Basic questions on machinery and equipment; discussions are welcome

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Test Questions on xjbzhexb
I. True or False Questions
1. When a bolt gets stuck in a hole and is difficult to remove, it can generally be taken out by drilling a hole in the bolt. (True)
2. A V-belt should be installed in the corresponding pulley groove and make good contact with both sides of the groove as well as the bottom of the groove. (False)
3. The inner diameter of a rolling bearing with the code “42607” is 42 mm. (False)
4. The liquid film between the two end surfaces of a mechanical seal can lubricate these end surfaces. (True)
5. When installing a pump, oil stains and scale on the anchor bolts should be removed thoroughly, and a small amount of grease should be applied to the threaded parts. (True)
6. When installing a pump, the shims should be placed evenly; diagonal shims should be used in pairs, with flat shims placed on top of the diagonal shim set. (False)
7. The mouth ring of a centrifugal pump serves to prevent the medium on the high-pressure side from leaking to the low-pressure side. (True)
8. The oil level in the bearing housing of a centrifugal pump is generally higher than that of the rolling elements. (False)
9. After assembling the inlet and outlet valves of a piston metering pump, test for leaks using kerosene; there should be no leakage within 5 minutes. (True)
10. When assembling thin-walled bearing shells with bearings, an appropriate amount of interference is needed to achieve a tight fit, and the split surface of the thin-walled shell should be slightly higher than that of the bearing housing. (True)
11. The main function of the inducer wheel of a high-speed centrifugal pump is to increase the pump’s flow rate. (False)
12. If the oil injection hole of the crosshead pin becomes blocked, it can cause damage to the small-end bearing shell of the reciprocating compressor’s connecting rod and the crosshead. (True)
13. The main reasons for damage to the thrust bearings of a centrifugal compressor are excessive axial force and abnormal lubrication. (True)
14. To achieve axial balance, a three-screw pump often has a balance piston installed at the outlet. (False)
15. A shielded pump uses lubricating oil to lubricate its bearings. (False)
16. Severe wear or excessive clearance in the moving parts of a reciprocating compressor can cause the oil pressure to rise. (False)
17. Industrial steam turbines are mainly used to drive rotating mechanical equipment such as fans and water pumps, and their rotational speed remains constant. (False)
18. The plunger stroke of a diaphragm metering pump is adjusted based on the speed of the motor. (False)
19. If the lapping of the shaft bearing shells of a Roots blower is uneven or the centering design is incorrect, it can cause wear of the sealing rings; this can be addressed by adjusting the clearances or replacing the bearing shells. (True)
20. Deformation of the contact end surfaces of the moving ring and the stationary ring can cause periodic leakage; if the end surface clearance is too large, frictional heat can cause thermal deformation of both the moving and stationary rings. (False)

II. Fill-in-the-Blank Questions
1. A mechanical seal relies on (elastic elements) to keep the end surfaces of the moving and stationary rings in close contact.
Seal ring, gland, medium, elastic elements
2. During major repairs of a centrifugal pump, since the pump shaft has been in operation for a certain period, a (bendness) check should be carried out.
Bendness, strength, stiffness, hardness
3. When installing a pump, the (hooked part) of the anchor bolts should not touch the bottom hole or the wall of the hole.
Hooked part, upper part, middle part, lower part
4. As the piston of a reciprocating compressor moves back and forth, the working (volume) of the compressor changes periodically.
Volume, pressure, temperature, efficiency
5. A diaphragm metering pump uses (hydraulic oil) to push the diaphragm and enable it to expand and contract to do work.
Hydraulic oil, water, main plunger rod, crankshaft connecting rod
6. The method to adjust the clearance of a rolling bearing is to move the inner and outer rings appropriately in an (axial) direction.
Axial, radial, in the same direction, directional
7. After assembling a multi-stage centrifugal pump, the rotor should have a certain amount of (axial) runout.
Directional, axial, radial, relatively large
8. In most cases, medium-carbon steel is treated by (normalizing).
Normalizing, quenching, tempering, annealing
9. If the rotor of a single-stage single-suction centrifugal pump is unbalanced and vibrates excessively, it can cause (seal leakage).
Inability to pump water, overheating of bearings, insufficient flow rate, seal leakage
10. After assembling the rotor of a multi-stage centrifugal pump, the (roundness runout and end face runout) of the rotor should be checked.
Straightness, roundness runout, end face runout, roundness runout and end face runout
11. For the static balance of a rigid rotating body, generally (1) alignment surface is required.
1, 2, 3, 4
12. When repairing bearing shells, the shell seat should be checked first. If the shell seat is prone to wear, it should be (repaired) first, and then the bearing shells should be fitted accordingly.
Repairing, adjusting, repairing, grinding
13. There is a (rotor impeller) between two adjacent plates in a centrifugal compressor; therefore, the plane of the partition plate must be flat.
Rotor impeller, bend, returner, diffuser
14. If the opening degree of the outlet valve of a centrifugal ventilator is too small, it can cause (vibration); the outlet valve should be adjusted accordingly to eliminate the problem.
Reduced air volume, reduced air pressure, vibration, high bearing temperature
15. An incorrect rotation direction of a shielded pump can cause (insufficient flow rate).
Bearing damage, excessive vibration, abnormal noise, insufficient flow rate
16. In the base hole system, the lower deviation is equal to (0).
0, 1, 2, 3
17. The annular valves of reciprocating compressors are simple to manufacture and reliable in operation; the (number of rings) can be changed to meet various air volume requirements.
Annular, number of rings, ring thickness, ring size
18. When initially installing the air valves of a reciprocating compressor, check whether the (end face) locking device of the valve plate lift limiter is reliable.
Side surface, middle, end face, circumference
19. Triangular belts are classified into (7) types according to different cross-sectional dimensions.
8 types, 7 types, 6 types, 5 types
20. Pumps that use the energy of fluid flow to convey liquids are called (fluid-driven pumps).
Positive displacement pump, vane pump, fluid-driven pump, gear pump

III. Short Answer Questions
1. What are the methods for adjusting the bearing shell back pressure?
2. What are the methods for measuring the dead center clearance of a compressor?
3. What are the methods for balancing the axial thrust of a multi-stage centrifugal pump?
4. What are the methods for aligning mechanical equipment?