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破碎機轉子動平衡計算器

依據 ISO 21940 計算破碎機轉子(衝擊式、顎式、錘式破碎機)的允許不平衡量。包含單個元件公差、離心力及軸承壽命影響估算。

ISO 21940G16 – G40軸承壽命

結果

允許不平衡量(總量)
—
單個元件公差
—
比不平衡(偏心)
—
公差下的離心力
—
指定半徑處的校正質量
—
軸承壽命影響
—

關鍵公式

e_per = G × 1000 / ω [μm]
U_per = e_per × M [g·mm]
F = M × e_per × ω² / 10⁶ [N]

其中 G 為平衡等級(mm/s),ω = 2π×n/60(rad/s),M 為轉子質量(kg),e_per 為允許比不平衡量,U_per 為允許剩餘不平衡量,F 為產生的離心力。

破碎機平衡等級選擇

破碎機類型典型等級典型 RPM
水平軸衝擊式(HSI)G16 – G40500–800
垂直軸衝擊式(VSI)G6.3 – G161000–2000
錘式破碎機G16 – G401000–1800
顎式破碎機(飛輪)G16200–400
錐式破碎機G6.3 – G16300–600

單個元件質量公差

更換錘頭或打擊板時,單個元件的質量差異會直接導致轉子不平衡。每個元件位於旋轉軸的特定半徑處。單個元件的質量公差應為:

Δm_element ≤ U_per / (r_element × N_elements)

其中 r_element 為元件的重心半徑, N_elements 為元件數量。

對軸承壽命的影響

不平衡力會作為額外的旋轉徑向負荷作用於軸承上。軸承的基本額定壽命 (L10) 對施加的負荷極為敏感:

  • 球軸承: L10 ∝ (C/P)³
  • 滾子軸承: L10 ∝ (C/P)^(10/3)

即使是不平衡力不大,當與破碎機中已經很高的工藝負荷結合時,也會顯著縮短軸承壽命。

破碎機實用動平衡校正程序

  • 步驟 1: 個別稱重所有錘頭/打擊板並記錄質量
  • 步驟 2: 依質量對元件進行排序,並將其配對為質量相近的組合(最重者與次重者配對,依此類推)
  • 步驟 3: 將每一配對組合的兩個元件安裝於轉子上徑向相對(180°)的位置,使相對位置的質量相互抵銷
  • 步驟 4: 確認相對位置之間的總質量差異在單個元件公差範圍內
  • 步驟 5: 安裝後,運行破碎機並測量兩個軸承處的振動
  • 步驟 6: 如果振動超過限制,請執行單平面現場動平衡

離心力與軸承壽命

由不平衡產生的離心力會為軸承增加旋轉徑向負荷。軸承 L10 壽命關係式為:

  • 球軸承: L10 = (C/P)³ × 10⁶ / (60 × n)
  • 滾子軸承: L10 = (C/P)^(10/3) × 10⁶ / (60 × n)

其中 C 為動載荷額定值,P 為當量動載荷(包含不平衡力),n 為轉速 (RPM)。即使是很小的不平衡力,當加到破碎機中已經很高的工藝負荷上時,也會顯著縮短壽命。

破碎機的振動限值

由於破碎機固有的衝擊特性,其振動限值高於平穩運轉的機器:

  • 良好: < 10 mm/s 軸承座速度 RMS
  • 可接受: 10–18 mm/s — 運轉中破碎機的典型值
  • 預警: 18–28 mm/s — 需調查,檢查磨損件
  • 危險: > 28 mm/s — 停機檢查

基礎與結構考量

破碎機基礎必須設計為能吸收衝擊力。基礎質量應為破碎機質量的 3–5 倍,以確保足夠的振動隔離。關鍵檢查項目:

  • 地腳螺栓: 在每次主要維護時確認鎖緊扭矩
  • 隔振墊: 檢查橡膠隔振器是否老化並確認撓度正確
  • 混凝土狀況: 檢查是否有裂縫,特別是地腳螺栓孔周圍
  • 灌漿料完整性: 確認底板與基礎之間無空隙

破碎機類型與動平衡考量

  • 水平軸衝擊式破碎機 (HSI): 打擊板是主要磨損件。應成套更換並個別稱重。轉子通常校正至 G16 級。
  • 垂直軸衝擊式破碎機 (VSI): 較高轉速要求更嚴格的動平衡 (G6.3–G16)。磨損盤和砧環會間接影響動平衡。
  • 錘式破碎機: 多個錘頭安裝在樞軸銷上。可逆錘頭必須以配對方式旋轉。根據轉速不同,動平衡等級為 G16–G40。
  • 顎式破碎機: 飛輪動平衡至關重要。偏心軸的不平衡是設計固有的,但必須在公差範圍內。
  • 錐式破碎機: 破碎壁和碗形壁磨損會影響動平衡。頭部組件的動平衡會在主要大修期間進行檢查。

最佳實務: 為每個轉子位置記錄個別錘頭/打擊板的質量。追蹤隨時間的質量損失,以預測最佳更換間隔,並在整個磨損週期內保持動平衡在公差範圍內。

⚠️ 實用提示: 更換錘頭/打擊板後,務必逐一稱重元件並進行排列以達到最小不平衡:將質量相近的元件置於徑向相對(180°)的位置(最重者與次重者相對),隨後透過量測驗證殘餘振動。即使在 G40 公差範圍內,元件配對也能顯著延長軸承與機架的使用壽命。

Crushers experience massive impact forces during normal operation that dwarf any unbalance forces. The practical benefit of achieving G6.3 is minimal because the process-induced forces are so large. G16 provides a good balance between bearing life protection and practical achievability given the harsh operating conditions and wear.

Rebalance whenever wear items (hammers, blow bars, liners) are replaced, or when vibration at 1× RPM exceeds baseline by more than 50%. For impact crushers with replaceable blow bars, this typically means every bar change — weigh and arrange elements for minimum unbalance.

Yes, single-plane field balancing is commonly performed on crusher rotors. Mount a vibration sensor on the drive-end bearing housing, use a keyphasor for phase reference, and run at normal speed (with no feed). The trial-weight method works well. Correction weights can be welded to the rotor end plates.

Two-plane (couple) balancing is generally not required for crusher rotors because their L/D ratio is typically low (disc-like). Single-plane balancing is sufficient. However, if you see significant phase differences between bearings, two-plane balancing may help.

As hammers wear, they lose mass unevenly. The rotor becomes progressively more unbalanced. Monitor vibration at 1× and trend over time. When vibration reaches the alert level or when hammer tips are worn to the rotation limit, it is time to replace and rebalance.

Crushers have inherently high vibration due to the impact process. Bearing housing velocity below 10 mm/s RMS is considered good. Between 10–18 mm/s is acceptable for most crushers during normal operation. Above 18 mm/s warrants investigation, and above 28 mm/s is a danger level requiring shutdown.

1) Match blow bar masses within tolerance. 2) Ensure all blow bars are seated properly with no gaps. 3) Check for worn rotor side plates. 4) Verify bearing condition and clearances. 5) Inspect foundation bolts for looseness. 6) If 1× vibration is dominant, perform field balancing. 7) Check drive components (belts, sheaves, coupling) for wear.

Most crushers use spherical roller bearings (SRB) due to their ability to handle both radial and axial loads as well as shaft misalignment from housing deflection. These have an L10 life exponent of 10/3. The dynamic load rating C is typically 500–2000 kN depending on crusher size.

Balance with hammers in the position they will operate in. If hammers are reversible, balance in the initial operating position. When hammers are reversed to use the second edge, re-check balance. Some operations balance at mid-life mass to optimize the average unbalance over the full wear cycle.

Crusher rotors are heavy and have stored energy. Key precautions: 1) Lock out/tag out all energy sources. 2) Use proper rigging when handling blow bars/hammers. 3) For field balancing, ensure the crusher chamber is empty and guards are in place. 4) Never run a crusher above rated speed. 5) Keep personnel clear of the discharge area during trial runs.

A deteriorated foundation amplifies vibration from all sources including unbalance. Check for: cracked concrete, loose anchor bolts, grout deterioration, and soil erosion under the foundation. Foundation natural frequency should be well separated from 1× RPM. A foundation assessment is recommended if vibration suddenly increases without rotor changes.

本頁所述的操作流程由 Vibromera 團隊使用 Balanset-1A(一款用於現場轉子平衡的便攜式雙通道動平衡儀及振動分析儀)開發並經過實地測試。

Vibromera — 便攜式動平衡校正與振動分析
專業現場動平衡校正儀器與軟體。已在 50 多個國家使用。
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Nikolai Shelkovenko

Nikolai Shelkovenko

Nikolai Shelkovenko是一名振動分析工程師,也是Vibromera的創辦人兼執行長。 15年多來,他一直在現場——而非在試驗台上——為旋轉設備進行動平衡校正:粉碎機、工業風機、破碎機、離心機、軸與主軸。正是這些實際工作催生了Balanset系列儀器——它們被設計為一種專業人員可以隨身攜帶到機器旁、在現場獨立使用的工具,而非實驗室設備。 Vibromera成立於2017年,自2023年起總部設於葡萄牙波爾圖。Balanset系列產品的研發、組裝與支援均在此完成。旗艦產品是Balanset-1A,一款用於單平面及雙平面動平衡校正與振動診斷的可攜式分析儀。 Nikolai親自參與客戶支援工作,處理各種棘手的動平衡校正案例,並參與軟體開發。他以任何語言為全球客戶提供服務。

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