JP2020018135A - Electric motor and pump including the same - Google Patents

Abstract

To provide a pump in which cooling performance is improved by creating a new airway space with use of an external member instead of providing in the rotor an open hole that will worsen magnetic characteristics.SOLUTION: An electric motor comprises a stator including winding, a rotor, and a housing. The stator is fixed in the housing, a top side space and a bottom side space are formed in the housing, an open hole A is provided vertically above the top side space, an open hole B is provided vertically above the bottom side space, and a ventilation hole is provided on the bottom side of the housing. Furthermore, a cooling air course is provided on the outside of the housing so as to connect the open holes A and B. Since the air inside the motor warmed by heat evolution from the winding is exhausted to the outer space through the open hole A, the cooling air course, the open hole B and the ventilation hole, the electric motor having improved cooling performance is provided.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a motor having a housing and a cooling structure outside the housing.

  For example, in a motor having a structure in which a stator and a winding portion are covered by a housing portion, the heat generated from the windings causes the temperature inside and outside the motor to rise, so that it is necessary to improve the cooling capability and the heat discharging capability of the motor.

  For this reason, conventionally, a rotor made of laminated electromagnetic steel sheets has a plurality of through holes, and has a plurality of blade pieces in the vicinity of the through holes, so that the air in the electric motor can be circulated. In addition, the cooling performance is improved (for example, see Patent Document 1).

  Hereinafter, the electric motor will be described with reference to FIGS.

  FIG. 6 is a side sectional view of a conventional electric motor, and FIG. 7 is a longitudinal sectional view of a rotor portion thereof. The motor 100 is a motor having a rotor 102 made of laminated electric steel sheet rotatably held via a bearing 101, a bracket holding the bearing 101, and a stator (stator) sandwiched by the bracket. The electric motor has a plurality of through-holes 105, and a plurality of blade pieces A106 near the through-hole 105 and on one side or both sides. It is stated that the air inside the motor can be circulated through the through holes 105 present in the rotor 102 of the motor, and the cooling performance of the motor can be improved.

JP 2006-42543 A

  In such a conventional motor, in order to improve the cooling performance of the motor, by providing a plurality of through holes for the air passage in the rotor, there is a problem that magnetic characteristics are deteriorated due to obstruction of a magnetic flux path flowing through the rotor. Had.

  The present invention has been made to solve such a conventional problem, and promotes the movement of air and heat on the top and bottom sides of the housing without deteriorating the magnetic properties of the rotor, thereby improving the cooling performance inside the motor. An object is to provide an improved electric motor.

  In order to achieve this object, an electric motor according to the present invention includes a cylindrical rotor that rotates about a rotation axis, a stator disposed on an outer peripheral side of the rotor, and a top surface and a bottom surface. A housing having a cylindrical shape and rotatably supporting the rotor on the top surface side and the bottom surface side and having the stator fixed to an inner surface thereof; and a top surface side of the stator in an internal space of the housing. A top space provided further on the top surface side than an end portion, a bottom space provided further on the bottom surface side than the bottom end portion of the stator in the internal space of the housing, and the housing A ventilating hole that connects the external space and the bottom side space, and a cooling air path that is connected outside the housing so that the top side space and the bottom side space can ventilate, It is intended to achieve a more desired object.

  ADVANTAGE OF THE INVENTION According to this invention, the air inside a motor can be circulated, without providing the through-hole for a wind path in a rotor, and the cooling performance of a motor can be improved, without deteriorating the magnetic characteristic of a rotor.

FIG. 1 is a perspective view of a pump according to Embodiment 1 of the present invention. Simplified sectional view from the side of the electric motor according to Embodiment 1. Sectional simplified view from the front of the electric motor according to Embodiment 1. Simplified sectional view from the side of the electric motor according to Embodiment 2. Simplified sectional view from the front of a motor according to a third embodiment. Side sectional view showing a conventional electric motor End sectional view of rotor related to conventional motor

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are examples embodying the present invention, and do not limit the technical scope of the present invention.
In all the drawings, the same portions are denoted by the same reference numerals, and description thereof is omitted. Further, in each drawing, the description of the details of each part not directly related to the present invention is omitted.

(Embodiment 1)
Hereinafter, the internal configuration of the electric motor 1 according to the present embodiment will be described with reference to FIGS. FIG. 1 is a perspective view of a pump according to Embodiment 1 of the present invention. FIG. 2 is a simplified cross-sectional view from the side of a motor provided in the pump according to Embodiment 1 of the present invention. FIG. 3 is a simplified cross-sectional view from the front of an electric motor provided in the pump according to Embodiment 1 of the present invention.

  The pump 60 includes a casing 62 and a casing cover 61 for forming a water passage leading to the electric motor 1, and is used, for example, when pumping water for a shallow well. When the electric motor 1 is driven, water is pumped up and discharged through the water channel.

  The electric motor 1 is an adduction type AC motor, and is used, for example, as a drive source of a pump. The electric motor 1 includes a rotor 2 that rotates around a rotation axis, a shaft 12, and a stator 3, and the outer periphery of the electric motor 1 is covered with a housing 4.

  The rotor 2 is obtained by pouring an aluminum alloy into a rotor core and solidifying it. The rotor 2 has a cylindrical shape, and is fixed to a shaft 12 that penetrates the top and bottom surfaces of the cylindrical shape.

  The shaft 12 has a cylindrical rod shape, and the top side of the rotor 2 is inserted into the bearing 13 and the bottom side is inserted into the bearing 14.

  The bearing 13 and the bearing 14 are an inner ring that is a cylindrical ring, an outer ring that is a cylindrical ring having a diameter larger than the inner ring, and a plurality of rings that independently and rotatably hold the inner ring and the outer ring. Rolling elements. The bearing 13 has an outer ring fixed to the top surface of the housing 4, and the bearing 14 has an outer ring fixed to the bottom surface of the housing 4. The inner rings of the bearings 13 and 14 are fixed to the shaft 12, respectively.

  The stator 3 is arranged on the outer peripheral side of the rotor 2. The stator 3 has a cylindrical shape, and includes a stator core 30, an insulating member 31, and a winding 32.

  The stator core 30 is formed by laminating donut-shaped iron plates, has a cylindrical space at the center, and has an inner hole 52 that is a circular space when viewed in cross section. The outer periphery of the donut-shaped iron plate, that is, the outer diameter portion of the stator core 30 includes a straight portion 33 and an arc portion 34 in a cross-sectional view on a plane perpendicular to the shaft 12.

  The straight portion 33 has a straight shape, that is, has two straight lines facing each other. When the stator core 30 has a columnar shape, the straight portion 33 forms a side plane in the columnar shape.

  The arc portion 34 has an arc shape, that is, has two opposing arcs. When the stator core 30 has a columnar shape, the arc portion 34 forms a side surface in the columnar shape.

  The straight portion 33 connects one ends of two arc portions 34 to both ends of the straight portion 33.

  The inner hole 52 includes the rotor 2 inside the inner hole. That is, the shaft 12 connected to the rotor 2 becomes a rotation axis, and the rotor 2 rotates. The stator core 30 has a plurality of slots penetrating from the top surface to the bottom surface, that is, a plurality of spaces for winding windings.

  The arc portion 34 of the stator core 30 and the inside of the housing 4 are in contact with each other at the contact surface 21.

  The insulating member 31 is an insulator formed of an insulating material, and is inserted into a slot of the stator core 30 so as to face each other in the axial direction, that is, from the top surface side and the bottom surface side in the cylindrical shape.

  The winding 32 is a copper wire or an aluminum wire coated with an insulating film, and is wound around the stator core 30 via the insulating member 31. That is, the winding 32 is brought into a non-contact state with the stator core 30 by the insulating member 31 inserted into the slot of the stator core 30.

  The housing 4 has a cylindrical shape having a top surface and a bottom surface, and has a center hole that is a through hole at the center of the top surface and the bottom surface. Outer races of the bearings 13 and 14 are fixed to the center hole of the housing 4. The housing 4 rotatably supports the rotor 2, and the outer periphery of the stator 3 is fixed to the inner surface. The housing 4 has a top surface side space 6 further on the top surface side (left side in FIG. 2) than the top surface end portion of the stator core 30 in the internal space, and a bottom surface further lower than the bottom surface side end portion of the stator core 30. A bottom side space 7 is provided on the side (the right side in FIG. 2). The housing 4 has a ventilation hole 11 for connecting the bottom side space 7 and the external space 50 of the electric motor 1. The housing 4 has a through hole 8 and a through hole 9 as end openings formed on the inner side surface, and the opening position is located vertically above when the electric motor 1 is installed.

  One end of the through hole 8 communicates with the top surface side space 6.

  One end of the through hole 9 communicates with the bottom space 7.

  Further on the outer periphery of the housing 4, there is provided a cooling air passage 10 for connecting the top space 6 and the bottom space 7 outside the housing 4 through the through holes 8 and 9. The cooling air passage 10 is formed by, for example, a hollow tube having elasticity or a square tube made of plastic.

  The cooling air passage 10 is provided with a lead wire outlet 20, and the lead wire 16 is taken out from the bottom space 7 through the through hole 9 and the lead wire outlet 20 to the external space 50, for example. The lead wire outlet 20 is provided with a rubber packing 23 as an elastic member that allows the internal space 51 and the external space 50 to be shut off regardless of the presence or absence of the lead wire 16.

Next, the positional relationship between the stator core 30 and the housing 4 will be described with reference to FIG.
The housing 4 has a contact surface 21 on the inner surface where the housing 4 and the arc portion 34 are in contact, and a non-contact surface 22 that is not in contact with the linear portion 33.

  In this state, the inside surface of the housing 4 forming the top surface side space 6 and the bottom surface side space 7 and adjacent to the contact surface 21 (the left and right positions of the stator core 30 in FIG. 2) and the electric motor 1 In the installation state, a through hole 8 and a through hole 9 are provided vertically above.

  The above is the configuration of the electric motor 1 according to the first embodiment.

  In the above configuration, the warmed air in the top space 6 moves vertically upward due to the heat generated from the windings 32. The warmed air that has moved vertically upward usually stays there, but in the present embodiment, it is possible to move to the bottom space 7 through the cooling air passage 10. The warmed air that has moved to the bottom side space 7 is discharged to the external space 50 through the ventilation holes 11, so that the electric motor 1 is cooled. That is, there is an effect that the cooling performance of the electric motor 1 is improved.

<Modification 1>
FIG. 4 is a diagram showing Modification Example 1, and is a cross-sectional view of the electric motor 1b provided in the pump according to Modification Example 1, as viewed from the side.

  The electric motor 1b having the same configuration as that of the first embodiment includes an outer cover 19 that can be attached to and detached from the housing 4, instead of the cooling air passage 10 located on the outer surface of the housing 4.

  The outer cover 19 uses the outer peripheral side surface of the housing 4 as a wall surface of the cooling air passage 10 and is detachably provided on the side surface of the housing 4. The outer cover 19 is configured such that the inner space 51 of the outer cover 19 is isolated from the outer space 50 and the top space 6 and the bottom space 7 are connected to each other through the through holes 8 and the through holes 9, thereby providing cooling air. It has the same function as the road 10. Further, in the internal space 51 of the outer cover 19, for example, a condenser 15, which is an electrical component for controlling the rotation of the rotor 2, can be arranged on the outer peripheral side surface of the housing 4. The capacitor 15 is also connected to the lead 16.

  The above is the configuration of the electric motor 1b according to the first modification.

  According to the above configuration, in addition to the effects of the first embodiment, the electrical components can be directly mounted on the outer periphery of the housing 4, and an effect of improving the workability of assembling the electric motor is achieved.

  The ventilation holes 11 may not be provided in the housing 4 but may be provided in the external cover 19, or the ventilation holes 11 may be provided in the housing 4 and the external cover 19.

  Further, a structure may be adopted in which air heated by the heat generated from the windings 32 is discharged from the lead wire outlet 20 which secures air permeability by removing the rubber packing 23. In this case, heat radiation from both the ventilation hole 11 and the lead wire outlet 20 can be expected.

  As described above, since the electrical components (for example, the condenser 15) stored in the outer cover 19 need to be protected from humidity, it is preferable to cover the electrical components with, for example, a polyester bag.

<Modification 2>
FIG. 5 is a diagram showing Modification Example 2, and is a cross-sectional view from the front of a motor provided in the pump according to Modification Example 2.

  The electric motor 1c according to Modification 2 is an inner surface that is inside the housing 4 that forms the top space 6 and the bottom space 7 and that is not adjacent to the contact surface 21, in other words, the inner surface that is adjacent to the non-contact surface 22. A through hole 8 and a through hole 9 are provided on the side surface.

  Other configurations are the same as those in the first embodiment.

  The above is the configuration of the electric motor 1c according to the second modification.

  Also in the above configuration, in addition to the effect of the first embodiment, since the non-contact surface 22 is located vertically above the installed state, which is the same as the through-hole 8 and the through-hole 9, inside the motor, vertically above and below In the case where the temperature difference is high, the effect of Embodiment 1 is further enhanced, and the cooling performance is further improved.

(Modification)
In order to press-fit the stator 3 into the housing 4, the housing 4 may be divided so that a plurality of members can be fitted. However, the position at which the housing 4 is divided and the number of divisions do not matter.

(Outline of Embodiment)
The electric motor according to the present invention,
A cylindrical rotor that rotates about a rotation axis,
A stator arranged on the outer peripheral side of the rotor,
A housing having a cylindrical shape having a top surface and a bottom surface, rotatably supporting the rotor at the top surface side and the bottom surface side, and fixing the stator to an inner surface;
A top space provided further on the top surface than the top end of the stator in the internal space of the housing,
A bottom space provided further on the bottom surface than the bottom end of the stator in the internal space of the housing;
Ventilation holes connecting the outer space of the housing and the bottom space;
A cooling air passage connected to the outside of the housing so that the top space and the bottom space can be ventilated;

  Due to the heat generated from the windings provided in the stator, the warmed air in the top space moves to the bottom space through the cooling air path, is discharged to the outside through the ventilation holes, and is discharged inside the motor. This has the effect of improving the cooling performance of the device.

An outer cover is provided on an outer surface of the housing,
The outer cover,
The internal space of the external cover is isolated from the external space,
The top surface side space and the bottom surface side space may be connected to each other via the internal space of the external cover to function as the cooling air passage.

  Further, an electrical component for controlling the rotation of the rotor may be arranged in the internal space of the outer cover.

The housing is
An inner surface of the housing includes a contact surface with which the stator contacts and a non-contact surface with which the stator does not contact,
An end opening of the cooling air passage may be provided on an inner side surface of the housing constituting the top side space and the bottom side space and adjacent to the contact surface.

  Thereby, in addition to the movement path of the air from the top surface side space to the bottom surface side space through the cooling air passage from the terminal opening, the cooling air passage is formed by the non-contact surface between the housing and the stator. Form 2 is formed, and the movement of air in the top side space and the bottom side space is further accelerated through the cooling air path 2, so that the cooling performance inside the motor is improved.

In addition, the cooling air passage,
An end opening may be provided on the inner surface of the housing.

In addition, the cooling air passage,
In the installation state of the housing, the housing may be positioned vertically above.

  This makes it possible to promote the movement of the air to the cooling air path by utilizing the phenomenon that the air having a high calorie moves to a high place, thereby improving the cooling performance inside the electric motor.

  INDUSTRIAL APPLICABILITY The electric motor according to the present invention can improve the cooling performance of the electric motor and suppress a rise in the temperature of the electric motor, and can be applied to, for example, a driving electric motor for a pump.

DESCRIPTION OF SYMBOLS 1, 1b, 1c Electric motor 2 Rotor 3 Stator 4 Housing 6 Top side space 7 Bottom side space 8, 9 Through hole 10 Cooling air path 11 Ventilation hole 12 Shaft 13, 14 Bearing 15 Condenser 16 Lead wire 19 External cover 20 Lead Wire outlet 21 Contact surface 22 Non-contact surface 23 Rubber packing 30 Stator iron core 31 Insulating member 32 Winding 33 Straight part 34 Arc part 50 External space 51 Internal space 52 Inner hole 60 Pump 61 Casing cover 62 Casing 100 Motor 101 Bearing 102 Rotor 105 Through hole 106 Blade piece A

Claims (6)

A cylindrical rotor that rotates about a rotation axis,
A stator arranged on the outer peripheral side of the rotor,
A housing having a cylindrical shape having a top surface and a bottom surface, rotatably supporting the rotor at the top surface side and the bottom surface side, and fixing the stator to an inner surface;
A top space provided further on the top surface than the top end of the stator in the internal space of the housing,
A bottom space provided further on the bottom surface than the bottom end of the stator in the internal space of the housing;
Ventilation holes connecting the outer space of the housing and the bottom space;
An electric motor comprising: a cooling air passage connected outside the housing so that air can flow through the top space and the bottom space. An outer cover is provided on an outer surface of the housing,
The outer cover,
The internal space of the external cover is isolated from the external space,
2. The electric motor according to claim 1, wherein the top surface space and the bottom surface space are connected via an internal space of the outer cover to function as the cooling air passage. 3. The electric motor according to claim 1, wherein an electric component for controlling rotation of the rotor is arranged in an internal space of the outer cover. The housing is
An inner surface of the housing includes a contact surface with which the stator contacts and a non-contact surface with which the stator does not contact,
4. An end opening of the cooling air passage is provided on an inner side surface of the housing constituting the top side space and the bottom side space and adjacent to the contact surface. An electric motor as described in Crab. The cooling air passage,
The electric motor according to any one of claims 1 to 4, wherein an end opening is provided on an inner surface of the housing. The cooling air passage,
The electric motor according to any one of claims 1 to 5, wherein the electric motor is located at an upper part when the housing is installed.