External oil pump for motor makes heat sinking performance much better thus prolong service lifeofmachine.
电机油泵外置，散热效果更佳，人而延长机器的使用寿命。
2
The main beam is the main hoist gantry crane force components, main beam directly affects the service lifeofmachine.
主梁是葫芦门式起重机的主要受力部件，主梁的质量直接影响到整机的使用寿命。
3
Improving the surface properties of material is an important method that prolongs service lifeofmachine parts and brings out latent potentialities of materials.