Shaft is an important component of motor products. Different specifications of products and different working conditions of products will be reflected in different degrees on the shaft of the motor. A distinctive feature of the shaft is that the steps are concentrated and carry the function of interconversion of electrical and mechanical energy. From an intuitive analysis of the mating relationship, in terms of the motor body, the shaft is directly matched with the rotor core, bearing and end cover, which is the supporting equipment. The shaft is the link between the motor and the equipment. In view of the characteristic function of the shaft, the design, processing and maintenance of the shaft are particularly important.
Shaft turning is generally divided into coarse and fine turning two processes, under normal circumstances, respectively in two different precision lathes, so that the arrangement of the process is more economic.
From the literal meaning of understanding, the thickness of the shaft seems to be not important, but some problems are often caused by improper handling of this link, such as, in the process of production and processing of black car, center hole damage and other problems.
Fine turning is to obtain the required size and surface roughness of the shaft. Fine turning requirements are higher, should be carried out by skilled workers on a more precise lathe. If the center hole of the rear axle of the coarse car is worn, the center hole must be corrected to get the accurate machining positioning datum, and then the fine car can be carried out.
Introduction to rough machining of motor shaft
Rough turning is the machining allowance for cutting out most of the shaft blank, which is needed to obtain the contour shape similar to the shaft and the machining allowance for finishing the shaft. In order to increase productivity, the maximum number of chips can be cut per unit time. Therefore, the rough car when the cutting amount is large, the working temperature is high, the lathe power is required, the clamping firm.
There are many clamping methods used in rough car. Generally, one end of the shaft is clamped with a four-jaw chuck, and the other end is supported by a top (usually with an active top). This method clamping firmly, small vibration, but need to turn. Such as the case of clamping with a chicken chuck, one end of the shaft is set on the dead center of the front, with a chicken chuck will clamp the shaft; The other end is supported by a movable center on the tailframe. Chicken core chuck clamping convenient, but the adjustment range is small, only suitable for small diameter shaft.
When the production batch is larger, the processing of small and medium-sized shaft can also be used pneumatic chuck or hydraulic chuck clamping. Automatic clamping chucks are often used on single spindle semi-automatic lathes to clamp the shaft to save auxiliary time.
Rough car, generally the first car out of the shaft extension end, must be carried out according to the stage according to the segment. In mass production, especially in the processing of multi-step small and medium-sized motor shaft, often adopt multi-tool machining or copying machining. Multi - tool machining can be done on multi - tool semi - automatic lathe or ordinary lathe.
In multi-tool machining, several turning tools simultaneously process several surfaces of the workpiece, which can shorten the maneuver time and auxiliary time, thus greatly improving productivity. But the disadvantage of this method of processing is adjustment
The cutting tool takes more time, and the cutting force is larger, and the power required by the machine tool is larger.
The shaft copying machining can be carried out on the hydraulic copying semi-automatic lathe, or on the ordinary lathe with the hydraulic copying tool holder. Hydraulic copying machining can reduce the labor intensity of workers, reduce the auxiliary time of measuring parts and improve productivity.
Rough car when the use of strong cutting or high-speed cutting, deep knife, knife fast. To this end, the turning tool should be strong, and there is a large cooling surface.
Precautions when driving rough
●The shaft should be clamped tightly to prevent the chuck from breaking the turning tool when it is loose.
● Don't push the top too tight or too loose. When the dead center is selected, lubricating oil should be added frequently, so as not to jam the center hole and wear the center hole.
● To set aside a certain fine car margin.