KR102815002B1 - Cooling structure of motor integrated hollow reducer - Google Patents

Abstract

The present invention discloses a cooling structure for a motor-integrated hollow reducer.
Specifically, the invention comprises: a drive module including a motor case, a stator fixed to an inner surface of the motor case and having a coil wound thereon, and a rotor having a magnet attached to an outer surface and being rotatable at the center of the motor case; a hollow shaft having one end coupled to the rotor and rotating and the other end extended to the outside of the motor case and exposed; and a deceleration module directly coupled to the drive module and performing deceleration in a cycloidal manner using the other end of the hollow shaft as an input shaft; wherein a heat dissipation sheet is formed on the motor case.

Description

Cooling structure of motor integrated hollow reducer

The present invention relates to a cooling structure for a reducer, and more specifically, to a cooling structure in which a motor is integrally connected to a reducer, input and output shafts have hollow shafts, and the cooling function of the motor is improved by applying a heat dissipation structure.

A reducer is used to reduce the rotational speed of a high load transmitted through a drive shaft of a power source such as an electric motor or servo motor in automation, precision control equipment, etc., and is used by combining external or internal gears.

These reducers, in line with the trend toward miniaturization and precision, require a large number of gears in multiple stages to achieve a high reduction ratio, so they are larger and require high precision and complex processing.

In particular, among reducers, the cycloid reducer is a reducer widely used in the automobile, robot, and defense industries, and in particular, it is used as a main component in unmanned weapons in the defense industry.

According to the prior art Republic of Korea patent application number 20-2016-0005323 'Cooling structure of a motor' below, "a housing having an internal space and a sealed surface formed at one end with a plurality of wind outlets and an opening formed at the other end; a rotating shaft mounted in the housing and capable of rotating, the one end of which extends to the sealed surface as an output end and the other end is a connection end; a cover body having a first shaft hole on a central axis line and the rotating shaft extending through the first shaft hole; and a cooling blade fan inserted and fixed to the connection end of the rotating shaft and capable of synchronously rotating with the rotating shaft; a plurality of first flow guide openings having a space therebetween are formed on the outer periphery of the first shaft hole of the cover body, a wind-driven ring-shaped cover is provided on the cover body in front of the first flow guide opening, and a central shaft holder having a second shaft hole is provided at the center of the wind-driven ring-shaped cover, and the central shaft holder and the wind-driven ring-shaped cover A cooling structure of a motor is disclosed, wherein a plurality of second flow-guiding openings exist between the first flow-guiding openings on the cover body, and the second flow-guiding openings can correspond to the first flow-guiding openings on the cover body, and the two penetrate each other so that the circular forward airflow generated when the cooling blade fan rotates flows along the space surrounded by the wind-driving ring-shaped cover and the central shaft holder, thereby directly entering the inner space of the motor housing through the first and second flow-guiding openings.

And the prior art Republic of Korea patent application number 10-2009-0092319 'Cooling structure of a vehicle motor' below includes: "a cooling hole formed in a housing so that outside air can be introduced into a rotating body installation space of a housing in which a rotating body that receives current and rotates is located; an electromagnet that receives current together with the rotating body to generate magnetic force when the current is applied to the rotating body in the housing to rotate; a cooling hole opening/closing body having a cooling hole blocking portion capable of blocking the cooling hole and installed so as to be rotatable in response to the magnetic force, but in a state where the cooling hole blocking portion does not block the cooling hole when rotated in response to the magnetic force of the electromagnet and in a state where the cooling hole blocking portion blocks the cooling hole when rotated in the opposite direction; and an elastic body that rotates the cooling hole opening/closing body so that the cooling hole is blocked by the cooling hole blocking portion when the cooling hole opening/closing body is not rotated by the magnetic force of the electromagnet; The "composed motor cooling structure" was announced.

Also, in the prior art Republic of Korea 10-2017-0165191 'Motor Cooling Structure' below, a motor cooling structure including "a motor housing having an inner wall and an outer wall, and a plurality of heat dissipation fins formed on the inner wall; an inlet boss obliquely connected to the motor housing; an outlet boss obliquely connected to the motor housing and spaced apart from the inlet boss; and a first cooling channel and a second cooling channel formed between the inner wall and the outer wall and connected in parallel to the inlet boss and the outlet boss" is proposed.

Meanwhile, a hollow reducer with an integrated motor is often used in a cycloidal reducer with a planetary gear reduction method.

In the case of hollow reducers, cables and shafts can be arranged through the hollow shaft, ensuring applicability and providing the advantage of lightweight and compact products.

However, most conventional reducers use transmission means such as gears or pulleys to couple the motor to the input shaft, and the motor is attached separately to one side of the reducer, so there is no structure that is integrated with the reducer. Therefore, the structure becomes complex, the volume increases, and there are disadvantages of being heavy.

And there is a problem that the efficiency of the motor decreases when operating for a long time because there is no structure to cool the actual motor heat.

Republic of Korea Application No. 20-2016-0005323 Republic of Korea application number 10-2009-0092319 Republic of Korea Application No. 10-2017-0165191

Accordingly, an object of the present invention is to provide a cooling structure for a motor-integrated hollow reducer having a structure capable of cooling the heat generation of the motor and a reducer sharing a single hollow shaft, thereby having a simple structure and a structure that can be miniaturized and made lightweight.

In order to achieve these purposes, a cooling structure of a hollow reducer integrated with a motor according to the present invention may include a motor case, a drive module including a stator fixed to an inner surface of the motor case and having a coil wound thereon, and a rotor having a magnet attached to an outer surface and being rotatably driven at the center of the motor case; a hollow shaft having one end coupled to the rotor and rotating and the other end extended to the outside of the motor case and exposed; and a deceleration module directly coupled to the drive module and performing deceleration using the other end of the hollow shaft as an input shaft.

In addition, the motor case includes a body in the shape of a circular tube, a cover covering the body, and a partition part separating the body from the reduction module. Preferably, the body, the cover, and the partition part are each provided with a heat dissipation sheet part having repetitive unevenness formed thereon to increase the surface area with respect to air.

Here, the heat dissipation sheet part formed on the body may have a structure in which the protrusions are formed parallel along the longitudinal direction of the body, the heat dissipation sheet part formed on the cover may have a structure in which the protrusions are formed concentrically in the radial direction, and the heat dissipation sheet part formed on the partition part may have a structure in which the protrusions are formed radially in the radial direction.

In addition, the lubricating oil circulating inside the above-mentioned reduction module can perform cooling by coming into contact with the heat dissipation sheet portion of the above-mentioned plate portion.

According to the present invention described above, the following effects are achieved.

First, the use of a hollow shaft improves space utilization and makes it lightweight.

Second, by attaching a heat-dissipating sheet to the surface of the drive module, the motor cooling efficiency is improved. In particular, the lubricating oil that cools the reduction module can also cool the drive module, so the cooling efficiency is greatly improved.

Figure 1 is a perspective view showing the exterior of the cooling structure of a motor-integrated hollow reducer according to one embodiment of the present invention.
Figure 2 is a cross-sectional perspective view of the present invention shown in Figure 1.
Figure 3 is a perspective view showing the motor case of the present invention illustrated in Figure 1.
Figure 4 is a perspective view showing the hollow shaft of the present invention illustrated in Figure 1.
Figure 5 is an exploded perspective view showing the structure of the reduction module of the present invention illustrated in Figure 1.

Hereinafter, the embodiments of the present invention are provided for easier understanding of the present invention, and the scope of the present invention is not limited thereto. That is, the embodiments below are provided to ensure that the disclosure of the present invention is complete, and to fully inform a person having ordinary skill in the art to which the present invention belongs of the scope of the invention, and the present invention is defined only by the scope of the claims.

And the terminology used in this specification is for the purpose of describing embodiments, and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated in the phrase. As used in the specification, "comprises" and/or "comprising" do not exclude the presence or addition of one or more other components in addition to the mentioned components.

In addition, unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with a meaning that can be commonly understood by a person of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries shall not be ideally or excessively interpreted unless explicitly and specifically defined.

In addition, when explaining the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, a detailed description may be omitted.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Fig. 1 is a perspective view showing the exterior of a cooling structure of a motor-integrated hollow reducer according to one embodiment of the present invention, and Fig. 2 is a longitudinal sectional perspective view of the present invention shown in Fig. 1.

Referring to the drawing, the present invention may be composed of a driving module (100) that inputs a high-speed driving force, a hollow shaft (200) that is coupled to the input shaft of the driving module (100) and rotates, and a deceleration module (300) that is directly coupled to the driving module (100) and shares the hollow shaft (200) while decelerating the high speed input to the input shaft to a low speed and outputting it.

First, the driving module (100) will be described with reference to Fig. 3. Fig. 3 is a perspective view showing the motor case of the present invention illustrated in Fig. 1.

The above driving module (100) is implemented including a motor case (110), a stator (120), a rotor (130), and a cooling structure formed in the motor case (10).

First, the motor case (110) has a hollow cylindrical shape.

To explain in more detail, the motor case (110) may be composed of a body (111) in the shape of a circular tube, a partition (112) that seals one end of the body (111) and divides the space between the reduction module (300) and the drive module (100), and a cover (113) that is assembled and detachably connected to the other end of the body (111).

And a donut-shaped stator (120) is fixed to the inner surface of the motor case (110).

The above stator (120) has a structure in which coils (123) are wound around a plurality of teeth (122) that are formed to protrude radially toward the center of the core (121) along the inner surface of the core (121) in the shape of a circular ring. At this time, the core (121) and the teeth (122) are made of a metal material, and an insulator is interposed between the teeth (122) and the coil (123).

In addition, the rotor (130) is rotatably provided in the center of the motor case (110) and is rotationally driven. The rotor (130) may have a hollow tube shape as illustrated.

At this time, a step (131) is formed on one end of the inner surface of the rotor (130), so that the hollow shaft (200) can be inserted into the rotor (130) and joined while being seated on the step (131).

A plurality of magnets (132) are attached to the outer surface of the rotor (130). Here, the magnets (132) are adjacent to and facing the coils (123) of the stator (120), so that the rotor (130) is rotated by the magnetic field formed by the coils (123).

In the present invention, it is preferable that a cooling structure made of a heat dissipation sheet part (114) is provided in the motor case (110) to cool the heat generated in the driving module (100).

Specifically, the heat dissipation sheet portion (114) has a structure in which mountains and valleys are repeatedly formed on part or the entire outer surface of the motor case (110).

These unevennesses increase the surface area of the motor case (110) that comes into contact with a fluid such as air or lubricant, thereby facilitating heat dissipation.

At this time, the heat dissipation sheet portion (114) formed on the body (111), cover (113) and partition portion (112) may have the same uneven shape, but it is preferable to form them in various ways as illustrated.

As an example, the body (111) may have a recessed structure in which mountains and valleys are repeatedly formed in a straight line along the length direction of the body (111), the cover (113) may have a recessed structure in which circular mountains and valleys are repeatedly formed in a radial direction from the center of the cover (113), and the partition wall portion (112) may have a recessed structure in which mountains and valleys are formed in a straight line in a radial direction from a central hole formed in the center through which the hollow shaft (200) passes. However, the present invention is not limited thereto, and it is obvious that the present invention may have various shapes.

In addition, the uneven heat dissipation sheet (114) formed on the motor case (110) not only has a heat dissipation effect, but also has the effect of increasing the strength of the motor case.

Next, the hollow shaft (200) will be described with reference to FIG. 4. FIG. 4 is a perspective view showing the hollow shaft of the present invention illustrated in FIG. 1.

The above hollow shaft (200) has a hollow tube shape and one end is connected to the rotor (130) as described above.

And the other end of the hollow shaft (200) is extended and exposed to the outside through the central hole of the plate portion (112).

The above hollow shaft (200) operates as an input shaft of the reduction module (300) described later.

To this end, it is preferable to have an eccentric shaft structure in which a pair of eccentric cams (210) are formed on the outer surface of the other end of the hollow shaft (200).

Next, the deceleration module (300) will be described with reference to FIG. 2 and FIG. 5 together. FIG. 5 is an exploded perspective view showing the structure of the deceleration module of the present invention illustrated in FIG. 1.

When the rotational power driven at high speed from the above driving module (100) is input through the above hollow shaft (200), deceleration is performed in the above reduction module (300). The above reduction module (300) can use various reducers, but the present invention describes a reduction module using a cycloid gear method.

In the present invention, the reduction module (300) is integrated by being joined to the motor case (110) of the drive module (100), which is a combination of the body (111) and the cover (113), and is partitioned by the partition plate (112) as described above, and accommodates the other end of the hollow shaft (200) exposed to the outside from the motor case (110) inside.

In detail, the above reduction module (300) can be implemented to include a reduction case (310), a ring gear pin groove (320), a ring gear pin (330), an eccentric cam (210), a roller bearing (340), a disk gear (350), a first output flange (360), a second output flange (370), a disk pin (380), and a flange fixing pin (390).

The above-mentioned reduction gear case (310) has a cylindrical shape with both ends open to correspond to the above-mentioned motor case (110) and is directly connected to the above-mentioned motor case (110). In addition, the hollow shaft (200) penetrates and is received through the inner center.

And the above ring gear pin groove (320) is a ring gear formed on the inner surface of the reduction gear case (310) and may have a (hypo)cycloidal tooth shape.

In addition, the above ring gear pin (330) has a roller shape, and a plurality of them mesh with each tooth of the above ring gear pin groove (320).

At this time, the ring gear pins (330) are arranged in a parallel circle at regular intervals, and both ends can be fixed with a tapered bearing (331, 332) in the shape of a circular ring. The outer surface of each of the tapered bearings (331, 332) is coupled to the inner surface of the reducer case (310), and the inner surface rotatably supports the first output flange (360) and the second output flange (370), respectively.

In addition, the eccentric cam (210) is formed symmetrically at 180° with a first eccentric cam and a second eccentric cam divided to form an eccentricity with respect to the center of the hollow shaft (200) on the outer surface of the other end of the hollow shaft (200). A roller bearing (340) is connected to the eccentric cam (210).

The above roller bearing (340) has a circular ring shape through which the hollow shaft (200) passes, and is provided as a pair of a first roller bearing (341) and a second roller bearing (342) of the same shape, and is provided to surround the outer periphery of the first eccentric cam (211) and the second eccentric cam (212), respectively. A plurality of rollers are installed at regular intervals in the roller bearing (340).

Accordingly, the roller bearing (340) also rotates eccentrically in different phases in conjunction with the eccentric cam (210). For reference, the rollers of the first roller bearing (341) and the second roller bearing (342) are arranged misaligned from each other.

Meanwhile, the above disk gear (350) has a circular ring shape through which the hollow shaft (200) passes, and an (epi) cycloidal tooth shape is formed along the outer periphery, and is provided as a pair of first disk gears (351) and second disk gears (352) that are overlapped in parallel with each other.

At this time, the first disk gear (351) is provided to surround the outer circumference of the first roller bearing (341), and the teeth form a rolling contact with the ring gear pin (330). Similarly, the second disk gear (352) is provided to surround the outer circumference of the second roller bearing (342), and the teeth form a rolling contact with the ring gear pin (330).

At this time, the first disk gear (351) and the second disk gear (352) also mesh with the ring gear pin (330) with different phases, and revolve eccentrically with a phase difference of 180° according to the rotation of the roller bearing (340). And, since they come into contact with the ring gear pin (330), they rotate eccentrically with different phases due to the difference in the number of teeth of the disk gear (350) and the number of ring gear pins.

What is important is that the first disk gear (351) and the second disk gear (352) are integrated by having one or more flange fixing pins (390) pass through them and the first output flange (360) and the second output flange (370) are respectively coupled to both ends of the flange fixing pins (390).

And the first output flange (360) is formed in a circular ring shape so that the hollow shaft (200) penetrates through it, and is provided between the first disk gear (351) and the plate portion (112) of the drive module (100).

The above second output flange (370) is also formed in a circular ring shape so that the hollow shaft (200) passes through it, and is provided on the outside of the second disk gear (352).

Accordingly, the first disk gear (351) and the second disk gear (352) are arranged facing each other between the first output flange (360) and the second output flange (370).

Here, a first output flange groove (361) is formed on the side of the first output flange (360) so that one end of the flange fixing pin (390) can be inserted and fastened, and a second output flange groove (371) is formed on the side of the second output flange (370) so that the other end of the flange fixing pin (390) can be inserted and fastened.

In addition, one or more disk pins (380) are inserted while penetrating through the first and second output flanges (360, 370) and the first and second disk gears (351, 352) along with the above flange fixing pins.

To this end, a disk pin hole (353) having a corresponding shape is formed in the disk gear (350) so that the disk pin (380) can pass through it.

Since it is structured in this way, when the disk gear (350) rotates eccentrically, the first output flange (360) rotates in the same phase, and at the same time, the second output flange (370) also rotates in the same phase.

And the rotational power of the first output flange (360) is transmitted to the output flange (370) by the flange fixing pin (390). This second output flange (370) is connected to an output shaft (not shown) to obtain a reduced output.

In the present invention, lubricating oil circulating in the reduction module (300) can contact the grating portion to perform cooling.

In other words, lubricating oil is injected and circulated inside the reduction module (300) for lubrication and cooling, and since this lubricating oil comes into direct contact with the heat dissipation sheet portion (114) of the plate portion (112), it also cools the drive module (100).

Therefore, there is an advantage in that the lubricating oil can simultaneously cool the driving module (100) by integrating the reduction module (300) and the driving module (100).

Although the present invention has been described with reference to drawings according to embodiments thereof, those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above contents.

100 : Drive module
110: Motor case 111: Body
112 : Grip 113 : Cover
114: Heat dissipation sheet 120: Stator
121: Core 122: Teeth
123 : Coil 130 : Rotor
131: Single jaw 132: Permanent magnet
200: Hollow shaft 210: Eccentric cam
211: 1st eccentric cam 212: 2nd eccentric cam
300: Reducer module 310: Reducer case
320: Ring gear pin home 330: Ring gear pin
331, 332: Tapered bearing 340: Roller bearing
341: First roller bearing 342: Second roller bearing
350 : Disc gear 351 : 1st disc gear
352: 2nd disc gear 353: Disc pin hole
360: 1st output flange 361: 1st output flange home
370: 2nd output flange 371: 2nd output flange home
380: Disc pin 390: Flange fixing pin

Claims (4)

A cooling structure of a hollow reducer integrated with a motor, comprising: a motor case; a drive module including a stator fixed to an inner surface of the motor case and having a coil wound thereon; and a rotor having a magnet attached to an outer surface and being rotated at the center of the motor case; a hollow shaft having one end coupled to the rotor and rotating and the other end extended to the outside of the motor case and exposed; and a reduction module directly coupled to the drive module and performing reduction using the other end of the hollow shaft as an input shaft;
The above motor case comprises a body in the shape of a circular tube, a cover covering the body, and a partition part separating the reduction module, and the body, cover, and partition part are each provided with a heat dissipation sheet part having repetitively formed unevenness to increase the surface area with which air or lubricating oil comes into contact.
The heat dissipation sheet portion formed on the body has a rough structure in which mountains and valleys are repeatedly formed in a straight line along the longitudinal direction of the surface of the body, the heat dissipation sheet portion formed on the cover has a rough structure in which circular mountains and valleys are repeatedly formed in a radial direction from the center, and the heat dissipation sheet portion formed on the partition portion has a rough structure in which mountains and valleys are formed in a straight line in a radial direction from the central hole, thereby
A cooling structure for a hollow reducer integrated with a motor, characterized in that the lubricating oil circulating inside the reduction module comes into contact with the heat dissipation sheet of the plate section to cool the drive module. delete delete delete