Cooling structure of hollow reducer integrated with motor

Abstract

Disclosed is a cooling structure of a hollow reducer integrated with a motor. In particular, the present invention comprises: a driving module which comprises a motor case, a stator fixed to the inner circumferential surface of the motor case and having a coil wound therearound, and a rotor having a magnet attached to the outer circumferential surface thereof and rotatably driven at the center of the motor case; a hollow shaft which rotates with one end thereof coupled to the rotor, and the other end of which extends to the outside of the motor case to be exposed; and a deceleration module which is directly coupled to the driving module and performs deceleration in a cycloid manner by using the other end of the hollow shaft as an input shaft, wherein a heat dissipation sheet is provided in the motor case.

Description

Cooling structure of a motor-integrated hollow reducer

[0001] 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.

[0002] 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 and precision control equipment, and is used as a combination of external or internal gears.

[0003] 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, which increases their volume and requires high precision and complexity in processing.

[0004] In particular, among reducers, the cycloid reducer is a reducer widely used in the automobile, robot, and defense industries, and is particularly used as a major component in unmanned weapons in the defense industry.

[0005] According to the prior art patent application number 20-2016-0005323 of the Republic of Korea, '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 rotatable, one end of which extends to the sealed surface as an output end and the other end of which 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 synchronous rotation 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, and 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 are connected to each other. A cooling structure of a motor is disclosed, characterized in that there are a plurality of second flow guide openings therebetween, and the second flow guide openings can correspond to the first flow guide openings on the cover body, and the two are mutually penetrating, so that the circular swirling 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, and directly enters the internal space of the motor housing through the first and second flow guide openings.

[0006] And the prior art patent application number 10-2009-0092319 of the Republic of Korea, '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 where a rotating body that rotates when current is applied is located; an electromagnet that generates a magnetic force by receiving a current when a 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 a magnetic force, such that when the cooling hole blocking portion is rotated in response to the magnetic force of the electromagnet, the cooling hole blocking portion is not blocked, and when the cooling hole blocking portion is rotated in the opposite direction, the cooling hole blocking portion is installed so as to block the cooling hole; 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.

[0007] 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" was proposed.

[0008] Meanwhile, a hollow reducer with an integrated motor is often used in a cycloidal reducer with a planetary gear reduction method.

[0009] In the case of hollow reducers, cables and shafts can be arranged inside the hollow shaft, ensuring applicability and providing the advantage of lightweight and compact products.

[0010] However, most conventional reducers employ transmission mechanisms, such as gears or pulleys, to couple the motor to the input shaft. Furthermore, the motor is attached separately to one side of the reducer, lacking an integrated structure. This results in a complex structure, increased volume, and heavy weight.

[0011] And there is a problem that the efficiency of the motor decreases when operated for a long time because there is no structure that can cool the heat generated by the actual motor.

[0012] <Prior Art Literature>

[0013] (Patent Document 1) Republic of Korea Application No. 20-2016-0005323

[0014] (Patent Document 2) Republic of Korea Application No. 10-2009-0092319

[0015] (Patent Document 3) Republic of Korea Application No. 10-2017-0165191

[0016] 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 made small and lightweight.

[0017] In order to achieve this purpose, a cooling structure of a hollow motor-integrated reducer 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.

[0018] In addition, the motor case includes a body in the shape of a circular tube, a cover covering the body, and a partition plate that separates the body from the deceleration module. Preferably, the body, the cover, and the partition plate are each provided with a heat dissipation sheet having repetitive protrusions formed thereon to increase the surface area with respect to air.

[0019] 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.

[0020] Additionally, the lubricating oil circulating inside the above-mentioned reduction module can be cooled by contacting the heat dissipation sheet of the above-mentioned plate.

[0021] According to the present invention described above, the following effects are achieved.

[0022] First, the hollow shaft is applied to improve space utilization and enable weight reduction.

[0023] Second, by attaching a heat-dissipating sheet to the surface of the drive module, motor cooling efficiency is improved. In particular, the lubricant used to cool the reduction module also cools the drive module, significantly improving cooling efficiency.

[0024] 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.

[0025] Figure 2 is a cross-sectional perspective view of the present invention shown in Figure 1.

[0026] Figure 3 is a perspective view showing the motor case of the present invention illustrated in Figure 1.

[0027] Figure 4 is a perspective view showing the hollow shaft of the present invention illustrated in Figure 1.

[0028] Figure 5 is an exploded perspective view showing the structure of the reduction module of the present invention illustrated in Figure 1.

[0029] <Explanation of symbols>

[0030] 100: Drive module

[0031] 110: Motor case 111: Body

[0032] 112: Grip 113: Cover

[0033] 114: Heat dissipation sheet 120: Stator

[0034] 121: Core 122: Teeth

[0035] 123: Coil 130: Rotor

[0036] 131: Step 132: Permanent magnet

[0037] 200: Hollow shaft 210: Eccentric cam

[0038] 211: First eccentric cam 212: Second eccentric cam

[0039] 300: Reduction module 310: Reduction case

[0040] 320: Ring gear pin groove 330: Ring gear pin

[0041] 331, 332: Tapered bearing 340: Roller bearing

[0042] 341: First roller bearing 342: Second roller bearing

[0043] 350: Disc gear 351: First disc gear

[0044] 352: Second disc gear 353: Disc pinhole

[0045] 360: First output flange 361: First output flange home

[0046] 370: Second output flange 371: Second output flange home

[0047] 380: Disc pin 390: Flange fixing pin

[0048] The following examples of the present invention are provided to facilitate a better understanding of the present invention and are not intended to limit the scope of the present invention. In other words, the following examples are provided to ensure a complete disclosure of the present invention and to fully inform those skilled in the art of the invention of the scope of the invention. The present invention is defined solely by the scope of the claims.

[0049] The terminology used herein 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 otherwise. As used herein, the terms "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components in addition to the components mentioned.

[0050] Additionally, unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with meanings commonly understood by those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0051] 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, the detailed description may be omitted.

[0052] Hereinafter, a preferred embodiment 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 the cooling structure of a motor-integrated hollow reducer according to an embodiment of the present invention, and Fig. 2 is a longitudinal sectional perspective view of the present invention illustrated in Fig. 1.

[0053] 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 the same.

[0054] First, the drive 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.

[0055] The above driving module (100) is implemented by including a motor case (110), a stator (120), a rotor (130), and a cooling structure formed in the motor case (10).

[0056] First, the motor case (110) has a hollow cylindrical shape inside.

[0057] 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 deceleration 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).

[0058] And a donut-shaped stator (120) is fixed to the inner surface of the motor case (110).

[0059] The above stator (120) has a structure in which a coil (123) is wound around each of a plurality of teeth (122) that 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).

[0060] In addition, the rotor (130) is rotatably provided at the center of the motor case (110) and is driven to rotate. The rotor (130) may have a hollow tube shape as shown.

[0061] At this time, a step (131) is formed on one end of the inner surface of the rotor (130), and the hollow shaft (200) can be inserted into the rotor (130) and joined while being seated on the step (131).

[0062] A plurality of magnets (132) are attached to the outer surface of the rotor (130). Here, the magnets (132) are adjacent to and opposite the coils (123) of the stator (120), so that the rotor (130) is driven to rotate by the magnetic field formed by the coils (123).

[0063] In the present invention, it is preferable that a cooling structure composed of a heat dissipation sheet portion (114) is provided in the motor case (110) to cool the heat generated in the drive module (100).

[0064] 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).

[0065] 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.

[0066] 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 shown.

[0067] In one embodiment, 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 portion (112) may have a recessed structure in which a central hole through which the hollow shaft (200) passes is formed in the center, and mountains and valleys are formed in a straight line in the radial direction from the central hole. However, the present invention is not limited thereto, and it is obvious that the present invention may have various shapes.

[0068] In addition, the uneven heat dissipation sheet portion (114) formed on the motor case (110) has not only a heat dissipation effect but also an effect of increasing the strength of the motor case.

[0069] 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.

[0070] The above hollow shaft (200) has a hollow tube shape and one end is connected to the rotor (130) as described above.

[0071] 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).

[0072] The hollow shaft (200) described above operates as an input shaft of the reduction module (300) described below.

[0073] For this purpose, 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).

[0074] Next, the deceleration module (300) will be described with reference to FIG. 2 and FIG. 5. FIG. 5 is an exploded perspective view showing the structure of the deceleration module of the present invention illustrated in FIG. 1.

[0075] When the rotational force driven at high speed in the above driving module (100) is input through the hollow shaft (200), deceleration is performed in the deceleration module (300). The deceleration module (300) may use various reducers, but the present invention describes a deceleration module using a cycloid gear method.

[0076] In the present invention, the deceleration module (300) is integrated by being connected 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.

[0077] In detail, the above reduction module (300) can be implemented by including a reduction gear 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).

[0078] The above-mentioned reducer 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) is received by penetrating through the inner center.

[0079] 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.

[0080] In addition, the above ring gear pin (330) has a roller shape, and a plurality of them are each meshed with each tooth of the ring gear pin groove (320).

[0081] At this time, the ring gear pins (330) are arranged at regular intervals in a parallel circle, and both ends can be fixed with tapered bearings (331, 332) in the shape of circular rings. The outer circumference of the tapered bearings (331, 332) is respectively coupled to the inner circumference of the reducer case (310), and the inner circumference rotatably supports the first output flange (360) and the second output flange (370), respectively.

[0082] In addition, the eccentric cam (210) is formed symmetrically at 180° to the center of the hollow shaft (200) with a first eccentric cam and a second eccentric cam split on the outer surface of the other end of the hollow shaft (200) to form an eccentric cam. A roller bearing (340) is coupled to the eccentric cam (210).

[0083] The above roller bearing (340) has a circular ring shape so that the hollow shaft (200) passes through it, 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).

[0084] 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 to be misaligned from each other.

[0085] Meanwhile, the above disk gear (350) has a circular ring shape so that the hollow shaft (200) passes through it, and an (epi) cycloidal tooth shape is formed along the outer circumference, and a pair of first disk gears (351) and second disk gears (352) are provided in parallel with each other.

[0086] At this time, the first disk gear (351) is provided to surround the outer circumference of the first roller bearing (341), and the teeth are in 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 are in rolling contact with the ring gear pin (330).

[0087] 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 rotate eccentrically with a phase difference of 180° according to the rotation of the roller bearing (340). In addition, 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.

[0088] 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).

[0089] And the first output flange (360) is formed in a circular ring shape so that the hollow shaft (200) passes through it, and is provided between the first disk gear (351) and the plate portion (112) of the drive module (100).

[0090] 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).

[0091] 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).

[0092] 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.

[0093] In addition, one or more disk pins (380) are inserted 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.

[0094] 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.

[0095] 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.

[0096] And the rotational force 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.

[0097] In the present invention, the lubricating oil circulating in the reduction module (300) can contact the grating portion to perform cooling.

[0098] In other words, lubricating oil is injected and circulated inside the deceleration 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).

[0099] Therefore, by integrating the reduction module (300) and the drive module (100), there is an advantage in that the lubricant can also cool the drive module (100).

[0100] 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.

Claims

1. A drive module including a motor case, a stator fixed to the inner surface of the motor case and having a coil wound thereon, and a rotor having a magnet attached to the outer surface and rotating at the center of the motor case; A hollow shaft having one end connected to the rotor and rotating, and the other end extended to the outside of the motor case and exposed; and A cooling structure for a motor-integrated hollow reducer, characterized by including a reduction module that is directly coupled to the driving module and performs reduction using the other end of the hollow shaft as an input shaft.

2. In paragraph 1, The above 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. A cooling structure for a hollow reducer integrated with a motor, characterized in that the body, cover, and grating portion are provided with a heat-radiating sheet portion having repetitive unevenness formed therein to increase the surface area with which air or lubricating oil comes into contact.

3. In paragraph 2, The heat dissipation sheet formed on the above body has unevenness formed on the surface of the above body, The heat dissipation sheet formed on the above cover is formed with irregularities in the radial direction, A cooling structure for a hollow reducer integrated with a motor, characterized in that the heat dissipation sheet formed on the above-mentioned grating portion is formed with irregularities in the radial direction.

4. In paragraph 2, A cooling structure for a motor-integrated hollow reducer, characterized in that the lubricating oil circulating inside the reduction module is cooled by contacting the heat dissipation sheet of the plate section.

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