DD Motor revolving stage designs technical overview

The article the direct drive revolving stage around machining center, the configuration of the composition that treats revolving stage and basic structure, crucial part and choose, and the problem that the attention answers in structural design. DD Motor (Direct Drive Motor, direct drive electric machinery) the child that is development of technology of servo electric machinery, by its the revolving stage of drive is direct drive technology on machining center again revolutionary application. Its structure characteristic is, electric machinery rotor is direct with rotate workbench join, electric machinery stator is secured together with installation base, direct drive revolving stage realizes whirligig. Its dispense with the complex drive such as worm of gear, worm wheel, have following multinomial advantages: Structure torque of simple, output big, noise low, speed and accuracy tall, control is easy, safeguard convenient, dependability is advanced. As a result of the special design of electric machinery structure, can realize output of low speed big torque, machine tool of contented machining center uses the need of feed of revolving stage cutting; Electric machinery has very good servo tigidity and dynamic character, can make revolving stage acceleration increases, slewing speed rises substantially. Be linked together with rotational load directly as a result of DD Motor electric machinery, because this is between electric machinery and load,came true " 0 " transmission. Be based on this, DD Motor revolving stage applies at machining center will be a kind of better choice. Current, abroad already had a lot of manufacturer production and sale this kind of electric machinery and revolving stage, be like German SIEMENS, Cytec; Foal of field of Japanese FANUC, ferry, china also had partial unit to buy configuration to have the machine tool of similar revolving stage, basically use at gear cutting to wait. The basic form composition of a picture with the common revolving stage of structural type DD Motor with common place of revolving stage of graph 1 DD Motor is shown 1 times for the structural type sketch map with common place of DD Motor revolving stage, it basically divides composition by the following: (1) electric machinery stator and rotor; (2) bearing; (3) coder; (4) revolving stage and rotate part; (5) base, coat and fixed part; (6) what place of DD Motor revolving stage needs is sealed with dustproof structure; (7) circular refrigeration structure. The configuration of crucial part and choose 1.

Direct drive electric machinery all has the direct drive electric machinery that can be used at revolving stage like the company such as SIEMENS, FANUC at present, its have distinguishing feature each in power, torque and rotate speed respect, installation dimension also has each different, can undertake choosing according to need. To satisfy the use requirement of revolving stage, should consider mainly on the choice of electric machinery the following 3 content: 1) the biggest torque needs the biggest torque the target requirement of contented load and rotational part acceleration. Namely: The acceleration of inertia × target of mobile part of ≧ of the biggest torque + laden torque. 2) successive torque is successive torque the torque that revolving stage issues to rotate continuously in hot nevertheless circumstance, computation should consider attrition torque and cutting torque when successive torque. In the meantime, if revolving stage tilts perpendicular perhaps use and when doing not have apply the brake or clamp structure, need considers the torque impact of gravitational generation. The hot condition performance of the function as a result of electric machinery and rigid structure and cooling state have very big concern, the beard when the choice stays have enough surplus. 3) the function that inertia distributes brandish electric machinery to fill, the moment of inertia of revolving stage should as far as possible small, the inertia that wants part of roll of strict computation revolving stage (the inertia that includes load) , satisfy the requirement of moment of inertia that electric machinery allows. The inertia of revolving stage and tigidity are a pair of contradiction, can ask to undertake accepting or reject according to the user only. In be chosen actually, answer to undertake communicating with electric machinery manufacturer, be based on close computation to reach in order to ensure best choice. 2.

The bearing of revolving stage of bearing DD Motor uses alternate roller bearing, thrust normally / afferent roller bearing or ball bearing of thrust horn contact. Graph the 2 sketch map that are 3 kinds of bearing respectively, actual design chooses Shi Kegen to come according to installing dimension, load, life to wait integrated balance. Graph sketch map of bearing of bearing of 2 revolving stage (by left to right it is A, B, C respectively) graph 2a is thrust / afferent roller bearing. It can two-way bear axial load and add and radial load and installation moment of force, particularly comfortable at bearing big capsize moment of force, have rotate higher precision. Graph 2b is alternate roller bearing. The columnar roller of this bearing passes interval to maintain on face of scroll of the V that shows 90 ° groove implement the permutation that realized mutual and perpendicular way, a bearing can bear the bear of all direction such as bear of radial load, axial and pitching moment bear. Graph 2c contacts bearing for thrust horn. It can two-way bear axial load and add and radial load and capsize moment of force, particularly comfortable at accurate circumgyrate workbench and workbench of high speed circumgyrate. Its carrying capacity and rigid photograph are told than on two kinds of bearing weaker, but performance of its high speed is good. 3.

The electric machinery of revolving stage of coder DD Motor does not contain coder, the beard in be being used actually accordingly chooses the coder that matchs, in order to ensure the position of electric machinery and speed feedback. Problem of face of the following tripartite should note on the choice. Above all, need to notice target precision is reached rotate the resolution of coder, its are optimal the 10~20 that installs limits to be target precision times. The 2nd, need to notice stability. What because the temperature of coder is met,itself temperature fetterses randomly in using a process is elevatory and elevatory, bring about the fall of precision, must choose to have the coder of the stable function that heat up voice. Finally, want attention and electric machinery and numerical control system match. The problem that the attention answers in design of revolving stage structure 1.

Rotor of direct drive electric machinery has sealed and dustproof structure permanent magnetism sex, if workbench machines the metallic dirt of the area to enter revolving stage interior, can be gotten on to rotor by adsorption, the performance that affects electric machinery can bring about its invalidation even, in be being designed normally so, need takes the kind that labyrinthian structure and hermetic seal tie, continuously the gas with clean and dry inbreathe, in order to assure the movement of electric machinery on the safe side. In sealed respect must mature, if electric machinery encounters cooling fluid inbreaks, reduce those who cause its insulating properties or degrade. Additional, the bearing that uses on revolving stage and coder all move for nicety with detecting element, in using, must make sure its are sealed structural dependability. 〔 of example of revolving stage of graph 3 DD Motor by left to right it is A respectively the DD revolving stage that institute of machine tool of Beijing of company product, B develops Shefule (the structure pursues) , the DDM630 revolving stage that place of C Beijing machine tool develops is used at 〕 of TH6363 product example 2.

The meeting when the electric machinery of interior of circular refrigeration revolving stage runs produces quantity of heat, handle badly, can affect the precision stability of revolving stage and machine tool. For this, need is covered in stator of revolving stage electric machinery go up groove is used at circular refrigeration, circular cooling water or oil are connected to take away quantity of heat when the job. The cooling photograph of the acquisition of electric machinery torque and electric machinery is associated, only electric machinery gets ability achieves its demarcate torque cooling effectively. But excessive refrigeration can produce condensation phenomenon again, reduce the insulating properties of electric machinery thereby, because this is recommended,use room temperature to dog type refrigeration system. Relative to character, the effect with cooling water compares the effect of oily refrigeration to be close friends, the successive torque of the electric machinery below oily cooling circumstance is the biggest meeting loss 20% . But below the circumstance with cooling water, must consider antirust issue, because this needs a basis,diverse demand and side key make a choice. 3.

Revolving stage of apply the brake serves as the workbench of the machine tool, need has graduation and the function that locate truly definitely. The direct drive electric machinery that DD Motor revolving stage installs and servo electric machinery is normally identical, should receive when stopping to dictate, by its circuit of dynamic apply the brake comes to electric machinery of apply the brake. But because there are decelerate and main transfer machinery between electric machinery of DD Motor revolving stage and revolving stage, the electric machinery with very high rotate speed, those who produce very small point of view is meet turn too when stopping urgently, need to have another machine in DD Motor revolving stage consequently or orgnaization of hydraulic pressure locking decides with assuring to allow. Below heavy cut circumstance, also need axis of locking revolving stage. If revolving stage tilts or perpendicular use, the action of brake compose will be more outstanding. Epilogue is in in view of DD Motor revolving stage the good character of the respect such as rotate speed, torque, more manufacturer is devoting oneself to to its are developed and apply actually, and as DD Motor electric machinery mature with each passing day, the relatively mature revolving stage product on international already got very good applying on machining center. Above paragraphs is brief the technical spy a note of the ancient Chinese five-tone scale that summarized DD Motor revolving stage, and in actual design and there still can be a lot of specific issues to remain in rigging a process each revolving stage are made manufacturer fumbles further and solve. Relative to international level, home still shows lag on the technical capability of this respect, extremely the maturity application that treats revolving stage of ceaseless in applying actually stimulative DD Motor, reach the effect that promotes a machine tool effectively performance characteristics. CNC Milling