1、 Structure and Characteristics

● Structure

The "Yigongpai" roller cross guide pair is composed of two guide rails with V-shaped raceways, roller cages, cylindrical rollers, etc. The cylindrical rollers arranged in a cross pattern move back and forth on the precision ground V-shaped raceway surface, which can withstand loads in all directions and achieve high-precision and smooth linear motion.

　● Characteristics

Low rolling friction resistance and good stability performance;

◆ Low starting friction and good follow-up performance;

Large contact area, small elastic deformation, multiple effective moving bodies, easy to achieve high rigidity and high load movement;

The structural design is flexible and easy to install and use.

2、 Rated service life of roller cross guide pair

　　Calculation of rated lifespan

In the formula: L - rated life f_t-Temperature coefficient f_w-Load factor C - rated dynamic load P_c-Calculate load

Temperature coefficient f_tWhen the working temperature is ≤ 100 ° C, f_t=1

Load factor f_w

● Calculation of lifespan time

In the formula: L_h-Life time L - rated life l - stroke length (unit: meter) n - number of reciprocating times per minute

　3、 Load calculation

● Travel length and number of rollers

◆ Calculation of guide rail length

The length of the guide rail shall not be less than 1.5 times the stroke: L ≥ 1.5l

In the formula: L - rail length (mm); I - Running stroke length (mm)

◆ Holder length: K ≤ L-1/2

In the formula: K-holder length (mm);

Roller count calculation: N=(K-2a)/f+1

In the formula: N-number of rollers (ignoring decimals); A - Maintain the end distance of the bracket; F-roller spacing

● Load calculation

In the table: C-rated dynamic load (N) C₀-Rated static load (N) C₁-Rated dynamic load of each roller (N)

C₀₁-Rated static load of each roller (N) N - number of rollers N/2- number of rollers (ignoring decimals)

4、 Selection of Accuracy

5、 Numbering rules and size series

● Rules for numbering roller cross guide pairs

Note: Two guide rails form a set of guide rail pairs, and the number of guide rail pairs used in the same plane refers to how many sets of guide rail pairs are used simultaneously in the same plane. In the above formula, II refers to two sets of guide rail pairs in the same plane, that is, four guide rails are used simultaneously.

● Size series

Basic dimensions of roller cross guide pair

6、 Precautions for use

● Accuracy of paired installation surfaces

The structures of the mating installation surfaces of the roller cross guide pair are shown in Figure 5:

The accuracy of the mating installation surface directly affects the operational precision and performance of the roller cross guide pair. To achieve high operational accuracy, it is necessary to correspondingly improve the accuracy of the paired installation surface.

A-side: Its accuracy directly affects the operational accuracy.

B and C surfaces: Flatness: directly affects preload.

Verticality: The verticality relative to surface A affects the stiffness of assembly in the preload direction.

Therefore, it is recommended to improve the accuracy of the installation surface as much as possible, and its accuracy value should be approximately equal to the parallelism value of the guide rail.

● Preloading method

As shown in Figure-6, the preload is usually adjusted using preload adjustment screws. The size specification of this screw is the same as the installation screw of the guide rail. The center of the screw is half the height of the guide rail.

The value of preloading varies depending on the machine tool and equipment. Overloading will reduce the lifespan of the guide rail pair and damage the raceway, and during use, the cylindrical rollers are prone to tilting, resulting in self-locking phenomenon. Therefore, it is usually recommended to have no preload or a smaller preload. If high precision and stiffness are required, it is recommended to use an assembly plate as shown in Figure-7 or a wedge block as shown in Figure-8 for pre tightening.

Roller cross guide pairs can operate at high temperatures, but it is recommended to use temperatures not exceeding 100 ° C.

7、 Lubrication

The main purpose of lubrication is to reduce friction and wear to prevent overheating, damage to its internal structure, and affect the motion function of the guide rail pair. When the operating speed of the roller cross guide pair is high (V ≥ 15m/min), it is recommended to use lubricating oil for regular lubrication or forced lubrication through oil pipes. At low speeds (V<15m/min), it is recommended to use bearing specific lubricating grease for lubrication, but ordinary butter containing large solid lubricating particles (such as graphite and molybdenum disulfide) should not be used.