JP2001057759A - Commutator motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a commutator motor having high efficiency by confining the relation of area between an wind path defined by a permanent magnet and a core and an wind path defined by a permanent magnet, a magnet holder and a core within an appropriate range thereby adjusting balance of wind path resistance. SOLUTION: A stator 1 comprises a set of two split tubular permanent magnets 3 bonded to the inner circumferential part of a yoke 2 while being magnetized with N and S poles, respectively, and a magnet holder 4 interposed between the permanent magnets 3 along the inner circumferential part of the yoke 2 such that the permanent magnets 3 are biased in the radial direction of the yoke 2. The relation of area between an wind path defined by the permanent magnets 3 and a core 7 and an wind path defined by the permanent magnets 3, the magnet holder 4 and the core 7 is confined within an appropriate range thus adjusting balance of wind path resistance. According to the structure, a commutator motor can be utilized efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling air passage for a commutator motor using a permanent magnet as a field.

[0002]

2. Description of the Related Art A cooling air path of a conventional commutator motor will be described with reference to FIG. FIG. 5 is a sectional view of a conventional commutator motor. The stator 31 has a pair of split-cylindrical permanent magnets 33, which are magnetized on the N and S poles and adhered to the inner peripheral portion of the yoke 32, respectively. In order to prevent the permanent magnet 33 from being attracted to and coming into contact with the iron core 37, the magnet holding member disposed between the permanent magnets 33 along the inner periphery of the yoke 32 so as to bias the permanent magnet 33 in the radial direction of the yoke 32. It comprises a vessel 34. In the rotor 35, an iron core 37, an end plate 38 and an end plate 39 from both sides so as to sandwich the iron core 37, and a shaft insulator 40 from both sides so as to sandwich them are pressed into the shaft 36 serving as a core. Iron core 37 and end plate 3
8. A slot liner 42 is inserted into a plurality of grooves 41 provided in the end plate 39 so as to communicate with each other in the axial direction. A coil 43 wound around the iron core 37 is housed in the groove 41 so as to press the coil 43. , A wedge 44 is inserted. End plate 38, end plate 39,
Shaft insulator 40, slot liner 4
2. The wedge 44 is made of an insulating material, and has an end plate 38, an end plate 39, a slot liner 42,
The wedge 44 insulates the coil 43 from the iron core 37, and the shaft insulator 40 insulates the coil 43 from the shaft 36. The terminal end of the coil 43 is connected to a commutator piece 46 on a commutator 45 pressed into the shaft 36. A fan 47 is provided on the side of the shaft 36 opposite to the commutator 45.
Is press-fitted, and as the rotor 35 rotates,
A cooling air for cooling the coil 7 and the coil 43 housed in the groove 41 is generated. At the end of the shaft 36 on the fan 47 side, a gear 48 for transmitting rotational power to the outside is formed.

The stator 31 has an outer periphery of the yoke 32 gripped by a plurality of guide ribs 50 and 51 formed on the housing 49, and has a positioning groove 52 formed at an end of the yoke 32 and a housing 49. Positioning rib 53
Are fitted, and one end of the yoke 32 is abutted against a seat 54 provided continuously to the guide rib 50, and is contacted to the other end of the yoke 32, and a screw seat provided continuously to the guide rib 51. It is fixed to the housing 49 by screws 56 screwed into 55.

[0004] The rotor 35 is inserted into the stator 31,
Ball bearings 5 mounted on both ends of shaft 36
It is supported by a housing 49 and a housing (not shown) provided continuously with the housing 49 via the members 7 and 58.

The housing 49 is provided with a fan guide 59 for efficiently discharging cooling air so as to face the fan 47. Although not shown, the commutator 4
Two brushes facing each other are in contact with the outer peripheral surface of 5, and supply electric power to the rotor 35.

[0006]

The cooling air generated due to the rotation of the rotor is sucked from the commutator side and discharged from the fan side, and the passing air path is formed by the outer periphery of the stator and the housing 49. Air passage A60 passing through the space,
It is roughly classified into an air path B (not shown) that passes through a space formed by the stator 31 and the rotor 35. Airway A60
Has a large air path area, but has a U-shaped air path bypassing the stator, so that the air path resistance is large and a large amount of cooling air is difficult to pass through. The air path B (not shown) is divided into an air path C61 mainly composed of the permanent magnet 33 and the iron core 37, and an air path D62 mainly composed of the permanent magnet 33, the magnet holder 34 and the iron core 37. In order to efficiently cool the iron core 37 and the coil 43 housed in the groove 41, more cooling air needs to pass near the surfaces of the iron core 37 and the wedge 44. Is
The cooling air passes through an air passage C61 having a large contact area with the iron core 37 and the wedge 44. FIG. 6 shows a pair of straight lines drawn on a plane perpendicular to the rotation axis of the rotor so that the included angle becomes the smallest from the center of the rotation axis of the rotor and comes into contact with the opposite end face of the permanent magnet. 63a, 63b and 63
Of the lines c and 63d, the straight lines 63a and 63b and the magnet holder,
And a space composed of concentric circles with the same diameter as the outer diameter of the iron core,
FIG. 7 shows a projection view from the rotation axis direction of the rotor.
FIG. 3 is a projection view of a space formed by 3a, 63c, a permanent magnet, and a concentric circle having the same diameter as the outer diameter of the iron core, as viewed from the rotation axis direction of the rotor. In this prior art, the area of the projection in FIG. 6 is the area of the projection in FIG.
The space defined by the circles 3b and 63d, the permanent magnets, and the concentric circle having the same diameter as the outer diameter of the iron core is about 207% of the projected area as viewed from the rotation axis direction of the rotor. Although this relationship is not shown, the projected area of the space defined by the straight lines 63c and 63d, the magnet retainer, and the concentric circle having the same diameter as the outer diameter of the iron core as viewed from the rotation axis direction of the rotor is also illustrated. Is the same. Here, the projection shown in FIG.
7 corresponds to the wind path C61, but the area of the projected view of FIG. 6 is too large with respect to the area of the projected view of FIG. Since the airflow resistance was too small for the airflow resistance of C61, a large amount of cooling air passed through the airflow path D62 having a small airflow resistance, and the cooling efficiency with respect to the total cooling airflow was low.

As a result, sufficient cooling cannot be performed.
The temperature of the coil 43 increases, the resistance of the coil 43 increases, and the efficiency of the commutator motor decreases. Also, the coil 43
If a large amount of cooling air is generated to cool the motor, there is a problem in that the efficiency of the commutator motor decreases because the fan loss increases.

An object of the present invention is to efficiently cool a commutator motor.

[0009]

The object of the present invention is to improve the shape of the air path formed by the stator and the rotor and to improve the air path C6.
This is achieved by adjusting the balance between the airflow resistance of the airflow path D62 and the airflow resistance of the airflow path D62 so that more cooling air passes through the airflow path C61.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cooling air passage of a commutator motor according to the present invention will be described with reference to FIGS. FIG.
1 is a sectional view of a commutator motor according to the present invention. Stator 1
Are a pair of split cylindrical permanent magnets 3 magnetized on the N pole and S pole and bonded to the inner peripheral portion of the yoke 2, respectively. The magnet holder 4 disposed between the permanent magnets 3 along the inner periphery of the yoke 2 so as to urge the permanent magnets 3 in the radial direction of the yoke 2 in order to prevent the permanent magnets 3 from being attracted to and coming into contact with the magnets. It is configured. In the rotor 5, an end plate 8 and a shaft insulator 9 are press-fitted from both sides so as to sandwich the iron core 7 on a shaft 6 serving as a core. A slot liner 11 is inserted into a plurality of grooves 10 provided in the core 7 and the end plate 8 so as to communicate with each other in the axial direction. A coil 12 wound around the core 7 is housed in the groove 10 and holds the coil 12. As described above, the wedge 13 is inserted. The end plate 8, the shaft insulator 9, the slot liner 11, and the wedge 13 are made of an insulating material. The end plate 8, the slot liner 11, and the wedge 13 insulate the coil 12 from the core 7, and the shaft insulator 9 is the coil 12 and the shaft 6. Is responsible for the insulation. Coil 1
The end of 2 is connected to a commutator piece 15 on a commutator 14 pressed into the shaft 6. A fan 16 is press-fitted on the side of the shaft 6 opposite to the commutator 14, and generates cooling air for cooling the iron core 7 and the coil 12 housed in the groove 10 as the rotor 5 rotates. A gear 17 for transmitting rotational power to the outside is cut out at an end of the shaft 6 on the side of the fan 16.

The stator 1 has an outer periphery of the yoke 2 gripped by a plurality of guide ribs 19 and 20 formed on a housing 18 and a positioning groove 21 formed at an end of the yoke 2.
And a positioning rib 22 formed on the housing 18 is fitted, and one end of the yoke 2 is brought into contact with a seat 23 provided continuously with the guide rib 19, and is brought into contact with the other end of the yoke 2. Screw seat 2 provided continuously with 20
4 is fixed to the housing 18 by screws 25 tightened. The rotor 5 is inserted into the stator 1 and the shaft 6
Are supported by a housing 18 and a housing (not shown) provided continuously with the housing 18 via ball bearings 26 and 27 mounted on both ends of the housing 18. The housing 18 is opposed to the fan 16,
A fan guide 28 for efficiently discharging the cooling air is provided. Although not shown, two opposing brushes are in contact with the outer peripheral surface of the commutator 14 to supply electric power to the rotor 5.

FIG. 2 shows a magnet holder 4 of the present embodiment. The magnet holder 4 is formed of a synthetic resin, and the upper surface 4a is
, And the bottom surface 4b has a curved surface shape facing the iron core 7 at an appropriate distance. Permanent magnet 3
The ribs 29 are formed on the side surfaces 4c that are in contact with the permanent magnets 3, respectively.

FIG. 3 shows a plane drawn perpendicular to the rotation axis of the rotor 5 from the center of the rotation axis of the rotor 5 so that the included angle becomes the smallest and comes into contact with the opposite end face of the permanent magnet 3. Of the set of straight lines 30a, 30c, and 30d, the rotation axis of the rotor 5 in a space formed by the straight lines 30a, 30b, the magnet holder 4, and a circle concentric with the outer diameter of the core 7 FIG. 4 is a projection view as viewed from the direction.
FIG. 3 is a projection view of a space defined by a circle having the same diameter as the outer diameter of the permanent magnet 3 and the iron core 7, as viewed from the rotation axis direction of the rotor 5. In the present embodiment, the area of the projection in FIG. 3 is the area of the projection in FIG.
The projected area, as viewed from the rotation axis direction of the rotor 5, of each of the space formed by a circle having the same diameter as the outer diameter of the permanent magnet 3 and the iron core 7 is 159%. This relationship is not shown, but is a projection of the space formed by the straight lines 30c and 30d, the magnet holder 4, and the concentric circle having the same diameter as the outer diameter of the iron core 7 as viewed from the rotation axis direction of the rotor 5. The same applies to the area.

[0014]

According to the present invention, the relationship between the air passage area mainly composed of the permanent magnet and the iron core and the air path area of the air path mainly composed of the permanent magnet, the magnet retainer and the iron core is set within an appropriate range. By adjusting the balance of the airflow resistance, the cooling air passes through the former airflow, which has a large contact area with the iron core and the wedge. A good commutator motor can be constructed.

[Brief description of the drawings]

FIG. 1 shows a commutator motor according to the present invention,
(A) is a side view, (b) is a front view.

FIG. 2 shows a magnet holder according to the invention,
(A) is a side view, (b) is a front view, (c) is B of (b)
FIG. 4 is a cross-sectional view taken along line B.

FIG. 3 is a projection view showing an air path according to the present invention.

FIG. 4 is a projection view showing an air path according to the present invention.

5A and 5B show a conventional commutator motor, wherein FIG. 5A is a side view and FIG. 5B is a front view.

FIG. 6 is a projection view showing an air path of a conventional commutator motor.

FIG. 7 is a projection view showing an air path of a conventional commutator motor.

[Explanation of symbols]

1 is a stator, 2 is a yoke, 3 is a permanent magnet, 4 is a magnet holder, 5 is a rotor, 7 is an iron core, 12 is a coil, 14 is a commutator, and 16 is a fan.

Claims (1)

[Claims] 1. A rectifier having a stator and a rotor having a magnet holder between the permanent magnets for urging one or more sets of permanent magnets disposed on the inner periphery of the yoke in a direction away from each other. In the sub-motor, on a plane perpendicular to the rotation axis of the rotor, the included angle becomes the smallest from the center of the rotation axis of the rotor, and a pair of straight lines contacting the opposed end faces of the permanent magnet is formed. When pulled according to the number of permanent magnets,
The projected area of the space formed by a pair of two straight lines and a circle concentric with the outer diameter of the magnet retainer and the iron core of the rotor as viewed from the rotation axis direction of the rotor is different. And 50% or more of the projected area of a space defined by two straight lines of the set and a circle concentric with the outer diameter of the permanent magnet and the iron core sandwiched between the straight lines as viewed from the rotation axis direction of the rotor. And 17
A commutator motor characterized by being configured to be 0% or less.