|d2||d3||h1 ±0.012||h2 ±0.012||h3 ±0.012||h4||Load rating C|
|15||0.62||0.94 ±0.003||1.22||0.83||0.37||0.20||0.11||112 lbf (500 N)||15.74 lbf (70 N)||67.44 lbf (300 N)||67.44 lbf (300 N)|
|22||0.87||1.42 ±0.003||1.77||1.16||0.39||0.24||0.11||270 lbf (1200 N)||22.48 lbf (100 N)||202 lbf (900 N)||202 lbf (900 N)|
|30*||1.19||1.77 ±0.004||2.17||1.49||0.54||0.28||0.15||450 lbf (2000 N)||33.72 lbf (150 N)||337 lbf (1500 N)||-|
When determining the size of the ball transfer units, it is necessary to consider not only the weight but also the size and nature of the base area of the load.
The maximum distance between the ball transfer units „a2“ (assuming a flat base area) is calculated by dividing the shortest edge length of the load by 2.5. This ensures that the load always rests on the ball transfer units, preventing it from tipping over into the spaces between them.
The required load capacity of the ball transfer units is calculated by dividing the weight of the load by 3. This results from the assumption that, due to tolerances of the load base area and the ball transfer units, only three ball transfer units are normally used.
a1 = Shortest edge length of the load
a2 = Max. distance between ball transfer units
a2 = a1/2.5
F1 = Load weight
F2 = Load per ball transfer unit
F2 = F1/3
The permissible conveying speed is up to 2 m / sec. With larger ball transfer units at speeds exceeding 1 m / sec., depending on the load weight, an increase in temperature must be expected.
The friction values of the ball transfer units are about 0.005 µ at a speed of 1 m / sec. However, this value is subject to large variations depending on the operating conditions.
Compared to ball transfer units with steel sheet housing (GN 509), those with solid steel housing (GN 509.1) have a higher rigidity. In this case, the static values of steel balls can be applied.
Lubrication is recommended as protection against corrosion. The general rolling bearing regulations can be applied. In most applications, lubrication can be dispensed with.
Ball transfer units from size 36 upwards are fitted with a felt seal as protection against ingress of dust and dirt. With this version, the max. operating temperature is 212 °F (100 °C) for balls made of steel.
Ball transfer units without felt seal can also be used at higher temperatures. However, this will lead to a reduced load rating (C). The following guide values apply:
257 °F (125 °C) ./. 10 %
The max. operating temperature for ball transfer units with plastic ball is 140 °F (60 °C).