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本帖最后由 liuhongwei08 于 2011-6-22 20:25 编辑
刚才看了一篇关于这实验的话题，突然想到一个问题，想问问有什么大师能帮我。
轴系校中计算书 计算出轴系很多状态时各个轴承的负荷，但是我们平常在主机浇注之后所做的称之为“冷态负荷”和在试航时，主机停住所作的“热态负荷”在计算书中的轴系状态的标准是一个吗？
比如说计算书上有轴系在静止状态下的轴承负荷，在low power状态，在fullpower状态。
就是想问问是不是冷态和热态的轴负荷在计算书参考的标准值不一样。
这个是我截取的“轴系计算书”的一部分，请懂行的大师帮我分析分析，估计这个只有做轴舵设计的才研究过。
1.5. Load cases
1.5.1. Load case 1: Status after coupling of shaftline
• Shaft line positioned at ½ of bearings clearance below center line
• No propeller thrust, not rotating
• Cold conditions
• The position of the bearing support point in aft the stern tube bearing, is assumed on
the aft end of effective stern tube length
1.5.2. Load case 2: Low power service
• Shaft line positioned at ⅜ of bearings clearance below center line
• Gear box bearings with an upward displacement due to thermal expansion
• No propeller thrust (10% MCR, 100% speed)
• Hot conditions
• The position of the bearing support point in aft the stern tube bearing, is assumed on
the aft end of effective stern tube length
1.5.3. Load case 3: Full power service, free running, warm
• Shaft line positioned at ⅜ of bearings clearance below center line
• Gear box bearings with an upward displacement due to thermal expansion
• Nominal propeller thrust (100% MCR, 100% speed)
• Hot conditions
• The position of the bearing support point in aft the stern tube bearing, is assumed to
be one third of effective stern tube length
1.5.4. Load case 4: Full power service, free running, cold
• Shaft line positioned at ⅜ of bearings clearance below center line
• Nominal propeller thrust (100% MCR, 100% speed)
• Cold conditions
• The position of the bearing support point in aft the stern tube bearing, is assumed to
be one third of effective stern tube length
1.5.5. Load case 5: Status before coupling of shaftline
• Shaft line positioned at ½ of bearing clearance below center line
• Propeller afloat
• Cold conditions
• The position of the bearing support point in aft the stern tube bearing, is assumed on
the aft end of effective stern tube length
1.5.6. Load case 5b: Status before coupling of shaftline, 150 mm distance
• Shaft line positioned at ½ of bearing clearance below center line
• Propeller afloat
• Cold conditions
• The coupling flange is flush to the fwd end of the propeller shaft. The distance between
propeller shaft/coupling flange to the gear box flange is 150 mm.
• The position of the bearing support point in aft the stern tube bearing, is assumed on
the aft end of effective stern tube length
这个计算书把计算的数据分成了5种条件，第5种的条件是用来找正GAP和SAG的（本船8000T散货，齿轮箱和艉轴的可拆联轴节），其余的1~4是在各个方面的负荷条件，第一种就是常用的在水下的冷态负荷值，请问如果在试航中热态的负荷值选哪个？如果选第4个的热冷态，怎么上面写的螺旋桨还有100%的桨速呢？
在有个问题没看懂，上面的第一句话，“轴线位于在中心线之下的轴承负荷二分之一或八分之三处”是什么意思？ |
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发表于 2011-6-21 20:21
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