**Core tips for installing Roots blower impeller (with step-by-step operation guide)**
**1、 Key preparations before installation**
1. * * Gap detection tool**
-Must be fully prepared:
-Feeler gauge (0.02~1.00mm)
-Dial gauge (accuracy 0.01mm)
-Laser alignment instrument (essential for high-precision models)
2. * * Cleaning standards**
-Clean the bearing seat and gear contact surface with 120 gasoline
-The residual burrs on the surface of the impeller need to be polished with 800 grit oilstone
**2、 Core steps for impeller positioning**
1. Axial clearance control**
-Standard value: 0.20~0.40mm (take the smaller value for high-voltage models)
-Adjustment method:
```
1. Push the impeller towards the drive end
2. Measure the non drive end clearance with a dial gauge
3. Control by adjusting the thickness of the gasket
```
-* * Error case * *: A factory failed to detect axial clearance, resulting in overheating and expansion of the impeller. After 72 hours of operation, the end face was worn 0.8mm
2. Radial clearance adjustment**
-Control points:
|Position | Allowable deviation (mm)|
|---------------|----------------|
|Impeller shell | 0.15~0.30|
|Inter impeller meshing | 0.10~0.25|
-Detection method:
! [Schematic diagram of radial clearance measurement]（ https://via.placeholder.com/300x200text=Radial +Clearance+Measurement)
(Measure with a feeler gauge at the top, bottom, left and right four points of the impeller)
**3、 Installation tips for synchronous gears**
1. * * backlash control**
-Standard value: 0.05~0.08mm (measured by lead pressure method)
-Key points:
-Gear heated to 80 ℃ for hot installation (interference fit 0.02~0.03mm)
-Mark the contact spots on the tooth surface (should be greater than 60 tooth widths)
2. * * Phase angle calibration**
-Operation process:
```
1. Place the dial gauge on top of the impeller
2. Rotate the manual turning wheel 360 °
3. Bounce<0.03mm
```
-* * Attention * *: Phase angle deviation>0.5 ° will cause an increase of 15% in exhaust pulsation
**4、 Dynamic balance correction**
1. * * Balance level requirements**
-ISO 1940 G2.5 standard
-Formula for calculating residual unbalance:
\[
U_{\text{perm}} = 9549 \times \frac{G \times W}{n}
\]
(G: Balance level, W： Impeller weight kg, n： Rotational speed (rpm)
2. On site correction method**
-Weight distribution at the non transmission end of the impeller (requires specialized balancing adhesive)
-Case: When the diameter of the impeller is 1450rpm, the allowable counterweight is ≤ 8g
**5、 Required inspection items after installation**
|Test Item | Standard Value | Tool|
|-----------------|-------------------|----------------|
|Bearing clearance | 0.03~0.05mm | dial gauge|
|Coupling alignment | Radial<0.05mm | Laser alignment instrument|
|Gear backlash | 0.06 ± 0.01mm | Lead compression method|
**6、 Special working condition handling**
1. Installation of high temperature fan**
-Reserved thermal expansion gap: axial+0.1mm/100 ℃
-Case: A gap of 0.3mm should be left behind at 200 ℃ compared to room temperature
2. Construction of anti-corrosion coating**
-Sandblasting treatment before spraying (Sa2.5 level)
-Polyurea coating thickness 150-200 μ m
**7、 Common installation errors and consequences**
1. * * Reverse installation**
-Phenomenon: The exhaust port becomes the intake port
-Consequence: Gear instantaneous overload and fracture
2. * * Gap too small**
-Performance: Operating current exceeds the set value by 20
-Detection: Infrared thermal imager displays local temperature>120 ℃
**8、 Suggested maintenance cycle**
-* * First run * *: Tighten all bolts after 50 hours
-* * Routine inspection * *: Measure gap changes every 500 hours
-Overhaul standard: When the radial clearance is greater than 0.5mm, the impeller must be replaced
Attachment: Comparison Table of Impeller Installation Torque (Different Bolt Specifications)
|Bolt specifications | Torque value (N · m) | Lubrication status|
|----------|---------------|----------------|
|M10 | 45~55 | Molybdenum disulfide lubrication|
|M12 | 75~90 | Dry Friction|
Mastering these tips can extend the lifespan of the impeller by more than 30 years. It is recommended to keep this guide as a reference for installation specifications. For special models (such as twisted blade rotors), installation must strictly follow the phase angle drawings provided by the manufacturer.
