155 驱动电机绝缘件用什么改性尼龙
电机绝缘件的种类
驱动电机里的改性尼龙绝缘件有:绕组绝缘骨架(骨架式绕组的骨架)、槽绝缘与槽楔、端部绝缘件、引出线护套与接线端子座、转子护环。
共同要求:耐温等级(通常 155℃ 或 180℃)、绝缘强度、耐绝缘漆和润滑油、尺寸精度、以及长期热老化稳定性。
这里的第一指标是耐温等级,不是力学性能。
现场还原:一台浸漆槽边的对比试验
前年七月,一家电机厂的新平台定绝缘件材料,把三家供应商的标准试片直接泡进了产线的浸漆槽。这个做法在材料行业不算常见——多数选型用标准漆样做试验,他们用的是产线在用漆,浓度、温度、杂质含量全是真实状态。
七天后捞出来,三家的试片拉开了差距:两家的表面无变化,一家的表面出现了细密裂纹。
裂纹那家的技术员起初不服,拿标准漆样复测,数据漂亮。电机厂的工艺工程师把浸漆槽的照片发过去,配了一句话:你的漆是干净的,我们的漆里有机溶剂残留和金属屑,材料要在我们的环境里活十五年。
这句话后来成了他们选型的固定话术——实验室条件验证材料本征性能,产线条件验证材料适应性能,两套数据缺一不可。
最终中标的牌号在绝缘漆浸泡、一百五十五度热老化、冷热冲击三项里全部保持稳定,定点后服役三年,电机绝缘故障率维持在万分之三以下。那次槽边试验的照片还被电机厂贴在实验室墙上,标题就四个字:现场为王。
耐温等级怎么理解
绝缘材料的耐温等级(如 F 级 155℃、H 级 180℃)不是短期耐温,而是长期使用寿命温度——
在该温度下要满足 20000 小时以上的使用寿命。PA66 的实际长期耐温在 120-140℃,所以普通 PA66 只能做 B 级或 F 级绝缘。
要做 H 级(180℃)通常要走 PPA 或 PPS。这是电机绝缘件选料的第一道筛。
耐绝缘漆和耐油
电机绕组要浸绝缘漆(聚酯或环氧),塑料件要耐绝缘漆的溶剂和高温烘烤(浸漆后通常要 150℃ 烘烤数小时)。
同时轴承润滑油和齿轮油也会接触到绝缘件。所以绝缘件要同时耐绝缘漆、耐油、耐 150℃ 烘烤。
验证要做浸漆 + 烘烤 + 热老化的组合测试——这是电机件的标准流程。
尺寸精度和装配
绝缘骨架和槽楔的尺寸精度直接影响绕线质量和装配。PA 的吸湿膨胀在这里是风险(吸湿 2.5% 膨胀 0.6%)。
在电机里还有个额外问题:浸漆和烘烤过程中的尺寸变化——
高温烘烤会让 PA 进一步结晶,尺寸会变化 0.1%-0.3%。
所以关键尺寸要在浸漆烘烤后测量,而不是成型后测量。
绝缘强度和耐电弧
绝缘件的介电强度通常要求 > 20 kV/mm,耐电弧性要求 > 120 s。
PA 在干燥状态下绝缘性能良好,但吸湿后会下降——这是电机绝缘件需要注意的点。
另外,电机内的局部放电(PD)是高压电机的失效机理——800V 平台的电机要关注耐局部放电性能,这是新的技术要求。
深一层:耐温等级的字母背后是什么
电机绝缘材料的耐温等级用字母表示,A级一百零五度、E级一百二十度、B级一百三十度、F级一百五十五度、H级一百八十度。
这个等级不是材料能承受的最高温度,是在该温度下寿命达到两万小时的评定值,理解这一点,选材的思路就对了——等级是温度和寿命的绑定值,单独看温度没有意义。
改性尼龙在电机绝缘件上的定位集中在 B 级到 F 级之间的辅助绝缘位置,槽楔、垫片、接线板这类结构件。主绝缘位置仍由云母、聚酰亚胺薄膜等专职绝缘材料承担,塑料件的角色是承载、隔离和固定。
认清这个定位,就不会提出让塑料件去干云母活的要求,也不会把塑料件按主绝缘的价格买。
耐绝缘漆是绕不开的考验。浸漆工艺里漆液含活性稀释剂和固化促进剂,固化前的漆对塑料的溶胀攻击最强,浸漆温度下暴露时间长的工艺,材料验证就要按最坏暴露时间做。接线板这类先装配后浸漆的件,验证工况比槽楔严酷一档。
延伸判断:电机绝缘件的隐性变量
有三件最容易漏掉的隐性变量。一是水分——PA 在浸漆前如果吸湿,高温烘烤时水汽会造成绝缘漆起泡和绝缘性能下降,成型后要干燥保存。
二是铜离子的催化老化——PA 接触铜会加速热氧老化(铜害),要用铜抑制剂配方。
三是振动下的磨损——绕组在电磁力下会微动,绝缘件磨损会导致匝间短路。
工程实测:4 条强制测试
测试1:长期耐温。PA66 长期 120-140℃(F 级),PPA 180℃(H 级)——先定耐温等级再选料。
测试2:浸漆烘烤 150℃ 后尺寸。结晶变化导致尺寸变化 0.2%——关键尺寸要烘烤后测量。
测试3:介电强度。干燥态 25 kV/mm,吸湿后降至 15 kV/mm——电机件要控制水分。
测试4:铜害老化 150℃ 1000 h。加铜抑制剂体系拉伸保持 85%,未加的降至 45%。
边界声明
| 工况 | 推荐材料 |
|---|
| F 级(155℃)绝缘件 | 耐热 PA66 + 铜抑制剂 |
| H 级(180℃)绝缘件 | PPA 或 PPS |
| 耐绝缘漆件 | 浸漆 + 烘烤组合验证 |
| 精密尺寸件 | 烘烤后测量 + 预留变化量 |
| 800V 高压电机 | 关注耐局部放电性能 |
工程备忘
电机绝缘件第一指标是耐温等级(不是力学性能)——PA66 只能做 F 级,H 级要走 PPA 或 PPS。关键尺寸要在浸漆烘烤后测量,因为高温烘烤会让 PA 尺寸变化 0.2%。
实战案例:常见踩坑与正解
踩坑一:按传统汽车的思路选料,忽略了电气安全要求。正解:新能源车上的塑料件第一判据往往是电气性能——CTI(相比漏电起痕指数)、阻燃等级、耐电弧性,这些在传统车上不重要的指标在这里是硬门槛。踩坑二:只看阻燃等级,忽略了长期湿热下的电痕化。正解:阻燃是着火时的表现,CTI 是长期运行的表现——两者都要,高压件通常要求 CTI ≥ 600V 且阻燃 V-0,缺一项就是长期隐患。踩坑三:把电池的工况简单理解为"高温",忽略了冷热交变和湿热。正解:电池包内是温度交变 + 湿度变化 + 冷却液的复合环境,验证要做温度冲击 + 湿热 + 冷却液相容性的组合测试。这三个坑都是量产前必须自查的清单。
追问三连:电机绝缘件读者的三个高频问题
第一问:绝缘件的 CTI 要多少?按电机的工作电压和污染等级定,低压电机的接线板 CTI 四百伏档普遍够用,变频供电的电机因电压尖峰存在,建议按六百伏档选。变频器的普及让这条从加分项变成了常规项。
第二问:槽楔要承多大力量?嵌线时的敲击力和运行时的电磁力是两个载荷来源,嵌线工艺的冲击是短期考核,电磁振动是长期考核。槽楔料的冲击强度和抗疲劳性能两头都要,验证时模拟嵌线动作做冲击试验,再叠加振动耐久。
第三问:绝缘件的吸湿会影响电机吗?会。尼龙类绝缘件吸湿后绝缘电阻下降,湿热带电机的规范里对绝缘电阻有湿态要求,选低吸水牌号或做防潮封装处理,两条路都通,按成本选。
反向案例:一批在南方雨季趴窝的接线板
有家电机厂的低成本款电机用的是普通 PA66 接线板,北方市场两年无事,南方梅雨季批量出现绝缘电阻告警,返工更换用掉一个季度利润。接线板的材料差价每件不到两元,更换成本是它的百倍。湿热带的电机的材料清单,从来都是另一张表。
增补:另外三个读者的实际问题
第四问:绝缘件的耐电弧要求怎么理解?耐电弧指材料表面承受电弧作用而不导电的能力,接线板这类靠近带电体的件要看这个指标。耐电弧和 CTI 是两个维度,一个管电弧烧蚀,一个管漏电起痕,都要看。
第五问:电机件的注塑精度对电机性能影响多大?槽楔偏厚会顶伤漆包线,垫片厚度偏差影响气隙均匀性。绝缘件的尺寸公差看起来宽松,实际每一丝都连着电机的效率和质量稳定,精密注塑在这里不是加分项是底线。
第六问:电机厂对绝缘件供应商的审核重点是什么?清洁度和追溯。绝缘件的表面粉尘会在嵌线时带入绕组,清洁生产的管控记录是审核必查项;追溯则要求每批可查到配方和工艺版本,变更管理是否规范直接决定审核结果。
一组现场的观察
观察一,电机厂的来料检验越来越细。有家电机厂把绝缘件的来料检验从外观尺寸扩到了介质损耗测试,一批材料介质损耗偏高的批次被拦下,事后证明那批料的助剂体系换了版本。检验项目的深度,反映的是这家厂吃过的亏。
观察二,变频电机的普及正在改写绝缘件规范。变频器输出的高频尖峰电压让绕组首匝承受更高应力,间接提高了对绝缘件电气指标的要求,新材料定点时按变频工况验证,是这两年的新常态。
收口的一组数字
数字一,关于绝缘件的单车用量。一台电机的绝缘结构件从槽楔到接线板超过十种,混动车双电机直接翻倍。这个类目单件金额不高,总量可观,是电机配套里典型的长尾聚宝盆。
数字二,关于寿命指标的换算。电机设计寿命按两万小时起步,绝缘件的同温等级寿命曲线要覆盖它并留三成余量。供应商给寿命数据时问清评定条件,不同条件的两万小时不是一个概念。
数字三,关于清洁度等级。绝缘件的清洁度验收普遍按颗粒数计,行业主流口径是每平方分米可见颗粒不超过个位数。清洁生产的投入是一次性的,被退货的风险是持续的,这笔账不难算。
最后一句话
电机绝缘件的选材说到底是跟着电机的工况表走,工况表写得越诚实,材料选得越准。把温度、浸漆、湿热带三个变量如实填进表里,剩下的交给数据和验证。
附记
新接触绝缘件的读者常问:这些件明明看起来不起眼,为什么定点周期这么长?答案在失效的隐蔽性——绝缘件的轻微缺陷要到电机老化几千小时后才显形,验证周期的长度就是失效显形的时间,省不掉。
结语
把料倒进机器之前——选料这件事,越早问越省事。
这类件的选料与试模,可以一起聊。
155 What type of modified nylon is used for drive motor insulation?
Types of motor insulation components
Modified nylon insulation components in drive motors include: winding insulation skeleton (the skeleton of skeleton windings), slot insulation and slot wedges, end insulating parts, lead wire sheath and terminal block, and rotor rings.
Common requirements: temperature resistance rating (usually 155°C or 180°C), insulation strength, resistance to insulating varnish and lubricants, dimensional accuracy, and long-term thermal aging stability.
The primary indicator here is the temperature resistance grade, not mechanical properties.
On-site reconstruction: Comparative test at the edge of a paint immersion tank
In July two years ago, a new platform for a motor factory soaked standard test pieces from three suppliers directly into the production line's paint immersion tank. This practice is uncommon in the materials industry—most models use standard paint samples for testing, and they use paint from the production line, with concentration, temperature, and impurity levels all showing the real state.
After seven days, the samples from the three companies showed a clear gap: two showed no surface changes, while one showed fine cracks.
The technician at the crack company was initially unconvinced and retested the standard paint sample, finding the data good. The process engineer at the motor factory sent photos of the paint immersion tank over with a caption: Your paint is clean, our paint contains organic solvent residues and metal shavings, and the material must survive in our environment for fifteen years.
This phrase later became their fixed choice — laboratory conditions verify the intrinsic performance of materials, production line conditions verify material adaptability, both sets of data are indispensable.
The final winning grade remained stable in three categories: insulating paint immersion, 155-degree thermal aging, and thermal shock. After designation, it served for three years, with the motor insulation failure rate remaining below 0.03%. The photo of that tank edge test was even posted by the motor factory on the laboratory wall, with the title just four words: 'On-site is king.'
How to understand temperature resistance ratings ?
The temperature resistance rating of insulation materials (such as Class F 155°C, Class H 180°C) is not short-term resistance but long-term service life—
must meet a service life of over 20,000 hours at this temperature. PA66's actual long-term temperature resistance is 120-140°C, so ordinary PA66 can only be used for Class B or Class F insulation.
To make Class H (180°C), PPA or PPS is usually used. This is the first step in selecting motor insulation materials.
Resistant to insulating paint and oil
Motor windings need to be impregnated with insulating varnish (polyester or epoxy), and plastic parts must withstand solvents and high-temperature baking (usually baked at 150°C for several hours after impregnation).
At the same time, bearing lubricants and gear oil also come into contact with insulating parts. Therefore, insulating parts must be resistant to insulating paint, oil, and baking at 150°C.
Verification requires a combined test of varnish dipping + baking + thermal aging—this is the standard process for motor components.
Dimensional accuracy and assembly
Dimensional accuracy of insulating skeleton and slot wedges directly affects winding quality and assembly. The moisture absorption and expansion of PA is a risk here (2.5% moisture absorption, 0.6 % expansion).
There is an additional issue in motors: dimensional changes during paint dipping and baking—
High-temperature baking causes further crystallization of PA, changing size by 0.1%-0.3%.
Therefore, key dimensions should be measured after varnish immersion baking, not after forming.
Insulation strength and arc resistance
The dielectric strength of insulating components is usually required to be > 20 kV/mm, and arc resistance to > 120 s.
PA Good insulation performance in dry conditions but decreases after moisture absorption—this is a point to note in motor insulation.
Additionally, partial discharge (PD) inside the motor is the failure mechanism of high-voltage motors—motors on 800V platforms must focus on partial discharge resistance, which is a new technical requirement.
Deeper layer: What is behind the letters of temperature resistance grade ?
The temperature resistance ratings of motor insulation materials are indicated by letters: Class A 105°C, Class E 120°C, Class B 130°C, Class F 155°C, Class H 180°C.
This grade is not the maximum temperature the material can withstand; it is the rated value for a lifespan of 20,000 hours at that temperature. Understanding this makes the material selection approach correct—grade is a link between temperature and lifespan; looking at temperature alone is meaningless.
Modified nylon is positioned in motor insulation components at auxiliary insulation positions between Class B and F, such as slot wedges, gaskets, and terminal boards. The main insulation position is still handled by specialized insulating materials such as mica and polyimide film, while plastic parts serve to bear, isolate, and fix.
Recognizing this positioning means there will be no demand for plastic parts to do mica work, nor will plastic parts be bought at the main insulation price.
Insulating paint resistance is an unavoidable test. In the impregnation process, the paint solution contains active thinner and curing accelerator. Before curing, the paint has the strongest swelling attack on the plastic. For processes exposed for long periods at the dipping temperature, material verification must be conducted at the worst exposure time. For parts like junction boards that are assembled first and then impregnated, the validation conditions are a level harsher than slot wedges.
Extended judgment: Hidden variables of motor insulation components
There are three most easily missed hidden variables. First is moisture—if PA absorbs moisture before coating, high-temperature baking will cause the insulation paint to bubble and reduce insulation performance; after molding, it should be dried and stored.
Second, catalytic aging of copper ions—PA in contact with copper accelerates thermal oxidation aging (copper damage), so copper inhibitors should be used.
Third is wear under vibration—windings will slight under electromagnetic force, and insulation wear can lead to inter-turn short circuits.
Engineering Testing: 4 mandatory tests
Test 1: Long-term temperature resistance. PA66 long-term 120-140°C (Class F), PPA 180°C (Class H) — determine the temperature resistance grade before selecting materials.
Test 2: Dimensions after 150°C lacquer baking. Crystallization changes cause dimensional change of 0.2%—key dimensions must be measured after baking.
Test 3: Dielectric strength. Dry state 25 kV/mm, after moisture absorption it drops to 15 kV/mm—moisture control of the motor component.
Test 4: Copper damage aging at 150°C for 1000 hours. Copper inhibitor system tensile rate maintains 85%, without copper suppression reduced to 45%.
Boundary Declaration
| Working Conditions | Recommended Materials Grade |
|---|
| F (155°C) Insulation Components | Heat-Resistant PA66 + Copper Inhibitor Grade |
| H (180°C) Insulation Parts | PPA or PPS |
| Insulating Resistant Paint Parts | Immersion paint + baking combination verification |
| Precision dimensioning parts | Post-baking measurement + reserved variation |
| 800V High-voltage motor | Focus on partial discharge resistance |
Engineering memo
Motor insulation The first indicator is temperature resistance rating (not mechanical properties)—PA66 can only be made as F grade; H grade requires PPA or PPS. Key dimensions should be measured after varnish immersion and baking, as high-temperature baking causes PA size to change by 0.2%.
Practical Case: Common pitfalls and correct answers
Pitfall 1: Choosing materials based on traditional automotive thinking ignores electrical safety requirements. Correct answer: The primary criterion for plastic parts in new energy vehicles is often electrical performance—CTI (compared to leakage trace index), flame retardant rating, arc resistance. These insignificant indicators in traditional cars are hard thresholds here. Pitfall 2: Only looking at flame retardant rating, ignoring electric marks under long-term damp heat. Correct answer: Flame retardant is behavior during fire, CTI is long-term operation—both are needed. High-voltage parts usually require CTI ≥ 600V and flame retardant V-0; missing one means long-term hidden dangers. Pitfall 3: Simply interpreting battery conditions as "high temperature," ignoring alternating hot and cold and damp heat. Correct answer: The battery pack is a composite environment of temperature alternating + humidity changes + coolant. Verify that a combination test of temperature shock + damp heat + coolant compatibility should be conducted. These three pitfalls are all checklists that must be checked before mass production.
Follow-up Triple Question: Three high-frequency questions readers have about motor insulation components
First question: What is the CTI of the insulating parts? Depends on the motor's operating voltage and pollution level. For low-voltage motors, the 400V CTI range is generally sufficient. For inverter power supply motors, due to voltage spikes, it is recommended to choose the 600V range. The widespread adoption of frequency converters has made this a standard item from a plus.
Second question: How much force does the slot wedge need to bear? The impact force during wire insertion and the electromagnetic force during operation are two sources of load. The impact of the wire insertion process is a short-term assessment, while electromagnetic vibration is a long-term assessment. Both the impact strength and fatigue resistance of the slot wedge material are required. During verification, simulate the wire embedding action for impact tests, then add vibration durability.
Third question: Does the moisture absorption of insulating components affect the motor? Yes. After moisture absorption by nylon insulating parts, the insulation resistance decreases. The standards for wet and tropical motors require insulation resistance to be wet. Choose a grade with low water absorption or use moisture-proof packaging. Both methods are feasible, so choose according to cost.
Reverse Case: A batch of terminal boards that have been stalled during the southern rainy season
A Motor Factory's low-cost motor uses ordinary PA66 circuit boards. The northern market has been fine for two years, but during the southern rainy season, insulation resistance warnings appear in bulk, and rework and replacement cost a quarter's profit. The material price difference for terminal boards is less than two yuan per piece, and replacement costs are a hundred times higher. The material list for motors in the humid and tropical regions is always a separate table.
Supplement: Another practical question from three readers
Fourth Question: How should the arc resistance requirements for insulating components be understood? Arc resistance refers to the material's ability to withstand arcs without conductivity. For components like terminal boards close to live parts, this indicator should be considered. Arc resistance and CTI are two different dimensions: one is tube arc ablation, the other is leakage and marking, both need to be considered.
Question 5: How much does the injection molding accuracy of electrical components affect motor performance? Thicker slot wedges can damage enameled wire, and shim thickness deviations affect air gap uniformity. Although the dimensional tolerances of insulating parts appear loose, in reality, every wire is connected to the motor's efficiency and quality stability. Precision injection molding here is not a bonus but a bottom line.
Question 6: What is the focus of motor factories' audits on insulating parts suppliers? Cleanliness and traceability. Surface dust from insulating parts can be introduced into windings during wire insertion; clean production control records are mandatory items for audits; Traceability requires that each batch can have traceable formula and process versions, and whether change management is standardized directly determines the audit results.
On-site observation
Observation 1: Incoming material inspections at motor factories are becoming more detailed. One motor factory expanded incoming insulation inspection from appearance dimensions to dielectric loss testing. A batch with high dielectric loss was stopped, only to be found to have its additive system updated in later years. The depth of inspection items reflects the losses the factory has suffered.
Observation 2: The widespread adoption of variable frequency motors is rewriting insulating component specifications. High-frequency spike voltages output by frequency converters cause higher stress on the first turn of windings, indirectly raising the electrical requirements for insulating components. Verification of new materials at designated locations under variable frequency operating conditions has become the new normal in recent years.
A set of numbers at the end
Number One: Regarding the usage per vehicle of insulating components. A single motor has more than ten types of insulation components from slots to terminals, and hybrid dual motors can directly double the price. The price per unit in this category is not high, but the total quantity is considerable, making it a typical long-tail treasure trove in motor matching.
Number Two, regarding the conversion of lifespan indicators. The motor's design life starts at 20,000 hours, and the insulation component's temperature rating life curve should be covered with a 30% margin. When suppliers provide life data, they clarify the evaluation criteria; 20,000 hours under different conditions are not the same concept.
Number Three, regarding cleanliness grades. Insulating component cleanliness acceptance is generally based on particle count; the mainstream industry standard is that visible particles per square decimeter do not exceed single digits. Clean production investment is one-time, and the risk of returns is ongoing, so this account is not hard to calculate.
Last Sentence
Ultimately, the selection of materials for motor insulation parts follows the motor's operating schedule. The more honestly the data is written, the more accurate the material selection. Fill in the three variables—temperature, paint immersion, and humidity—into the table, and leave the rest to data and verification.
Postscript
Readers new to insulating parts often ask: These parts look inconspicuous, so why are the fixed-point intervals so long? The answer lies in the hidden nature of failure—minor defects in insulating parts only become apparent after the motor ages for several thousand hours. The length of the verification cycle is the time it takes for failures to appear, so you can't skip them.
Conclusion
Before Pouring Materials into the Machine — The earlier you ask about material selection, the easier it is.
For material selection and mold trials for these types of pieces, you can chat together