A grinding machine is a type of machine tool that uses grinding tools to perform grinding processing on the surface of workpieces. Most grinding machines use high-speed rotating grinding wheels for grinding processing, while a few use other grinding tools such as oilstones, abrasive belts, and free abrasive particles for processing, such as honing machines, ultra-precision processing machines, abrasive belt grinding machines, grinding machines, and polishing machines, etc.
 
  Then, what are the influences of the grinding machine's accuracy on the processing of workpieces? Let's take a look together!
 
1.The geometric accuracy of the grinding machine
  It refers to the motion accuracy and mutual positional accuracy of each component when there is no load. It is impossible to manufacture a machine tool with perfect accuracy. There will always be inevitable and varying degrees of errors. These errors will be reflected to the workpiece to varying degrees during the processing, thereby affecting the machining accuracy of the workpiece. Generally, there are radial runout and axial runout of the spindle, straightness of the movement of the worktable and other moving components, mutual positional errors of the working components and transmission errors, etc.
  The radial runout and axial runout of the grinding wheel spindle, as well as the motion error of the headstock of the grinding machine, are all quite large. These factors not only affect the surface roughness of the workpiece after grinding, but also cause the workpiece to have roundness and end face runout, resulting in uneven sparks during the grinding process. When the worktable moves in a non-perpendicular manner in the vertical plane, it will affect the straightness of the workpiece's generatrix on internal and external cylindrical grinding machines, and cause large plane degree errors on the grinding plane of the surface grinding machine.
  The center lines of the spindle of the external cylindrical grinding machine's grinding wheel and that of the internal cylindrical grinding machine's grinding wheel are not at the same level as that of the spindle of the workpiece headstock. When grinding internal and external conical surfaces, the workpiece's generatrix is a hyperbola. The center line of the spindle of the grinding wheel is not parallel to the moving direction of the worktable, which affects the flatness of the end face of the workpiece after grinding. The transmission error of the grinding machine has a significant impact on the machining accuracy of thread grinding and gear grinding.
 
2.The rigidity of the grinding machine
  It refers to the ability of the grinding machine components to resist deformation when subjected to external forces (grinding forces). That is, under the same grinding force, the smaller the deformation of the components, the greater the stiffness. Conversely, if the deformation of the components is large, it indicates that the stiffness of this component is small. The magnitudes of these deformations damage the original static geometric accuracy of the grinding machine and will cause the size of the machining error of the workpiece. Therefore, a machine with good stiffness has higher machining accuracy for the workpiece.
 
3.热变形
  The heat sources within the grinding machine are unevenly distributed. The amount of heat generated by each part during movement varies. The influence of external heat sources on different parts of the machine varies as well. Due to the different thermal expansion coefficients of components made of different materials, there are also different micro-deformations in each part of the machine, which leads to a decline in the original geometric accuracy of the machine and affects the machining accuracy of the workpiece. Therefore, it is best to install precision grinding machines in a constant temperature room to prevent temperature changes from affecting the accuracy of the machine and the workpiece.
 
4.The crawling of the moving parts of the grinding machine
  When the moving parts such as the worktable and the grinding wheel frame of the grinding machine make slight periodic feed or low-speed continuous movement, the phenomenon of uneven motion occurs, which is generally called crawling. When this phenomenon occurs in the grinding machine, it causes the feed during the grinding process to be uneven, thereby affecting the surface roughness of the workpiece.

5.Vibration of the grinding machine
  During the grinding process, the grinding machine generates vibrations, causing the relative positions between the grinding wheel and the workpiece to change periodically. This leads to the formation of vibration marks on the workpiece surface, seriously affecting the processing quality and accuracy.
 
  To enhance the machining accuracy of the workpiece after grinding, in addition to making efforts to eliminate the influence of the aforementioned factors, it is also necessary to pay attention to the reasonable selection of the positioning datum during the machining process, the appropriate clamping method, the selection and correct repair of the grinding wheel, and the reasonable choice of grinding parameters and processing methods.