The machining quality of the stator and rotor of the cam rotor pump refers to the surface roughness of the stator cavity, the rubber straightness of the stator cavity, the bonding strength of rubber and steel sleeve, the non-leakage of the threads at both ends of the stator under the rated working pressure and the surface roughness of the rotor. whether the straightness of the rotor, whether the rotor eccentricity and cross-section circle diameter meet the design requirements, whether the rotor key layer is smooth and intact, whether the rotor connecting thread meets the standard, etc.
(1) The influence of the roughness of the inner cavity surface and the outer surface of the rotor on the characteristics of the cam rotor pump.
Generally speaking, the surface roughness of the stator cavity is not greater than Ra16, and the surface roughness of the rotor is not greater than Ra0.8, so as to ensure that the cam rotor pump has higher cam rotor pump efficiency and relatively small torque, because there is a certain interference between the stator and the rotor, and the contact between the rotor and the stator surface produces friction, which depends on the interference value between the stator and the rotor. It also depends on the roughness of the stator and rotor surface. if the surface is too rough without treatment, it is bound to produce greater torque due to friction and automatic heating and fatigue of the friction surface. The temperature of the well fluid and the synthetic temperature produced by the cam rotor pump exceed the temperature resistance limit of the rubber, which accelerates the aging of the rubber, reduces the tensile strength and increases the hardness, and greatly reduces the service life of the screw pump. At the same time, it also reduces the strength of the binder on the metal sleeve and the rubber bonding surface, causing the rubber to fall off from the metal pipe wall prematurely.
(2) The influence of straightness of stator and rotor on the characteristics of cam rotor pump.
The influence of the straightness of the stator cavity on the characteristics of the cam rotor pump: the reason for the poor straightness of the stator cavity is that the domestic screw pump adopts horizontal glue injection, if the stator core is not righted well or no measures are taken, the stator core is deformed and bent and deviated from the axis due to the glue injection pressure and the gravity of the core. After the stator is vulcanized, the rubber shape is bonded to the metal tube wall, and the rubber where the core deviates from the axis also deviates from the axis. As a result, the thickness of the stator rubber is uneven in the symmetrical direction, and during the use of the cam rotor pump, the light components of hydrocarbons and aromatic compounds in the downhole crude oil permeate into the rubber under the action of differential pressure, and at the weak part of the rubber, the light components penetrate the interaction between the rubber and the binder, making the binder fail prematurely, causing the rubber to fall off from the pipe wall and accelerate the rubber shedding under the action of torque. Make the cam rotor pump fail prematurely due to degumming, in addition, due to the poor straightness of the stator, the torque of the cam rotor pump is too large, the vibration during operation is intensified, and the sealing performance of the screw pump is poor. In addition, it will also cause uneven pressure in each stage, affecting the performance of the screw pump.
