Roots Blower It is a kind of positive displacement blower, which is composed of an approximately elliptical casing and two wall panels to form a cylinder (there are air inlets and outlets on the casing), a pair of impellers that "mesh" with each other (actually do not contact because there is clearance), and rotate reversely at constant speed through synchronous gear transmission. The air inlets and outlets are separated by the "mesh" of the two impellers; During rotation, the gas in the cylinder volume is pushed from the air inlet to the air outlet.
Assembly clearance: there is relative movement between the impellers of Roots blower and between the impellers and the engine body, which is in a non-contact state. There must be a proper working clearance to ensure both sealing and normal operation of the blower.
The assembly clearance is the theoretical static clearance value at 20 ℃. It can ensure the working clearance required for dynamic operation under rated working conditions. Therefore, assembly clearance is an important factor to ensure fan performance and safe operation. When each Roots blower leaves the factory, the assembly clearance has been adjusted, and the user shall not change it at will. See the following table for specific clearance values:
Assembly clearance table of Roots blower, unit: mm. Under the condition of ensuring the performance and normal operation of Roots blower, the above clearance values are allowed to be properly adjusted.
Clearance adjustment: 1. Adjustment of clearance 1: loosen the fastening bolts of gear ring and gear hub, remove the locating taper pin, and adjust the installation angle position of gear ring and gear hub. The purpose of adjusting clearance 1 can be achieved. After the clearance is adjusted, the locating pin hole must be corrected (or placed separately) before positioning with a taper pin. Tighten the fastening bolts. Adjust the clearance 1 when the impeller rotates 360 °.
2. Adjustment of clearance 2
Loosen the fastening bolts between the casing and the wall panel, and remove the locating taper pin. According to the specific situation, the relative position of the high-speed casing and the wall panel is used to adjust the radial clearance between the roller and the casing. After the adjustment, the locating pin hole must be corrected (or placed separately), and then be positioned with the taper pin. Then use bolts to fasten the shell and wallboard together
3. Adjustment of clearance 3 and 4
There are fastening screws and adjusting screws on the bearing shell of the positioning end wall plate. If 3 is expected to decrease and 4 is expected to increase, loosen the fastening screws first. Then tighten the adjusting screw. At this time, the impeller moves towards the positioning end wall plate. On the contrary, if 3 is expected to increase and 4 is expected to decrease, loosen the adjusting screw first, and then tighten the fastening screw. At this time, the impeller moves towards the non positioning end wall plate. See Figure 3. To ensure the coaxiality, gaskets must be properly supplemented or reduced between the bearing seat flange and the wall plate, so that the gap between them is basically the same, And prevent the gap from changing. If 3 meets the requirements and 4 does not meet the requirements, paper pads can be added or reduced between the junction surface of the casing and the non positioning end wall panel.
Requirements after clearance adjustment: no-load test run must be carried out after clearance adjustment.
The safe operation and service life of Roots blower depend on correct and frequent maintenance and attention should be paid to any accident. In addition to general maintenance procedures, attention should be paid to the following points:
1. Check the fastening of each part and whether the locating pin is loose.
2. Whether there is water or oil leakage inside the blower body.
3. There shall be no scaling, rust and scaling inside the blower body.
4. Pay attention to whether the lubrication and cooling conditions are normal, and pay attention to the quality of lubrication. Always listen to the blower for noise. Pay attention to whether the unit operates under conditions that do not meet the requirements.
5. The overload of the blower is sometimes not displayed immediately, so pay attention to the increasing trend of the inlet and exhaust pressure, bearing temperature and motor current to judge whether the machine operates normally.
6. Before disassembling the machine, measure the matching dimensions of the machine, make records, and mark the parts to ensure that the original matching requirements are maintained after assembly.
7 Splash lubrication is adopted for the bearing and gear of the blower. It is recommended to use N68-N150 medium extreme pressure industrial gear oil. Users can also choose appropriate lubricating oil by themselves. It must ensure that the performance of the lubricating oil is equivalent to the above lubricating oil to facilitate the normal operation of the gear and bearing. The oil volume in the oil tank must be 3-5mm above the centerline of the oil mark when stopping.
The lubricating oil shall be changed regularly (200 hours for the first start, and the first oil change), and then every half a year. Clean the oil tank and gear with neutral kerosene before injecting new oil.
8. The maintenance and overhaul shall be carried out on schedule according to the specific use conditions, and a reasonable maintenance system shall be developed. Records shall be kept. It is recommended to overhaul once a year, and replace bearings and relevant vulnerable parts.
