The schematic diagram of two processing technologies of circular arc tooth line cylindrical gear is shown in Fig. 1
Processing technology of parallel connecting rod
The parallel connecting rod processing device of circular arc tooth line cylindrical gear is shown in Fig. 1 (a), and the kinematic relation diagram of its mechanism is shown in Fig. 1 (b).
It can be seen from Figure 1 that the tooth surface machining tool is installed on the driven bar, and the driving rod is driven by the power source to rotate, and the power on the driving bar is transmitted to the driven bar through the frame connecting rod of the parallelogram mechanism; In the whole machining process, the tool rake face remains unchanged, that is to say, the radius of the concave / convex tooth surface of the cylindrical gear with circular arc tooth profile can be ensured to be equal. Theoretically, the gear has the characteristics of equal tooth thickness, equal tooth width and full tooth width contact.
However, this method also has some disadvantages, such as low stiffness, poor dynamic stability, unable to realize high-speed cutting and so on.
Milling technology of rotary cutter head
The schematic diagram of circular arc tooth line cylindrical gear milling with rotating cutter head is shown in Fig. 1 (c). In this device, there are some milling blades on the rotary cutter head; in actual processing, the gear blank rotates at a given speed to do feed motion. By adjusting the speed matching relationship between the rotary cutter head and the gear blank, the generating motion of the tooth surface of the circular arc tooth line cylindrical gear can be realized.
Relevant theoretical studies have shown that:
When the cylindrical gear with circular tooth profile is milled by a rotating cutter head, there is a phenomenon that the width or thickness of the teeth are not equal when measuring at different positions. Drum shaped teeth are formed in the direction of the tooth line, which is not sensitive to the installation error and easy to form dynamic pressure oil film, which has good lubrication performance;
Moreover, the cutting efficiency of this kind of gear processing method is high. By reforming the existing machine tool or designing a special machine tool, the cutting of this kind of gear can be easily realized.