Assembly sequence and requirements of ZJ type slurry pump


Apr 28,2024

Assembly sequence and requirements of ZJ type slurry pump

Before assembling the slurry pump, all parts should be thoroughly inspected and cleaned to check whether the parts meet the use requirements. If they are damaged, they must be replaced with new parts before assembly. ZJ series slurry pump assembly sequence and basic requirements:

1. Assembly of rotor assembly:

The bearings used in slurry pumps are generally domestic bearings, and the lubrication system is thin oil.


(1) Precautions for bearing assembly:


1. Bearings that have been inspected and certified as qualified must be used;


2. Check the inner diameter, outer diameter, width, parallelism of the two end faces of the raceway, surface roughness, and whether there are defects such as rust and spots, and whether the rotation is flexible;


3. For angular contact bearings and double-row self-aligning bearings, check the bearing clearance separately, find the center of the ball raceway, and decide whether to add pads and the thickness of the pads based on the height of the inner ring relative to the outer ring. The thickness of the pads is determined to ensure the standard clearance of the bearing. Radial thrust bearings must not be reversed;


4. When assembling removable (inner and outer rings are separated) bearings, they must be installed according to the inner and outer ring alignment marks and must not be installed randomly;


5. For bearings with adjustable heads, the numbered end should be facing outward during assembly for easy identification.


(2) Shaft assembly:


1. To avoid biting with the mating surface, a layer of lubricating oil should be applied to the mounting surface before assembly to protect the shaft hole from damage;


2. The bearing is installed by hot-installation, that is, the bearing is placed in a heating box filled with oil and heated to 80-100℃ with the oil. The mating surface should be completely immersed in the oil. A thermometer should be placed in the oil tank to strictly control the temperature not to exceed 100℃. After heating, it should be cooled naturally. Sudden cooling is not allowed to avoid damage or deformation of parts; a. Install the rear bearing first, then install the stopper sleeve and round nut and press the bearing. b. Check whether the bearing is close to the shaft shoulder and the rotation should be flexible and stable. Then install the bearing box. The bearing box should also be assembled by hot-installation, with the same requirements as above. c. Finally, install the front bearing, with the same requirements as above. d. Install the sealing ring on the bearing box. e. After the main shaft assembly and bracket are installed, other accessories of the shaft should be installed again according to the assembly drawing.


2. Assembly of the bracket part:

First, clean the dirt in the bracket cover and bracket body oil pool, and wipe the bearing hole clean.

  1. After cleaning the joint surface of the bracket body and the bracket cover, ensure that the upper and lower bearing holes meet the tolerance of the drawing, and within the range of ±0.015mm, determine the thickness of the added paper pad (when adjusting the thickness, no more than three layers of pads). Apply sealant evenly on the joint surface of the bracket body, place the pad on the bracket body, and tighten the stud bolts.

(2) Install the oil pool M16×1.5 hexagonal bolts and oil mark, and draw a horizontal line of -0.2~0.5mm through the center of the circle on the oil mark plate and apply red paint to indicate the oil level.

(3) Install the oil pool cooler components and water cooling chamber cover (put a 2mm rubber pad under the cover. Note: Some pumps do not have this cover).

(4) Assembly of shaft assembly and bracket: Lift both ends of the main shaft, install the main shaft assembly into the matching hole of the bracket, lift the bracket cover, apply oil-resistant sealant on the green shell paper on the bracket joint surface, and close the bracket cover. Reserve a gap of 3mm between the end face of the bearing box flange and the end face of the bracket. Drive in the taper pin and pre-tighten the bolts.


(5) Install the oil seal on the front bearing cover, pad the green shell paper, install it on the shaft and connect it to the bracket with bolts.


(6) Install the water retaining plate and disassembly ring. When installing the disassembly ring, add a small amount of grease to the bolt hole, and the disassembly ring should be pressed against the water retaining plate.


(7) Install the adjusting bolts and set screws on the bearing box.


(8) Install a magnetic dial gauge on the shaft to detect the coaxiality and verticality of the semicircular positioning hole connecting the bracket and the rear pump housing and the end face and the shaft rotation center. They should not be greater than 0.25mm.


3. Mechanical seal installation:

1. Check the mechanical seal model according to the drawing or instruction manual, and prepare all related accessories.


2. Clean the stuffing box shaft seal cavity and stopper.


3. Install the mechanical seal assembly into the stuffing box body, install the mechanical seal clamping bolts, and do not tighten them.


4. Installation of the rear pump casing and rear guard plate:

(1) Install the rear pump casing on the bracket. (Note: It is best not to remove the rear pump casing from the bracket during overhaul);


(2) Install the sealing rubber ring on the shaft sleeve and install it on the shaft, and then install the stuffing gland and water seal ring on the shaft sleeve;


(3) Install the stuffing box and install the sealing ring in the groove, install the auxiliary impeller sealing ring and auxiliary impeller;


(4) Install the studs of the rear guard plate, lift the rear guard plate with a lifting tool, install it on the rear pump casing, and tighten the nuts. Measure whether the gap between the inner hole of the rear guard plate and the hub of the auxiliary impeller is uniform, and observe whether there is any friction by turning the wheel.


5. Install the impeller and volute:

(1) Apply grease to the impeller T-thread, install the impeller on the shaft, tighten it, and compact the auxiliary impeller.

(2) Install the rear guard plate seal.

(3) Use the volute lifting tool to lift the volute, install it on the rear guard plate, install the pump casing connection bolts and clamps, adjust the distance from the top surface of the volute outlet to the top surface of the rear pump casing outlet to 5mm, and then clamp the volute.


6. Installation of the front pump casing and front guard plate:

(1) Raise the front pump casing and place it flat on the ground. Install the front guard plate into the studs and lift it into the front pump casing with the lifting tool and fasten it to the front pump casing.

(2) Install the front guard plate seal and the front pump casing lifting eye screws.


(3) Lift the front pump casing and the front guard plate, push the outer circle of the front guard plate into the cone hole of the volute casing, adjust the distance from the top surface of the volute outlet to the top surface of the front pump casing outlet to 5mm, and then tighten all the pump body bolts.


(4) Adjust the gap between the impeller and the front guard plate to 0.75mm-1.00mm. The adjustment method is the same as above.


VII. Manual turning:

Before the packing is compressed, the slurry pump should rotate lightly, evenly, and without tightness.