空心轴与实心轴 - 哪个更好？

Before Selection of Shaft you must be considered whether to choose hollow shaft or Solid Shaft depending upon the type of application, power Requirement, torque transmission requirement, weight, cost, machining time, Material.

Difference /Comparison Between Hollow Shaft and Solid shaft as Below:

• Weight:与固体轴相比，空心轴的重量较轻，对于给定的长度和直径。这非常明显，并且不需要进一步的解释。此外，如果我们强调减肥和成本切割，这是一个好主意。
• Hollow shafts are much better to take torsional loads compared to solid shafts。如图所示，经受扭转的“轴”中的剪切应力从中心处线性地线性变化到边界处的最大值。在实心轴内，大部分材料经历/携带剪切应力，其值远低于轴的最大剪切应力[内部部分]。但是，它们正在加入重量，而不会对轴的能力贡献太大，以携带扭转载荷。
  由空心轴（τ）（τ）中的点处的剪切应力由，τ=行程=跳闸其中τ=τ=空心轴中的剪切应力

  TT = Torque in shaft (N-m)

  

  rr = radial distance from the center to the point of interest (m)

  IP = IP =极性区域惯性矩（M4M4）

  Average shear stress[ (Min. Shear stress + Max. Shear Stress))/ 2 ] in a hollow shaft will be higher compared to a solid shaft and its value is closer to the maximum shear stress.
  空心轴具有更大的重量比强度。

• 室壁厚度：如果我们减少壁厚，那么轴壁有机会皱纹或屈曲。所以我们必须小心这些事情。
• Cost Consideration:由于耗时的空心轴需要加工，空心轴的成本远远超过固体轴。
• 中空轴对应力具有高抗性，而实心轴可能趋于在一定限度下断裂。

Selection Of Hollow Shaft or Solid Shaft Depends On :

• 对于承载轴承型轴，然后其总是更好地选择空心轴，因为它具有更高的刚度和刚性并且可以抵抗稍高的弯曲力矩。
• 用于扭矩传递的轴，如曲轴，驱动轴始终更好地选择固体轴，因为它具有更高的扭转刚度。
• Hollow shaft is not always better compare to a solid shaft. It depends on our uses. When there is no space constraint, then for the same mass, the hollow shaft is better than the solid shaft. But if we have a radial space constraint then the solid shaft is preferred since, in this case solid shaft has more power transfer capacity than the hollow shaft.
• Practical use:In some mixing applications, gas is fed through a hollow shaft to aerate the product. Other fluids can be supplied this way, either directly or inside a tube-like compressed air, hydraulic fluid, or coolant.
• Assembly:Sometimes, it is simpler to affix the appropriate ends to a hollow shaft for custom length shafts, similar to RWD vehicle drivelines. One could stock tube and the end pieces, cut the tube to whatever length is needed, and attach the ends. This can be simpler for some shops and applications than building a custom solid shaft.
• Weight:The strength of circular members is mainly contributed by their outer surface. The core of a solid shaft is essentially wasted material in some cases. It may be helpful from a mechanical standpoint to reduce rotating mass, or it can simply be a matter of value.
• Vibration:空心轴的固有频率与实心轴不同。通常，与实心轴相比，空心轴可以增加约20％的临界速度

Advantage of hollow sh缩短：

1. Lightweight comparable to the solid shaft of the same diameter.
2. Low rotational inertia.
3.更便宜。
4. High tolerance to rotational imbalance due to low weight.
此外，由于低特异性质量，空心轴可容许高温。

Disadvantage of hollow shafts:

1.耐扭矩较少。
2. Prone to bending especially when exposed to lateral stress.
Ex. boat propeller shaft.
3. Even though it is tolerant to mild imbalance, this however increases as rotational speed exceeds the critical limit.

Advantages of solid shafts:

1. Suitable for high torque applications.
2.非常耐弯曲。
3.当完美滚动时，即使在高速时也具有非常平稳的操作。
4. High rigidity even at a small diameter.

Disadvantages of solid shafts.

1.高成本。
2.它必须完全直接从制造。轻微的不平衡是不可能的，很难处理。
3. High rotational inertia especially on larger diameters.
4. On application where the shaft is exposed to very high temperatures, solid shaft made of mild steel bends even at rest. Special metal is used for this application thus adding cost.