泵和驱动机找正对中.docVIP

Subject: Pump and driver alignment 14-3 In the pump business alignment means that the centerline of the pump is aligned with the centerline of the driver. Although this alignment was always a consideration with packed pumps, it is critical with sealed pumps especially if you are using rotating seal designs where the springs or bellows rotates with the shaft. A little misalignment at the power end of the pump is a lot of misalignment at the wet end, and unfortunately that is where the seal is located in most pump applications. Misalignment will cause many problems: It can cause rotating mechanical seals to move back and forth axially two times per revolution. The more the seals move the more opportunity for the lapped faces to open Packing could support a misaligned shaft. A mechanical seal cannot. Misalignment will cause severe shaft or sleeve fretting if you use spring loaded Teflon? as a secondary seal in your mechanical seal design. The pump bearings can become overloaded. The misalignment could be severe enough to cause contact between stationary and rotating seal components: The wear rings can contact. The shaft can contact the restriction bushing often found at the end of the stuffing box. The shaft or sleeve can contact the stationery face of the mechanical seal. The shaft can contact the disaster bushing in an API (American Petroleum Institute) gland. The impeller could contact the volute or back plate. Regardless of the alignment method you select, you must start with a pump and driver in good repair. A perfectly aligned piece of junk is still a piece of junk. You should also check the following: A straight shaft that has been dynamically balanced. Good wear rings with the proper clearance. The correct impeller to volute, or backplate clearance. The elimination of soft foot. Eliminate all pipe strain. Good bearings installed on a shaft with the proper finish and tolerances. A good mechanical seal set at the proper face load. The closer the s