Force calculation of screw motor

1.

The electric screw can be designed with different thrust according to different application load. Generally, the maximum thrust can reach 20KN, and the no-load running speed is 4 ~ 45mm / s. The electric screw takes the 24 V / 12 V / 220 / 380 V DC / AC permanent magnet motor as the power source, which transforms the rotary motion of the motor into linear reciprocating motion. Push a group of linkage to complete the switching work of damper, valve, gate and baffle

The motor drives a pair of screw nuts after gear rection. The rotary motion of the motor is changed into linear motion, and the forward and reverse rotation of the motor is used to complete the push rod action. Such as through a variety of levers, rocker or connecting rod and other mechanisms can complete the rotation, shaking and other complex actions. By changing the length of lever arm, the stroke can be increased or enlarged

extended data

I. protection of oil and water of servo motor. Therefore, the servo motor should not be placed or used in the environment of water or oil invasion

b: if the servo motor is connected to a rection gear, it should be sealed with oil when using the servo motor to prevent the oil of the rection gear from entering the servo motor

C: the cable of the servo motor should not be immersed in oil or water

2. Servo motor cable → rece stress

A: ensure that the cable is not subject to torque or vertical load e to external bending force or its own weight, especially at the cable outlet or connection

b: when the servo motor is moving, the cable (the one configured with the motor) should be firmly fixed to a static part (relative to the motor), and an additional cable installed in the cable support should be used to extend it, so that the bending stress can be minimized

C: the elbow radius of the cable should be as large as possible

2.

The formula F = 2 * m / (d * Tan (a + b)) should be the stress formula of screw pair in textbook. If we change the formula: f * (d * Tan (a + b)) / 2 = m --- & gt; F*2 π( d/2)*tan(A+B)=M*2 π

the greater the mass flow rate of the working fluid through the engine, the greater the thrust of the engine. Under the sea level standard atmospheric conditions, the thrust generated by the engine when the aircraft is at rest is called sea level static thrust. The thrust proced by rocket engine in near vacuum environment is called vacuum thrust

extended data:

purpose:

ball screw bearings provide a wide range of standardized procts for various purposes. It is widely used in machine tools. The circulation ways of ball include circulation conit type, circulator type and end cover type. Preloading methods include positioning preloading (double nut, position preloading) and constant preloading

the appropriate type can be selected according to the use. The screw has high precision grinding precision ball screw (precision is divided into 6 grades from co-c7) and high precision cold rolling forming cold rolling ball screw bearing (precision is divided into 3 grades from C7-C10). In addition, in order to meet the urgent need of delivery, there are also finished procts that have been processed at the end of the shaft

the semi-finished procts and cold-rolled ball screw bearings which can finish the end of the shaft freely. As the peripheral parts of the bearing, the necessary lead screw support unit, nut support and lock nut have been standardized for users to choose

source of reference: network thrust

3. It plays a transmission role in the electric displacement table, and plays a decisive role in the positioning accuracy, repeated positioning accuracy, axial clearance, speed, resolution and other indicators of the electric displacement table. Generally, ball screw, grinding screw and trapezoidal screw are used. Ball screw and nut realize dynamic transmission through steel ball. By selecting the diameter of steel ball or using double nut preloading, Shanghai manlu can rece the axial clearance and improve the rigidity. Therefore, it has great advantages in transmission accuracy, transmission efficiency, rigidity and service life.

4. In the case of inexact constant speed transmission, the following formula can be applied:
T1 = (TA + tpmax + TU)
where T1: driving torque at constant speed; Ta=Fa*I/2*3.14*n1); FA: axial load n; Fa=F+ μ MGF: axial cutting force of lead screw, etc; μ: Friction coefficient of guide surface; m: Weight of moving object (worktable + workpiece) kg; g: 9.8 tpmax: the upper limit of dynamic friction torque of lead screw is n.cm; Tu: friction torque of support bearing n.cm

if there is recer, motor torque = T1 / rection ratio / transmission efficiency of recer
considering acceleration load, inertia and torque margin, please consider multiplying by safety factor

5. Please refer to the question you answered earlier:
http://..com/question/42593457.html
calculate the transmission ratio again, and finally check the gear strength. If you still have questions, please email: [email protected]

6.

Thrust P = 2 πη T / L

attention must be paid to whether the unit of length in torque T and lead screw L is consistent. If t is kg * cm and lead screw L is cm, the calculated result is kg

if n * m is used for T and cm or mm is used for lead screw, conversion is necessary

The preloading methods include positioning preloading (double nut preloading, position preloading) and constant preloading. The appropriate type can be selected according to the use. The screw has high precision grinding precision ball screw (precision is divided into 6 grades from co-c7) and high precision cold rolling forming cold rolling ball screw bearing (precision is divided into 3 grades from C7-C10)

screw rod bearing is a special bearing for screw rod, which belongs to thrust angular contact bearing. It has larger contact angle than general angular contact bearing, and can bear larger axial force

extended data:

features

1, small friction loss, high transmission efficiency

because there are many balls rolling between the screw shaft and the screw nut of the ball screw pair, high movement efficiency can be obtained. Compared with the past sliding screw pair, the driving torque is less than 1 / 3, that is, the power required to achieve the same movement result is 1 / 3 of using the sliding screw pair. It's very helpful in saving electricity

The ball screw pair is generally proced with the world's highest level of mechanical equipment, especially in the grinding, assembly and inspection of the factory environment, the temperature and humidity are strictly controlled, and the accuracy is fully guaranteed e to the perfect quality management system

High speed feed and micro feed may be

e to the use of ball motion, the starting torque of ball screw pair is very small, and the creeping phenomenon like sliding motion will not appear, which can ensure the accurate micro feed

7. It can be used in the situation where the speed is not high, but the precision is high.

8. Thrust is measured, it is related to screw rod, threaded hole, guide groove and so on. We should use the thrust to calculate the parameters of the motor, not know the motor parameters to calculate the thrust

9. The main reference parameters are stepping motor output torque, screw pitch. Friction coefficient (T-type screw friction coefficient is larger, ball screw friction coefficient is smaller)
example: take 86 stepper motor, static torque 6nm as an example,
calculation formula of axial force (thrust) of linear stepper motor: torque = axial force (thrust) x lead / 2 π N (n is efficiency)
for example: the static torque of linear motor is 1nm, the lead of linear motor is 8mm, the efficiency of motor is 80%, and the calculated thrust is 1 = fx0.008/2 π X80% F = 628n
converted to the weight that can push the goods: weight = 628 / GXF (F is the friction coefficient) ≈ 30kg, that is, the thrust of 1nm linear stepper motor is 628n, which can drive about 30-40kg goods
therefore, the thrust of 86 stepper motor 6nm is about 180 ~ 240kg