Wind power gear box of labyrinth seal

The labyrinth seal 2019 - wind power gear box 12 - 13 nanjing AnWeiShi transmission technology co. , LTD. , senior engineer Chai Feng into 1. Gear box of shaft end seal gear and bearing in the operation process of wind power gear box need lubricating oil for lubrication, so the seal of the lubricating oil must be considered, prevention of environmental pollution by oil leak even breakdowns. Because of the gear and bearing during operation of wind power gear box, can make the oil temperature is high, at the same time is uneven pressure inside and outside, lubricating oil is easy to produce the problem such as oil spill, swing. In order to reduce leakage loss, and guarantee the gear box and efficient work, a common kind of gearbox shaft end seal is a non-contact labyrinth seal. 2. Labyrinth seal is set around the axis of the principle of labyrinth seal several lined circular sealed teeth, tooth and tooth form a series of river closure gap between with expansion of cavity, the sealed medium during winding through a maze of clearance throttle effect and achieve the goal of leakage resistance. Fluid through the maze to produce resistance and reduce the flow of the function is called 'maze effect'. For liquid, fluid mechanics effect, including hydraulic friction effect, flow bunch contraction effect; Of gases and thermodynamic effects, namely the gas caused by compression or expansion in the maze of thermal conversion; In addition, there are 'ventilation effect, etc. The maze effect is the effect of the synthesis reaction. Figure ( 1) Flow through a maze to produce throttle effect because of the labyrinth seal clearance between the rotor and the casing, without a solid contact, without lubrication, and allows for thermal expansion, to adapt to the high temperature and high pressure, high speed frequency occasions, this kind of seal is widely used in steam turbine, gas turbine, compressor, blower shaft end and at all levels between the seal and other dynamic seal front seal. 3. Labyrinth runner model of labyrinth seal form of common ideal, it is made of small circular tooth clearance and tooth cavity between series. There are various types, the actual design of labyrinth seal as shown in figure ( 2) Shown below. Figure ( 2) A common form 4 of labyrinth seal. Maze of the structure of the sealing effect because of wind power gear box lubricating oil is liquid, lubricating oil through the maze structure mainly affected by the friction effect and flow bunch contraction effect. Friction effect refers to the leakage of liquid flow in the maze, due to liquid viscous friction, the slow velocity of flow ( Leakage) Reduced. Simply put, the path friction of the fluid along the flow channel and the partial resistance constitutes the grinding resistance effect, the former is associated with the length and cross section shape of the channel, which is related to the bending number and shape of the maze. General is: under the condition of the flow channel section must, when flow long, turn nasty, tooth top, differential pressure loss, reduce leakage. Flow bunch contraction effect refers to the flow through a maze of seam shrink due to the influence of inertia, the cross section of a beam is reduced, mainly affected by the seam area. Thus, to achieve good sealing effect, labyrinth seal structure should be designed reasonable tooth seal ring, the liquid through a maze of seam meet with, stream long, turn nasty, the characteristics of the tooth top. 5. Other influencing factors of wind power gear shaft end seal sealing effect of the actual is not only related to the sealing structure, also with the quantity of lubricating oil, oil pressure, oil return structure and the internal and external cavity pressure is related to the poor. Therefore, in order to guarantee the gearbox shaft end seal, besides should design good sealing structure, should also be appropriate oil and hydraulic control, ensure lubricant oil return channel smooth, adopting appropriate balance inside and outside the cavity pressure, etc.