Hello, the basic dynamic rated load is used to calculate the life of linear guide rail when it is rolling with load. Its definition is the maximum load when the rated life of linear guide rail is 50km under the condition that the load direction and magnitude are unchanged.
How to calculate the selection of guide rail
1- Determines the track width.
Track width refers to the width of the slide rail. Rail width is one of the key factors to determine its load. Generally, the square track products of four volleyballs (there are also two volleyballs) are 15, 20, 25(23), 30(28), 35(34), 45, 55(53) and 65(63), and some brands only produce to the maximum. There are also 85, 120 futures products, but most manufacturers do not produce them.
2- Determine the track length.
This length is the total length of the track, not the stroke. Total length = effective stroke+slider spacing (more than 2)+slider length × number of sliders+safe stroke at both ends. If protective sleeves are added, it is necessary to increase the compression length of protective sleeves at both ends. It should be noted that ask the maximum length of the whole guide rail of this brand in advance, if it exceeds this length, it needs to be docked. Most manufacturers have a maximum length of 4000 (micro-track is generally 1000), and some have a length of 3000, which is related to the processing equipment of the manufacturers. Need docking, users want to process the installation holes on the machine in advance, it is best to provide interface drawings. Another point, please pay special attention to, the spacing of mounting holes on the guide rail is fixed, and users should pay attention to the position when determining the length of the guide rail. For example, the guide rail of 15 is 600 long. If you don't tell the supplier the required end size, the general arrival status is 10 installation hole, and the distance between the two ends of the guide rail and the center of the nearest installation hole is 30 or 30, but it may be other sizes. Different brands have slightly different delivery regulations for the end size, and most of them are equal at both ends by default. One more thing, the error of guide rail length is generally below 2000 1 ~ 2mm by default, and below 2000~4000, it is 2 ~ 3mm. If users require higher accuracy, it is best to indicate the error value or provide drawings in the order contract. In this case, the supplier may charge additional processing fees.
3- Determine the type and number of sliders.
There are two kinds of commonly used sliders: flange and square. The former is lower in height but wider, and the mounting hole is a threaded hole, while the latter is higher and narrower, and the mounting hole is a threaded blind hole. Both of them are divided into short type, standard type and extended type (some brands also call them medium load, heavy load and super heavy load). The main difference is that the length of the slider body (metal part) is different, of course, the hole spacing of the mounting holes may also be different. Most short sliders have only two mounting holes. The number of sliders is determined by the user through calculation, and only one is recommended here: small enough to carry and large enough to install. The type and number of sliders and the width of the slide rail constitute three elements of the load size.
How to calculate the basic rated static load of lead screw?
Basic rated static load When the guide rail system is subjected to a large load or impact in static or low-speed operation, the track groove and steel ball will be permanently deformed. Assuming that this variable parameter reaches a certain level, the guide rail will not run smoothly. The basic rated static load (C0) is the static load when the total permanent deformation caused by the static load acting on the track groove and the steel ball reaches one ten thousandth of the diameter of the steel ball.
How to calculate how much torque the two sliders for linear guide rail can bear?
It depends on the load of the linear guide rail itself. Each train has a static load and a dynamic load.
How to get the rated static load and rated static torque in the linear guide data, thank you! 10 point
There is no uniform standard for this thing. Manufacturers have their own calculation formulas. The size of this data cannot be used as the only criterion for the quality of the guide rail.
Generally speaking, the rated static load is used to calculate the safety factor. Dynamic load is used to calculate life.
What is the bearing capacity of the lead screw and guide rail? 10 point
Specification of ball guide: rgh65har 15980zahrg: roller linear guide; H: square slider; 65: size series; H: overweight load; A: the locking slide block fixing mode; 8: The number of sliders assembled by a single guide rail; R: locking guide rail fixing mode; 15980: the length of the guide rail is15980mm; ZA: preloading method; H: accuracy grade.
What do you mean by heavy-duty guide rail?
At present, the Industry 4.0 standard has been issued, and the standards of domestic production lines have been improved. Many robots and automatic shelves need more heavy slide rails. Heavy-duty slide rail is a drawer slide rail with high load-bearing requirements, which is generally used for industrial drawers and RV drawer slide rails. At present, there are many heavy-duty slide rails for 76 and 53 RV in China, which can carry 220kg for 76 guide rail and 0/60 kg for 53 guide rail. It is said that there will be fewer and fewer companies in the factory in the future, and there will be more demand for heavy guide rails.
How to choose the rail width of square guide rail is best calculated by examples.
Please refer to the guide rail selection manual of the selected brand for details.
Choose the track width? First of all, it depends on whether your own installation platform is limited, and then refer to the rated dynamic load of the brand guide rail to see if your load is less than 20% of the rated dynamic load.
Taishunfeng Technology Co., Ltd. is an authorized agent of linear sports products.
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How to calculate the selection of lead screw?
1- Determine the diameter by load. There is output torque in the performance parameters of the motor, and if the reducer is also included, it should be included (considering efficiency). Calculate how much thrust is needed in the actual working condition, and the ball screw sample (provided by the manufacturer) has load parameters (that is, thrust parameters, which are generally marked as dynamic load and static load, only the former), and select the nominal diameter of the ball screw.
2- Determine the lead of ball screw with linear speed and rotational speed. When the motor is determined, the output speed will be known. Consider the maximum linear speed you need. Multiplying the motor speed (if there is a reducer, divided by the reduction ratio) by the lead value of the lead screw is the linear speed, which is greater than the required value.
3- Determine the length of the ball screw according to actual needs (total length = working stroke+nut length+safety margin+installation length+connection length+margin). If protection is added, such as sheath, the expansion ratio of sheath (generally 1: 8, that is, the maximum elongation of sheath divided by 8) needs to be considered.
4- Determine the accuracy of the ball screw according to actual needs. General machinery can be selected below C7, and CNC machine tools can be selected above C5 (domestic corresponding standards are generally P5~P4 and P4~P3, see samples for details).
5- Determine the nut form of the ball screw according to the installation conditions and size structure (nuts have many structures, and the sizes of different nuts are slightly different, so it is recommended not to choose too special ones, and there is no way to repair and replace them in case of problems).
6- Ask the price, payment terms and delivery time of the selected product manufacturer. Designers should not think that this is a procurement problem. In fact, many manufacturers (both imported and domestic) do not produce or accept small orders at all. Probably printed to show that I am a big factory and can do everything. Don't wait until you have finished choosing and painting, and other parts will start to make accessories according to this model. You buy it, and people tell you that the delivery time of this model will take 3 or 4 months to die.
7- Select and confirm the installation method (End). This mounting piece can be designed by yourself or bought off-the-shelf, and there are standard mounting seats to choose from. Pay attention to the stress state in your own design. It is best to choose 7000 or 3000 series bearings, because the screw is mainly subjected to axial force when working, and try to avoid radial force.
8- Consider orientation and installation capability. It is recommended to choose the ball linear guide rail as the guide part matching with the ball screw. Of course, the combination of linear shaft and linear bearing is a relatively economical choice.
9- Draw the drawing of the ball screw according to the above conditions (mainly the installation size of the end, which should be detailed, and provide the shape, position, size and tolerance).
DN value: d: the nominal diameter of the ball screw pair, which is also the diameter at the center of the ball (mm);
N: limit speed of ball screw pair (rpm)
DN value is not limited to the smaller the diameter, the higher the rotation speed, because the feed speed is determined first. When the screw rotation speed calculated by the feed speed is too high, the rotation speed can be reduced by increasing the lead to meet the DN value requirements.
Selection of specifications and models of ball screw
1 to determine the positioning accuracy.
2, through the motor and screw speed requirements to determine.
3. Check the nut size to determine the stroke of the screw shaft end and related data.
4. Determine the average axial force and rotational speed by load and velocity distribution (acceleration and deceleration).
5. Determine the pre-pressure by the average axial force.
6, life, axial load, speed to determine the dynamic rated load.
7, basic dynamic rated load, lead, critical speed, DmN value limit to determine the screw diameter and nut form.
8. Stiffness determined by outer diameter, nut, preload and load (machine design)
9, environmental temperature, the total length of the nut to determine the thermal change and lead accumulation.
10, screw stiffness and thermal displacement to determine the pretension.
1 1, the maximum speed of the machine tool, the temperature rise time and the specifications of the lead screw determine the motor driving torque and specifications.
The torque calculation load is 500KG, driven by linear guide rail, ball screw and stepping motor, and the lead of the screw is 6MM, and the torque of stepping motor is calculated.
Ball screw and stepping motor should be selected at the same time. Relative to a certain requirement of load, inertia and acceleration, their parameters * * * are all functional variables of the requirement.
F=2πM/P, the theoretical torque (m) of the motor can be obtained by substituting the load (f) and the lead (p) of the lead screw.
In fact, if it is too much trouble, you can also browse the website of Institute of Technology, where there is an online calculation module, which can calculate the torque and other related parameters according to the design conditions, select typical specifications, do all the verification, and give the applicable specifications and matching motor core parameters for selection.