蜗杆传动的效率

1 蜗杆传动的效率
闭式蜗杆传动的效率由三部分组成，蜗杆总效率η为
η=η1η2η3
式中：η1-传动啮合效率；
蜗杆总效率η主要取决于传动啮合效率。

其考虑齿面间相对滑动的功率损失；啮合效率可近似地按螺纹副的效率计算，即
式中：γ-普通圆柱蜗杆分度圆上的导程角；
φ-当量摩擦角，，其值可根据滑动速度vs 查表选取。

蜗轮蜗杆传动
蜗轮蜗杆传动用于两轴交叉成90度，但彼此既不平行又不相交的情况下，通常在蜗轮传动中，蜗杆是主动件，而蜗轮是被动件。

蜗轮蜗杆传动有如下特点：
1）结构紧凑、并能获得很大的传动比，一般传动比为7-80。

2) 工作平稳无噪音
3) 传动功率范围大
4）可以自锁
5）传动效率低，蜗轮常需用有色金属制造。

蜗杆的螺旋有单头与多头之分。

传动比的计算如下：
I=n1/n2=z/K
n1-蜗杆的转速 n2-蜗轮的转速 K-蜗杆头数 Z-蜗轮的齿数
滑动速度vs由图得：
m/s。

蜗轮蜗杆传动比和传动效率的关系英文回答：The relationship between the gear ratio and transmission efficiency of a worm and worm gear is complex and depends on several factors, including:The geometry of the worm and worm gear.The materials used in the worm and worm gear.The operating conditions, such as the speed and torque.The lubrication conditions.In general, the gear ratio of a worm and worm gear is inversely proportional to the transmission efficiency. This means that as the gear ratio increases, the transmission efficiency decreases. This is because the worm and worm gear are in sliding contact with each other, and as thegear ratio increases, the amount of sliding contact also increases. This increased sliding contact leads to increased friction, which in turn reduces the transmission efficiency.However, the relationship between the gear ratio and transmission efficiency is not linear. At low gear ratios, the transmission efficiency is relatively high. As the gear ratio increases, the transmission efficiency decreases, but at a decreasing rate. This means that the transmission efficiency does not drop off as quickly at high gear ratios as it does at low gear ratios.The materials used in the worm and worm gear also have an impact on the transmission efficiency. In general, materials with a higher coefficient of friction will have a lower transmission efficiency. This is because materials with a higher coefficient of friction will generate more heat when they are in sliding contact with each other. This heat can cause the worm and worm gear to wear more quickly, which can further reduce the transmission efficiency.The operating conditions, such as the speed and torque, also have an impact on the transmission efficiency. In general, higher speeds and torques will lead to lower transmission efficiency. This is because higher speeds and torques will generate more heat, which can cause the worm and worm gear to wear more quickly.The lubrication conditions also have an impact on the transmission efficiency. In general, well-lubricated worm and worm gears will have a higher transmission efficiency than poorly lubricated worm and worm gears. This is because lubrication reduces friction, which in turn increases the transmission efficiency.中文回答：蜗轮蜗杆传动比和传动效率的关系很复杂，取决于以下几个因素：蜗轮蜗杆的几何形状。

普通圆柱蜗杆传动的效率、润滑及热
平衡
(一)蜗杆传动的效率
闭式蜗杆传动的功率损耗一般包括三部分，即啮合摩擦损耗、轴承摩擦损耗及浸入油池中的零件搅油时的溅油损耗。

因此总效率为
η=η1·η2·η3
式中η1,η2,η3分别为单独考虑啮合摩擦损耗、轴承摩擦损耗及溅油损耗时的效率。

而蜗杆传动的总效率，主要取决于计入啮合摩擦损耗时的效率η1。

当蜗杆主动时，则
式中：γ—普通圆柱蜗杆分度圆柱上的导程角；
—当量摩擦角，，其值可根据滑动速度vs由表<普通圆柱蜗杆传动的vs，fv，值>或表<圆弧圆柱蜗杆传动的vs，fv，值>中选取。

滑动速度vs由图<蜗杆传动的滑动速度>得
m/s) (m/s)
运动粘度
H2=S(t0-ta)
:箱体的表面传热系数，围空气所冷却的箱体表面面积，
式中
风扇叶轮的圆周速度，m/s
' --
的表面传热系数'>
数'
'[W/(·℃)]。

自锁蜗轮蜗杆传动效率计算英文回答：Gear efficiency is an important factor to consider in mechanical power transmission systems. It represents the ability of the gears to transmit power effectively without significant losses. In this context, I will discuss the calculation of the efficiency of a self-locking worm gear drive.The self-locking worm gear drive is commonly used in applications where it is necessary to prevent the reverse rotation of the driven load. It consists of a worm gear (also known as a worm screw) and a worm wheel (also known as a worm gear). The worm gear has a helical thread, while the worm wheel has teeth that mesh with the worm gear.To calculate the efficiency of a self-locking worm gear drive, we need to consider the power losses that occur during the transmission. These losses can be categorizedinto several types, including friction losses, tooth meshing losses, and bearing losses.Friction losses occur due to the sliding contact between the worm gear and the worm wheel. These losses depend on factors such as the surface roughness, lubrication, and load conditions. Tooth meshing losses occur due to the deformation and sliding of the gear teeth during the meshing process. These losses are influenced by factors such as the gear geometry, material properties, and lubrication.Bearing losses occur in the bearings that support the shafts of the worm gear and the worm wheel. These losses are influenced by factors such as the bearing type, lubrication, and load conditions. It is important to note that self-locking worm gear drives typically have higher bearing losses compared to other types of gear drives due to the higher axial thrust forces.To calculate the efficiency of the self-locking worm gear drive, we need to determine the power input and thepower output. The power input is the power supplied to the worm gear, while the power output is the power delivered to the load. The efficiency is then calculated as the ratio of the power output to the power input, multiplied by 100 to express it as a percentage.For example, let's consider a self-locking worm gear drive used in a conveyor system. The power input to the worm gear is 10 kW, and the power output to the load is 8 kW. The efficiency of the worm gear drive can be calculated as follows:Efficiency = (Power output / Power input) 100。

蜗杆传动辅导1．蜗杆传动的受力分析蜗杆传动受力分析类似于斜齿轮，但由于齿面滑动摩擦大，不能忽略啮合摩擦损失；又因蜗杆与蜗轮两轴交错，各分力的对应关系与斜齿轮也不同，如图9-5所示。

受力关系式中，T1、T2分别为蜗杆和蜗轮的转矩，由T2=T1·i·η可知，计入啮合效率η即表示在受力分析中已经计入了齿面摩擦力。

判断蜗杆蜗轮受力方向的方法类似斜齿轮传动，蜗杆轴向力F a1的指向可利用教材158页所述“左、右手法则”。

2．失效分析和设计准则蜗杆传动的失效形式与齿轮传动相似，但传动过程中齿面滑动摩擦大，其主要失效形势是胶合和磨损。

蜗杆传动的强度取决于蜗轮轮齿，由于胶合与磨损尚无成熟计算方法，当前仍沿用齿轮轮齿的计算方法。

（1）开式蜗杆传动轮齿易磨损，按蜗轮齿根弯曲疲劳强度设计时，应适当考虑磨损对轮齿强度的影响。

（2）闭式蜗杆传动则按齿面接触强度计算，限制齿面接触应力以避免胶合和点蚀。

3．蜗杆蜗轮常用材料蜗杆蜗轮材料的一般选用原则是：材料在满足一定强度条件下，具备良好的减摩性、耐磨性和抗胶合性。

蜗杆常用材料为优质碳素钢或合金钢，可用表面淬火或调质等热处理方法提高性能。

蜗轮材料有铸铁、铝青铜、锡青铜等，可根据滑动速度来选择。

4．蜗杆传动的效率和热平衡计算（1）蜗杆传动的效率在计算蜗杆传动的效率时应考虑啮合摩擦、轴承摩擦和搅油油阻三部分功率损耗。

通常，轴承摩擦效率和搅油油阻效率取为0.95~0.97；啮合效率可按螺旋传动的效率公式计算。

（2）热平衡的计算连续工作的闭式蜗杆传动，如果摩擦所产生的热量不能及时散发，将引起油温上升而导致胶合，因此要进行热平衡计算以控制油的温度。

所谓热平衡就是在蜗杆传动工作一段时间后，传动中单位时间的发热量与传动装置通过介质在单位时间内散热量逐渐接近而达到平衡，此时油温不再继续上升。

由热平衡条件，可得蜗杆传动达到热平衡时的油温，若工作油温超过许用值，可增大散热面积和改善通风条件，必要时可使用冷却装置。