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轴对准的热膨胀补偿
计算驱动电机和从动电机因热膨胀引起的垂直中心线增长。确定冷态对准预偏移目标值，以实现工作温度下的对准。
成果
热生长公式
机器发热时，其机架会垂直膨胀，导致轴中心线升高：
- H — 脚到中心线的高度（毫米）
- α — 热膨胀系数（×10⁻⁶ /°C）
- Top — 工作温度（摄氏度）
- T环境（amb） — 环境温度（摄氏度）
材料热膨胀系数
| 材料 | α (×10⁻⁶ /°C) |
|---|---|
| 碳钢 | 12.0 |
| 铸铁 | 10.5 |
| 不锈钢（304/316） | 16.0 |
| 铝 | 23.0 |
典型工作温度
| 机器类型 | 典型外壳温度（摄氏度） |
|---|---|
| 电动机 | 60 – 90 |
| 离心泵（冷水） | 40 – 70 |
| 蒸汽轮机 | 80 – 200 |
| 变速箱 | 50 – 80 |
| 压缩机 | 60 – 120 |
实例
已知： 环境温度 = 20°C
电机：H = 200 mm，钢（α = 12×10⁻⁶），Top = 80°C
泵：H = 250 mm，钢（α = 12×10⁻⁶），Top = 60°C
ΔH电机 = 200 × 12×10⁻⁶ × (80 − 20) = 0.144毫米
ΔH泵 = 250 × 12×10⁻⁶ × (60 − 20) = 0.120毫米
差值 = 0.144 − 0.120 = 0.024毫米
电机热增长更多 → 将电机设置为 0.024 毫米 低 在冷对准期间。
💡提示： 冷态对准时，生长较多的机器应设置为较低位置。当两台机器都升温后，生长差异会使它们对齐。
⚠️ 注意： 此计算假设机器框架的热膨胀是均匀的。实际上，温度梯度、管道应变和地基效应可能会导致额外的位移。尽可能进行热对准检查以验证结果。
Thermal growth is the vertical expansion of a machine's shaft centerline height as the machine heats up from ambient to operating temperature. All materials expand when heated, and for rotating machinery this means the shaft centerline rises.
The growth is calculated as: ΔH = H × α × (Top − Tamb), where H is the foot-to-centerline height, α is the coefficient of thermal expansion, and the temperatures are in °C.
Machines are aligned when cold (not running) but operate when hot. If the driver and driven machines grow by different amounts vertically, perfect cold alignment will result in misalignment at operating temperature.
By intentionally offsetting the cold alignment by the expected differential growth, the machines come into proper alignment when they reach operating temperature. The machine that grows more is set low during cold alignment.
Operating temperatures can be measured on running equipment using:
- Infrared thermometer — quick non-contact measurement at machine feet or bearing housings
- Contact thermocouple probes — more accurate surface temperature
- RTDs/thermocouples — permanently installed sensors
Measure at the machine feet or base, not at the top of the casing, as this best represents the temperature affecting vertical growth. Allow the machine to reach thermal steady state (typically 2–4 hours).
Typical casing/foot temperatures for common machines:
- Electric motors: 60–90°C (depending on frame size and load)
- Centrifugal pumps: 40–70°C (cold water), up to 200°C+ (hot process)
- Steam turbines: 80–200°C
- Gearboxes: 50–80°C
- Compressors: 60–120°C
These are approximate values. Always measure on the actual equipment when possible.
A hot alignment check is performed immediately after shutting down equipment that has been running at normal operating temperature. The alignment is measured before significant cooling occurs (typically within 15–30 minutes of shutdown).
This check verifies whether:
- The calculated thermal growth predictions were accurate
- The cold pre-offset was correct
- Other factors (piping strain, foundation movement) are affecting alignment
A hot check is the gold standard for validating alignment and should be performed whenever practical, especially on critical machinery.
本页所述的操作流程由 Vibromera 团队使用 Balanset-1A（一款用于现场转子平衡的便携式双通道动平衡仪及振动分析仪）开发并经过实地测试。
专业激光对准和振动分析仪器。可现场进行热膨胀补偿，实现精准对准。产品已在全球50多个国家使用。
Nikolai Shelkovenko
Nikolai Shelkovenko是一名振动分析工程师，也是Vibromera的创始人兼首席执行官。 15年多来，他一直在现场——而非在试验台上——为旋转设备进行平衡：粉碎机、工业风机、破碎机、离心机、轴和主轴。正是这些实际工作催生了Balanset系列仪器——它们被设计为一种专业人员可以随身携带到机器旁、在现场独立使用的工具，而非实验室设备。 Vibromera成立于2017年，自2023年起总部设于葡萄牙波尔图。Balanset系列产品的研发、组装与支持均在此完成。旗舰产品是Balanset-1A，一款用于单平面及双平面平衡和振动诊断的便携式分析仪。 Nikolai亲自参与客户支持工作，处理各种棘手的平衡案例，并参与软件开发。他以任何语言为全球客户提供服务。
