A method and apparatus for painting a motor winding

Abstract

This application provides a method for dripping varnish onto a motor winding, comprising: placing the motor winding in a dripping process box; and dripping varnish onto the motor winding during a first time period t1, wherein the dripping is performed under negative pressure, or sequentially under negative pressure and positive pressure; during negative pressure dripping, the pressure inside the dripping process box is a negative pressure P1, which is less than 0.101 MPa; during positive pressure dripping, the pressure inside the dripping process box is a positive pressure P2, which is greater than or equal to 0.101 MPa. The negative pressure dripping step facilitates varnish penetration and reduces voids, while the positive pressure dripping further reduces varnish overflow and improves the filling rate.

Description

Technical Field

[0001] This application relates to the field of paint dripping, specifically to a paint dripping method and apparatus for motor windings. Background Technology

[0002] The purpose of impregnating motor windings with varnish is to remove moisture from the windings and insulation materials, fill the air gaps with insulating varnish, and bond the winding copper wires, slot insulation, and slot wedges, fixing them within the iron core slots. This improves the winding's insulation strength and moisture resistance, as well as its heat resistance and heat dissipation. It also enhances the mechanical properties and chemical stability of the winding insulation, while preventing movement of the windings and insulation materials within the slots. There are two main methods for impregnating motor windings with varnish: impregnation and dripping. Compared to impregnation, dripping reduces motor temperature rise, shortens the impregnation period, and lowers the energy consumption and cost of insulation treatment, making it widely used in small motors.

[0003] The following methods for dripping paint are disclosed in the prior art:

[0004] Before varnish application: The preheating zone temperature of the varnish application machine is set to 130℃, which allows the moisture in the rotor windings, iron core, and shaft to evaporate quickly, enabling the rotor to quickly reach a suitable temperature for the varnish application stage. This also helps to reduce the viscosity of the varnish, making it easier for the varnish to penetrate the rotor windings. After varnish application and before gelation and curing: The preheating temperature of the varnish application machine is set to 130℃, which allows the rotor to reach a more suitable temperature value after passing through the varnish application zone. This avoids the sudden temperature increase that could cause cracking of the varnish layer when the rotor enters the gelation and curing zone, and also better ensures that the rotor coil has strong rigidity during the gelation and curing stage, stabilizing each turn of the coil. After varnish application, the first curing temperature is set to 140℃, and the second curing temperature is set to 155℃, ensuring that the insulating varnish is completely cured and has strong rigidity. By employing preheating before and after paint application, as well as first and second curing after gelation, the temperature difference of the rotor is kept small throughout the entire paint application process. This reduces the sudden temperature changes of the rotor during the preheating, paint application, gelation, and curing processes, resulting in higher paint absorption efficiency, better insulation after paint application, and extended service life of the motor rotor.

[0005] The above-mentioned paint dripping method only considers the effect of temperature, and the optimization effect is still poor.

[0006] For example, in the varnishing process of stator windings in flat-wire motors, the high slot fill factor makes varnish penetration more difficult. Even with methods such as stator tilting to enhance penetration, problems like varnish overflow still exist, resulting in low varnish load and filling rate. How to improve varnish load and filling rate through optimization of the varnishing process is the technical problem this application aims to solve. Summary of the Invention

[0007] This application provides a method and apparatus for dripping varnish onto motor windings to improve the amount of varnish applied and the filling rate.

[0008] The first aspect of this application provides a method for dripping varnish onto a motor winding, comprising:

[0009] Place the motor windings in the paint dripping process box;

[0010] During the first time period t1, paint is applied to the motor windings;

[0011] The dripping can be performed under negative pressure throughout the first time period t1, or under negative pressure and positive pressure sequentially within the first time period t1.

[0012] During negative pressure dripping, the pressure inside the dripping process box is the dripping negative pressure P1, which is less than 0.101 MPa.

[0013] During positive pressure dripping, the pressure inside the dripping process chamber is the dripping positive pressure P2, which is greater than or equal to 0.101 MPa.

[0014] Based on the first aspect of the embodiments of this application, in the first implementation of the first aspect of the embodiments of this application, the negative pressure P1 of the dripping paint is less than or equal to 10 kPa, preferably less than or equal to 100 Pa; for example, it can be 0.01 Pa, 1 Pa, 10 Pa, 20 Pa, 30 Pa, 40 Pa, 50 Pa, 60 Pa, 70 Pa, 80 Pa, 90 Pa, etc.

[0015] The positive pressure P2 of the paint dripping is greater than or equal to 0.101 MPa, which can be atmospheric pressure, but is preferably 0.102-0.11 MPa, such as 0.102 MPa, 0.105 MPa, 0.106 MPa, 0.108 MPa, 0.11 MPa, etc.

[0016] Based on the first aspect of the embodiments of this application or the first implementation of the first aspect, in the second implementation of the first aspect of the embodiments of this application, the duration t2 of the negative pressure dripping paint is 0.5*t1-0.8*t1;

[0017] Preferably, the duration of the first time period t1 is 10-30 minutes, for example, it can be 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, etc.

[0018] Based on any one of the first aspect, the first implementation and the second implementation of the embodiments of this application, in the third implementation of the first aspect of this application, when the motor winding is dripped with paint, the motor winding is kept at a first temperature T1, and the temperature of T1 is 60-80℃, for example, it can be 60℃, 65℃, 70℃, 75℃, 80℃, etc.

[0019] Based on the first aspect of the embodiments of this application, and any one of the first to third implementations of the first aspect, in the fourth implementation of the first aspect of the embodiments of this application, the method further includes, before the negative pressure dripping of paint:

[0020] During the preheating period t4, the temperature of the motor windings is the preheating temperature T2, and the pressure inside the paint dripping process box is the preheating negative pressure P3.

[0021] The pressure of the preheating negative pressure P3 is less than or equal to 1 kPa, preferably less than or equal to 100 Pa, for example, it can be 10 Pa, 20 Pa, 30 Pa, 40 Pa, 50 Pa, 60 Pa, 70 Pa, etc.

[0022] Furthermore, the preheating temperature T2 is 90-140℃, for example, it can be 90℃, 95℃, 100℃, 105℃, 110℃, 120℃, 130℃, 140℃, etc.;

[0023] Furthermore, the duration of the preheating period t4 is 10-40 minutes, for example, it can be 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, etc.

[0024] Based on the first aspect of the embodiments of this application, and any one of the first to fourth implementations of the first aspect, in the fifth implementation of the first aspect of the embodiments of this application, after the first time period t1, the method further includes:

[0025] During the gelation period t5, the temperature of the motor winding is the gelation temperature T3, and the pressure inside the paint dripping process box is the gelation positive pressure P4.

[0026] The positive pressure P4 of the gel is greater than or equal to 0.102 MPa, preferably 0.102-0.11 MPa, for example, it can be 0.102 MPa, 0.105 MPa, 0.106 MPa, 0.108 MPa, 0.109 MPa, etc.;

[0027] Preferably, the gelation temperature T3 is in the range of 100-140℃, for example, it can be 100℃, 105℃, 110℃, 120℃, 130℃, 140℃, etc.

[0028] Furthermore, the duration of the gelation period t5 can range from 20 to 50 minutes, for example, it can be 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, etc.

[0029] Based on any one of the first to fifth implementations of the first aspect of the embodiments of this application, in the sixth implementation of the first aspect of the embodiments of this application, after the gelation period t5, during the curing period t6, the temperature of the motor winding is the curing temperature T4, and the pressure of the paint dripping process box is maintained at atmospheric pressure P0.

[0030] Preferably, the curing temperature T4 is in the range of 120-180℃, for example, it can be 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, etc.

[0031] Furthermore, the curing period t6 is 60-120 minutes, for example, it can be 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, 110 minutes, 120 minutes, etc.

[0032] Based on any one of the first to sixth implementations of the embodiments of this application, in the seventh implementation of the first aspect of the embodiments of this application, the axis of the motor winding has an inclination angle with the horizontal plane, where 0 degrees ≤ inclination angle ≤ 20 degrees.

[0033] Based on any one of the first to seventh implementations of the first aspect of the present application, in the eighth implementation of the first aspect of the present application, during the dripping, gelling, and curing processes, the motor winding rotates around the axis of the motor winding at a preset speed, where 5 rpm ≤ preset speed ≤ 25 rpm.

[0034] The first aspect of this application provides a varnish-drip device for motor windings, comprising: a varnish-drip process box, a rotating shaft, a dripping tube, a varnish storage tank, a vacuum pump, an air filling tank, and a heating device, to perform the varnish-drip method for motor windings of the first aspect;

[0035] The rotating shaft is set inside the paint dripping process box and is used to install the motor windings and drive the motor windings to rotate;

[0036] The paint dripping process box is connected to a vacuum pump and an air filling tank. The vacuum pump and air filling tank are used to regulate the air pressure in the paint dripping process box.

[0037] The inlet of the dropper is connected to the paint storage tank, the dropper extends into the paint dripping process box, and the outlet of the dropper guides the paint liquid to the motor windings;

[0038] Heating equipment is used to control the temperature inside the paint dripping process box.

[0039] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0040] In this embodiment, the paint dripping is performed under vacuum negative pressure. The negative pressure facilitates paint penetration and reduces voids. Following negative pressure dripping is positive pressure dripping, which helps reduce paint overflow and improves the filling rate. Compared to existing technologies that only consider temperature, this embodiment introduces pressure, making paint dripping control more multi-dimensional and flexible, and resulting in better dripping effects. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the process curve of the paint dripping method for the motor windings in an embodiment of this application;

[0042] Figure 2 This is a schematic diagram of a paint dripping device for a motor winding according to an embodiment of this application;

[0043] Figure 3 This is a flowchart of a method for dripping paint onto motor windings according to an embodiment of this application;

[0044] Figure 4 This is another flowchart of the method for dripping paint onto the motor windings according to an embodiment of this application;

[0045] 1. Paint dripping box; 2. Rotating shaft; 3. Drip pipe; 4. Paint storage tank; 5. Vacuum pump; 6. Air filling tank; 7. Motor winding. Detailed Implementation

[0046] The varnish application process for motor windings can be roughly divided into four steps: preheating, varnish application, gelation, and curing. The key technical points to consider for each step in the optimal solution include:

[0047] like Figure 1 As shown, dehumidification is performed during the preheating stage. Negative pressure dripping is used in the initial stage of the dripping process, and positive pressure dripping is used in the later stage. Positive pressure is maintained during the gelation stage. Atmospheric pressure is maintained during the curing stage. Negative pressure dripping requires evacuating the dripping chamber to create a negative pressure environment; this can also be called vacuum dripping.

[0048] Temperature should be maintained as consistently as possible during drying, dripping, gelling, and curing, but variations are acceptable within a limited timeframe. Heating equipment can be an oven or electric heating, among other methods. Generally, a temperature control accuracy of ±5℃ is required.

[0049] The pressure of the paint dripping negative pressure P1 and the preheating negative pressure P3 should be kept as constant as possible, or they can change in a certain regular or irregular manner.

[0050] The pressure of the paint dripping positive pressure P2 and the gel positive pressure P4 should be kept as constant as possible, or they can change in a certain regular or irregular manner.

[0051] During the varnish dripping and gelling stages, the motor windings need to rotate. This can be combined with a tilt angle. The motor windings consist of silicon steel sheets and coils, and can be either the motor stator or the motor rotor.

[0052] Fill ratio: Each motor winding is vertically cut at a certain position along its axis. The ratio of the actual area filled by the insulating varnish on each cross-section to the theoretical total area is measured and calculated. This ratio is the fill ratio of that cross-section. The lowest fill ratio of each cross-section is taken as the fill ratio of the motor winding. In the actual implementation and comparative examples, three regions are used (top, middle, and bottom are 10mm from the stator end face, and the middle is the position between the two end faces).

[0053] Volatility: Take the required number of motor windings and measure the fill rate of all the above sections. Volatility = (maximum value - minimum value) / minimum value. Example and Comparative Example: 5 motor windings were actually used.

[0054] This application provides a varnish-drip device for motor windings, including: a varnish-drip process box, a rotating shaft, a dripping pipe, a varnish storage tank, a vacuum pump, an air filling tank, and a heating device, to perform a varnish-drip method for motor windings;

[0055] The rotating shaft is set inside the paint dripping process box and is used to install the motor windings and drive the motor windings to rotate;

[0056] The paint dripping process box is connected to a vacuum pump and an air filling tank. The vacuum pump and air filling tank are used to regulate the air pressure in the paint dripping process box.

[0057] The inlet of the dropper is connected to the paint storage tank, the dropper extends into the paint dripping process box, and the outlet of the dropper guides the paint liquid to the motor windings;

[0058] Heating equipment is used to control the temperature inside the paint dripping process box.

[0059] like Figure 2 The paint-drip device for the motor winding shown in this embodiment of the application is used for single-machine paint dripping.

[0060] like Figure 3 As shown, this application provides a method for dripping varnish onto motor windings, comprising:

[0061] 101. Place the motor windings in the paint dripping process box;

[0062] 102. During the first time period t1, the motor windings are sequentially subjected to negative pressure varnish dripping and positive pressure varnish dripping.

[0063] During the first time period t1, the motor winding is kept at the first temperature T1, and the motor winding rotates around the axis of the motor winding at a preset speed, and varnish is dripped onto the motor winding.

[0064] The first time period t1 is divided into the first sub-time period t2 and the second sub-time period t3, where t1 = t2 + t3;

[0065] 103. During negative pressure dripping (i.e., the first sub-time period t2), the pressure inside the dripping process box is maintained at the dripping negative pressure P1;

[0066] 104. During positive pressure dripping (i.e., the second sub-time period t3), the pressure inside the dripping process box is maintained at the positive pressure P2.

[0067] In this embodiment, the paint dripping step is divided into two segments: the first segment (first sub-segment) and the second segment (second sub-segment). Negative pressure dripping is applied in the first segment, while positive pressure dripping is applied in the second segment. The negative pressure of the negative pressure dripping facilitates paint penetration and reduces voids, while the positive pressure of the positive pressure dripping helps reduce paint overflow and improves the filling rate. Compared to existing technologies that only consider temperature, this embodiment introduces pressure, making paint dripping control more multidimensional and flexible, and resulting in better dripping effects.

[0068] like Figure 4 As shown, this application provides a method for dripping varnish onto motor windings, comprising:

[0069] 201. Place the motor windings in the paint dripping process box;

[0070] 202. During the preheating period t4, the motor windings are kept at the preheating temperature T2, and the paint dripping process box is kept at the preheating negative pressure P3.

[0071] The motor windings are heated and dried in a vacuum.

[0072] 203. During the first time period t1, the motor winding is kept at the first temperature T1. The motor winding rotates around the axis of the motor winding at a preset speed. Paint is dripped onto the motor winding. The first time period t1 is divided into the first sub-time period t2 and the second sub-time period t3, t1 = t2 + t3.

[0073] 204. During the first sub-period t2, maintain the paint dripping process box at the paint dripping negative pressure P1;

[0074] 205. After the first sub-period t2, during the second sub-period t3, the paint dripping process box is kept at the positive pressure P2 for paint dripping.

[0075] 206. During the gelation period t5, the motor windings are kept at the gelation temperature T3, and the paint dripping process box is kept at the gelation positive pressure P4.

[0076] 207. After the gelation period t5, during the curing period t6, the motor windings are kept at the curing temperature T4, and the paint dripping chamber is kept at atmospheric pressure P0.

[0077] The first temperature T1 is 60-80℃;

[0078] The duration of the first time period t1 is 10-30 minutes;

[0079] The duration of the first sub-period t2 is (0.5*t1-0.8*t1);

[0080] The negative pressure P1 for dripping paint is less than or equal to 10 kPa, preferably less than or equal to 100 Pa;

[0081] The positive pressure P2 for dripping paint is greater than or equal to 0.102 MPa, preferably 0.102-0.11 MPa.

[0082] The preheating temperature T2 is 90-140℃;

[0083] The preheating period t4 lasts for 10-40 minutes.

[0084] The preheating negative pressure P3 is less than or equal to 1 kPa, preferably less than or equal to 100 Pa;

[0085] The gelation temperature T3 is 100-140℃;

[0086] The duration of gelation time t5 is 20-50 min.

[0087] The positive pressure of the gel, P4, is greater than or equal to 0.102 MPa, preferably 0.102-0.11 MPa;

[0088] The curing temperature T4 is 120-180℃;

[0089] The curing period t6 lasts for 60-120 minutes.

[0090] The axis of the motor winding has an inclination angle with the horizontal plane, 0 degrees ≤ inclination angle ≤ 20 degrees.

[0091] The workpiece rotates at a preset speed during paint application, with a speed between 5 rpm and 25 rpm. The motor windings can also be considered part of the workpiece.

[0092] It should be noted that the above range of values ​​is for illustrative purposes only and is not a limitation.

[0093] To verify the beneficial effects of the embodiments of this application, specific embodiments and comparative examples are given below.

[0094] Example 1:

[0095] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of 140 degrees Celsius, and the pressure in the paint dripping chamber is kept at atmospheric pressure of 101000 Pa.

[0096] During the first 30-minute period, the motor winding is kept at a first temperature of 80 degrees Celsius. The motor winding rotates around the axis of the motor winding at a preset speed. Paint is dripped onto the motor winding. The first period t1 is divided into the first sub-period t2 and the second sub-period t3, where t1 = t2 + t3.

[0097] During the first 24-minute period, the pressure in the paint dripping process box is maintained at a negative pressure of 10 kPa.

[0098] After the first sub-period t2, during the second sub-period of 6 minutes, the pressure of the paint dripping process box is maintained at a positive pressure of 102000Pa.

[0099] During the 20-minute gelation period, the motor windings were kept at a gelation temperature of 100 degrees Celsius, and the pressure in the paint dripping chamber was kept at atmospheric pressure of 101000 Pa.

[0100] After the gelation period t5, during the curing period of 120 minutes, the motor windings are kept at a curing temperature of 120 degrees Celsius, and the paint dripping chamber is kept at an atmospheric pressure of 101000 Pa.

[0101] The axis of the motor winding has an inclination angle of 20 degrees relative to the horizontal plane.

[0102] The workpiece rotates at a preset speed during the paint dripping process. The preset speed is 5 rpm.

[0103] The resulting motor winding had a varnish filling rate of 91.9% and a fluctuation rate of 4.3%.

[0104] Example 2:

[0105] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of 140 degrees Celsius, and the pressure in the paint dripping chamber is kept at atmospheric pressure of 101000 Pa.

[0106] During the first 30-minute period, the motor winding is kept at a first temperature of 80 degrees Celsius. The motor winding rotates around the axis of the motor winding at a preset speed. Paint is dripped onto the motor winding. The first period t1 is divided into the first sub-period t2 and the second sub-period t3, where t1 = t2 + t3.

[0107] During the first 15-minute period, the paint dripping process box should be maintained at a negative pressure of 100Pa.

[0108] After the first sub-period t2, during the second sub-period of 15 minutes, the paint dripping process box will be maintained at a positive pressure of 102000Pa.

[0109] During the 20-minute gelation period, the motor windings were kept at a gelation temperature of 100 degrees Celsius, and the pressure in the paint dripping chamber was kept at atmospheric pressure of 101000 Pa.

[0110] After the gelation period t5, during the curing period of 120 minutes, the motor windings are kept at a curing temperature of 120 degrees Celsius, and the paint dripping chamber is kept at an atmospheric pressure of 101000 Pa.

[0111] The axis of the motor winding has an inclination angle of 20 degrees relative to the horizontal plane.

[0112] The workpiece rotates at a preset speed during the paint dripping process. The preset speed is 5 rpm.

[0113] The resulting motor windings had a varnish filling rate of 92.1% and a fluctuation rate of 4.1%.

[0114] Example 3:

[0115] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of 140 degrees Celsius, and the pressure in the paint dripping chamber is kept at atmospheric pressure of 101000 Pa.

[0116] During the first 30-minute period, the motor winding is kept at a first temperature of 80 degrees Celsius. The motor winding rotates around the axis of the motor winding at a preset speed. Paint is dripped onto the motor winding. The first period t1 is divided into the first sub-period t2 and the second sub-period t3, where t1 = t2 + t3.

[0117] During the first 12-minute period, the paint dripping process box was maintained at a negative pressure of 100Pa.

[0118] After the first sub-period t2, during the second sub-period of 18 minutes, the paint dripping process box will be maintained at a positive pressure of 102000Pa.

[0119] During the 20-minute gelation period, the motor windings were kept at a gelation temperature of 100 degrees Celsius, and the pressure in the paint dripping chamber was kept at atmospheric pressure of 101000 Pa.

[0120] After the gelation period t5, during the curing period of 120 minutes, the motor windings are kept at a curing temperature of 120 degrees Celsius, and the paint dripping chamber is kept at an atmospheric pressure of 101000 Pa.

[0121] The axis of the motor winding has an inclination angle of 20 degrees relative to the horizontal plane.

[0122] The workpiece rotates at a preset speed during the paint dripping process. The preset speed is 5 rpm.

[0123] The resulting motor winding had a varnish filling rate of 91.4% and a fluctuation rate of 4.3%.

[0124] Example 4:

[0125] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of 140 degrees Celsius, and the pressure in the paint dripping chamber is kept at atmospheric pressure of 101000 Pa.

[0126] During the first 30-minute period, the motor winding is kept at a first temperature of 80 degrees Celsius. The motor winding rotates around the axis of the motor winding at a preset speed. Paint is dripped onto the motor winding. The first period t1 is divided into the first sub-period t2 and the second sub-period t3, where t1 = t2 + t3.

[0127] During the first 10-minute period, the paint dripping process box should be maintained at a negative pressure of 100Pa.

[0128] After the first sub-period t2, during the second sub-period of 20 minutes, the paint dripping process box will be maintained at a positive pressure of 102000Pa.

[0129] During the 20-minute gelation period, the motor windings were kept at a gelation temperature of 100 degrees Celsius, and the pressure in the paint dripping chamber was kept at atmospheric pressure of 101000 Pa.

[0130] After the gelation period t5, during the curing period of 120 minutes, the motor windings are kept at a curing temperature of 120 degrees Celsius, and the paint dripping chamber is kept at an atmospheric pressure of 101000 Pa.

[0131] The axis of the motor winding has an inclination angle of 20 degrees relative to the horizontal plane.

[0132] The workpiece rotates at a preset speed during the paint dripping process. The preset speed is 5 rpm.

[0133] The resulting motor windings had a varnish filling rate of 91.2% and a fluctuation rate of 4.5%.

[0134] Example 5:

[0135] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of 140 degrees Celsius, and the paint dripping process box is kept at a preheating negative pressure of 0.01 Pa.

[0136] During the first 30-minute period, the motor winding is kept at a first temperature of 80 degrees Celsius. The motor winding rotates around the axis of the motor winding at a preset speed. Paint is dripped onto the motor winding. The first period t1 is divided into the first sub-period t2 and the second sub-period t3, where t1 = t2 + t3.

[0137] During the first 18-minute period, the paint dripping process box was maintained at a negative pressure of 50Pa.

[0138] After the first sub-period t2, during the second sub-period of 12 minutes, the paint dripping process box will be maintained at a positive pressure of 102000Pa.

[0139] During the 20-minute gelation period, the motor windings are kept at a gelation temperature T3 = 100 degrees Celsius, and the pressure in the paint dripping chamber is kept at atmospheric pressure of 101000 Pa.

[0140] After the gelation period t5, during the curing period of 120 minutes, the motor windings are kept at a curing temperature of 120 degrees Celsius, and the paint dripping chamber is kept at an atmospheric pressure of 101000 Pa.

[0141] The axis of the motor winding has an inclination angle of 20 degrees relative to the horizontal plane.

[0142] The workpiece rotates at a preset speed during the paint dripping process. The preset speed is 5 rpm.

[0143] The resulting motor windings had a varnish filling rate of 92.7% and a fluctuation rate of 4.2%.

[0144] Example 6:

[0145] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of 140 degrees Celsius, and the paint dripping process box is kept at a preheating negative pressure of 0.01 Pa.

[0146] During the first 30-minute period, the motor winding is kept at a first temperature of 80 degrees Celsius. The motor winding rotates around the axis of the motor winding at a preset speed. Paint is dripped onto the motor winding. The first period t1 is divided into the first sub-period t2 and the second sub-period t3, where t1 = t2 + t3.

[0147] During the first 20-minute period, the paint dripping process box should be maintained at a negative pressure of 100Pa.

[0148] After the first sub-period t2, during the second sub-period of 10 minutes, the paint dripping process box will be maintained at a positive pressure of 110,000 Pa.

[0149] During the 20-minute gelation period, the motor windings were kept at a gelation temperature of T3 = 100 degrees Celsius, and the paint dripping chamber was kept at a gelation positive pressure of 110,000 Pa.

[0150] After the gelation period t5, during the curing period of 120 minutes, the motor windings are kept at a curing temperature of 120 degrees Celsius, and the paint dripping chamber is kept at an atmospheric pressure of 101000 Pa.

[0151] The axis of the motor winding has an inclination angle of 20 degrees relative to the horizontal plane.

[0152] The workpiece rotates at a preset speed during the paint dripping process. The preset speed is 5 rpm.

[0153] The resulting motor windings had a varnish filling rate of 93.1% and a fluctuation rate of 3.8%.

[0154] Example 7:

[0155] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of T2 = 140 degrees Celsius, and the paint dripping chamber is kept at a preheating negative pressure of 5 Pa.

[0156] During the first 30-minute period, the motor winding is kept at a first temperature of 80 degrees Celsius. The motor winding rotates around the axis of the motor winding at a preset speed. Paint is dripped onto the motor winding. The first period t1 is divided into the first sub-period t2 and the second sub-period t3, where t1 = t2 + t3.

[0157] During the first 18-minute period, the paint dripping process box was maintained at a negative pressure of 15 Pa.

[0158] After the first sub-period t2, during the second sub-period of 12 minutes, the paint dripping process box will be maintained at a positive pressure of 102000Pa.

[0159] During the 20-minute gelation period, the motor windings were kept at a gelation temperature of T3 = 100 degrees Celsius, and the paint dripping chamber was kept at a gelation positive pressure of 120,000 Pa.

[0160] After the gelation period t5, during the curing period t6 = 120 minutes, the motor windings are kept at the curing temperature T4 = 120 degrees Celsius, and the paint dripping chamber is kept at an atmospheric pressure of 101000 Pa.

[0161] The axis of the motor winding has an inclination angle of 20 degrees relative to the horizontal plane.

[0162] The workpiece rotates at a preset speed during the paint dripping process. The preset speed is 5 rpm.

[0163] The resulting motor winding had a varnish filling rate of 92.8% and a fluctuation rate of 4.1%.

[0164] Example 8:

[0165] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of 140 degrees Celsius, and the paint dripping process box is kept at a preheating negative pressure of 5 Pa.

[0166] During the first 30-minute period, the motor winding is kept at a first temperature of 80 degrees Celsius. The motor winding rotates around the axis of the motor winding at a preset speed. Paint is dripped onto the motor winding. The first period t1 is divided into the first sub-period t2 and the second sub-period t3, where t1 = t2 + t3.

[0167] During the first 24-minute period, the paint dripping process box will be maintained at a negative pressure of 15 Pa.

[0168] After the first sub-period t2, during the second sub-period of 6 minutes, the paint dripping process box will be maintained at a positive pressure of 105000Pa.

[0169] During the 20-minute gelation period, the motor windings were kept at a gelation temperature of 100 degrees Celsius, and the paint dripping chamber was kept at a gelation positive pressure of 105,000 Pa.

[0170] After the gelation period t5, during the curing period of 120 minutes, the motor windings are kept at a curing temperature of 120 degrees Celsius, and the paint dripping chamber is kept at an atmospheric pressure of 101000 Pa.

[0171] The axis of the motor winding has an inclination angle of 20 degrees relative to the horizontal plane.

[0172] The workpiece rotates at a preset speed during the paint dripping process. The preset speed is 5 rpm.

[0173] The resulting motor windings had a varnish filling rate of 92.9% and a fluctuation rate of 4.0%.

[0174] Example 9:

[0175] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of 140 degrees Celsius, and the paint dripping process box is kept at a preheating negative pressure of 0.01 Pa.

[0176] During the first 30-minute period, the motor winding is kept at a first temperature of 80 degrees Celsius. The motor winding rotates around the axis of the motor winding at a preset speed. Paint is dripped onto the motor winding. The first period t1 is divided into the first sub-period t2 and the second sub-period t3, where t1 = t2 + t3.

[0177] During the first 24-minute period, the paint dripping process box will be maintained at a negative pressure of 1 Pa.

[0178] After the first sub-period t2, during the second sub-period of 6 minutes, the paint dripping process box will be maintained at a positive pressure of P2 = 102000Pa.

[0179] During the 20-minute gelation period, the motor windings were kept at a gelation temperature of 100 degrees Celsius, and the paint dripping chamber was kept at a gelation positive pressure of 102000 Pa.

[0180] After the gelation period t5, during the curing period t6 = 120 minutes, the motor windings are kept at the curing temperature T4 = 120 degrees Celsius, and the paint dripping chamber is kept at an atmospheric pressure of 101000 Pa.

[0181] The axis of the motor winding has an inclination angle of 15 degrees relative to the horizontal plane.

[0182] The workpiece rotates at a preset speed during the paint dripping process. The preset speed is 5 rpm.

[0183] The resulting motor windings had a varnish filling rate of 93.0% and a fluctuation rate of 3.9%.

[0184] Example 10:

[0185] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of 140 degrees Celsius, and the pressure in the paint dripping chamber is kept at atmospheric pressure of 101000 Pa.

[0186] During the first 30-minute period, the motor windings are kept at a first temperature of 80 degrees Celsius. The motor windings rotate around the axis of the motor windings at a preset speed. The pressure of the paint dripping process box is kept at 100 Pa, and paint is dripped onto the motor windings.

[0187] During the 20-minute gelation period, the motor windings were kept at a gelation temperature of 100 degrees Celsius, and the pressure in the paint dripping chamber was kept at atmospheric pressure of 101000 Pa.

[0188] After the gel phase, during the 120-minute curing phase, the motor windings are kept at a curing temperature of 120 degrees Celsius, and the paint dripping chamber is kept at an atmospheric pressure of 101000 Pa.

[0189] The axis of the motor winding has an inclination angle of 20 degrees relative to the horizontal plane.

[0190] The workpiece rotates at a preset speed during the paint dripping process. The preset speed is 5 rpm.

[0191] The resulting motor winding had a varnish filling rate of 89.2% and a fluctuation rate of 6.4%.

[0192] Example 11:

[0193] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of 140 degrees Celsius, and the pressure in the paint dripping chamber is kept at a preheating negative pressure of 5 Pa.

[0194] During the first 30-minute period, the motor windings are kept at a first temperature of 80 degrees Celsius. The motor windings rotate around the axis of the motor windings at a preset speed. The pressure of the paint dripping process box is kept at 15 Pa, and paint is dripped onto the motor windings.

[0195] During the 20-minute gelation period, the motor windings were kept at a gelation temperature of 100 degrees Celsius, and the pressure in the paint dripping chamber was kept at atmospheric pressure of 101000 Pa.

[0196] After the gel phase, during the 120-minute curing phase, the motor windings are kept at a curing temperature of 120 degrees Celsius, and the paint dripping chamber is kept at an atmospheric pressure of 101000 Pa.

[0197] The axis of the motor winding has an inclination angle of 20 degrees relative to the horizontal plane.

[0198] The workpiece rotates at a preset speed during the paint dripping process. The preset speed is 5 rpm.

[0199] The resulting motor winding had a varnish filling rate of 89.6% and a fluctuation rate of 6.1%.

[0200] Example 12:

[0201] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of 140 degrees Celsius, and the pressure in the paint dripping chamber is kept at a preheating negative pressure of 5 Pa.

[0202] During the first 30-minute period, the motor windings are kept at a first temperature of 80 degrees Celsius. The motor windings rotate around the axis of the motor windings at a preset speed. The pressure of the paint dripping process box is kept at 15 Pa, and paint is dripped onto the motor windings.

[0203] During the 20-minute gelation period, the motor windings are kept at a gelation temperature of 100 degrees Celsius, and the pressure in the paint dripping chamber is kept at a positive gelation pressure of 110,000 Pa.

[0204] After the gel phase, during the 120-minute curing phase, the motor windings are kept at a curing temperature of 120 degrees Celsius, and the paint dripping chamber is kept at an atmospheric pressure of 101000 Pa.

[0205] The axis of the motor winding has an inclination angle of 20 degrees relative to the horizontal plane.

[0206] The workpiece rotates at a preset speed during the paint dripping process. The preset speed is 5 rpm.

[0207] The resulting motor windings had a varnish filling rate of 89.9% and a fluctuation rate of 5.8%.

[0208] Comparative Example 1:

[0209] During the 40-minute preheating period, the motor windings are kept at a preheating temperature of 140 degrees Celsius, and the paint dripping chamber is kept at atmospheric pressure.

[0210] During the 30-minute dripping period, the motor windings are kept at a first temperature of 80 degrees Celsius. The motor windings rotate around the axis of the motor windings at a preset speed of 5 rpm. The dripping process box is kept at atmospheric pressure to drip paint onto the motor windings.

[0211] During the 20-minute gelation period, the motor windings are kept at a gelation temperature of 100 degrees Celsius, and the paint dripping chamber is kept at atmospheric pressure.

[0212] After the gel phase, during the 120-minute curing phase, the motor windings are kept at a curing temperature of 120 degrees Celsius, and the paint dripping chamber is kept at atmospheric pressure.

[0213] The axis of the motor winding has an inclination angle of 20 degrees relative to the horizontal plane.

[0214] The resulting motor windings had a varnish filling rate of 87.4% and a fluctuation rate of 6.9%.

[0215] As can be seen from the comparison between Examples 1-12 and Comparative Example 1, the filling rate of the varnish in the motor winding obtained by the embodiments of this application is significantly increased and the fluctuation is significantly reduced compared with the prior art. In other words, the varnish dripping quality of the motor winding obtained by the embodiments of this application is better and more stable.

[0216] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0217] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0218] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0219] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0220] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

Claims

1. A method for dripping varnish onto motor windings, characterized in that, include: Place the motor windings in the paint dripping process box; During the preheating period t4, the temperature of the motor winding is the preheating temperature T2, and the pressure inside the paint dripping process box is the preheating negative pressure P3. The motor winding is placed in a vacuum for heating and drying. The pressure of the preheating negative pressure P3 is less than or equal to 1 kPa. During the first time period t1, paint is applied to the motor windings; The paint dripping process consists of sequential negative pressure dripping and positive pressure dripping; the duration t2 of the negative pressure dripping is 0.5*t1-0.8*t1; During negative pressure dripping, the pressure inside the dripping process box is the dripping negative pressure P1, which is less than 0.101 MPa. During positive pressure dripping, the pressure inside the dripping process box is the dripping positive pressure P2, which is greater than or equal to 0.101 MPa. During the gelation period t5, the temperature of the motor winding is the gelation temperature T3, and the pressure inside the paint dripping process box is the gelation positive pressure P4; the value range of the gelation positive pressure P4 is greater than or equal to 0.102MPa.

2. The method for dripping varnish onto motor windings according to claim 1, characterized in that, The negative pressure P1 for dripping paint is less than or equal to 10 kPa; The positive pressure P2 for the dripping paint is 0.102-0.11 MPa.

3. The method for dripping varnish onto motor windings according to claim 1 or 2, characterized in that, The duration of the first time period t1 is 10-30 minutes.

4. The method for dripping varnish onto motor windings according to claim 1, characterized in that, When applying varnish to the motor windings, the temperature of the motor windings is the first temperature T1, which is 60-80℃.

5. The method for dripping varnish onto motor windings according to claim 1, characterized in that, The pressure of the preheating negative pressure P3 is less than or equal to 100 Pa; The preheating temperature T2 is 90-140℃; The preheating period t4 lasts for 10-40 minutes.

6. The method for dripping varnish onto motor windings according to claim 1, characterized in that, The positive pressure of the gel, P4, ranges from 0.102 to 0.11 MPa. The gelation temperature T3 ranges from 100 to 140℃; The duration of gelation time t5 is 20-50 min.

7. The method for dripping varnish onto motor windings according to claim 1, characterized in that, After the gelation period t5, during the curing period t6, the temperature of the motor winding is the curing temperature T4, and the pressure of the paint dripping process box is maintained at atmospheric pressure P0. The curing temperature T4 ranges from 120 to 180℃; The curing period t6 lasts for 60-120 minutes.

8. The method for dripping varnish onto motor windings according to claim 1, characterized in that, The axis of the motor winding has an inclination angle with the horizontal plane, where 0 degrees ≤ inclination angle ≤ 20 degrees.

9. The method for dripping varnish onto motor windings according to claim 1, characterized in that, During the dripping, gelling, and curing processes, the motor windings rotate around the axis of the motor windings at a preset speed, where 5 rpm ≤ preset speed ≤ 25 rpm.

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