Tong Mao allows you to read linear motors and linear Motors
time£º2017/5/26 click£º7566
What is a linear motor, a linear motor? A linear motor, also known as a linear motor or linear motor, is a transmission that converts electrical energy directly into linear motion mechanical energy without the need for any intermediate conversion mechanism. We also call it a linear motor, a linear motor, a linear motor, and a pushrod motor. Commonly used linear motor types are flat linear motor, U-slot linear motor and cylindrical linear motor. It has the advantages of simple system structure, less wear, low noise, strong combination, and convenient maintenance. The varieties of rotary motors and linear motors have almost all corresponding varieties. The structure of linear motor of traditional motor consists of three parts: stator, mover and support wheel of linear motion. In order to ensure a good electromagnetic field coupling between stator and mover within the stroke range, the length of the core of the stator and motor varies. The stator can be made into two forms: short stator and long stator. Due to the high cost of long stator structure and high operating cost, it is rarely used. Like a rotating magnetic field, a linear motor has a stator core that is also superimposed by a Silicon steel sheet with a toothed surface; The slot is embedded with three-phase, two-phase or single-phase windings; Single-phase linear asynchronous motor can be made into a shield type, but also through capacitance phase shift. The linear motor straightens the primary expansion of the traditional cylindrical motor, turns the primary closed magnetic field into an open magnetic field, and the stator part of the rotating motor becomes the primary part of the linear motor, and the rotor part of the rotating motor becomes the secondary of the linear motor. If the primary is stationary, the secondary can move straight along the direction of the magnetic field of the traveling wave. The linear motor of high speed machine tool can be directly driven by the feed mode, and the primary and secondary of the linear motor are directly installed on the work table and bed of high speed machine tool. Since the transmission chain of this feed transmission mode is shortened to 0, it is called the "zero drive" of the machine tool feed system. The working principle of a linear motor in a linear motor is equivalent to the stator of a rotating motor, which is called a primary; Equivalent to the rotor of the rotating motor, it is called the secondary, the primary middle pass is communicated, and the secondary motion is made along the primary line under the action of electromagnetic force. At this time, the primary is to be done very long, extending to the position required for the movement, while the secondary is not so long. In fact, the linear motor can do both the primary and the secondary. It can be either primary fixed, secondary movement, or secondary fixed, primary movement. Linear induction Motors evolved from rotary Motors. When the three-phase(or multi-phase) winding of the primary side enters a symmetric sinusoidal AC current, an air gap magnetic field is generated. The distribution of this gap magnetic field is similar to that of a rotary motor, and is distributed according to sinusoidal law along a straight line direction, without considering the longitudinal edge effect caused by the disconnection of both ends of the core. The main classification of linear motors can be divided into: DC, asynchronous, synchronous and stepping; Linear motors can be divided into structural forms; Unilateral flat, bilateral flat, disc, cylindrical(or tubular) and so on. Commonly used linear motor types are flat linear motor, U-slot linear motor and cylindrical linear motor. The ring motor is named after its structure similar to that of the horn. It has the characteristics of high frequency loudness and high precision. This type of motor is divided into cylindrical ring motor and swing ring motor. That is, the so-called cylindrical linear motor. The iron core of the flat-plate linear motor is mounted on a steel stack structure and then installed on an aluminum back plate. The iron stack structure is used to guide the magnetic field and increase thrust. The suction generated between the track and the mover is proportional to the thrust generated by the motor, and the stack structure leads to the junction force. Care must be taken when installing the movers on the track to avoid damage caused by the suction between them. The U-slot linear motor U-slot linear motor has two parallel tracks between the metal plates and both face the coil movers. The movers are supported by the guide rail system in the middle of the two magnetic rails. The kinematics are non-steel, meaning that there is no suction and there is no interference between the track and the thrust coil. The non-steel coil assembly has a small inertia and allows very high acceleration. The coil is generally three-phase, brushless phase change. Air cooling can be used to cool the motor to obtain performance enhancement. There are also water-cooled methods. This design can better reduce the flux leakage because the magnet is mounted face to face in the U-shaped guide groove. This design also minimizes the damage caused by powerful magnetic attraction. This design of the track allows the combination to increase the length of the journey, limited to the operating length of the cable management system, the length of the encoder, and the ability of the mechanical structure to be large and flat. The linear motor of cylindrical linear coil motor is a cylindrical structure. A cylinder that moves along a fixed magnetic field. This motor is an early discovered commercial application but can not be used in flat and U-shaped linear motors that require space saving. The magnetic path of a cylindrical dynamic magnet linear motor is similar to that of a dynamic magnetic actuator. The difference is that the coil can be copied to increase the journey. The typical coil winding is composed of three phases and uses a Hall device to achieve brushless phase switching. The thrust coil is cylindrical and moves up and down the magnetic rod. This structure is not suitable for magnetic flux leakage sensitive applications. You have to be careful to make sure your fingers don't get stuck between the magnetic rod and the attractive side. A potential problem with tubular linear motor design occurs when the stroke increases, as the motor is cylindrical and moves up and down the magnetic rod, supporting the point at both ends. Ensure that the radial deviation of the magnetic rod does not cause the length of the magnet contact thrust coil to be always limited. The advantage of linear motor 1. The structure is simple. The linear motor does not need to pass through the intermediate conversion mechanism to directly generate linear motion, so that the structure is greatly simplified, the motion inertia is reduced, and the dynamic response performance and positioning accuracy are greatly improved. At the same time, it also improves reliability, saves costs, and makes manufacturing and maintenance easier. Its initial level can be directly part of the institution, and this combination makes this advantage more evident. 2. High acceleration. This is a linear motor drive, compared to other screw, synchronous belt and gear rack drive a significant advantage. 3. Suitable for high-speed linear movement. Because there is no constraint of centrifugal force, ordinary materials can also achieve higher speeds. And if the air cushion or magnetic pad is used to preserve the gap between the primary and secondary, there is no mechanical contact during the movement, so that the movement part is also free of friction and noise. In this way, there is no wear on the transmission parts, which can greatly reduce the mechanical loss and avoid the noise caused by tow cables, steel cables, gears and pulleys, thereby improving the overall efficiency. 4. High utilization rate of primary winding. In the tubular linear induction motor, the primary winding is cake type, there is no end winding, so the winding utilization rate is high. 5. No lateral edge effect. The transverse effect refers to the weakening of the boundary magnetic field caused by the transverse opening, while the cylindrical linear motor has no lateral opening, so the magnetic field is evenly distributed along the circumference. 6. It is easy to overcome unilateral magnetic pull problems. Radial tension counteracts each other, and there is basically no problem of unilateral magnetic tension. 7. Easy to adjust and control. By adjusting the voltage or frequency, or replacing the secondary material, different speeds and electromagnetic thrusts can be obtained, which are suitable for low-speed reciprocating operations. 8. Adaptable. The primary iron core of linear motor can be sealed into a whole by epoxy resin, which has better corrosion protection and moisture protection performance, and is convenient for use in humid, dust and harmful gas environments. And it can be designed into a variety of structural forms to meet the needs of different situations. The development of linear motors In 1840 Wheatsone began to propose and produce a slightly embryonic linear motor. In 1905, two people proposed that the linear motor be used as a propulsion mechanism for the train. One proposal was to put the primary on the track, and the other proposal was to put the primary on the bottom of the vehicle. These suggestions were undoubtedly a stimulant for researchers in the field of linear motor research at that time, so that in many areas
Linear motor