Spline Shaft Method to Improve Centering Accuracy

• Posted by Shi Tai 6 September 2022 - Filed in Other - #Spline Shaft  - 32 views

  Spline shaft connections are often used in mechanical transmission devices. Because splines work with multiple teeth, they have the high load-bearing capacity, large torsion force and good guidance, so they are widely used in various machinery. Splines are generally divided into rectangular splines and involute splines, and involute splines are divided into pressure angles of 30 degrees, 37.5 degrees, and 45 degrees. Among them, rectangular splines are easier to process and pass through small-diameter keyways. It can obtain higher centering accuracy after grinding, so it is widely used. According to the national standard GB/T rectangular spline centering method, the small diameter is centered. Because the small diameter centering can easily improve the accuracy and the hardness of the contact surface of the spline pair, the service life of the product is prolonged.

  Machining errors that may occur during grinding of spline shafts and their solutions:

  1. When grinding small diameters on a spline grinder, the rotation center of the grinding wheel dresser and the centerline of the workpiece often cannot completely coincide due to operating errors, that is, the theoretical center of the small diameter of the spline shaft does not coincide with the arc center of the grinding wheel, resulting in an offset. In addition, the axial movement of the grinding wheel spindle of the grinder exceeds the usual range, which will also cause the small diameter of the spline shaft to not coincide with the arc center. In this way, the measured value is less than the actual maximum value during the inspection, so that the spline shaft cannot be installed in the spline hole. This kind of clarity often occurs in production practice. In actual operation, it is very difficult to adjust the rotation center of the grinding wheel restores to completely coincide with the centerline of the workpiece. However, through production practice, it is found that the method of reducing the arc radius of the grinding wheel is more practical. Basically, it will not happen that the spline shaft cannot be installed in the spline hole. The specific detection method is to put the center hole of the two ends of the spline shaft on the inspection instrument, and then use the dial indicator contact to push on the small diameter, manually rotate the workpiece, and record the specific data of the small-diameter center high point between each spline. This test is over.
  2. When grinding the side edges on a spline grinder, it often appears that the symmetrical centerline of the spline tooth thickness deviates from the theoretical centerline, resulting in an excessive symmetry, but the deviation is mainly caused by the misalignment of the center of the machine tool spindle and the center of the workpiece. The accuracy of the machine tool is determined, and there are many reasons for the misalignment of the center of the machine tool spindle and the center of the workpiece.

  does not coincide with the centerline of the connected tapered shank, the centerline of the spindle of the machine tool does not coincide with the centerline of the tailstock taper sleeve, and the round runout caused by the machining error of the center hole at the two ends of the workpiece. Therefore, for the grinding of the side of the spline shaft, first, choose a higher precision grinder, then adjust the tailstock offset as much as possible, and choose a high precision one to keep the centerline of the machine tool consistent with the centerline of the workpiece, and improve The machining error of the center hole at the two ends of the spline shaft. In this way, after the above various measures, the symmetry error is controlled within the scope of the drawing design. In the position error of the rectangular spline shaft, in addition to the symmetry error, there is an equal division error. The error value is specified in the national standard. If you do not pay attention to the control during processing, the processing accuracy of the workpiece will be reduced. In addition, in addition to finishing, the quality of the workpiece is also affected in the process of material selection, quenching and tempering, and quenching. No matter which process has a problem, it will affect the quality of the product. Therefore, high-quality products can only be produced through thorough checks.

  Ningbo Shitai Precision Machinery Co., Ltd. is a spline shaft manufacturer, providing customers with high-quality products and services. Welcome to visit our official website.