WO2021208285A1

WO2021208285A1 - Motor spindle assembly

Info

Publication number: WO2021208285A1
Application number: PCT/CN2020/103653
Authority: WO
Inventors: 张春晖
Original assignee: 江苏嘉轩智能工业科技股份有限公司
Priority date: 2020-04-16
Filing date: 2020-07-23
Publication date: 2021-10-21
Also published as: CN111220115B; CN111220115A

Abstract

A method for detecting the eccentricity of a bearing cap of an outer rotor motor, comprising: step 1: multiple proximity sensors are provided on each inner bearing cap; step 2: each proximity sensor measures the distance between the inner wall of the corresponding inner bearing cap to a spindle; step 3: the distances measured by the multiple proximity sensors are compared with a gap standard value to produce offsets, the maximal offset, the minimal offset, and an offset angle are calculated; and step 4: the maximal offset and the minimal offset are compared to see if a critical value is exceeded. The method allows the eccentricity of the bearing cap to be dynamically detected on the basis of a state of movement of the inner bearing cap, ensures explosion-proof safety, allows an alerting prompt when the eccentricity exceeds the critical value and the bearing to be serviced in a timely manner, thus protecting the motor. Also disclosed is a motor spindle assembly.

Description

Motor spindle assembly

Technical field

The invention relates to the technical field of external rotor motors, in particular to a motor spindle assembly.

Background technique

The outer rotor motor is often used to drive the conveyor drum in the mining industry. The main shaft of the permanent magnet direct drive outer rotor motor is fixed, and the inner bearing cover together with the end cover rotates around the shaft. There is a gap between the inner bearing cover and the shaft. The function of this gap is to prevent friction between the inner bearing cover and the shaft, and it is also an explosion-proof gap. According to the requirements of explosion-proof standards, the gap cannot be greater than 0.7 mm. If it is greater than 0.7 mm, there is a risk of explosion; the gap cannot be less than 0.05 mm. If it is less than 0.05 mm, there is a risk of contact friction. Once the inner bearing cover is in contact with the shaft and rubs, it will cause strain on the end cover and the shaft, damage to the accumulation of tumors, and then expand the gap and fail to explode. Once the eccentricity is too large, it will cause friction and heat generation between the roller stator and the rotor, and the whole machine will be scrapped. At present, the external rotor motor of the prior art does not detect the eccentricity of the bearing cover, and it is often discovered when wear or shutdown has occurred.

Summary of the invention

When the bearing of the permanent magnet direct drive outer rotor motor is worn out or damaged, the shaft and the end cover will be eccentric, and the above phenomenon will occur. This patented technology detects the eccentricity of the inner bearing cover by detecting the distance between the inner bearing cover and the shaft by the proximity sensor. When the eccentricity occurs, the display instrument will display the eccentricity and azimuth angle. When the eccentricity exceeds the standard, it will alarm and automatically stop.

The inventors of the present invention have conducted in-depth research in order to achieve the above objectives. Specifically, the present invention provides a method for detecting the eccentricity of an outer rotor motor bearing cover, which includes the following steps:

Step 1: Set up multiple proximity sensors on each inner bearing cover;

Step 2: Each proximity sensor measures the distance from the inner wall of the inner bearing cover to the shaft;

Step 3: Compare the distance measured by multiple proximity sensors with the standard value of the gap to obtain the deviation value, and calculate the maximum deviation value, the minimum deviation value and the deviation angle;

Step 4: Compare the maximum deviation value and whether the minimum deviation value exceeds the critical value.

The eccentricity detection can be completed when the number of proximity sensors is two, and the connections between the two proximity sensors and the shaft are perpendicular to each other. At the same time, 3, 4 or more proximity sensors can also be provided. When multiple proximity sensors are provided, they should be evenly distributed along the circumference.

If the deviation values measured by the two proximity sensors are ΔX, ΔY, the method of calculating the maximum deviation value and the deviation angle is:

Eccentricity value R=(ΔX2+ΔY 2)1/2;

If the gap standard value is D, the maximum deviation value is D+R, and the minimum deviation value is D-R;

The deviation angle θ=arcsin(ΔY/R).

Based on the above-mentioned outer rotor motor bearing cover eccentricity detection method, the present invention also provides a motor spindle assembly, including a main shaft, a bearing, an outer bearing cover, an end cover, an inner bearing cover, an eccentricity detection device, and the eccentricity detection device It includes a plurality of proximity sensors, a processor, a display device for displaying the eccentricity value, and an alarm device for alarming when the deviation value and the deviation angle exceed the critical value. The bearing is arranged between the outer bearing cover and the inner bearing cover, And installed on the main shaft, the outer shell of the bearing is installed in the hole of the end cover, the outer bearing cap is installed on the outside of the bearing, the inner bearing cap is installed on the inside of the bearing, and there is a gap between the inner bearing cap and the main shaft. The main shaft has a central hole, multiple proximity sensors are installed inside the main shaft, the end of the proximity sensor is set on the side of the inner hole wall of the inner bearing cover, the end of the proximity sensor is flush with the surface of the main shaft, the processor is connected to the display device and the alarm The device is electrically connected, the processor is connected to the proximity sensor through a shielded cable, and the method for detecting the eccentricity of the inner bearing cover adopted by the processor is the above-mentioned detecting method of the present invention.

In order to protect the proximity sensor, a protective sleeve can be provided on the proximity sensor. The material of the protective sleeve can be steel pipe or other metal pipes. The protective sleeve has the function of protecting and shielding the cable and also has the function of anti-electromagnetic interference. One end of the sheath tube is bent, and the bent end of the sheath tube is installed in the hole on the spindle through the fixing sleeve. The other end of the sheath tube is flush with the end of the center hole of the spindle. The sheath tube is fixedly connected to the spindle. The cable is inserted into the protective sleeve, and the proximity sensor is installed in the hole of the fixed sleeve. The fixed sleeve is potted with epoxy resin.

Preferably, the proximity sensor is an inductive sensor or a capacitive sensor. The proximity sensor converts the distance from the inner wall of the inner bearing cap to the shaft into an electrical signal and transmits it to the processor. After the processor calculates according to the eccentricity detection method of the inner bearing cap, the deviation value and the deviation angle are displayed on the display device. When the maximum deviation exceeds the critical value, the processor controls the alarm device to give an alarm.

The technical effects of the present invention are as follows: The method for detecting the eccentricity of the outer rotor motor bearing cover of the present invention can dynamically detect the eccentricity of the bearing cover according to the movement of the inner bearing cover, ensuring explosion-proof safety, and can alarm when the eccentricity exceeds the critical value. Prompt to maintain the bearing in time to protect the motor.

Description of the drawings

Fig. 1 is a schematic diagram of the structure of a motor spindle assembly of the present invention.

Fig. 2 is a schematic cross-sectional view of a main shaft of a motor main shaft assembly of the present invention.

Fig. 3 is an enlarged schematic diagram of the installation of a proximity sensor of a motor spindle assembly of the present invention.

Fig. 4 is an example diagram of the eccentricity detection method of the inner bearing cover of the outer rotor motor of the present invention under a working condition.

Fig. 5 is an enlarged schematic diagram of a spindle center hole of an embodiment of a motor spindle assembly of the present invention.

Fig. 6 is a side view of another embodiment of a motor spindle assembly of the present invention.

Detailed ways

Hereinafter, specific embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Although specific embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that they may use different terms to refer to the same component. This specification and claims do not use differences in terms as a way to distinguish components, but use differences in functions of components as a criterion for distinguishing. If "include" or "include" mentioned in the entire specification and claims is an open term, it should be interpreted as "include but not limited to". The following description of the specification is a preferred embodiment for implementing the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The protection scope of the present invention shall be subject to those defined by the appended claims.

In order to facilitate the understanding of the embodiments of the present invention, several specific embodiments will be taken as examples for further explanation and description in conjunction with the accompanying drawings, and each of the drawings does not constitute a limitation to the embodiments of the present invention.

Specifically, the method for detecting the eccentricity of the outer rotor motor bearing cover of the present invention includes the following steps:

Step 1: Set up multiple proximity sensors on each inner bearing cover;

Eccentricity value R=(ΔX2+ΔY 2)1/2;

The deviation angle θ=arcsin(ΔY/R).

Example: As shown in Figure 4 and Figure 5, when the inner bearing cover is in the center, the gap is the standard value of 0.35 mm. When the inner bearing cover is eccentric, the deviation value measured by the proximity sensor is L1 = 0.24 mm, L2 = 0.22 mm , The value of L1 is set to Y, that is, Y=0.24 mm, and L2 is set to X, that is, X=0.22 mm.

Deviation value ΔY = 0.24-0.35 = -0.11 mm,

ΔX = 0.22-0.35 = -0.13 mm,

Eccentricity R=(ΔX2+ΔY2)1/2=((-0.11)2+(-0.13)2)1/2=0.17mm

Maximum gap = 0.17 (mm) + 0.35 (mm) = 0.52 mm

The minimum gap = 0.35 (mm)-0.17 (mm) = 0.18 mm.

Deviation angle θ=arcsin(ΔY/R)

=arcsin(-0.11/0.17)=220.32°

When the critical value of the explosion-proof clearance is 0.7 mm, the clearance value and the deviation angle are qualified. The current situation can operate normally.

As shown in Figure 6, in one embodiment, when there are three proximity sensors, the three proximity sensors are respectively S1, S2, and S3. The three sensors can form an angle of 120° with each other, and the sensor detection surface and the shaft surface Coplanar settings. If the deviation values of the three sensors are L1, L2, L3, and the standard gap between the bearing cap and the shaft is L, the method of calculating the maximum deviation value and the deviation angle is:

Calculate intermediate parameters:

ΔY1=(L1*SIN(90)-L*SIN(90))

ΔY2=(L2*COS(210)-L*COS(210))

ΔY3=(L3*SIN(330)-L*SIN(330))

ΔX1=(L1*COS(90)-L*COS(90))

ΔX2=(L2*SIN(210)-L*SIN(210))

ΔX3=(L3*COS(330)-L*COS(330))

Maximum offset ΔAmax=2/3*((ΔY1+ΔY2+ΔY3)2+(ΔX1+ΔX2+ΔX3)2)1/2

Azimuth θ=arctan((ΔY1+ΔY2+ΔY3)/(ΔX1+ΔX2+ΔX3))

As shown in Figure 6, when the deviation values measured by the three sensors are L1 = 0.2805 mm, L2 = 0.1680 mm, and L3 = 0.5803 mm, it is calculated according to the method of the present invention:

ΔY1=(L1*SIN(90)-L*SIN(90))=-0.0695mm

ΔY2=(L2*COS(210)-L*COS(210))=0.091mm

ΔY3=(L3*SIN(330)-L*SIN(330))=-0.1152mm

ΔX1=(L1*COS(90)-L*COS(90))=0mm

ΔX2=(L2*SIN(210)-L*SIN(210))=0.1576mm

ΔX3=(L3*COS(330)-L*COS(330))=0.1995mm

ΔAmax=2/3*((ΔY1+ΔY2+ΔY3)2+(ΔX1+ΔX2+ΔX3)2)1/2

＝2/3*((-0.0695+0.091-0.1152)2+(0+0.1576+0.1995)2)1/2

= 0.2461 mm

So the maximum gap is 0.35+0.2461=0.596; the minimum gap is 0.35-0.2461=0.104 mm.

Azimuth θ=arctan(-0.0937/0.3571)=-14.7°

Based on the above-mentioned method for detecting the eccentricity of the outer rotor motor bearing cover, the present invention also provides a motor spindle assembly, as shown in Figs. Inner bearing cover 5, eccentricity detection device, the eccentricity detection device includes a plurality of proximity sensors 7, a processor, a display device 10 for displaying the eccentricity value and an alarm when the deviation value and the deviation angle exceed the critical value Alarm device, the bearing 3 is arranged between the outer bearing cap 2 and the inner bearing cap 5, and is installed on the main shaft 1, the outer shell of the bearing 3 is installed in the hole of the end cover 4, and the outer bearing cap 2 is installed on the bearing 3. The inner bearing cap 5 is installed inside the bearing 3, and there is a gap between the inner bearing cap 5 and the main shaft 1. The main shaft 1 has a central hole, and a plurality of proximity sensors 7 are installed inside the main shaft 1. The end is arranged on the side of the inner hole wall of the inner bearing cover 5, the end of the proximity sensor 7 is flush with the surface of the main shaft 1, the processor is electrically connected to the display device and the alarm device, and the processor is connected to the proximity sensor through a shielded cable 9 The sensor 7 is connected, and the method for detecting the eccentricity of the inner bearing cap adopted by the processor is the above-mentioned detecting method of the present invention.

In order to protect the proximity sensor 7, a protective sleeve 8 can be provided on the proximity sensor 7. The material of the protective sleeve 8 can be steel pipe or other metal pipes. The protective sleeve has the function of protecting and shielding the cable 9 and is also anti-electromagnetic. The role of interference. One end of the sheath tube 8 is bent, the bent end of the sheath tube 8 is installed in the hole on the spindle 1 through the fixing sleeve 12, the other end of the sheath tube 8 is flush with the end of the center hole of the spindle 1, and the sheath tube 8 is aligned with The main shaft 1 is fixedly connected, the shielded cable 9 is inserted into the sheath 8, and the proximity sensor 7 is installed in the hole of the fixed sleeve 12. The fixing sleeve 12 is potted with epoxy resin.

Preferably, the proximity sensor 7 is an inductive sensor or a capacitive sensor. The proximity sensor 7 converts the distance from the inner wall of the inner bearing cap 5 to the main shaft 1 into an electrical signal and transmits it to the processor. After the processor calculates according to the eccentricity detection method of the inner bearing cap, the deviation value and the deviation angle are displayed on the display device 10. When the maximum deviation exceeds the critical value, the processor controls the alarm device to give an alarm.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above specific embodiments and application fields. The above specific embodiments are only illustrative, instructive, and not restrictive. . Under the enlightenment of this specification and without departing from the scope of protection of the claims of the present invention, those of ordinary skill in the art can also make many forms, which all belong to the protection of the present invention.

Claims

A motor spindle assembly, which is characterized by comprising a spindle, a bearing, an outer bearing cover, an end cover, an inner bearing cover, and an eccentricity detection device. The eccentricity detection device includes two proximity sensors, a processor, The display device and the alarm device, the bearing is arranged between the outer bearing cover and the inner bearing cover and installed on the main shaft, the outer shell of the bearing is installed in the hole of the end cover, the outer bearing cover is installed on the outside of the bearing, and the inner bearing The cover is installed on the inner side of the bearing, there is a gap between the inner bearing cover and the main shaft, the main shaft has a central hole, the proximity sensor is installed inside the main shaft, and the end of the proximity sensor is set on the side of the inner hole wall of the inner bearing cover , The end of the proximity sensor is flush with the surface of the main shaft, the proximity sensor is provided with a protective sleeve, one end of the protective sleeve is bent, and the bent end of the protective sleeve is installed in the hole on the main shaft through a fixed sleeve. The other end is flush with the end of the central hole of the main shaft, the protective sleeve is fixedly connected to the main shaft, the shielded cable is inserted into the protective sleeve, the proximity sensor is installed in the hole of the fixed sleeve, the processor and the display device and The alarm device is electrically connected, the processor is connected to the proximity sensor through a shielded cable, and the bearing cover eccentricity detection method adopted by the processor includes the following steps: Step 1: Each proximity sensor measures the distance from the inner wall of the inner bearing cover to the shaft; Step 2: Compare the distance measured by the two proximity sensors with the standard value of the gap to obtain the deviation value, calculate the maximum deviation value, the minimum deviation value and the deviation angle, the calculation method is: the deviation value measured by the two proximity sensors is ΔX, ΔY, eccentricity value R=(ΔX2+ΔY2)1/2; if the standard value of the gap is D, the maximum deviation value is D+R, and the minimum deviation value is DR; deviation angle θ=arcsin(ΔY/R); step 3 : Compare the maximum deviation value and whether the minimum deviation value exceeds the critical value.
The motor spindle assembly according to claim 1, wherein the jacket tube is a metal tube.
The motor spindle assembly of claim 1, wherein the fixing sleeve is potted with epoxy resin.
The motor spindle assembly of claim 1, wherein the proximity sensor is an inductive sensor.
The motor spindle assembly of claim 1, wherein the proximity sensor is a capacitive sensor.