Basic requirements for the guide rail

In theory, we should first select the lead screw to choose the motor. Now that the motor has been finished, we choose the screws according to the following steps.

1, determine the diameter with the load. The motor performance parameters have the output torque, if the speed reducer is also included (considering the efficiency), how much thrust is needed in the actual working condition, and the ball screw sample (with the manufacturer) has the load parameters (i.e. the thrust parameter, generally marked as the dynamic load and static load, the former can), and the ball screw is selected. Nominal diameter.

2, determine the lead of ball screw with linear speed and rotation speed. The motor is determined to know the output speed, and consider the maximum linear speed you need. The speed of the motor (if the reducer is then divided by the reduction ratio) is multiplied by the lead of the screw, which is a straight line speed, which is greater than the required value.

3, determine the length of ball screw (total length = working stroke + nut length + safety margin + installation length + connection length + allowance) according to actual needs. If additional protection is required, such as sheath, it is necessary to consider the expansion ratio of the sheath (usually 1:8, i.e. the maximum elongation of the sheath is divided by 8).

4, the precision of ball screw is determined according to the actual needs. The general machinery can be selected below C7. There are more C5 in the numerical control machine class (corresponding to the domestic standard generally P5~P4 and P4~P3 level, specifically refer to the sample).

5, determine the ball screw nut form with the installation conditions and size structure (the nut has many structures, the different nut structure and size are slightly different, depending on the choice of the situation, it is recommended not to choose too special, in case of a point defect maintenance without door).

6, ask the price, payment terms and delivery time of the selected products manufacturer. This designer does not think that it is the purchase of the matter, in fact, many manufacturers (imported domestic sample) on the sample of some of the model it does not produce or do not accept small orders, it is printed to show that I am a big factory, do not build. Do not wait for you to finish the drawing out of the other pieces of parts to start doing accessories to buy, people told you that the model delivery time needs 3, 4 months will be finished.

7, select the installation method (end). This installer can be designed by itself, or can be purchased readily available, with standard mounting seats optional. Self design pays attention to the force state, bearing preferably chooses 7000 or 3000 series, because the screw is mainly subjected to axial force when working, and the radial force should be avoided.

8, consider the guidance and installation capacity. The guide parts of the ball screw and the ball screw are chosen to choose the ball linear guide. Of course, the collocation of the linear and linear bearings is the choice of relative economy. 9, according to the above determined conditions, draw the ball screw drawings (mainly the end mounting dimensions, which need to be detailed, and provide geometric dimensions and tolerances).