WO2021024486A1

WO2021024486A1 - Coreless motor

Info

Publication number: WO2021024486A1
Application number: PCT/JP2019/031502
Authority: WO
Inventors: 白木学; 田中邦幸; 川野将太郎
Original assignee: コアレスモータ株式会社
Priority date: 2019-08-08
Filing date: 2019-08-08
Publication date: 2021-02-11
Also published as: JP7320875B2; TW202107800A; JP2021045043A; JP2022093450A; WO2021024509A1

Abstract

Provided is a coreless motor which has a simple structure and with which overheating of a coil during motor operation can be suppressed, and excess current can be supplied to the coil to cause an electric motor to output at high rotation.　The coreless motor comprises: a rotation center shaft that extends in the axial direction at the center of a sealed housing; a cylindrical coil that is disposed concentrically with respect to the rotation center shaft in the housing, an end surface on one side of the cylindrical coil being supported by a stator and extending in the direction in which the rotation center shaft extends; a rotor that is disposed concentrically with respect to the rotation center shaft in the housing, and that rotates in the circumferential direction of the rotation center shaft; and a liquid refrigerant that is accommodated in the housing, that flows inside the housing due to the rotation of the rotor, and that contacts the cylindrical coil.

Description

Coreless motor

For electric motors, the usage limit guaranteed against temperature rise of the coils, magnets, etc. that make up the electric motor during normal operation is generally displayed as a rating by the manufacturer. Ratings are proprietary standards guaranteed by the manufacturer when operating an electric motor at a given voltage at rated torque or rated output, and are generally listed in catalogs and specification tables. For example, the maximum output generated while the electric motor exhibits good characteristics at a predetermined voltage is the rated output, the rotation speed when operating at the rated output is the rated rotation speed, the torque at that time is the rated torque, and then Current is displayed as the rated current.

As an electric motor provided to the market by the applicant of the present application, a cylindrical coil arranged concentrically with respect to a rotation center axis in a housing, one end face being supported by a stator, and extending in a direction in which the rotation center axis extends. There is a structure including a rotor which is arranged concentrically with respect to the rotation center axis in the housing and rotates in the circumferential direction of the rotation center axis.

The rating of this coreless motor is that the rated torque T ₀ = 0.28 Nm, the rated current I ₀ = 9.7 Arms, the rated rotation speed n ₀ = 6537 rpm, under the condition that the temperature of the cylindrical coil does not exceed the allowable upper limit temperature 130 ° C. The rated output P ₀ = 191.67 W.

When this coreless motor was used and driven under conditions exceeding the rating, the allowable upper limit temperature of the cylindrical coil exceeded 130 ° C in just a few tens of seconds after the start of driving. The worst situation that can be easily assumed from this is that the cylindrical coil is burnt and destroyed when driven under conditions exceeding the rating. Moreover, even if the motor is not destroyed, it cannot be expected that the coreless motor will operate normally for a long time from the viewpoint of performance.

In this way, although the electric motor may momentarily exceed the rated current at the time of starting, etc., it is not normally assumed that the electric motor will be continuously operated in a state where the rated current is exceeded. When the electric motor is continuously operated in an overloaded state, that is, at a rating exceeding the rating, the coil of the electric motor generates heat more than expected due to the electric current.

Therefore, the inventor of the present application installs a cooling mechanism in a coreless motor provided with a cylindrical coil to prevent deterioration of the performance of the electric motor due to heat generation of the cylindrical coil and heating of the magnet, or exceeds the rating. We are proposing to enable operation under load (Patent Documents 1 and 2).

Further, various proposals have been made conventionally to add a cooling function to an electric motor (for example, Patent Documents 3 and 4).

Japanese Patent No. 59433333 Japanese Patent No. 6399721 Japanese Unexamined Patent Publication No. 4-359653 JP-A-2018-157645

An object of the present invention is to provide a coreless motor capable of suppressing overheating of a coil during motor operation and supplying an excessive current to the coil to output an electric motor at high speed with a simple structure. There is.

The housing that constitutes the coreless motor is sealed, and the liquid refrigerant is made finer and finer by flowing the liquid refrigerant at high speed in the housing by the rotor that rotates at high speed in the housing. As a result, the sprayed liquid refrigerant flows at high speed in the housing. Further, a part of the flowing liquid refrigerant comes into contact with the generating coil and vaporizes. As a result, the atmosphere inside the housing is made into a gas-liquid mixed state. The atmosphere inside the housing becomes a gas-liquid mixed state in which a sprayed liquid refrigerant exists, so that the heat conduction from the coil that generates heat by energization to the housing is improved. As a result, the temperature of the housing is efficiently raised to the same temperature as the heating coil, and heat is dissipated from the entire outer surface of the housing. This suppresses overheating of the coil during operation of the coreless motor, and makes it possible to supply an excessive current to the coil to output the coreless motor at high speed.

[1]
A central axis of rotation extending axially in the center of the sealed housing,
A cylindrical coil that is arranged concentrically with respect to the rotation center axis in the housing, and one end surface of which is supported by a stator and extends in a direction in which the rotation center axis extends.
A rotor that is arranged concentrically with respect to the rotation center axis in the housing and rotates in the circumferential direction of the rotation center axis.
A coreless motor housed in the housing and provided with a liquid refrigerant that flows in the housing by rotation of the rotor and comes into contact with the cylindrical coil.

[2]
The rotor includes an inner yoke and an outer yoke that sandwich the cylindrical coil between each other in the radial direction, and the outer yoke has a hole that penetrates the outer yoke in the radial direction [1]. Coreless motor.

[3]
A central axis of rotation extending axially in the center of the sealed housing,
A cylindrical coil that is arranged concentrically with respect to the rotation center axis in the housing, and one end surface of which is supported by a stator and extends in a direction in which the rotation center axis extends.
A rotor that is arranged concentrically with respect to the rotation center axis in the housing and rotates about the rotation center axis.
A speed reducer provided in the housing and composed of a planetary gear mechanism that transmits the rotational motion of the rotor about the central axis of rotation to the rotational motion of the rotational motion output unit.
A coreless motor housed in the housing and provided with a liquid refrigerant that flows in the housing by rotation of the rotor and comes into contact with the cylindrical coil.

[4]
The speed reducer is housed in a cylindrical gear case extending in a direction in which the central axis of rotation extends, and the gear case has a hole that penetrates the gear case in the radial direction [3]. Coreless motor.

[5]
A valve body is provided in the housing to prevent liquid from leaking from the inside of the housing to the outside and to eject gas from the inside of the housing to the outside when the pressure in the housing exceeds a predetermined pressure. The coreless motor according to any one of [1] to [4].

According to the present invention, it is possible to provide a coreless motor capable of suppressing overheating of a coil during motor operation and supplying an excessive current to the coil to output an electric motor at high speed with a simple structure. ..

FIG. 5 is an enlarged cross-sectional view in which a part for explaining the internal structure of the coreless motor according to the embodiment of the present invention is omitted. FIG. 1 is an enlarged cross-sectional view in which a part of explaining the internal structure of another embodiment of the coreless motor of the illustrated embodiment is omitted. FIG. 1 is a conceptual diagram illustrating another embodiment of the liquid refrigerant stirring means in another embodiment of the coreless motor of the illustrated embodiment. FIG. 5 is an enlarged cross-sectional view in which a part for explaining the internal structure of the coreless motor according to another embodiment of the present invention is omitted. FIG. 4 is an enlarged cross-sectional view in which a part of explaining the internal structure of another embodiment of the coreless motor of the illustrated embodiment is omitted. FIG. 5 is a side view of the cylindrical gear case used in the illustrated embodiment. FIG. 5 is a perspective view of a cylindrical gear case used in the illustrated embodiment. FIG. 4 is a perspective view of another embodiment of the coreless motor of the illustrated embodiment. FIG. 8 is a perspective view showing a part of the illustrated coreless motor for explaining the internal structure, with a part cut off and a part omitted. FIG. 8 is a cross-sectional view showing the internal structure of the illustrated coreless motor by omitting a part thereof.

(Embodiment 1)
The coreless motor 1 shown in FIG. 1 includes a sealed housing 4 and a rotation center axis 5 extending in an axial direction (horizontal direction in FIG. 1) at the center of the housing 4.

In the embodiment shown in FIG. 1, the rotation center shaft 5 is rotatably supported by the housing 4, and the rotation center shaft 5 serves as a rotary motion output unit in the coreless motor 1.

In the illustrated embodiment, the sealed housing 4 is composed of a cylindrical casing 2 and a disc-shaped lid 3 that closes the right end side opening of the cylindrical casing 2 in FIG. ..

The cylindrical casing 2 includes a disc-shaped portion 2b and a cylindrical portion 2a. The right end portion of the cylindrical portion 2a constituting the cylindrical casing 2 in FIG. 1 is crimped to the disc-shaped lid portion 3 via

packings

7a and 7b. The rotation center shaft 5 is rotatably supported by the housing 4 via the sealed

bearings

6a, 6b, 6c, and 6d inside the lid portion 3 in the radial direction. As the bearing 6a with a seal, for example, a bearing with an oil seal can be adopted. Hereinafter, in the present specification, the sealed

bearings

6a, 6b, 6c, 6d may be simply referred to as ringing 6a, 6b, 6c, 6d.

In the illustrated embodiment, the housing 4 is sealed by the presence of the

packings

7a and 7b and the

bearings

6a, 6b, 6c and 6d.

The coreless motor 1 is provided with a cylindrical coil 8 and a rotor 12 inside the housing 4.

The cylindrical coil 8 is arranged concentrically with respect to the rotation center axis 5, and the end face on one side (the right end face in the embodiment of FIG. 1) is supported by a stator supported by the housing 4 to provide a center of rotation. The shaft 5 extends in the extending direction.

The cylindrical coil 8 is an ironless core coil that can be energized. In the illustrated embodiment, in FIG. 1, a laminated structure of conductive metal sheets formed by superimposing a plurality of separated linear portions and an insulating layer in the longitudinal direction, which is the direction in which the central axis of rotation 5 extends. It is formed in a cylindrical shape. The thickness in the radial direction is, for example, 5 mm or less, and has a predetermined rigidity. Such a cylindrical coil is manufactured, for example, by the manufacturing method described in Japanese Patent No. 3704044.

The rotor 12 is arranged concentrically with respect to the rotation center axis 5 and is supported by the rotation center axis 5 on the radial center side. FIG. 1 In the illustrated embodiment, the rotor 12 is composed of an inner yoke 9 and an outer yoke 10 that sandwich the cylindrical coil 8 between them in the radial direction. The outer yoke 10 is provided with a magnet 11 on the inner surface in the radial direction facing the inner yoke 9. As a result, a magnetic field having a donut-shaped cross section is formed between the outer yoke 10 having the magnet 11 on the inner side surface in the radial direction and the inner yoke 9 sandwiching the cylindrical coils 8 between each other, and a magnetic circuit is formed. Has been done.

In the embodiment shown in FIG. 1, the magnet 11 is provided on the inner side surface in the radial direction of the outer yoke 10, but instead, the magnet 11 is provided on the outer surface in the radial direction of the inner yoke 9. You can also do it.

The liquid refrigerant 20 is housed in the sealed housing 4. FIG. 1 In the illustrated embodiment, the disc-shaped lid 3 of the housing 4 includes an opening 14 sealed by a plug 15.

The plug 15 is removed from the opening 14, a predetermined amount of the liquid refrigerant 20 is put into the housing 4, and then the opening 14 is closed again with the plug 15 to maintain the sealed state of the housing 4.

As the liquid refrigerant 20, oil, antifreeze, water, etc. used for lubricating the mechanical operation part can be adopted.

In the coreless motor 1 shown in FIG. 1, the rotor 12 is centered on rotation by supplying a predetermined current to the cylindrical coil 8 under a magnetic field having a donut-shaped cross section formed between the inner yoke 9 and the outer yoke 10. It rotates in the circumferential direction of the shaft 5. The inside of the inner yoke 9 constituting the rotor 12 in the radial direction is supported by the rotation center axis 5, whereby the rotation center axis 5 also rotates in the circumferential direction indicated by the arrow 21 in FIG.

In the coreless motor 1 of the embodiment shown in FIG. 1, in the liquid refrigerant 20 housed in the sealed housing 4, the rotor 12 rotates at high speed in the circumferential direction of the rotation center axis 5 as described above. As a result, it is made finer and finer, becomes a spray state, and flows in the housing 4 at high speed. The sprayed liquid refrigerant 20 that flows in the housing 4 at high speed has a donut-shaped gap formed between the radial inside of the magnet 11 and the radial outside of the cylindrical coil 8 and the inner yoke 9. It enters the gap having a donut-shaped cross section formed between the radial outside of the cylinder 8 and the radial inside of the cylindrical coil 8.

The cylindrical coil 8 receiving the electric current generates heat, and a part of the sprayed liquid refrigerant 20 in contact with the radial inner surface and the radial outer surface of the cylindrical coil 8 is a high-temperature cylindrical coil. It is vaporized by 8.

As a result, the internal space of the housing 4 is made finer and finer by the rotor 12 rotating at high speed, and becomes a gas-liquid mixed state in which the liquid refrigerant in the sprayed state exists. The rotor 12 rotates at high speed in a closed atmosphere in this gas-liquid mixed state. A gas-liquid mixture in a sprayed state flows in the housing 4 in a sealed state by a rotor 12 rotating at a high speed, so that a cylindrical coil that generates heat by energization is compared with a state in which only gas is contained in the housing 1. Heat conduction from 8 to housing 4 is improved.

As a result, when the energization of the cylindrical coil 8 is started, the rotor 12 starts to rotate, and the temperature of the cylindrical coil 8 starts to rise, the disk-shaped portions 2b and the cylindrical portions 2a constituting the housing 4 The temperature also begins to rise, and the temperatures of the disk-shaped portion 2b and the cylindrical portion 2a gradually approach the temperature of the cylindrical coil 8. In this way, heat is dissipated from a wide heat dissipation area of the outer surface of the disk-shaped portion 2b and the cylindrical portion 2a.

As a result, it becomes possible to suppress overheating of the cylindrical coil 8 during operation of the coreless motor 1 and supply an excessive current to the cylindrical coil 8 to output the coreless motor 1 at a high rotation speed.

FIG. 1 In the illustrated embodiment, the liquid refrigerant 20 stored in the sealed housing 4 is stored in the housing 4 in contact with a part of the rotor 12. Therefore, as soon as the rotor 12 rotates, the liquid refrigerant 20 starts to flow in the housing 4.

Although not shown, the liquid refrigerant 20 stored in the housing 4 may not be in contact with a part of the rotor 12. Even in this case, the rotor 12 rotates at high speed in the housing 4, so that a high-speed air flow is generated in the housing 4 in the rotation direction of the rotor 12, and the liquid refrigerant 20 flows in the housing 4 by this air flow. It will start.

In the embodiment shown in FIG. 1, the outer yoke 8 includes

holes

13a, 13b, 13c, and 13d that penetrate the outer yoke 8 in the radial direction.

When the rotor 12 rotates, the liquid refrigerant 20 can flow inward in the radial direction of the outer yoke 8 through the

holes

13a, 13b, 13c, and 13d.

Therefore, the flow state of the liquid refrigerant 20 in the housing 4 is more activated, and the gas-liquid mixed state in the housing 4 internal space described above is generated more efficiently.

As described above, even if the liquid refrigerant 20 housed in the sealed housing 4 is in contact with or not in contact with a part of the rotor 12, the high-speed rotation of the rotor 12 causes the internal space of the housing 4 to be in contact with the rotor 12. However, as described above, the rotor 12 is provided with the holes 13a penetrating in the radial direction, so that the gas-liquid mixed state is generated more efficiently and the cylindrical coil 8 is generating heat. More efficient heat conduction from to the housing 4 is provided.

FIG. 1 In the illustrated embodiment, a plurality of

holes

13a, 13b, 13c, and 13d are formed at predetermined intervals in the circumferential direction on the left end side of the cylindrical outer rotor 10 in FIG. The number and the position where the hole is provided are not limited to those shown in FIG.

Further, in this embodiment, instead of the closed structure by the opening 14 and the plug 15, the valve body 36 adopted in the embodiment shown in FIG. 4 described later is adopted, and the pressure in the housing 4 is predetermined. When the pressure is exceeded, gas is ejected from the inside of the housing 4 to the outside, and when the pressure inside the housing 4 falls below the predetermined pressure, the housing 4 can be sealed and sealed again.

(Embodiment 2)
FIG. 2 illustrates an example of an embodiment in which the liquid refrigerant 20 housed in the sealed housing 4 is more efficiently flowed in the housing 4 by the rotation of the rotor 12.

The rotor 12 includes stirring

blades

16 and 16 extending toward the inner peripheral surface side of the cylindrical portion 2a of the housing 4. Since the other structures are the same as those of the embodiment shown in FIG. 1, the common members are designated by common reference numerals and the description thereof will be omitted.

Since the rotor 12 includes stirring

blades

16 and 16 extending toward the inner peripheral surface side of the cylindrical portion 2a of the housing 4, the rotor 12 is generated by rotating in the circumferential direction of the rotation center axis 5. The flow of the liquid refrigerant 20 in the housing 4 becomes more reliable and powerful.

2 In the illustrated embodiment, the stirring

blades

16 and 16 are on the outer side in the radial direction of the rotor 12 and have a radius from the right end surface in FIG. 2 toward the inner peripheral surface side of the cylindrical portion 2a of the housing 4. It extends outward in the direction and toward the inner surface side of the disc-shaped portion 2b of the housing 4.

Therefore, when the coreless motor 1 is arranged in the arrangement shown in FIGS. 1 and 2 and the liquid refrigerant 20 is accommodated as shown in FIGS. 1 and 2, the coreless motor 1 is also not shown, although not shown. , The liquid refrigerant 20 stored in the housing 4 is arranged so that the disk-shaped portion 2b of the housing 4 is on the lower side and the tip of the rotation center shaft 5 extending toward the outside of the housing 4 is on the upper side. Even when the rotor 12 is located on the disk-shaped portion 2b side, the flow of the liquid refrigerant 20 in the housing 4 generated by the rotation of the rotor 12 in the circumferential direction of the rotation center axis 5 is more reliable and powerful. Will come to be.

(Embodiment 3)
FIG. 3 is a conceptual diagram illustrating another example of the embodiment in which the liquid refrigerant 20 housed in the sealed housing 4 is more efficiently flowed in the housing 4 by the rotation of the rotor 12.

The cylindrical coil 8 is provided with a protrusion 17 for stirring extending outward in the radial direction.

When the rotor 12 rotates, the liquid refrigerant 20 may be pressed against the radial outer surface of the cylindrical coil 8 by the centrifugal force generated by the rotation of the rotor 12, as shown in FIG.

In FIG. 3, a magnet 11 is provided on the inner surface of the outer yoke 10 in the radial direction, and the liquid refrigerant 20 enters around the magnet 11 to form a liquid pool.

Since the stirring protrusion 17 extending from the cylindrical coil 8 to the outside in the radial direction rushes into the liquid pool, the liquid pool is eliminated when the rotor 12 rotates, so that the liquid refrigerant 20 efficiently flows in the housing 4. become.

(Embodiment 4)
In the embodiment shown in FIGS. 1 and 2, the central axis of rotation extending axially at the center of the sealed housing 4 and being rotatably supported by the housing 4 is axially oriented in the embodiment shown in FIG. It is composed of a first rotation center axis 5a, a second rotation center axis 5b, and a third rotation center axis 5c extending in the left-right direction in FIG.

Further, in the embodiment shown in FIG. 4, a disk-shaped lid portion 3 is rotatably attached to the right end opening of the cylindrical portion 2a constituting the cylindrical casing 2 via

bearings

6a and 6b. The third rotation center shaft 5c is fixed to the disc-shaped lid portion 3 and rotates together with the disc-shaped lid portion 3.

In the embodiments of FIGS. 1 and 2, the inside of the rotor 12 in the radial direction is supported by the rotation center axis 5, and the rotation center axis 5 is directly rotated by the rotation of the rotor 12. FIG. 4 In the illustrated embodiment, a speed reducer including a planetary gear mechanism that transmits the rotational movement of the rotor 12 about the central rotation axis to the rotational movement of the third rotation central shaft 5c, which is the rotation movement output unit, is inside the housing 4. It is deployed in.

In the embodiment shown in FIGS. 1 and 2, the rotation center shaft 5 is the rotational movement output unit in the coreless motor 1, but due to the above-described configuration, in the embodiment shown in FIG. 4, the third rotation center shaft 5c is used. It is a rotary motion output unit in the coreless motor 1.

In the illustrated embodiment of FIGS. 1 and 2, the disc-shaped lid 3 of the housing 4 includes an opening 14 sealed by a plug 15, and the plug 15 is removed from the opening 14 to provide a predetermined amount. After the liquid refrigerant 20 was put into the housing 4, the opening 14 was closed again with the stopper 15 to maintain the sealed state of the housing 4.

On the other hand, in the embodiment shown in FIG. 4, the sealed housing 4 includes the valve body 36. In FIG. 4, the valve body 36 is arranged in the cylindrical portion 2a of the housing 4. The valve body 36 is detachable from the cylindrical portion 2a, the valve body 36 is removed from the cylindrical portion 2a, the liquid refrigerant 20 is put into the housing 4, and then the valve body 36 is shown again in FIG. As described above, the housing 4 is attached to the cylindrical portion 2a to seal the housing 4.

The valve body 36 has a function of preventing liquid from leaking from the inside of the housing 4 to the outside. Further, when the pressure inside the housing 4 exceeds a predetermined pressure, gas is ejected from the inside of the housing 4 to the outside, and when the pressure inside the housing 4 falls below the predetermined pressure, the housing 4 is sealed again. It has become.

Other configurations are basically the same as those of the first and second embodiments described with reference to FIGS. 1 and 2. Therefore, the members common to the embodiments shown in FIGS. 1 and 2 are designated by the same reference numerals as those shown in FIG. 4, and the description thereof will be omitted.

On the tip side (left side of FIG. 4) of the first rotation center shaft 5a which supports the inside of the rotor 12 in the radial direction and whose right end is rotatably supported by the disk-shaped portion 2b of the housing 4 in FIG. Is fixed with a first sun gear 30 constituting a speed reducer having a planetary gear mechanism.

When the first rotation center shaft 5a and the first sun gear 30 rotate according to the rotation of the rotor 12, this rotational motion is the second rotation from the first sun gear 30 via the first planet gear 31 and the first carrier 32. It is transmitted to the central axis 5b, and the second rotation central axis 5b rotates in the same circumferential direction as the first rotation central axis 5a.

A second sun gear 33 constituting a speed reducer composed of a planetary gear mechanism is fixed to the tip side (left side in FIG. 4) of the second rotation center shaft 5b.

When the second sun gear 33 rotates due to the rotation of the second rotation center shaft 5b, this rotational movement causes the third rotation center shaft 5c from the second sun gear 33 via the second planet gear 34 and the second carrier 35. It is transmitted to the disk-shaped lid portion 3 that is fixedly supported, and the third rotation center axis 5c rotates in the same circumferential direction as the second rotation center axis 5b (for example, the direction indicated by the arrow 21).

Also in this embodiment, the rotor 12 has a first rotation center axis by supplying a predetermined current to the cylindrical coil 8 under the formation of a donut-shaped magnetic field in cross section between the inner yoke 9 and the outer yoke 10. It rotates in the circumferential direction of 5a. The inner side of the inner yoke 9 constituting the rotor 12 in the radial direction is supported by the first rotation center axis 5a, whereby the first rotation center axis 5a also rotates in the circumferential direction.

The rotation of the first rotation center shaft 5a is transmitted to the third rotation center shaft 5c via the speed reducer including the planetary gear mechanism described above and is output.

In the embodiment shown in FIG. 4, the two-stage deceleration mechanism described above is used, and the torque due to the rotation of the rotor 12 is increased and output from the third rotation output shaft 5c.

The speed reducer having the configuration described above is a cylindrical gear case 18 in which the first rotation center shaft 5a, the second rotation center shaft 5b, and the third rotation center shaft 5c, which are the rotation center axes, extend in the extending direction. Is housed in.

FIG. 4 Even in the coreless motor 1 of the illustrated embodiment, in the liquid refrigerant 20 housed in the sealed housing 4, the rotor 12 rotates in the circumferential direction of the first rotation output shaft 5a as described above. As a result, it flows in the housing 4.

As a result, the internal space of the housing 4 becomes a gas-liquid mixed state, heat conduction is efficiently performed from the cylindrical coil 8 that generates heat by energization to the housing 4, and overheating of the cylindrical coil 8 during operation of the coreless motor 1 is suppressed. However, it is possible to supply an excessive current to the cylindrical coil 8 to output the coreless motor 1 at a high speed, which is the same as that described in the first and second embodiments.

In this embodiment, the housing 4 is provided with a valve body 36 having the above-mentioned function. Therefore, for example, when the coreless motor 1 is operated at a high output for a long time and the pressure inside the housing 4 exceeds a predetermined pressure, gas is ejected from the inside of the housing 4 to the outside. As a result, when the coreless motor 1 is movable at a high output for a long time and the pressure inside the housing 4 becomes equal to or higher than the allowable internal pressure, the above-mentioned ejection (exhaust) by the valve body 36 is performed. Therefore, it is possible to prevent the pressure inside the housing 4 from exceeding the allowable internal pressure.

In this embodiment, the housing 4 is the speed reducer including the planetary gear mechanism described above, which transmits the rotational movement of the rotor 12 about the central rotation shaft to the rotational movement of the third rotation center shaft 5c which is the rotation movement output unit. It is deployed inside.

When the oil used for lubricating the mechanical operation part is used as the liquid refrigerant 20, it is possible to lubricate each gear part in the speed reducer having the planetary gear mechanism described above.

As a result, in the embodiment shown in FIG. 4, a speed reducer including a planetary gear mechanism is provided in the housing 4, but the generation of sound due to the presence of a plurality of gears that rotate and mesh with each other is suppressed and quietly. It can be a driven coreless motor. The presence of an appropriately viscous oil keeps the rotating portion of the plurality of gears constituting the speed reducer stable.

Since the reducer is composed of a plurality of gears, metal powder is generated due to metal wear due to the rotation of the gears, and when the above-mentioned oil is used as the liquid refrigerant 20, the metal powder is mixed in the oil and the oil is mixed. It may get dirty.

However, since the magnet 11 is provided on the rotor 12 as described above, the metal powder is attracted to the magnet 11 and the oil can be prevented from becoming dirty.

Grease is generally used for motors, but highly viscous motors such as grease receive centrifugal force as they rotate and move away from the application site. On the other hand, in the present invention, since oil is used, grease is not required. In the first place, the grease used for lubrication of the gear portion of the gear mechanism generally liquefies at about 80 ° C., and the effect of using the grease cannot be obtained. Therefore, when grease is used for lubrication of a gear portion, it is common to prevent the temperature from reaching about 80 ° C.

In the coreless motor of the present embodiment, the temperature of the cylindrical coil portion that generates heat when energized generally exceeds 100 ° C., and this aspect also makes it unsuitable for the use of grease.

In addition, instead of the form in which the valve body 36 is adopted, the sealed structure with the opening 14 and the plug 15 described in the first embodiment can be adopted.

(Embodiment 5)
5 to 7 illustrate another embodiment of the fourth embodiment (FIG. 4). In the fourth embodiment (FIG. 4), as described above, the speed reducer extends in the direction in which the first rotation center axis 5a, the second rotation center axis 5b, and the third rotation center axis 5c, which are the rotation center axes, extend. It is housed in a cylindrical gear case 18.

5 to 7 In the illustrated embodiment 5, the gear case 18 is provided with a hole 19 that penetrates the gear case 18 in the radial direction.

As described above, when the rotor 12 rotates in the circumferential direction of the first rotation output shaft 5a, the liquid refrigerant 20 stored in the sealed housing 4 flows in the housing 4. A part of the liquid refrigerant 20 flowing in the housing 4 comes into contact with the heat-generating cylindrical coil and vaporizes, so that the internal space of the housing 4 becomes a gas-liquid mixed state, and the cylindrical coil generates heat when energized. Heat conduction is efficiently performed from 8 to the housing 4.

At the same time, the liquid refrigerant 20 flowing in the housing 4 is utilized for lubricating each gear portion in the speed reducer including the planetary gear mechanism.

5 to 7 In the illustrated embodiment, the cylindrical gear case 18 containing the speed reducer is provided with a hole 19 penetrating the gear case 18 in the radial direction, so that the liquid refrigerant 20 is generated. It is efficiently supplied to the reducer. Therefore, the lubrication of each gear portion by the liquid refrigerant 20 becomes more effective.

5 to 7 In the illustrated embodiment, a plurality of cylindrical gear cases 18 are spaced apart from each other in the circumferential direction and a plurality of intervals are spaced apart in the longitudinal direction of the cylindrical gear case 18. Hole 19 is formed.

The number of holes 19 and the position to be formed can be set variously.

(Embodiment 6)
8 to 10 show another embodiment of the fourth embodiment.

8 to 10 show the sealing structure of the housing 4 by the opening 14 and the plug 15 and the sealing structure of the housing 4 by the valve body 36, which were described in the first and fourth embodiments. Is omitted.

In the fourth embodiment (FIG. 4), the fixed shaft 5d penetrating the housing 4 through the rotation center shaft formed by the first rotation center shaft 5a, the second rotation center shaft 5b, and the third rotation center shaft 5c. I have to. The housing 4 is rotatably supported by the fixed shaft 5d via an oil seal while the inside of the housing 4 is hermetically sealed. The cylindrical portion 2a constituting the housing 4 is a rotary motion output portion.

In the embodiments of FIGS. 8 to 10, the radial center side of the inner yoke constituting the rotor 12 is rotatably supported by the fixed shaft 5d. The outer circumference 9a of the radial center side portion of the inner yoke rotatably supported by the fixed shaft 5d constitutes the first sun gear according to the fourth embodiment (FIG. 4).

In the fourth embodiment (FIG. 4), the rotational movement of the first sun gear that rotates with the first rotation central axis is transmitted via the first planet gear, the first carrier, the second sun gear, the second planet gear, and the third carrier. It was transmitted to the third rotary output shaft, which is the rotary motion output section.

8 to 10 In the illustrated embodiment, the rotational movement of the first sun gear including the outer circumference of the radial center side portion 9a of the inner yoke rotatably supported by the fixed shaft 5d is the first planetary gear, the first. The fixed shaft 5d of the cylindrical portion 2a constituting the housing 4, which is the rotary motion output portion via the carrier, the second sun gear, the second planet gear, and the third carrier rotatably supported by the fixed shaft 5d. It is transmitted to the rotational movement in the circumferential direction around the center.

Other basic structures and mechanisms are the same as those described in the fourth embodiment (Fig. 4).

Also in this embodiment, the liquid refrigerant 20 stored in the sealed housing 4 flows in the housing 4 when the rotor 12 rotates in the circumferential direction of the fixed shaft 5d. As a result, the internal space of the housing 4 becomes a gas-liquid mixed state, heat conduction is efficiently performed from the cylindrical coil 8 that generates heat by energization to the housing 4, and overheating of the cylindrical coil 8 during operation of the coreless motor 1 is suppressed. However, it is possible to supply an excessive current to the cylindrical coil 8 to output the coreless motor 1 at a high speed, which is the same as that described in the first and second embodiments.

Further, by using the oil used for lubricating the mechanical operation part as the liquid refrigerant 20, each gear part of the speed reducer having a planetary gear mechanism can be lubricated, and the speed reducer made of a planetary gear mechanism can be used. Although it is arranged in the housing 4, it can be a coreless motor that is quietly driven by suppressing the generation of noise due to the presence of a plurality of gears that rotate and mesh with each other.

(Test example)
The test was performed using a coreless motor (CPH80F) commercially available by the applicant of the present application. This coreless motor has a cylindrical coil that is arranged concentrically with respect to the rotation center axis in the housing and whose end face on one side is supported by the stator and extends in the direction in which the rotation center axis extends, and a rotation center in the housing. It has a structure in which a rotor is arranged concentrically with respect to the shaft and rotates in the circumferential direction of the rotation center axis.

The two coreless motors (CPH80F) used in the test were both sealed, and one was operated under normal conditions with water as a liquid refrigerant inside and the other with no water. ..

The test operation was carried out simultaneously in the same room with 24Vdc input, torque: 1Nm, and output: 380W for both units. The results are shown in Table 1 (Example (with liquid refrigerant (water)) and Table 2 (Comparative Example (without liquid refrigerant (water))).

From this test result, the liquid refrigerant is housed in the housing of the sealed coreless motor, and the liquid refrigerant is made to flow in the housing by the rotation of the rotor, and the liquid refrigerant is brought into contact with the generating cylindrical coil. By vaporizing a part of the housing to make the inside of the housing a mixture of gas and liquid, the heat conduction efficiency inside the housing is improved, and the temperature of the housing rises following the temperature rise of the cylindrical coil. It was confirmed that heat was dissipated well.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be variously changed within the technical scope grasped from the description of the claims.

Claims

A central axis of rotation extending axially in the center of the sealed housing,
A cylindrical coil that is arranged concentrically with respect to the rotation center axis in the housing, and one end surface of which is supported by a stator and extends in a direction in which the rotation center axis extends.
A rotor that is arranged concentrically with respect to the rotation center axis in the housing and rotates in the circumferential direction of the rotation center axis.
A coreless motor housed in the housing and provided with a liquid refrigerant that flows in the housing by rotation of the rotor and comes into contact with the cylindrical coil.
The rotor includes an inner yoke and an outer yoke that sandwich the cylindrical coil between each other in the radial direction, and the outer yoke includes a hole that penetrates the outer yoke in the radial direction. The coreless motor described.
A central axis of rotation extending axially in the center of the sealed housing,
A cylindrical coil that is arranged concentrically with respect to the rotation center axis in the housing, and one end surface of which is supported by a stator and extends in a direction in which the rotation center axis extends.
A rotor that is arranged concentrically with respect to the rotation center axis in the housing and rotates about the rotation center axis.
A speed reducer provided in the housing and composed of a planetary gear mechanism that transmits the rotational motion of the rotor about the central axis of rotation to the rotational motion of the rotational motion output unit.
A coreless motor housed in the housing and provided with a liquid refrigerant that flows in the housing by rotation of the rotor and comes into contact with the cylindrical coil.
The speed reducer is housed in a cylindrical gear case extending in a direction in which the central axis of rotation extends, and the gear case has a hole that penetrates the gear case in the radial direction. The coreless motor described.
A valve body is provided in the housing to prevent liquid from leaking from the inside of the housing to the outside and to eject gas from the inside of the housing to the outside when the pressure in the housing exceeds a predetermined pressure. The coreless motor according to any one of claims 1 to 4.