JP2002058204A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor of the construction to simultaneously assure good heat radiation property and reduce vibration and noise. SOLUTION: The motor comprises a stator 2 fixed at the internal circumferential surface of a cylindrical frame 27, and a rotor 3 in which magnets a disposed at the external circumferential surface of a rotary shaft supported to rotate freely via a bearing. The frame 27 integrally has a plurality of diametric direction projections 29, 30, 31 projected to the external side from a frame body 28, and a coupling rod 32 integrally formed with for coupling the end of at least two adjacent diametric direction projections among the projections 29, 30, 31. Moreover, this frame 27 is also provided with a plurality of ventilating through-holes 33a, 33b, 33c which are surrounded by the frame body 28, diametric direction projections 29, 30, 31 and coupling rod 32 and are extended in the direction parallel to the axial center of the rotary shaft. The ventilating through-holes 33a, 33b, 33c are formed to have different volumes at least in a couple of holes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a structure in which a rotor is disposed radially inward of a stator fixed to the inner peripheral surface of a frame. Thus, the present invention relates to a motor which can be suitably used for applications requiring relatively high torque.

[0002]

2. Description of the Related Art A conventional general motor of this kind is an AC motor.
The motor has a configuration as shown in a partial plan view of FIG. 5 and a longitudinal sectional view of FIG. FIG. 5 shows a stator and a frame which will be described later, and FIG. 6 is a longitudinal sectional view showing the motor of FIG. 5 cut along the line BB. A substantially cylindrical stator 2 fixed to the inner peripheral surface, and a rotor 3 rotatably provided in a radially inner side of the stator 2 so as to face the stator 2 with a predetermined gap therebetween. And as main components. The stator 2 includes an iron core (core) 4 formed by laminating magnetic thin plates obtained by punching a thin plate material made of a magnetic material into a circular shape by pressing, and a plurality of teeth 4 a formed in the iron core 4 in a circumferential direction. 7 and a winding 8 wound therearound. The end of the winding 8 is connected to a circuit board 20 fixed to the upper end side of the insulator 7 in the stator 2, and a lead 21
Are led out of the frame 1 through insertion holes (not shown) formed in the frame 1.

On the other hand, the rotor 3 has a columnar rotating shaft 9,
A permanent magnet 10 is disposed on the outer peripheral surface of the rotating shaft 9 and faces the stator 2 with a small gap. The rotating shaft 9 is
The portions near the upper and lower ends are connected to a pair of bushes 11, 12 screwed to upper and lower openings of the frame 1, respectively.
They are rotatably supported via bearings 13 and 14, respectively. An impeller 17 as a blowing means is fixed to the upper end of the rotating shaft 9 so as to rotate integrally. The impeller 17 is covered by a cover 19 fixed to the frame 1 on a fixing screw 18 of the bush 11.
An opening 19 a is formed on the top surface of the cover 19 so that the cover 1
Acts as an air inlet for guiding air into the interior of the housing.

In this motor, a predetermined current is supplied to the winding 8 of the stator 2 to generate a magnetic field for the rotor 3, and the magnetic field is generated between the stator 2 and the rotor 3. The rotating shaft 9 is rotated by the suction repulsion. Rotating shaft 9
The lower end of the motor is connected to a drive unit of a device on which the motor is mounted, and the rotation of the rotating shaft 9 is transmitted to the drive unit of the device.

In this type of motor, when used as a rotary drive source for industrial equipment, a large current is supplied for the purpose of obtaining a high torque. However, when electric energy due to the large current is converted into rotary power. As a result, a large amount of heat is generated as a conversion loss, and the entire body including the rotor 2 around the stator 2 is brought into a high temperature state. This heat may adversely affect the rotation speed and the operation of the motor, such as thermal expansion of each component of the motor and the destruction of the control circuit of the circuit board 20.

Therefore, in the above-mentioned motor, the cooling air W is supplied to the inside of the motor from the outside of the motor through the opening 19a by the impeller 17 attached to the rotor 3 so as to rotate integrally with the motor 3, thereby suppressing the temperature from becoming high. . Further, in the motor, as shown in FIG. 5, a plurality of rib-shaped heat dissipating fins 22 and 23 are integrally formed on the outer surface of an aluminum frame 1 having excellent heat dissipating properties, and a cover 19 covers the outside thereof. I have. The cooling air W supplied to the inside of the motor passes through the radiating fins 22 and 23 and a gap G formed by a rib 24 and a cover 19 to be described later, and the frame of the radiating fins 22 and 23 and the ribs 24 and the like. 1 through the outer surface. The heat generated inside the motor and transferred to the frame 1 is exchanged with the outside air of the frame 1 through the radiating fins 22 and 23 and the ribs 24 thereof to improve the heat radiation. The two radiating fins 22 at the center of the four radiating fins 22 and 23 provided at four locations on the entire circumference of the frame 1 have a semicircular portion 22a between them. The frame 1 and the bush 11,
12 functions as a screw hole for fixing the same.

Further, ribs 24 are formed at both ends of each of the four heat dissipating fins 22 and 23 of the frame 1 which serve as mounting portions when the motor is mounted on industrial equipment. The ribs 24 also contribute to heat dissipation.
The heat dissipating fins 22 and 23 and the ribs 24 (hereinafter referred to as reinforcing ribs 24) are formed from above the frame 1 in a direction parallel to the axis of the motor, that is, the axis of the rotating shaft 9. It also has the function of improving

[0008]

By the way, the above-mentioned stator is disclosed in Japanese Patent Application Laid-Open No. 2000-14057 so as to reduce waste of material, and to improve the space factor and the winding operation on the teeth of the winding. What is described in the gazette may be adopted. This stator structure is formed by laminating a plurality of magnetic thin plates formed by connecting a required number of circular arc-shaped base plates having teeth on the inner peripheral side in a linear manner at a connecting portion of the outer peripheral portion, and forming a laminated body. The stator is mounted by mounting the wound bobbin on each of a plurality of teeth formed by laminating each tooth piece, and welding both ends of the laminated body into a cylindrical shape. To form.

[0009] The stator constructed as described above has remarkable effects such as reduction of waste of material, but on the other hand, the connecting portion and welding portion of each tooth are weak in strength and inevitably have low rigidity. There are drawbacks. When such an iron core is used, the drawback is compensated for by fitting the frame 1 around the stator 2, but the rigidity of the stator 2 itself is weak, so that the influence of electromagnetic vibration generated on itself is used. As a result, the stator 2 and the frame 1 resonate, and there is a problem that vibration and noise during rotation driving of the motor are relatively large. In particular, when used as a rotary drive source for industrial equipment, a large current is supplied to the winding 8 of the stator 2 in order to obtain a relatively high torque. Become.

The rigidity of the stator 2 is improved by using a stator having a core formed by laminating a plurality of annular magnetic thin plates having tooth pieces instead of the stator 2. Although a certain amount of vibration and noise can be reduced, a conventional motor cannot satisfy the demand for further reduction.

The present invention has been made in view of the above-mentioned conventional problems, and has a structure in which a stator is fixed to an inner peripheral surface of a cylindrical frame. It is an object of the present invention to provide a motor having a configuration capable of simultaneously reducing power consumption.

[0012]

In order to achieve the above-mentioned object, a motor according to the present invention comprises a frame having a cylindrical frame body, and a cylindrical stator fixed to an inner peripheral surface of the frame body. A magnet is disposed on an outer peripheral surface of a rotating shaft rotatably supported via bearings at upper and lower ends of the frame body, and is concentric with a predetermined gap inward with respect to the stator. A frame comprising: a plurality of radial projections projecting outward from an outer surface of a frame main body; and at least two radial projections each adjacent to the frame. And a plurality of ventilation holes which are integrally formed with the connecting rod connecting the front ends of the shafts, and which are surrounded by the frame body, the radial projections, and the connecting rod and penetrate in a direction parallel to the axis of the rotating shaft. A plurality of holes are provided; Vent holes is characterized in that at least two of a shape to be a different volume.

In this motor, the frame body has sufficient strength by the plurality of radial projections protruding from the entire outer peripheral surface thereof and the connecting rods interconnecting the respective tips. It is reinforced and the rigidity is remarkably improved. Therefore, the frame body is less likely to resonate with electromagnetic vibrations generated from the stator fixed to the inner peripheral surface of the frame body, and vibration and noise of the entire motor are significantly reduced. At the same time, the impact resistance from the outside is improved. In addition, the ventilation holes are provided in the frame, and the frame main body, the radially projecting portion and the connecting rod communicate with the outside air, so that the heat radiation is not impaired. At this time, heat generated in the stator is transferred to the frame main body, and then heat exchange is performed between the radial projection formed on the frame main body and the connecting rod and the air in the ventilation hole. Dissipated efficiently to the outside.

The radial projections serve as reinforcing ribs for improving the rigidity of the frame, as heat dissipating fins for cooling the heat of the frame, or as mounting portions when the motor is mounted on equipment. .

Further, since the ventilation holes have a shape in which at least two of the plurality of ventilation holes have different volumes (that is, all of the plurality of ventilation holes are not the same shape), all the ventilation holes have the same volume. The effect of reducing vibration and noise is greater than in the case of (1). This is because even if the vibration and noise generated by the vibration of the frame body, the radial projection, and the connecting rod that form each ventilation hole, or the noise generated by the cooling wind passing through each ventilation hole resonate and resonate with each other, This is because by making at least two different volumes, resonance and the degree of resonance can be suppressed as compared with the case where all the ventilation holes have the same volume.

Therefore, in this motor, it is possible to simultaneously improve heat radiation and reduce vibration and noise, and, in addition, only to change the shape of the frame from that of the conventional motor. There is an advantage that does not lead to an increase.

[0017] In the above invention, the rotating shaft may be provided with a blowing means for flowing cooling air through the ventilation hole. This allows the heat generated by the stator to be forcibly supplied with cooling air to each ventilation hole, improving the fluidity of the air in the ventilation holes, and improving the heat transfer from the frame body to the cooling air. Dissipates quickly and efficiently.

In the above invention, in addition to the plurality of radial projections, the frame may include a base of the rib in the frame body and a tip of another radial projection adjacent to the rib or the connecting rod. It is possible to adopt a configuration in which the connecting brace sections are provided integrally. As a result, the overall strength of the frame is further reinforced, and the frame has extremely high rigidity. Therefore, the frame main body hardly resonates with the electromagnetic vibration generated from the stator, and the vibration of the entire motor is reduced. In addition, noise can be significantly reduced. In addition, since the cooling air from the blowing means is forcibly supplied to the ventilation holes, the heat radiation is not impaired.

In the above invention, the connecting rod may be configured to be annularly connected outside the frame body. Thus, the frame is integrally connected to the double cylindrical body by the radial projecting portion or the brace bar by the cylindrical frame main body and the cylindrical portion formed by the connecting rod outside the main body. Structure
An extremely rigid frame can be obtained.

[0020] In the above invention, the stator may be formed by bending a plurality of teeth, which are wound and partially connected to each other, in an annular shape.
Since this stator is formed by bending a plurality of teeth connected linearly and connecting them in an annular shape,
Although there is an advantage that the waste of the material is small and the space factor of the winding and the winding operation are good, the connecting portion between the teeth has low strength and the rigidity of the entire stator is low. Therefore, the stator itself is liable to vibrate due to the electromagnetic vibration generated from the stator, but when the frame is applied to such a stator, the frame is significantly improved in rigidity. Therefore, the stator is reinforced, and is strong against vibration, so that vibration and noise of the whole motor are remarkably reduced.

[0021]

Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a frame 27 in a motor according to a first embodiment of the present invention.
FIG. 2 is a plan view showing the motor of FIG.
FIG. 7 is a longitudinal sectional view cut along line A. In these figures, the same or substantially equivalent parts as those in FIGS. 5 and 6 are denoted by the same reference numerals, and the description thereof is omitted.

The motor of this embodiment differs from the conventional motors of FIGS. 5 and 6 only in the shape of the frame 27. That is, the frame 27 has a cylindrical shape, and a frame body 28 having the stator 2 fixed to the inner peripheral surface thereof;
A pair of heat dissipating fins 29 projecting radially outward from four locations at approximately 90 ° intervals on the outer surface of the frame body 28, and both sides of the pair of heat dissipating fins 29 on the outer surface of the frame body 28 Reinforcing ribs 30 projecting radially outward from eight locations at equal circumferential intervals, respectively;
Auxiliary ribs 31 protruding radially outward from four intermediate portions of each of two adjacent reinforcing ribs 30 on the outer surface of the frame main body 28, and the above-described heat radiation fins 2
9. The connecting rod 32 for mutually connecting the tips of the reinforcing ribs 30 and the auxiliary ribs 31 is integrally formed of aluminum, which is a material excellent in both heat dissipation and rigidity. Note that the radiating fins 29, the reinforcing ribs 30, and the auxiliary ribs 31 correspond to radial projections.

The frame 27 has a frame body 28
Fins 29, reinforcing ribs 30, auxiliary ribs 3
1 and a connecting rod 32 are formed from above to below the frame 27 in a direction parallel to the axis of the motor, that is, the axis of the rotating shaft 9.
0, 20 in the circumferential direction by the auxiliary rib 31 and the connecting rod 32
The individual ventilation holes are formed. These ventilation holes are formed by a frame main body 28, a pair of radiating fins 29, 29, and a connecting rod 3.
2 and a first ventilation hole 33a
a, the frame body 28 and the heat dissipating fins 29
And a pair of second ribs formed of the reinforcing ribs 30 and the connecting rods 32.
A pair of third ventilation holes 33c, 33c formed at the opposite ends of the ventilation ribs 33b, 33b and the auxiliary rib 31 and formed by the frame body 28, the reinforcing rib 30, the auxiliary rib 31, and the connecting rod 32.
The first to third ventilation holes 33a, 33
b and 33c are formed to be 90 degrees rotationally symmetric, for a total of 20 pieces. The ventilation holes 33a, 33b, and 33c have the same axial length, but have different capacities due to their different shapes in plan view as clearly shown in FIG.

The ventilation holes 33a, 33b, 33c
Is a motor shaft, that is, a rotating shaft 9 as shown in FIG.
The upper end opening of each hole communicates with the space formed by the cover 19 covering the upper end opening of the frame 27 through the through hole of the bush 11, and the lower end opening of each hole is formed. Is open to the outside of the motor. Rotating shaft 9
When the impeller 17 is rotated by the rotation of the air, air is sucked from the opening 19a of the cover 19 and is supplied as cooling air W to the ventilation holes 33a, 33b, 33c.

The first ventilation holes 33a are used as screw holes for fixing the bushes 11, 12 and the frame 27 by inserting screws 33s. In this case, the cooling air W cannot be supplied. When other fixing means (for example, press-fitting the bush into the frame) is adopted, the cooling air W can be supplied. The connecting rod 32 is shown in FIG.
As shown in FIG. 1, the whole has a cylindrical shape of a regular octagon in a plan view. When the motor of this embodiment is mounted on industrial equipment or the like, any one of the eight outer flat portions of the connecting rod 32 is used. It can be firmly fixed by contacting the flat surface of the device. At this time, a screw hole as a fixing means, a positioning portion, or the like may be appropriately formed near the flat portion serving as the mounting portion.

The frame body 28 of the frame 27 is
A plurality of heat dissipating fins 29, reinforcing ribs 30, and auxiliary ribs 31 projecting radially outward from substantially the entire outer peripheral surface thereof, and a connecting rod 32 for interconnecting the distal ends thereof. The overall strength is sufficiently reinforced by
The stiffness is significantly improved. In particular, this frame is composed of a cylindrical frame main body 28 and a connecting rod 32 having a regular octagonal cylindrical shape in a plan view. The structure is integrally connected by 31 and the frame is extremely rigid. This makes it difficult for the frame 27 to resonate with electromagnetic vibrations generated from the stator 2 fixed to the inner peripheral surface thereof. Also, the impact resistance from the outside is improved. Therefore, the motor according to the present embodiment does not vibrate even when a large current is supplied to the winding 8 of the stator 2 for the purpose of obtaining a large torque when applied as a rotary drive source of industrial equipment. And the noise is significantly reduced.

This means that the rigidity of the frame 27 itself is improved, and that the ventilation holes 33a, 33b, 33c
Also have three different shapes.

That is, in the plurality of ventilation holes, the vibration and noise generated in each ventilation hole or the noise generated by the cooling air flowing therethrough resonate and resonate with each other. It has become. When all of the plurality of ventilation holes have the same shape (that is, the shape having the same volume), they all easily resonate and resonate, and the degree of vibration and noise increases. On the other hand, when the ventilation holes are formed as in the frame 27, all the ventilation holes can be prevented from resonating, and the degree of vibration and noise due to this can be reduced.

Further, the motor according to this embodiment has a structure in which the stiffness of the frame 27 is improved as described above, while the heat dissipation is also improved. That is, each ventilation hole 33a, 33
The b and 33c penetrate in a direction parallel to the axis of the motor, and the inside of the motor above the impeller 17 is a space covered by a cover 19.

Therefore, the cooling air W generated by the rotation of the impeller 17 is forcibly sent to the ventilation holes 33a, 33b, 33c through the openings 19a of the cover 19, and is discharged to the outside from the lower end openings of the holes. You. At this time, the heat generated in the stator 2 is transferred to the frame main body 28, and then the heat radiation fins 29, the reinforcing ribs 30, the auxiliary ribs 31, and the connecting rods 32 projecting outward from the frame main body 28. Heat is exchanged with the cooling air W passing through the ventilation holes 33a, 33b, 33c, and is extremely efficiently radiated to the outside. That is, in the motor according to the present embodiment, the improvement of the heat radiation and the reduction of the vibration and the noise can be obtained at the same time, and the shape of the frame 27 is merely changed from the conventional one. There is an advantage that does not lead to an increase.

On the other hand, in the conventional motors shown in FIGS. 5 and 6, the wind generated by the rotation of the impeller 13 is sent to be in contact with the surfaces of the radiating fins 22 and 23 and the ribs 24 and radiated. However, the rigidity of the frame itself is low and vibration and noise are large.

In addition to the above-mentioned conventional motor, a motor having a ventilation hole extending in the axial direction of the motor to improve heat radiation has been proposed (for example, see Japanese Patent Application Laid-Open No. 11-299174). However, this motor has a frame structure in which a fin cover covers a portion of the frame main body having the heat radiation fins to form a ventilation hole, and heat radiation can be obtained, but the rigidity of the frame is not improved at all.

Further, apart from the above-mentioned conventional motor, a motor having a ventilation hole extending in the axial direction of the motor and a blowing means for supplying cooling air to the ventilation hole to improve heat radiation is also proposed (for example, Japanese Patent Application Laid-Open No. H11-157572). No. 2000-4561).
However, in this motor, the cooling air supplied to the ventilation holes is simply made to flow to both the inner fins and the outer fins of the frame by the branch plate. The stiffness does not improve at all.

Further, as a motor which is provided with a ventilation hole extending in the axial direction of the motor and a blowing means for supplying cooling air to the ventilation hole to improve heat radiation, Japanese Patent Application Laid-Open No. 10-1460 discloses a motor.
There are also those disclosed in JP-A-21 and JP-A-11-4559, respectively. However, in these motors, since the ventilation holes are formed in the stator, vibration and noise cannot be reduced by improving the rigidity of the frame.

None of the above known motors can simultaneously improve heat radiation and reduce vibration and noise.

FIG. 3 is a plan view showing a frame 37 and a stator 2 in a motor according to a second embodiment of the present invention. In FIG. And the description thereof is omitted. The frame 37 of this motor has a cylindrical shape, and has a frame body 38 to which the stator 2 is fixed on the inner peripheral surface thereof, and FIGS. 5 and 6 protruding from the outer surface of the frame body 38.
Heat dissipating fins 22 and 23 having the same shape as that of the conventional motor,
A pair of reinforcing ribs 24 formed at two locations, a connecting rod 39 for connecting between the tips of a pair of adjacent reinforcing ribs 24, 24, and a pair of connecting rods for connecting the intermediate portion of the connecting rod 39 and the base of the reinforcing rib 24. Has a shape integrally formed with the brace section 40 of FIG. Note that the reinforcing ribs 24 correspond to radial projections.

The frame 37 has a reinforcing rib 24, a connecting rod 39, a brace 4 and a frame main body 38.
0 is formed in the axial direction from above the frame 37 to below, and the frame body 38, the reinforcing rib 24, and the brace 4 are provided.
Twelve ventilation holes surrounded by 0 are formed. These ventilation holes are formed between the frame body 28 and the pair of brace bars 4.
0, 40, and a pair of fifth ventilation holes 41b, which are formed at both ends of the fourth ventilation hole 41a, by the reinforcing rib 24, the connecting rod 39, and the brace 40.
41b, and the fourth and fifth ventilation holes 41a,
41b are formed in 90-degree rotational symmetry, for a total of twelve.
Although each ventilation hole 41a, 41b has the same axial length,
Since the shapes in plan view are different as shown in FIG. 3, their volumes are different. The semicircular portion 22a formed by the heat dissipating fins 22 adjacent to the frame body 28
Are also used as screw holes for screws for fixing the bushes 11 and 12.

The frame body 38 of the frame 37 is
A connecting rod 39 is provided between the tips of two adjacent reinforcing ribs 24.
And the connecting rod 39 is reinforced by the brace 40, so that the overall strength is more reinforced than the conventional motor, and the rigidity is improved. Thus, the frame body 38 is fixed to the stator 2 fixed to the inner peripheral surface thereof.
, The resonance of the motor becomes difficult, and the vibration and noise of the entire motor are sufficiently reduced. This is due to the fact that the rigidity of the frame 37 itself is improved and the ventilation holes 41a and 41b have two types of different volumes as in the above-described embodiment. Furthermore, the impact resistance from the outside is also improved.

The cooling air W generated by the rotation of the impeller 17 is supplied to the frame 1 including the ventilation holes 41a and 41b.
After being forcibly sent to the outer peripheral surface of the frame 7 to cool the frame body 38, the reinforcing ribs 24 and the brace sections 40, and the radiating fins 22, 23, the lower end openings of the ventilation holes 41a, 41b, etc. Since it is released, heat dissipation is not impaired. This frame 37 is slightly inferior in rigidity to the frame 27 of the motor of the first embodiment, but unlike the first embodiment,
Since the connecting rods 2 and 23 are not covered with the connecting rod 39, they are excellent in heat dissipation.

FIG. 4 is a plan view showing a frame 42 and a stator 2 in a motor according to a third embodiment of the present invention. In FIG. And the description thereof is omitted. A frame 42 of this motor has a cylindrical shape, and has a frame main body 43 to which the stator 2 is fixed on an inner peripheral surface thereof, and protrudes radially outward from the outer surface of the frame main body 43 at equal circumferential intervals. Eight provided reinforcing ribs 44, four auxiliary ribs 45 projecting radially outward at equal intervals in the circumferential direction between the pair of reinforcing ribs 44, and each reinforcing rib 44.
And a connecting rod 46 for connecting the distal ends of the pair of reinforcing ribs 44 and the auxiliary rib 45 to each other, and a brace 47 for connecting the base of the reinforcing rib 44 in the frame body 43 and the intermediate portion of the connecting rod 46. It has an integrally formed shape.
In the frame 42, a reinforcing rib 44, an auxiliary rib 45, and a connecting rod 46 are formed axially below the frame 42 with respect to the frame main body 43, and the entire outer peripheral surface of the frame main body 43 is formed. , Frame body 4
3, 28 ventilation holes surrounded by any of the reinforcing ribs 44, the auxiliary ribs 45, the connecting rods 46, and the bracing bars 47 are provided.

The ventilation holes are provided at both ends of the auxiliary rib 45 and are provided at the frame body 43, the auxiliary rib 45, and the brace 47.
And a pair of sixth ventilation holes 48a formed by
At both ends of the ventilation hole 48a, the reinforcing rib 44 and the connecting rod 46
And a pair of seventh ventilation holes 48 formed by
b, an eighth ventilation hole 48c formed by the frame body 43 and a pair of brace bars 47, and formed by reinforcing ribs 44, connecting rods 46 and brace bars 47 at both ends of the eighth ventilation hole 48c. And a pair of ninth ventilation holes 48d, and the sixth to ninth ventilation holes 48a, 48b, 48c, 48d.
Are formed 90 degrees rotationally symmetrically, for a total of 28 pieces. Also,
The eighth ventilation hole 48c is provided in the bush 1 similarly to the above embodiment.
It is used as a screw hole of a screw for fixing the frame 1 and 12 to the frame 27.

The frame body 43 of the frame 42 is
A plurality of reinforcing ribs 44 and auxiliary ribs 45 each protruding radially outward from substantially the entire portion of the outer peripheral surface thereof;
Since the connecting rod 46 for connecting these tips to each other and the brace 47 are provided, the overall strength is higher than that of the frames 27 and 37 in each motor of the first and second embodiments. Are further reinforced to have extremely high rigidity. In particular, the frame 42 has a double cylindrical body composed of a cylindrical frame main body 43 and a connecting rod 32 having a cylindrical shape in a regular octagonal shape in a plan view, and a heat radiation fin 29, a reinforcing rib 44, The structure is integrally connected by the auxiliary rib 45 and the brace 47, and the frame is extremely rigid. As a result, the frame body 28 hardly resonates with the electromagnetic vibration generated from the stator 2 fixed to the inner peripheral surface thereof, and the vibration and noise of the entire motor are significantly reduced.
This means that the rigidity of the frame 42 itself is improved and the ventilation holes 48a and 48
This is also due to the fact that b, 48c and 48d have shapes having four different volumes. Of course, each ventilation hole 48a,
Since the cooling air W is sent to 48b and 48c, the heat radiation is not impaired.

Although the embodiment according to the present invention has been described above, the scope of the present invention is not limited to this, and can be variously changed. For example, frame body, connecting rod,
The detailed shapes of the reinforcing ribs, the auxiliary ribs, and the bracing bars are not limited to the above shapes and numbers as long as their functions are not impaired.

[0044]

As described above, according to the motor of the present invention,
The frame body is sufficiently reinforced by the presence of the plurality of radial projections and connecting rods formed on the entire outer surface thereof, and the rigidity is significantly improved. It becomes difficult to resonate with the electromagnetic vibration generated from the stator fixed to the peripheral surface, and the vibration and noise of the entire motor are remarkably reduced. In addition, since the cooling air generated by the air blowing means that rotates integrally with the rotating shaft is forcibly supplied to each ventilation hole, the frame body, the radial protrusion, and the connecting rod can be cooled very efficiently, so that heat radiation is improved. .

[Brief description of the drawings]

FIG. 1 is a plan view showing a frame and a stator in a motor according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the motor of FIG. 1 taken along line AA.

FIG. 3 is a plan view showing a frame and a stator in a motor according to a second embodiment of the present invention.

FIG. 4 is a plan view showing a frame and a stator in a motor according to a third embodiment of the present invention.

FIG. 5 is a plan view showing a frame and a stator in a conventional motor.

FIG. 6 is a vertical sectional view of the motor of FIG. 5 taken along line BB.

[Explanation of symbols]

2 Stator 3 Rotor 9 Rotary shaft 10 Permanent magnet (magnet) 13, 14 Bearing 17 Impeller (blower means) 19 Cover 22, 23, 29 Heat radiating fin (radial projection) 24, 30, 31, 40, 44 , 45 Ribs (radial projections) 27, 37, 42 Frames 28, 38, 43 Frame bodies 32, 39, 46 Connecting rods 33a, 33b, 33c, 41a, 41b, 48a, 4
8b, 48c, 48d ventilation hole 47

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) RR27 RR35 RR37 RR42 RR63 RR69 RR73 RR74 SS12

Claims (5)

[Claims] 1. A frame having a cylindrical frame main body, a cylindrical stator fixed to an inner peripheral surface of the frame main body, and rotatably supported by upper and lower ends of the frame main body via bearings. A magnet disposed on the outer peripheral surface of the rotating shaft, and a rotor concentrically disposed with a predetermined gap inward of the stator. A plurality of radial projections protruding outward from an outer surface of the main body, and a connecting rod for connecting at least a tip end of each of the two adjacent radial projections to each other; A plurality of ventilation holes are provided, which are surrounded by the main body, the radial projections, and the connecting rod, and penetrate in a direction parallel to the axis of the rotation shaft, and at least two of the plurality of ventilation holes have different volumes. Is characterized by Motor to do. 2. The motor according to claim 1, wherein the rotating shaft includes a blower for flowing cooling air through the ventilation hole. 3. A brace for connecting the base of the radial projection with the tip of another radial projection adjacent to the base or the connecting rod.
A motor according to claim 1. 4. The motor according to claim 1, wherein the connecting rod is annularly connected outside the frame body. 5. The motor according to claim 1, wherein the stator is formed by bending a plurality of teeth, which are wound and partially connected to each other, in an annular shape.