A hidden issue in vane pump design — oil trapping (hydraulic lock) — can lead to noise, pressure spikes, and component damage.
🔎 What Is Oil Trapping?
Oil trapping occurs when: 👉 A sealed chamber of oil is trapped between two vanes 👉 The chamber volume decreases during rotation 👉 But the oil cannot escape in time 📌 Result: Sudden pressure rise inside the trapped volume
❗ Why Does It Occur in Double-Acting Vane Pumps?
In double-acting vane pumps: • Two suction zones + two discharge zones • Complex port timing • Continuous chamber transitions Oil trapping typically happens when:
⚠️ 1️⃣ Improper Port Timing
• Inlet closes before outlet opens
• Oil is sealed in a shrinking chamber
⚠️ 2️⃣ No Pressure Relief Path
• Trapped oil has no escape route
• Pressure builds rapidly
⚠️ 3️⃣ High-Speed Operation
• Less time for oil to flow
• Increases trapping severity
⚠️ 4️⃣ Oil Viscosity Too High
• Slower fluid movement
• Delayed pressure release
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