Alat Kejuruteraan Percuma
Suhu Pemanasan Bearing untuk Pemasangan
Kirakan suhu pemanasan yang diperlukan untuk mengembangkan cincin dalam galas bagi pemasangan padanan gangguan. Masukkan diameter lubang, gangguan dan ruang yang diperlukan.
Keputusan
Prinsip Pengembangan Terma
Apabila galas dipanaskan, cincin dalamannya mengembang disebabkan oleh pengembangan haba keluli. Peningkatan diameter lubang adalah berkadar terus dengan kenaikan suhu dan diameter asal:
- α — pekali pengembangan haba untuk keluli galas ≈ 12.5 × 10⁻⁶ /°C
- d — diameter lubang galas (mm)
- ΔT — peningkatan suhu melebihi ambien (°C)
Kenaikan Suhu yang Diperlukan
Jumlah pengembangan diametral yang diperlukan ialah jumlah gangguan aci dan kelegaan tambahan untuk gelongsor mudah:
Had Suhu
| Jenis Galas | Suhu Maksimum | Sebab |
|---|---|---|
| Standard (terbuka) | 120°C (250°F) | Elakkan perubahan metalurgi dalam keluli galas |
| Dimeteraikan / Dilindungi (2RS, 2Z) | 80°C (175°F) | Mencegah degradasi gris dan kerosakan pengedap |
Contoh Praktikal
Diberi: d = 60 mm, gangguan = 30 μm, kelegaan = 15 μm, Tambien = 20°C
Jumlah pengembangan yang diperlukan = 30 + 15 = 45 μm = 0.045 mm
ΔT = 0.045 / (12.5 × 10⁻⁶ × 60) = 0.045 / 0.00075 = 60.0°C
Tpemanasan = 20 + 60 = 80°C ✓ (dalam had untuk galas terbuka)
💡 Petua: Sentiasa gunakan ukuran suhu yang dikalibrasi. Pemanas aruhan dengan kawalan suhu terbina dalam adalah kaedah yang paling boleh dipercayai untuk pemasangan galas.
Heating the bearing expands the inner ring bore, allowing it to slide easily over the shaft for an interference fit. This avoids the need for mechanical force (hammering, pressing), which can damage the bearing raceways and rolling elements.
Thermal mounting is the recommended method for medium and large bearings (bore > 50 mm) and for any bearing with significant interference.
Temperature limits depend on bearing type:
- Standard open bearings: Max 120 °C (250 °F) — higher temperatures risk metallurgical changes in the bearing steel that reduce hardness and fatigue life
- Sealed/shielded bearings (2RS, 2Z): Max 80 °C (175 °F) — grease degrades and seals may deform at higher temperatures
Heating duration depends on the method and bearing size:
- Induction heater: 2–10 minutes (fastest, most controlled)
- Oil bath: 20–40 minutes (limited to ~100 °C with mineral oil)
- Oven/furnace: 30–60 minutes depending on size
The bearing should be heated uniformly. Avoid localized hot spots that could cause distortion.
Common heating methods:
- Induction heaters — fastest, most precise, recommended for production. Demagnetize after heating.
- Electric hot plates — simple, suitable for small bearings
- Oil baths — uniform heating, max ~100 °C with mineral oil
- Ovens/furnaces — good for batch heating, slow but uniform
Never use open flames — they cause uneven heating and localized overheating.
Sealed (2RS) or shielded (2Z) bearings are pre-filled with grease and must not be heated above 80 °C. At higher temperatures:
- Grease properties degrade permanently
- Rubber seals may deform and lose sealing effectiveness
- Grease may leak out of the bearing
If the required heating temperature exceeds 80 °C, consider using an open bearing with a separate sealing arrangement, or reduce the interference fit.
Prosedur yang diterangkan pada halaman ini telah dibangunkan dan diuji di lapangan oleh pasukan Vibromera menggunakan Balanset-1A, iaitu pengimbang dua saluran mudah alih dan penganalisis getaran untuk pengimbangan rotor di tapak.
Instrumen dan perisian pengimbangan di tapak profesional. Capai pematuhan ISO di tapak. Digunakan di lebih 50 buah negara.
