背景材料:BMW N54 直六引擎使用的電子水泵,約十年七萬公裏發生不可修複損壞。
拆遷單幹戶來了,拆拆拆!
不可逆拆解,因裝配時定子線圈和磁性轉子之間有三相接線焊接在一起,然後整體嵌入鑄鋁腔體後並粘結於外殼固定,拆解時無法整體分離,故暴力拉斷三相接線才能一分為二。
定子線圈已經粘結在鑄鋁腔體內固定,不破壞性拆解無法分離,紅圈為三相接線。
生生被拉斷,遠處模糊可見脆裂的軸套【軸承】
注塑磁性轉子表麵多處開裂,有明顯刮蹭痕跡。
磁性軸套【軸承】脆裂 [不排除拆解時導致的損壞]
電子控製部分未見異常,其實除非有顯而易見的燒結或水漬痕跡,好壞是看不出什麽名堂的。
水泵不能正常運行大概率與轉子開裂和軸套脆裂有關【拆解造成的損壞除外】,結合從網上看到的信息,這種物理損壞並不少見,但凡拆解的都提到了轉子磨損的問題,至於那個軸套【軸承】不細致觀察或徹底拆解很難被發現。
如果是基於非電子控製模塊故障所致,估計通過改善轉子材料加工工藝有可能進一步延長水泵的工作壽命。
福利:這個節溫器收了!
可由MAP控製的節溫器,甩了純被動式節溫器幾條街。
左側隻露出一半的應該是check valve,這個閥門的保留還是很傳統的。
BMW Data for typical N55 Engine Cooling
The engine control unit regulates the following temperature ranges:
• 108°C/226°F = Economy mode
• 104°C/219°F = Normal mode
• 95°C/203°F = High mode
• 90°C/194°F = High mode and control with characteristic map thermostat
System Protection
If the coolant or the engine oil overheat during operation, certain vehicle functions are influenced to the effect that more energy is available to the engine cooling system.
These measures are divided over two operating modes:
• Component protection
- Coolant temperature between 117°C/242°F and 124°C/255°F
- Engine oil temperature between 150°C/300°F and 157°C/314°F
- Result: The output of the air conditioning system (up to 100%) and of the engine is reduced
• Emergency
- Coolant temperature between 125°C/257°F and 129°C/264°F
- Engine oil temperature between 158°C/316°F and 163°C/325°F
- Result: The power output of the engine is reduced (up to 90%)