[问答题,简答题] 振动筛轴承过热的原因有哪些？

目前在家用空调中替代R22的工质是（） ["A、R407C","B、氨","C、R134_a","D、R11"] 絮凝剂在选煤厂的主要用途是什么？ 完全不溶于油的制冷工制质是（） ["A、R22","B、氨","C、R134_a","D、R11"] 目前我国家用空调器中大量使用的制冷工质是（） ["A、R22","B、R123","C、R134_a","D、R152_a"] 离心机刚起车时如何进行给料？ 振动筛轴承过热的原因有哪些？