use a washer is not as effective as a cap. It requires an additional process of the shaft and extra pieces. The washer, mounted by providing a space between the roller and the commutator, may have negative impact on the balance due to its properly fitting to the shaft.

The object of the present invention is to realize a by-pass type electrical vacuum cleaner with a commutator fan coupling that protects the roller from the carbon dusts by providing a flow that eliminates the irregular air flow and turbulences generated when the cooling air is struck onto the upper surface of the commutator and returns to the roller bearing.

The by-pass type electrical vacuum cleaner motor with a commutator fan coupling that protects the roller, realized to attain the said object of the present invention, is illustrated in the attached drawings, wherein:

Figure 1, is the general view of the commutator fan coupling. Figure 2, shows the fan as mounted on the surface of the commutator. Figure 3, is the general view of the commutator and the commutator fan coupling consisting of independent blades.

Figure 4, shows the blades mounted on the commutator surface. Figure 5, shows the locations of the commutator, fan and roller in the bypass motor. Figure 6, shows the air flow provided by the fan around the commutator.

The fan (5) is designed in order to be mounted on the surface (2) of the commutator (1) facing the roller (9) in the by-pass type electrical vacuum cleaner motors and rotates with the commutator (1). This fan (5) provides a flow that eliminates the irregular air flow and turbulences, generated when the cooling air struck onto the upper surface (2) of the commutator and returns to the roller bearing (10). The penetration of the carbon dust particles into the roller bearing (10) is prevented in order to protect the roller (9) from a negative impact of the dust .

In a preferred embodiment of the invention, the fan (5) is a radial fan and the small blades (7) are tangential to the fan core (8). A rear surface or a base (6) is used to support the fan blades (7). The number of the fan blades (7) is important with respect to balancing. The preferred number of fan blades is in the range of three and six.

Some amount of the cooling air, coming by passing the roller (9) is deviated by the radial fan (5) in the section between the roller (9) and the commutator (1) in order to approach the shaft (14) according to the operational principle of the said fan. The air sucked towards the center of the fan (5) is then accelerated by the fan blades (7) and pushed towards the main flow path (12). It is observed that directing the cooling air in this manner prevents the orientation of the carbon dust particles towards the roller to a considerable extent.

In order to avoid its contact with the brushes during rotation, the diameter of the fan (5) to be mounted on the upper surface (2) of the commutator is either equal to or smaller than that of the commutator. As the commutator (1), and particularly the commutator bars (4) conduct electricity, they warm up excessively during the operation of the motor and the fan (5) has to be protected against heat as much as possible. In order to protect the fan against heat, in the preferred embodiment of the invention, the edge of the fan extends up to the inner edges (13) of the bars. A smaller diameter can also be preferred.

Mounting the fan (5) onto the commutator surface (2) as a separate part can be made by shrink fitting and by binding. Another preferable option may be, to mount more than one independent blade (15) onto the commutator surface (2) separately (Fig. 3-4).

Fans are manufactured of non-conductive, heat-resistant material. It may be of any type of plastics or any non-metallic, non-conductive material.

Fan can either be manufactured from a different material and mounted on the upper surface (2) of the commutator separately, or it can be manufactured as monoblock with the commutator with a non-conductive filling material (resin) (3).

The commutator fan coupling can also be used in motors with brushes of a larger size provided that it is brought to a size in proportion with the dimensions of the motor and that the number of the fan blades is optimized.

Claims

1. Electrical motor with a commutator fan coupling that protects the roller in the motors with brushes, particularly in by-pass type electrical vacuum cleaners, characterized in that it consists of a radial fan that is mounted on the surface (2) of the commutator (1) facing the roller (9) in such a manner that it rotates together with the commutator, that it has more than one blade (7) and that it prevents the carbon dusts from penetrating into the roller (9) by providing an air flow to avoid the irregular air flow and turbulences generated when the cooling air is struck onto the commutator upper surface (2) and returns to the roller bearing (10).

2. Electrical motor with a commutator fan coupling that protects the roller according to Claim 1, characterized in that the fan blades (7) are tangential at different angles to the fan core (8).

3. Electrical motor with a commutator fan coupling that protects the roller according to Claims 1 and 2, characterized in that the fan has a back surface or a base (6) to support the blades (7).

4. Electrical motor with a commutator fan coupling that protects the roller according to Claims 1 and 2, characterized in that the fan blades (7) are manufactured as monoblock with the commutator with a non-conductive filling material (resin).

5. Electrical motor with a commutator fan coupling that protects the roller according to the Claims 1 to 4, characterized in that the number of the fan blades is preferably between three and six.