Classification and differences of splines

Classification and differences of splines
Due to its advantages such as large contact area, high load-bearing capacity, good centering and guiding performance, shallow keyway, low stress concentration, minimal weakening of shaft and shaft strength, and compact structure, spline connection transmission is often used in static and dynamic connections that require high torque transmission and centering accuracy.
Types, characteristics, and applications of splines
According to the shape of the spline teeth, they can be divided into two categories: angular splines and involute splines. In angular splines, they can be divided into rectangular splines and triangular splines. From current applications, involute splines are the most common, followed by rectangular splines, and triangular splines are mostly used in loading and unloading tools.
1.1 Rectangular Spline
Easy to process, high precision can be achieved through grinding methods, but internal splines usually require a spline puller, which cannot be processed for splines without holes, and can only be machined using slotting, resulting in lower precision. At present, the relevant standards in China, Japan, and Germany are as follows: China GB1144-87: Japan JIS B1601-85: Germany SN742 (German SMS factory standard): American WEAN company's six slot rectangular spline standard.
1.2 Open line spline
The tooth profile is involute, and when loaded, there is a radial force on the teeth, which can play an automatic centering role, making each tooth evenly loaded, with high strength and long service life. The processing technology is the same as that of gears, and the cutting tools are relatively economical, easy to achieve high precision and interchangeability. Used for connections with large loads, high requirements for centering accuracy, and large dimensions. Widely used, the main standards at home and abroad are as follows: China GB/T3478.11999 (replacing GB3478.1-83), equivalent to ISO4156-1981: Japanese JIS B1602-1992, JIS D2001-1977: German DIN5480, DIN5482: American ANSIB92.1a.
1.3 Triangle spline
The internal spline tooth shape is triangular, and the external spline tooth profile is an involute with a pressure angle of 45 °. It is easy to process, with small and numerous teeth, making it convenient for adjusting and assembling the mechanism. For shafts and shafts, the weakening is minimized. Mostly used for static connections with light loads and small diameters, especially suitable for connecting shafts with thin-walled parts. The main standards are: Japanese TIS B1602-1991: German DIN5481
2 Chinese and major industrialized countries' spline standards
The rectangular spline standards currently issued in our country are similar to those in Japan and identical to those in Germany, but differ greatly from the British rectangular spline in the United States. When introducing equipment, we should be cautious about how to choose the appropriate fit and centering, clarify the original standards and requirements, and avoid unnecessary economic losses. The comparison of rectangular spline standards in various countries is shown in Table 1.
3. Open line spline standards between China and major industrialized countries
At present, most of the involute splines abroad are different from the standards in China. Even within the same country, the standards for involute splines are not the same. There are two types of involute splines in Germany, DIN5480 and DIN5482. There are JIS B1602 and JIS D2001 in Japan. There are two types of pressure angles in China: a=37.5 ° and a=45 °. Some countries use modular systems and a=30 ° pitch system, while others use dual-mode numerical systems or dual diameter control. The main technical parameters of involute spline standards in various countries are listed in Table 2.