Most of the elastic couplings have the function of compensating the relative displacement of the two drive shafts (axial or radial or angular or a combination of the three). When coupling users choose the coupling, most of them consider the radial and angular displacement compensation functions.In fact, axial clearance control is also a key factor affecting the stability of the transmission system. First, coupling manufacturers should be familiar with the elastic compensation functions of various elastic couplings, that is, the specific couplings that strictly control the three compensation functions. Structure size, for example, the gap control on both sides of the ML plum coupling, which needs to be manufactured by the coupling manufacturer when manufacturing the coupling, otherwise, the coupling user will easily make the plum elastomer during installation. (Coupling accessories) The contact state with the two halves of the coupling is difficult (close contact or both ends disengaged). The close contact between the plum blossom elastomer (coupling accessories) and the two halves of the coupling will cause the transmission system to be affected by the coupling. The micro-deformation of the accessories (plum elastic body) produces vibration and noise, and the separation of the two ends also produces noise.The axial gap control of the HL elastic pin coupling requires the coupling user to install in accordance with the axial gap standard of the HL elastic coupling half coupling when installing, so that the HL two half coupling can be installed. The device will not vibrate during operation.