DE20021972U1 - Direct drive motor for the rim of an electric car - Google Patents

Description

ZEITLER;&· P)CKEE..: IJ PATENT ATTORNEYS EUROPEAN PATENTAND TRADEMARK ATTORNEYS

PO BOX 26 02 51 TELEPHONE:+49-89-22 18 06 HERRNSTRASSE 15

D-80059 MUNICH FAX: +49-89-22 26 27 D-80539 MUNICH

EVT TECHNOLOGY CO., LTD.

9F ₁ No. 86, Lake. 2, Chien Kuo N Rd.

Taipei, Taiwan

R.O.C.

Direct drive motor for rim of an electric car

The invention relates to a direct drive motor for the rim of an electric car, in particular a motor suitable for electric cars or electric means of transport and characterized by direct drive, high torque, long life, low noise, simple structure and easy maintenance. A conventional motor for electric cars (Figure 1) consists essentially of a spindle (A), a rotor (B), a housing (C), a gear (D) and a clutch (E), wherein the spindle (A) is arranged in the housing (C) which is provided radially with carbon brushes (F) and accommodates several magnets (G), and passes through the rotor (B) as well as the gear (D) and the clutch (E), whereby the rotor is energized via the spindle (A) and forms a magnetic field with the magnets (G), so that the rotor (B) rotates and the clutch (E) thus couples due to the centrifugal force and carries the rim, which is rigidly connected to the clutch.

However, this engine has the following disadvantages:

1. Since the carbon brush (F) is supported radially on the circumference of the rotor (B), which is limited, only one pair of carbon brushes (F) can be provided normally (two-pole). When the rotor (B) is energized via the carbon brush (F) and forms a magnetic field with the magnets (G), only a small magnetic force is generated, so that the torque is insufficient. Therefore, this motor is only suitable for electric bicycles which have a small output power.

2. Since only a few carbon brushes (F) can be provided around the rotor (B) (e.g. two-pole), the rotor (B) rotates at high speed to drive the rim through the gear (D) and the clutch (E), which increases the wear of the carbon brush (F) and causes a loss of power transmission of the rotor (B) through the gear (D) and the clutch (E), so that the output power is impaired and the gear (D) is damaged at high speed due to poor lubrication. Since the rotor (B) is placed around the spindle (A) and the carbon brush (F) is supported radially on the circumference of the rotor (B), the frictional heat is generated when the rotor (B) rotates.

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accumulated and not directly discharged, causing the temperature to rise, increasing the internal resistance of the rotor (B) and thus affecting the output. Therefore, the service life of the motor is shortened and the motor is more susceptible to failure.

3. In order to increase the magnetic force of the motor with few poles, the number of turns of the winding is increased, which also increases the internal resistance, so that there is a relatively large impedance and the working power is thus low (0.6-0.7). Due to the high internal resistance, the starting current exceeds the charging capacity of the motor, which burns the winding, so that rapid starting or acceleration is not possible.

4. As the power of the engine is transmitted to the clutch via the transmission, noise is generated.

For this reason, considering the disadvantages of conventional solutions, the inventor has developed the present invention after long studies, numerous experiments and constant improvements.

The invention is explained in more detail below with reference to the accompanying drawings. They show:

Figure 1 is a sectional view of the conventional solution,

Figure 2 is an exploded view of the invention,

Figure 3 is a perspective view of the invention,

Figure 4 is a sectional view of the invention.

Referring to Figures 2 to 4, the invention essentially consists of a rim (1), a motor (2), a spindle (3) and a cover (4), the motor (2) being placed around the spindle (3) and accommodated in a receiving space of the rim (1), the cover (4) being attached to the rim (1) and positioning the motor (2) in the rim (1), characterized in that the motor (2) comprises a stator (21) and a rotor (22), the stator (21) being rigidly attached to the inner wall of the rim (1) and being provided on the underside with a converter (211)

is provided, and the rotor (22) is placed around the spindle (3), has a suitable distance (D) from the stator (21), is connected to the power line (31) through the spindle (3) and is connected to the converter (211) via the carbon brushes (222), whereby the stator (21) is fed by the converter (211) via the carbon brushes (222) of the rotor (22) with the current from the power line (31) through the spindle (3), so that a magnetic field is formed between the stator (21) and the rotor (22), so that the rotor (22) attached to the spindle (3) connected to the chassis (5) generates a torque due to the magnetic force with respect to the stator (21), which is rigidly attached to the inner wall of the rim (1) and has a suitable distance (D) from the rotor (22), whereby the stator (21) is driven to rotate and thus carries the rim (1) with it.

Figure 4 shows a sectional view of the invention which illustrates the structure of the stator and rotor. As shown, the stator (21) comprises an iron core (212), a plurality of windings (213) and a transformer (211), the windings (212) being accommodated at equal distances in the annular grooves (not shown) of the iron core (212) and being fixed at the two ends at two predetermined locations in the space formed by the transformer (211), whereby the transformer (211) can be positioned radially on the underside of the stator (21) so that the transformer can form a required space in accordance with the number of windings (213) in order to obtain the largest mechanical space for the respective design (e.g. 32 poles, 64 poles, etc.). Therefore, the magnetic field between the stator

(21) and the rotor (22) generate the greatest torque. The rotor

(22) comprises a carbon brush holder (221), several carbon brushes (222) and permanent magnets (223), the carbon brush holder (221) being connected to the spindle (3), being provided at the edge with several equally spaced axial bores for the carbon brushes (222) and being enclosed by a metal material (224), on the outside of which the permanent magnets (223) are arranged, which have a suitable distance (D) from the stator (22), whereby the rotor (22) is connected to the spindle (3) via the carbon brush holder (221) and the current from the power line (31) flows through the spindle (3) via the carbon brushes (222) into the converter (211) in order to supply the stator (21) with current. Since the permanent magnets (223) are rigidly attached to the

Outside of the carbon brush holder (221), the carbon brush holder (221) is connected to the spindle (3), the stator (21) is rigidly attached to the inner wall of the rim (1) and has a suitable distance (D) from the permanent magnets (223) of the rotor (22), a magnetic field is formed between the stator (21) and the rotor (22), the magnetic force of which generates a torque for the stator (22), so that the stator (21) is driven to rotate and thus carries the rim (1) with it.

The advantages of the invention are summarized below:

1. Since the converter is arranged radially on the bottom of the stator, a maximum space for design can be obtained. The carbon brushes (222) are accommodated in the axial holes on the edge of the carbon brush holder (221) and connected to the front face of the converter at the lower end, thereby obtaining the maximum mechanical space, so that a multi-pole structure can be used which is characterized by a low speed, a large torque and a high output. A multi-pole motor can bear the instantaneous starting current, so that a quick start and better acceleration can be achieved.

2. Since the windings are fixed to the inner wall of the rim, the heat dissipation of the motor can be accelerated, so that temperature rise during electromechanical operation is inhibited. Due to the multi-pole design, the length of the winding of each pole can be reduced, thereby reducing the internal resistance, so that the motor output is increased.

3. Since the rim is directly driven, a gearbox or clutch is not required, thus avoiding loss of power transmission and damage due to poor lubrication, so that better power transmission and longer service life can be achieved.

4. Since there is no gear, there is no wear and tear, so the susceptibility to failure is low and the noise is low. In addition,

The multipole motor is characterized by low speed and high torque, which can extend the life of the converter and carbon brushes. Furthermore, changing the carbon brushes is very easy.

A direct drive motor for the rim of an electric car is described, which essentially consists of a rim, a motor, a spindle and a cover, the motor being placed around the spindle and accommodated in a receiving space of the rim, characterized in that the motor comprises a stator and a rotor, the stator being rigidly attached to the inner wall of the rim and provided with a converter on the underside, and the rotor being placed around the spindle, having a suitable distance from the stator, being connected to the power line through the spindle and being connected to the converter via the carbon brushes, whereby the stator is fed by the converter via the carbon brushes of the rotor with the current from the power line through the spindle, so that a magnetic field is formed between the stator and the rotor, so that the rotor, which is attached to the spindle connected to the chassis, generates a torque due to the magnetic force relative to the stator, which is rigidly attached to the inner wall of the rim and having a suitable distance from the rotor, which is why the stator is Rotating and thus carrying the rim.

Claims (6)

1. Direct drive motor for the rim of an electric car, which essentially consists of a rim (1), a motor (2), a spindle (3) and a cover (4), wherein the motor (2) is placed around the spindle (3) and accommodated in a receiving space of the rim (1), the cover (4) is attached to the rim (1) and the motor (2) is positioned in the rim (1), characterized in that
the motor (2) comprises a stator (21) and a rotor (22), the stator (21) being rigidly attached to the inner wall of the rim (1) and being provided with a converter (211) on the underside, and the rotor (22) being placed around the spindle (3), having a suitable distance (D) from the stator (21), being connected to the power line (31) through the spindle (3) and being connected to the converter (211) via the carbon brushes (222),
whereby the stator (21) is fed by the converter (211) via the carbon brushes (222) of the rotor (22) with the current from the power line (31) through the spindle (3) so that a magnetic field is formed between the stator (21) and the rotor (22), so that the rotor (22) fixed to the spindle (3) connected to the chassis (5) generates a torque due to the magnetic force with respect to the stator (21) which is rigidly attached to the inner wall of the rim (1) and has a suitable distance (D) from the rotor (22), whereby the stator (21) is driven to rotate and thus carries the rim (1) along with it. 2. Direct drive motor according to claim 1, characterized in that the stator (21) comprises an iron core (212), a plurality of windings (213) and a converter (211), the windings (212) being accommodated at equal distances in the annular grooves of the iron core (212) and being fastened at the two ends at two predetermined locations in the space formed by the converter (211), whereby the converter (211) can be positioned radially on the underside of the stator (21) so that the converter can form a required space in adaptation to the number of windings (213) in order to obtain the largest mechanical space for the respective design (e.g. 32 poles, 64 poles, etc.). 3. Direct drive motor according to claim 1, characterized in that the rotor (22) comprises a carbon brush holder (221), a plurality of carbon brushes (222) and permanent magnets (223), the carbon brush holder (221) being connected to the spindle (3), being provided at the edge with a plurality of equally spaced axial bores for the carbon brushes (222) and being enclosed by a metal material (224), on the outside of which the permanent magnets (223) are arranged, which have a suitable distance (D) from the stator (22), whereby the rotor (22) is connected to the spindle (3) via the carbon brush holder (221) and the current from the power line (31) flows through the spindle (3) via the carbon brushes (222) into the converter (211) in order to supply the stator (21) with current; Since the permanent magnets (223) are rigidly attached to the outside of the carbon brush holder (221), the carbon brush holder (221) is connected to the spindle (3), the stator (21) is rigidly attached to the inner wall of the rim (1) and has a suitable distance (D) from the permanent magnets (223) of the rotor (22), a magnetic field is formed between the stator (21) and the rotor (22), the magnetic force of which generates a torque for the stator (22), so that the stator (21) is driven to rotate and thus carries the rim (1) with it. 4. Direct drive motor according to claim 1 or 3, characterized in that a bearing is provided between the spindle (3) and the rim (1), by means of which the rim (1) can rotate better. 5. Direct drive motor according to claim 3, characterized in that the motor uses a multi-pole arrangement, whereby the instantaneous starting current can be endured (seven to twelve times the rated current), so that a larger torque is generated, therefore a quick start and a low speed can be achieved. 6. Direct drive motor according to claim 3, characterized in that the carbon brushes (222) are accommodated in the axial bores of the carbon brush holder (221) and come into contact with the converter at the lower end, whereby the carbon brushes (222) can be easily removed and replaced.