Experiment of two axis linkage point milling of spiral bevel gear

Based on the theoretical analysis of two-axis linkage gear cutting, computer processing simulation analysis, the principle prototype of gear cutting machine has been developed and the point milling tool has been purchased, the milling experiment of spiral bevel gear can be carried out to verify the feasibility of the new method of two-axis linkage gear cutting.

1. Clamping of gear blank

The fixture of bevel gear blank is designed and developed by Changchun CNC Machine Tool Co., Ltd., the cooperative unit of spiral bevel gear research group. The final processed pinion blank fixture is shown in Figure 1. The clamping engineering drawing of gear blank is shown in Figure 2. Bevel gear blank Φ The radial positioning is realized between the shaft of gear blank 41 and the clamp hole, and the axial positioning is realized between the shaft shoulder of gear blank and the step hole of clamp, and then clamped through the expansion sleeve. In this way, the fixture holding the gear blank can be installed on the working plane of the tilting NC rotary worktable Φ The radial positioning is realized between the shaft and the hole of 30, and the axial positioning is realized between the lower end face of the fixture and the plane of the rotary worktable, and then clamped through the end face flange structure.

1. Locating pin shaft, 2. Copper sleeve I, 3. Copper sleeve II, 4. Expansion sleeve, 5. Clamp seat, 6. Gear blank.

2. Adjustment of initial position

Before cutting the spiral bevel gear, it must be adjusted manually to ensure that the following two requirements are met:

① Ensure that the base cone of the bevel gear blank to be processed is tangent to the horizontal plane; ② The apex of the base cone of the spiral bevel gear to be machined is located on the rotation axis – C axis of the horizontal rotary table.

For the first requirement, the b-axis of the tilting NC rotary table can be manually adjusted so that the included angle between the main shaft of the rotary table and the horizontal plane is the base cone angle of the bevel gear to be processed—— δ b。 Since the angle is only adjusted once for the processing of the same gear, it must be locked after manual adjustment.

For the second requirement, based on the completion of the first requirement, CAD software is used to draw and measure the inclination of gear blank δ In the case of angle B, the right end of the gear blank is away from the rotation axis of the horizontal rotary table – the theoretical value of axis C.

Then install the finger milling cutter on the tool spindle of the actual machine tool, drive the gear blank to move in the x-axis direction by controlling the gear cutting machine tool, make the right end contact the finger milling cutter, and record the value in the x-axis direction at this time. Calculate the difference between the value of the gear blank in the x-axis direction and the theoretical value, and complete the difference by manually adjusting the position of the tilting rotary table on the connecting plate, so as to realize the second requirement. The schematic diagram meeting the above two requirements is shown in Figure 3.

3. Machining experiment of two axis linkage gear cutting

The principle prototype of spiral bevel gear cutting machine tool developed uses Siemens 828d control system, and the NC program of gear cutting is compiled under the environment of sin840d control system, so the NC program can be directly applied to actual gear cutting. The “cutter 1” of the machine tool is not installed, but the “cutter 1” of the machine tool is not installed. On the basis that the gear blank has been installed, the initial position has been adjusted and the NC program has been compiled, the two-axis linkage gear cutting experiment can be carried out.

Firstly, start the spiral bevel gear cutting machine tool and release the emergency stop switch, and then import the NC machining program into Siemens 828d control system and convert it into MPF file that can be recognized by the system. Then, the two axis linkage milling of spiral bevel gear is carried out by executing NC program. The final processed right-hand spiral bevel gear with 15 teeth and 9 modulus is shown in Figure 4.

Scroll to Top