important role of lubrication in oil pump

77. What are the types of lubrication?

A: 1) drip oil lubrication, 2) oil mist lubrication, 3) splash lubrication, 4) pressure lubrication, 5) dry oil cup lubrication;

 

78. The selection of lubricating oil should consider the type of oil pump and the following factors: 1) moving speed, 2) moving properties, 3) working temperature, 4) pressure relations, 5) mating properties of friction surface, 6) surface roughness

 

79. What are the functions of lubricant?

A: 1) cooling effect, 2) rust prevention effect, 3) cooling effect, 4) washing effect,5) friction control effect, 6) wear reduction effect, 7) damping effect, 8) sealing effect;

 

80. Calcium-based grease, sodium based grease, lithium based grease are suitable for what occasions?

A: 1) calcium based grease: water resistance, can be used in wet workplace, but not high temperature, the use of temperature range -10 -- 60 degrees;

2) Sodium based grease: high temperature resistance, but not water resistance, the temperature range of -10 -- 110 degrees;

3) Lithium grease: heat resistance, water resistance, the temperature range of -20 -- 1200 degrees;

 

81. What are the "five determinations" of the management of pump lubricants?

Answer: The pump should be: fixed point, fixed time, fixed quality, fixed quantity, fixed personnel, check refueling, to ensure the normal operation of the pump;

 

82. What is the basic principle of the importance of lubrication to the pump?

A: Lubricants can be firmly attached to the friction surface of the machine parts to form an oil film, this oil film and the friction surface of the machine parts is very strong, the two lubrication surface is separated by lubricants, so that the friction of the machine parts into the friction of lubricant molecules, so as to reduce friction and wear, prolong the service life of the machine parts.

 

83. What are the causes of oil leakage in oil-lubricated pumps?

Answer: 1) The oil level is too high, and the inner hole of the bearing cover along the two ends of the bearing box leaks oil;

2) Oil leakage at static sealing point, such as oil drain wire to plug oil leakage;

3) Oil leakage between bearing gland and bearing joint surface;

 

84. What role does lubricant play in the rotation of the bearing?

A: 1) lubrication, 2) cooling, 3) washing, 4) rust prevention, 5) sealing, 6) cushioning and damping, 7) friction and wear prevention;

 

85. What are the main properties of lubricants?

A: acid value, viscosity, viscosity index, flash point, mechanical impurity, freezing point, carbon residue, ash.

 

86. How many ways are there to measure the clearance of radial journal bearings?

How to use the axis lifting method to measure?

Answer: commonly used method has three kinds: press lead method, lift shaft method, false shaft method.

Shaft lifting method: a dial gauge is installed near the axle diameter to the bearing bush. When used, a dial gauge is installed on the top of the shell of the bearing bush to monitor. Lift the axle diameter gently until it touches the upper tile shell, but the movement of the upper tile shell cannot be too large.

 

87. What are the faults of sliding bearings?

How to deal with it?

A: fault: gluing.

Treatment measures: 1) to ensure the correct installation position and clearance requirements, 2) to ensure good lubrication of the rotor.

Failure: fatigue rupture.

Treatment measures: 1) the bearing surface should be kept smooth, 2) to ensure a good balance of the rotor.

Failure: wear and tear.

Treatment measures: 1) to avoid insufficient lubrication,2) timely cleaning lubrication system.

Failure: scratch.

Treatment measures: 1) to prevent instantaneous oil cut off, 2) to avoid collision during installation or disassembly.

Trouble: Twisting.

Treatment measures: pay attention to oil clean, prevent dirt into.

Fault: cavitation erosion.

Treatment measures: 1) increase the oil supply pressure, 2) modify the shape of oil groove and oil groove of bearing bush, 3) reduce bearing clearance.

Fault: electrical erosion.

Treatment measures: 1) to ensure that the insulation and protection device of the machine is good, 2) to ensure that the grounding of the machine is intact;

3) Check the shaft diameter. If there is an electric pitting pit on the shaft diameter, the shaft diameter should be polished to remove the pitting pit.

 

88. What are the reasons for the adhesion of sliding bearings in use?

Answer: 1) overheated bearing, 2) excessive load, insufficient oil, 4) improper operation or temperature control failure.

 

89. What are the causes of abnormal sound when rolling bearings are in operation?

Answer: 1) the rolling body or raceway is stripped seriously and the surface is uneven.

2) The bearing accessories are not installed properly, and there is loosening or friction.

3) There are iron filings or dirt in the bearing.

4) Lack of lubricant.

 

90. What are the radial clearances of rolling bearings?

Answer: 1) Original clearance: clearance in free state before bearing installation.

2) Fit clearance: the clearance after the bearing is installed on the shaft or in the hole. Its size is determined by the amount of interference, and the fit clearance is less than the original clearance.

3) working clearance: some bearings, due to the characteristics of the structure, the clearance can be determined in the process of assembly or use by adjusting the mutual position of bearing rings, such as centripetal thrust ball bearings.