KR20180128730A - Heat-resistant stacking structure for servor motor - Google Patents

Abstract

A heat resistant stacked structure of a servo motor of the present invention comprises: an outer frame layer which is placed to be away from a motor frame of a servo motor by a predetermined gap; and a shielding layer which is interposed between the outer frame layer and the servo motor, is provided inside the outer frame layer to assist cooling by temporarily storing cool air flowing inside in a forging process, and shields the servo motor from an exterior environment at high temperatures. The shielding layer is made of Kevlar materials and the thickness of the shielding layer might be 0.05 to 0.15 mm. According to the present invention, the heat resistant stacked structure of a servo motor separates a rotational motor from an exterior environment at high temperatures, secures a space in which cool air is temporarily stored therein such that malfunction of or thermal damage to a rotational motor, especially, an encoder unit can be prevented, and protects the rotational motor from dust generated in a forging process to prevent malfunction of a robot and extend a lifespan of a robot.

Description

HEAT-RESISTANT STACKING STRUCTURE FOR SERVOR MOTOR [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a heat resistant laminated structure of a servo motor, and more particularly, to a heat resistant laminated structure of a servo motor in which heat resistance of motor packaging is enhanced by circulating the heat insulating layer and cooling air.

In general, an industrial robot refers to a tool (for example, a gripper or an end effector) that meets the purpose of automatically handling an object and a general device capable of being programmed for a plurality of axes of motion.

 In order to enable multi-axis motion of the robot, a driving unit is provided for each joint, a driving unit should be easy to precisely control, and a servo motor suitable for high torque and fast acceleration / deceleration is generally used. The servomotor can be roughly divided into a motor section that receives external power and generates torque, and an encoder section that is integrated with the rotor of the servo motor to transmit information such as the rotational speed and position of the rotor. The permanent magnet of the motor section, PCBs and electronic parts, cables connected to them, etc. may be vulnerable to high temperatures. Therefore, it is important to check the heat resistance of the materials constituting the servomotor, and to check the temperature characteristics that are combined when these are combined. This is important in designing, manufacturing and operating the forging robot.

For example, in a high-temperature manufacturing environment in which a person is hard to work, especially forging equipment, forgings and semi-finished products are heated to a high temperature of about 1200 degrees and peripheral temperatures of about 200 degrees, . Also, resistance to non-products and dust emitted from mold release agents and corrosion inhibitors, which are essentially added in the forging process, is also required.

However, when the conventional forging robot is placed in a working environment of a high-temperature forging process, there is a problem that the rotating motor, particularly the encoder portion, is left at a high temperature, causing malfunction or thermal damage of the motor.

Further, there is a problem that the lifetime of the motor is shortened due to accumulation of dusts such as non-product and slag generated during oxidation of the mold release agent and the corrosion inhibitor, which are essentially supplied in the forging process, and are damaged.

Disclosure of the Invention The present invention has been proposed in order to solve the above problems, and it is an object of the present invention to isolate a rotary motor from a high temperature external environment and to secure a space in which cooling air temporarily retreats therein to prevent malfunction or thermal damage of the rotary motor, The present invention provides a heat-resistant laminated structure of a servo motor that can prevent a malfunction of a robot and extend its service life by protecting a rotating motor from dust generated in a forging process.

According to an aspect of the present invention, there is provided a heat resistant laminated structure for a servo motor, comprising: an outer frame layer disposed at a predetermined interval from a motor frame of a servo motor; And an outer frame layer interposed between the outer frame layer and the servo motor. The cooling air is temporarily stored in the inner frame layer during the forging process to assist cooling, and the servo motor is shielded from a high- The shielding layer may be made of Kevlar, and the thickness of the shielding layer may be 0.05 mm to 0.15 mm.

The cooling air may be in a temperature range of 20 ° C to 30 ° C.

The outer frame layer may be provided in a volume of approximately 10 cm < 3 >.

The heat resistant laminated structure of the servo motor according to the present invention isolates the rotary motor from the high temperature external environment and secures a space in which the cooling air temporarily retreats therein to prevent malfunction or thermal damage of the rotary motor, It is possible to prevent malfunction of the robot and to prolong its service life by protecting the rotating motor from dust generated in the process.

1 is a view schematically showing an embodiment in which a heat resistant laminated structure of a servo motor of the present invention is applied to a joint portion of a forging robot.
Fig. 2 is an enlarged partial enlarged view of the heat-resistant laminated structure of the servo motor with respect to zone C of Fig. 1;
3 is a schematic view showing a basic structure of a heat resistance test of a heat resistant laminated structure of a servo motor according to an embodiment of the present invention.
4 is a view schematically showing temperature measurement points for heat resistance testing of a heat resistant laminated structure of a servo motor according to an embodiment of the present invention.
5 to 7 are graphs showing results of heat resistance test of the heat resistant laminated structure of the servo motor and experimental results of the comparative group according to the embodiment of the present invention, respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a heat resistant laminated structure of a servo motor according to the present invention will be described in detail with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a heat resistant laminated structure of a servo motor according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view schematically showing one embodiment in which a heat resistant laminated structure of a servo motor of the present invention is applied to a joint portion of a forging robot. FIG. 2 is a cross- Fig.

Prior to the description, the object of the heat resistant laminated structure of the servo motor according to the embodiment of the present invention is not limited to the high temperature environment (for example, forging, die casting, heat treatment or surface treatment, Dusty workplaces, hazardous factories that may cause safety accidents, etc. For convenience of explanation, the present invention is limited to a vertical multi-axis robot for forging.

1 and 2, the heat-resistant laminated structure of the servo motor according to the embodiment of the present invention includes an outer frame (not shown) spaced apart from the motor frame of the servomotors 411, 412, 413, Layer 510; And an outer frame layer 510 interposed between the outer frame layer 510 and the servo motors 411, 412, 413, and 420. Cooling air flowing inside the forging process is temporarily stored And a shielding layer 511 for shielding the servomotors 411, 412, 413 and 420 from a high temperature external environment while supporting the cooling. The shielding layer 511 is made of kevlar, The thickness of the shielding layer 511 may be 0.05 mm to 0.15 mm.

The outer frame layer 510 forms a storage space in which the servomotors 411, 412, 413 and 420 (in this embodiment, the upper drive module as an assembly of the servomotors 411, 412, 413 and 420) And substantially isolates the servomotors 411, 412, 413, and 420 from the external environment. The outer frame layer 510 is preferably made of a metal material. The outer frame layer according to the present embodiment may be provided in a volume of approximately 10 cm < 3 >.

Here, referring to FIG. 1, the upper drive module 400 may be disposed between the lower arm unit 200 and the upper arm unit 300. The upper drive module 400 interconnects the lower arm unit 200 and the upper arm unit 300 and rotates the upper arm unit 300 or the gripper of the end of the upper arm unit 300 It also plays a role of driving.

The upper drive module 400 includes a gripper driving unit 410 provided at one end of the upper arm unit 300 to drive a gripper provided at the other end of the upper arm unit 300; And an upper arm driving unit 420 for driving the upper arm unit 300 to relatively rotate the upper arm unit 300 with respect to the lower arm unit 200. [

The upper arm driving unit 420 is a portion that relatively rotates the upper arm unit 300 relative to the lower arm unit 200. [ The upper arm driving part 420 is preferably provided as a servo motor.

On the other hand, in forged equipment, forgings and semi-finished products are inevitably exposed to a high temperature working environment, which rises to approximately 1200 ° C and the peripheral temperature is approximately 180-200 ° C. Particularly, the gripper or end effector at the position corresponding to the final end portion of the robot, the joining portion thereof, and the upper arm structure provided adjacent to the gripper are required to have heat resistance to withstand the aforementioned extreme temperatures.

In addition, vibration and noise are generated in the forging process, and non-products and dust are generated from the mold release agent or the corrosion inhibitor which is essentially added in the forging process. It is necessary to block this.

A shielding layer 511 may be provided in the outer frame layer 510 of the vertical multi-axis robot according to the embodiment of the present invention. Referring to FIG. 2, the shield layer 511 may be stacked on the inner wall of the outer frame layer 510. Heat-resistant reinforced layer portion 511 in this embodiment The thickness of the heat-resistant reinforced layer portion 511 may be 0.05 mm to 0.15 mm, and it is preferably made of Kevlar material. On the other hand, the aramid material or the aramid material may be used together with the aramid material for the convenience of production or the unit price.

On the other hand, the air purging line of cooling air will be described. Although not shown in the drawing, an air purging line connected to the outside can be put into a receiving space in which the outer frame layer 510 is formed, and cool down inside the receiving space while staying inside and staying inside. The temporarily retained cooling air can be ejected to the outside through the air fan 520 at the discharge port. The cooling air according to this embodiment may be in a temperature range of 20 ° C to 30 ° C.

In this process, the upper driving module 400 can be protected. That is, the servomotors 411, 412, 413, and 420 are separated from the high-temperature external environment to isolate the upper drive module in the present embodiment, 420) Malfunction or thermal damage of the encoder part in particular can be prevented.

In addition, it is possible to solve the problem that the service life of the robot is shortened due to particulate matter, slag, and the like generated while oxidizing the release agent and the corrosion inhibitor, which are essentially supplied in the forging process. That is, since the flow direction of the cooling air flows in one direction and is eventually discharged to the outside through the air fan 520, the possibility that external dust generated in the forging process invades into the outer frame layer 510 is remarkably lowered The upper drive module 400 is protected to prevent the malfunction of the robot and the service life can be prolonged.

FIG. 3 is a view schematically showing a basic configuration of a heat resistance test of a heat resistant laminated structure of a servo motor according to an embodiment of the present invention. FIG. 4 is a graph showing a heat resistance test of a heat resistant laminated structure of a servo motor according to an embodiment of the present invention FIGS. 5 to 7 are graphs showing results of heat resistance test of the heat resistant laminated structure of the servo motor and experimental results of the comparative group according to the embodiment of the present invention, respectively.

3 to 7, the heat resistance test of the heat resistant laminated structure of the servo motor according to the embodiment of the present invention was performed.

≪ Evaluation of motor temperature tolerance according to heat resistance method >

1. Test Overview

1.1 Purpose of Exam

In order to construct an optimal heat - resistant method, various heat - resistant methods of vertical multi - axis robots which can be applied to the forging process are compared and tested.

1.2 Test subjects

With respect to the heat resistance of the vertical multi-axis robot, the components that are relatively vulnerable to heat are mainly motors (particularly, encoder parts) such as driving parts, particularly servomotors 411, 412, 413 and 420 or hollow motors. Particularly, the servomotors 411, 412, 413 and 420 are largely divided into an encoder section for receiving torque from the external power source and an encoder section for transmitting information such as the rotational speed and position of the rotor, And the permanent magnets and the PCB of the encoder section are vulnerable.

In this experiment, one of the servo motors 411, 412, 413, and 420 applied to the robot is tested in consideration of the size of the chamber and convenience of testing. The motor used for the temperature tolerance test uses a motor applied to a vertical multi-axis robot. The manufacturer is Panasonic, the model name is MSMD042G1S, and the number of samples is 1EA.

Also, the cable is an enamel wire, and temperature class B (130 degrees or more) is used.

1.3 Test condition setting

(1) Temperature condition of the chamber

The temperature in the chamber is kept at room temperature (25 ° C ± 5 ° C) before the test, and the temperature rise is increased by about 13 ° C per minute. After the temperature is raised, the holding temperature is 180 ° C. do.

(2) Motor driving conditions

The weight corresponding to about 10 times the inertia of the motor under test is attached to the lower end and driven for 2 hours at 100 rpm in the forward direction by using a drive drive. If no error occurs within 2 hours, rotation at 3000 rpm Sec).

(3) Temperature measurement point

The temperature sensor measures a main part as shown in FIG. 4 using a thermocouple wire (TC-T type) for measuring the temperature of the main representative material of the servomotors 411, 412, 413 and 420 do. That is, the inside and outside of the encoder cover, the motor surface, the power cable surface, the chamber temperature, and the ambient temperature are measured.

(4) Air purging cooling air setting

The cooling air is blown at a temperature of 25 ° C at a maximum static pressure of 19.5 / 25 mmAq with a maximum air flow rate of 1.7 / 2.1m ² / min.

2. Experimental Examples and Comparative Examples 1 and 2

2) a state where the motor to be tested is embedded in a sample cube of about 100 cm 2 or less (Comparative Example 2); 3) a state in which a test object is placed in a sample cube of about 100 cm 2 or less (Experimental example) in which the motor was built and the air purging line was installed. At the same time when the motor under test was driven, the ambient temperature was increased from about 20 ° C to about 13 ° C per minute to reach 180 ° C and the temperature was maintained at 180 ° C , The temperature change on the motor under test and the occurrence and time of the error of the motor under test were measured.

3. Test progress

 (1) Comparative Example 1

When the temperature of the inside of the chamber was increased by 13 占 폚 / min and the temperature of 180 占 폚 reached and maintained, the motor was driven to check the time when the error occurred.

Referring to FIG. 5, it took about 14 minutes (initial preparation state 5 minutes) to rise to 180.degree. C. from room temperature, and an encoder communication line disconnection error (Err 21.0) occurred in about 20 minutes after the temperature saturation.

time
[min] Temperature measurement [℃] Remarks Encoder
inside Encoder
cover Motor surface cable
surface chamber Ambient temperature 0 35.67 27.57 27.43 27.44 24.83 26.13 10 46.55 56.66 46.68 39.41 101.35 26.09 15 74.49 99.28 80.21 67.68 164.3 26.3 20 101.49 120.46 106.33 97.98 171.98 25.89 25 127.06 139.98 130.92 124.8 174.89 26.06 30 145.27 152.44 147.47 145.91 176.68 25.94 31 149.98 156.02 151.37 150.47 177.1 25.8 Alarm Occurred

As shown in Table 1, when the error occurred, the internal temperature of the encoder was 149.98 degrees, which was higher than the encoder operating temperature guaranteed by the manufacturer at 80 ° C. At this time, the motor surface temperature was about 151 ° C, and the temperature inside the chamber was 177.1 Lt; 0 > C, and the temperature of the test room was 25.8 [deg.] C.

(2) Comparative Example 2

A test motor in a single state was provided inside the outer frame layer 510 and inside the shielding layer 511. The temperature inside the chamber was increased by 13 ° C / min to reach 180 ° C, .

Referring to FIG. 6, it took about 19 minutes for the temperature to rise to 180 ° C at room temperature, and the encoder CS phase error error (Err 49.0) occurred about 53 minutes after the temperature saturation. The temperature measurement data of the motor and cable with the shielding layer 511 extracted one data every 10 seconds and the test time is about 72 minutes.

The operation error of the motor occurred about 71 minutes. The internal temperature of the encoder at the time of occurrence of the error was 150.33 캜, the frame was 144.88 캜, and the ambient temperature was 25.8 캜, which was measured similarly to the test result of Comparative Example 1.

 (3) Experimental Example

The experiment configuration as shown in Fig. 3 was completed. A test motor in a single state is provided in a housing space formed by the outer frame layer 510 and a shielding layer 511 laminated inside thereof. In a state where cooling air is supplied through the air purging line to the housing space , And when the temperature in the chamber was increased by 13 ° C / min to reach 180 ° C and maintained, a time point at which an error occurred was determined by driving the motor. The temperature measurement data is extracted one data every 10 seconds and the total test time is about 17 hours and 40 minutes.

Test result chamber Referring mainly to FIG. 7, no operation error occurred in the drive even if the internal temperature reached 180 ° C and maintained for more than 8 hours. Also, even when the external temperature was maintained at 180 ° C, the temperature of each measurement position was 64.62 ° C in the encoder, 57.34 ° C in the frame, and 44.8 ° C in the blowing temperature. The time taken to saturate was 75 minutes.

(4) Test results

(Comparative Example 1); 2) a state in which the outer frame layer 510 and the shielding layer 511 are formed in the housing space (Comparative Example 2); FIG. 3) Results of the heat resistance test of the state (experimental example) in which the cooling air is supplied through the air purging line into the accommodation space of Comparative Example 2 is summarized in the table.

Item  Saturation temperature [℃] Error occurrence time
[min] saturation
time
[min] Remarks Encoder
inside frame Blowing around 1) Comparative Example 1 149.98 151 - 25.8 31 - Encoder anomalies and cable sheath peeling 2) Comparative Example 2 150.33 145 - 25.8 71 - Encoder anomalies and cable sheath peeling 3) Experimental Example 64.62 57.34 55.11 26.8 - 75

As can be seen from Table 2, when the cooling air is supplied through the air purging line in the housing space in which the outer frame layer 510 and the shielding layer 511 are formed, the conditions under which the motor can operate normally at an external temperature of 180 ° C And the saturation temperature was lower than that of Comparative Example 2. As a result, it was confirmed that the saturation temperature was kept constant.

In addition, in the temperature test of the single product and Kevlar fiber heat-resistant state, an encoder-related error (encoder communication disconnection and encoder CS signal abnormality) occurred at an internal temperature of 150 ° C at the chamber temperature of 180 ° C. It was possible.

4. Conclusion

(Comparative Example 2) provided in the housing space in which the outer frame layer 510 and the shielding layer 511 are formed, (3) Comparing the state of supplying cooling air through the purging line, when the motor is exposed to a high temperature environment for a long time, the saturation temperature is similar, but the temperature saturation time is delayed (about 2 times) The shielding layer 511 used It was confirmed that selecting and configuring Kevlar material shields high temperature environment .

(2) Compared with the comparative example 2 and the experimental example in case of prolonged exposure to a high temperature condition, when the cooling air is blown into the inside of the accommodation space, the encoder temperature (64.62 degrees) It was confirmed that the temperature (57.34 degrees) was maintained within the normal range and the encoder error and operation error of the motor were not generated .

(3) It is necessary to select the temperature class of the power cable and the encoder cable as being composed of the movable wire (105 ° C) or more.

412, 413 and 420 from the external environment at a high temperature and secures a space in which the cooling air is temporarily retained inside the servo motors 411, 412, 413 and 420, Malfunction or thermal damage of the encoder unit can be prevented and the servomotors 411, 412, 413 and 420 can be protected from the dust generated in the forging process, thereby preventing malfunction of the robot and extending the service life.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed exemplary embodiments. It will also be appreciated that many modifications and variations will be apparent to those skilled in the art without departing from the scope of the present invention.

300: upper arm unit 310: gripper connection part
400: upper driving module 420: upper arm driving part
510: outer frame layer 511: shield layer

Claims (3)

An outer frame layer disposed at a predetermined interval from the motor frame of the servo motor; And
The cooling air being interposed between the outer frame layer and the servo motor and being provided inside the outer frame layer to temporarily store the cooling air flowing inside during the forging process so as to assist cooling and shield the servo motor from a high temperature external environment Shielding layer,
The shielding layer is made of kevlar material,
Wherein the thickness of the shielding layer is 0.05 mm to 0.15 mm. The method according to claim 1,
Wherein the cooling air has a temperature range of 20 to 30 占 폚. The method according to claim 1,
Wherein the outer frame layer is provided in a volume of about 10 cm < 3 >.

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