Technical standards for maintenance of components

Technical standards for the maintenance of various parts of the water pump unit

technical standards for the maintenance of various parts of the water pump unit:

1, the main shaft part

1) the taper and ovality of the journal shall not be greater than 1/0 of the shaft diameter. However, the maximum shall not exceed 0.05mm, and there shall be no scars on the surface. The surface roughness is required? 3.2。

2) if the shaft bending exceeds the allowable value, it can be straightened by mechanical method or heating method. The allowable bending value of shaft is shown in the following table (unit: mm)

the middle of the shaft at the shaft diameter (1500 rpm) the middle of the shaft (3000 rpm) the multi-stage pump shaft ≤ 0.02 ≤ 0.10 ≤ 0.08 ≤ 0.05

3) the key and the keyway should be closely connected, and no gasket is allowed. The matching tightening force of the key and the keyway of the shaft is shown in the following table (unit: mm)

shaft diameter key width tightening force 0 012 0.. 015 0.. 017

2. Rotor part

1) the shaking degree of the rotor shall not exceed the provisions in the following table (unit: mm)

parts shake radially, shake axially, journal, sleeve, collar, impeller, balance disc, shake degree ≤ 0.02 ≤ 0.05 0 12 ＜ 0.25 ＜ 0.03

2) shaft sleeve

(1) shaft sleeve and shaft cannot be made of the same material. In particular, the same kind of stainless steel cannot be used

(2) when the mechanical seal shaft sleeve is in a non corrosive medium, the surface of 25 steel can be chrome plated, and the surface of the packing seal shaft sleeve should be overlaid with cemented carbide, with a hardness of RC

(3) the non perpendicularity of the shaft sleeve end to the axis shall not be greater than 0.01mm

(4) the surface roughness of the contact surface between the shaft sleeve and the shaft shall not be less than? 1.6. D/d coordination is adopted

3) balance disc

balance disc and shaft adopt d/gd coordination

4) impeller

(1) the matching of impeller on shaft generally adopts d/gd matching

(2) static balance should be found for newly installed impeller, and dynamic balance should be found if necessary. Rotor components must undergo dynamic balance test when leaving the factory. The allowable residual unbalance weight on the outer diameter of the impeller during static balance shall not be greater than the allowable limit value of static balance in the following table when the impeller works at 3000r/min

impeller outer diameter (mm) static balance tolerance limit on the maximum diameter of the impeller (g) ≤ 3 58101520

(3) the impeller shall be balanced by the weight removal method, but the cut thickness shall not be greater than 1/3 of the wall thickness

(4) the impeller has no sand holes, perforations, cracks or is seriously reduced due to the punching wall thickness

(5) when the impeller is matched with the shaft, the top of the key should have 0 4mm clearance

5) after the assembly of rotor and stator, first measure the total axial displacement of rotor, and take half of the total displacement when centering the rotor

3. Bearing part

1) sliding bearing

(1) the tightening force between bearing bush and bearing cover should be 0 04mm, the contact between the lower pad back and the pad base should be uniform, and the contact area should reach 60%-80%. Pad is not allowed on the pad back

(2) the contact angle between the journal and the lower bush is °, the contact area should be uniform, and the color spots should not be less than points per square centimeter

(3) the clearance at the top of bearing bush shall comply with the provisions in the following table (unit: mm)

shaft diameter clearance below 1500r/min and above 1500r/min 0 160 0.. 34 0.. 195 0.. 40 0.. 235 0.. 46 0.. 285 0.. 53 180- 0.. 330 0.. 60

(4) the tungsten gold layer should be well combined with the tile shell. George Whitesides of the Weiss Institute of bioinspired engineering at Harvard University and his team came up with this idea when visiting laboratories in developing countries. There should be no defects such as cracks, sand holes, peeling, slag inclusion and so on

2) rolling bearing

(1) the fit between the inner race and the shaft is shown in the following table (unit: mm)

shaft diameter fit surplus shaft diameter fit surplus 0 027 0.. 046 0.. 032 0.. 055 0.. 038

(2) the fit between the outer race and the shaft is shown in the following table (unit: mm)

shaft diameter fitting interference shaft diameter fitting interference +0.029~-0.008 +0.045~-0.014 +0.033~-0.010 +0.052~-0.014 +0.038~-0.012 note: (+) indicates clearance; (-) refers to the interference

(3) the clearance in ball and roller bearings is shown in the table below (unit: mm)

bearing diameter radial clearance new ball bearing new roller bearing maximum allowable wear 20~30 0.01~0.02 0.03~0.05 0.1 35~50 0.01~0.02 0.05~0.07 0.2 55~80 0.01~0.02 0.06~0.08 0.2 85~120 0.02~0.03 0.08~0.10 0.3 130~150 0.02~0.04 0.10~0.1 but the minimum width shall not be less than 70mm2 0.3

(4) for pumps with rolling bearings for axial thrust, the outer ring of rolling bearings shall not be less than it should be crushed to death, and generally 0 08mm clearance

(5) special tools should be used when disassembling and assembling rolling bearings; If possible, it is best to use hot charging. The oil temperature heated by oil is about 100 ℃. Direct heating with flame is strictly prohibited

(6) the roller and slide surface of rolling bearing shall be free of corrosion, pits and spots, and the contact shall be smooth without noise

4. Sealing device

1) gland

(1) the diameter gap between gland and shaft sleeve is generally 0 00mm。

(2) the non perpendicularity of the contact plane between the gland and gasket of the mechanical seal to the shaft centerline is ≯ 0.02mm

(3) the diameter gap between the gland and the inner wall of the stuffing box is generally>0.20mm

(4) the gasket thickness between the mechanical seal gland and the stuffing box should be kept at mm

(5) the anti rotation groove root and anti rotation pin of the stationary ring in the gland, There should be an axial clearance of mm. "This requires a group of like-minded people to hold together to prevent the seal ring and suffocation.

2) packing ring

(1) the diameter clearance between packing ring and shaft sleeve is generally.5mm.

(2) The diameter gap between the packing ring and the packing box is 0 20mm。

3) the diameter gap between the packing bottom sleeve and the shaft sleeve is generally 0 00mm。

4) the diameter clearance between the balance sleeve and the shaft sleeve is generally 0 2mm。

5) the diameter clearance between the shell mouth ring and the impeller mouth ring, the intermediate bearing bush and the intermediate shaft sleeve is shown in the table below (unit: mm)

mouth ring diameter shell mouth ring and impeller mouth ring intermediate bearing bush and intermediate shaft sleeve standard clearance replacement clearance standard clearance replacement clearance ＜ 100 0.40~0.60 1.00 0.30~0.40 0.80 ≥ 100 0.60~0.70 1.20 0.40~0.50 0.90

5. The price requirements of the complete vehicle manufacturer of the coupling for the battery manufacturer are 35% lower (4) 0%

1) d/gd should be used for the coupling and shaft matching

2) the axial clearance between the two ends of the coupling is generally mm

3) install the toothed coupling to ensure that the outer teeth are in the middle of the inner tooth width

4) when installing the elastic cylindrical pin coupling, the rubber ring and the pin should be interference fit and have a certain tightening force. The diameter gap between the rubber ring and the coupling hole should be 5mm。

5) the concentricity deviation of the coupling shall comply with the following table (unit: mm)

type radial axial tooth shape <0.08 <0.06 elastic pin type 0.10 0.06 spring plate 0.15 0.10 fixed type 0.06 0.04

6) when finding concentricity, each group of gaskets under the motor shall not exceed four