During the working process, the large gear of the main drive spiral bevel gear pair of the rotary crusher is
eccentrically rotated around a fixed axis, causing the relative position between the large and small gears to change at any time during the working process. In order to determine the basic geometric parameters of the gear pair and the machine adjustment parameters of the gear cutting, the working position of the gear pair is set to 8 cases. The corresponding V-Hvariation is calculated（V represents the direction perpendicular to the axis of the wheel, and H represents the direction of the axis of the small wheel）. According to the V-H variation of 8 cases, the special software of bevel gear design analysis is used to determine the backlash value of the gear pair. By modifying the first-order and second-order shaping parameters of the tooth surface, combined with the results of tooth surface contact analysis and tooth surface loading contact analysis, the reasonable adjustment parameters of the gear machining machine are determined. The gear pair processed based on the design calculation results have been applied to the domestic gyratory crusher, which fully meets the needs of actual engineering.
The gyratory crusher is a large-scale crushing machine that uses the gyratory motion of the crushing cone in the inner cone cavity of the shell to squeeze, split and bend the material, thereby crushing ores or rocks of different hardness (as shown in the figure above). The upper end of the main shaft equipped with the crushing cone is supported in the bushing in the middle of the beam, and the lower end is placed in the eccentric hole of the eccentric bushing. The large wheel of the main drive spiral bevel gear pair is installed on the eccentric shaft sleeve. Therefore, when the small wheel of the spiral bevel gear pair drives the large wheel and drives the shaft sleeve to rotate, the crushing cone makes eccentric gyratory movement around the center line of the machine, and its broken The action is carried out continuously, so the working efficiency is higher than that of the jaw crusher.
Since the crushing cone makes eccentric gyratory motion around the center line of the machine, during the working process of the gyratory crusher, the axis of the large wheel of the spiral bevel gear pair fixed with the eccentric shaft sleeve also makes eccentric gyration motion around the center line of the machine, which This causes the relative positions of the large and small wheels of the gear pair to change at any time during the working process. In order to ensure the normal operation of the spiral bevel gear pair, it is necessary to ensure
It must have a reasonable backlash in different working positions to avoid jamming the tooth surface. In addition, it should also be ensured that at different working positions, the meshing contact areas of the tooth surfaces are all located in the tooth surfaces, and no edge contact can be generated to avoid the gear teeth from being broken under load.
How to determine the basic parameters and backlash of a spiral bevel gear set
Taking a gyratory crusher produced by a mining equipment manufacturer as an example, the basic parameters of the central spiral bevel gear pair are: the number of teeth on the small gear 16, the number of teeth on the large gear 49, the modulus of the big end face is 17 mm, and the axis angle is 90°. The pressure angle is 20°, the midpoint helix angle is 30°, the tooth surface width of the large wheel is 125 mm, the rotation of the small wheel is left-handed, the transmission power of the gear pair is 220 kW, and the input speed of the small wheel is 490 r/min. During the working process, the axis of the big rotation makes an eccentric rotary motion around the center line of the machine, and its eccentricity is 0.65 mm.
According to the bevel gear design standard, the minimum average backlash value of the big end is 0.69 mm for this spiral bevel gear pair. Since the giant wheel of the gear pair performs eccentric rotation during the working process, the relative position between the large and small wheels of the gear pair is constantly changing. Changes in relative position also cause changes in backlash. To ensure the gear pair has proper backlash when meshing at different places, the working positions of the gear pair are divided into 8 situations as shown in image B. The position of “0” in the above image indicates that the axis of the large wheel is at the theoretical installation position, and the positions represented by numbers 1 to 8 respectively represent the different positions where the actual axis of the significant rotation rotates eccentrically around the center line of the machine.
When the axis of the bevel gear is in 8 different positions, represented by 1~8 in picture B, the position between the gear pairs deviates from the theoretical installation position. Use V and H to describe the deviation of the relative position. Picture C shows that H represents the positional deviation of the pinion gear close to the bevel gear along its axis. It is a positive value away from the axis of the bevel gear; V represents the pinion gear along the axis perpendicular to its axis. The direction’s deviation is relative to the position of the bevel gear.
According to the position determined in picture B and the position deviation defined in picture C, using the special software KIMoS for bevel gear design and analysis, through repeated trial and calculation and considering a certain safety margin, the gear pair is placed on the side of the theoretical installation position. If the gap value is set to 1.05 mm, the V, H, and side gap values corresponding to the 8 parts can be calculated, as shown in Table 1.
| Location | V/mm | H/mm | Normal backlash |
| 1 | 0 | -0.65 | 0.853 |
| 2 | -0.46 | -0.46 | 0.842 |
| 3 | -0.65 | 0 | 0.980 |
| 4 | -0.46 | 0.46 | 1.135 |
| 5 | 0 | 0.65 | 1.152 |
| 6 | 0.46 | 0.46 | 1.050 |
| 7 | 0.65 | 0 | 0.978 |
| 8 | 0.46 | -0.46 | 0.927 |
It can be seen from Table 1 that when the axis of the significant wheel moves to 8 different positions, the backlash value of the gear pair is all greater than 0.69 mm, so the backlash requirements for the regular operation of the gear pair are met.
How to adjust the parameters of the bevel gear production machine
For the traditional spiral bevel gear pair, when determining the adjustment parameters of the gear processing machine is only necessary to ensure that the gear pair has a suitable contact area at the
theoretical installation position. However, for the spiral bevel gear pair of the gyratory crusher, since the relative position between the bevel gear & pinion gear changes all the time during the working process when determining the adjustment parameters of the gear processing machine, it is necessary to
ensure that the gear pair meshes at different positions. The contact area should be located on the tooth surface, not on the edge of the tooth surface or overflowing the tooth surface.
| Item | Parameter Values |
| tool cutting-edge inclination(°） | 0 |
| swivel angle(°） | 0 |
| horizontal gear position allowance （mm） | 0 |
| main aspects scroll position (°） | 43.1738 |
| center scroll position (°） | 57.3257 |
| small end scroll position (°） | 70.5496 |
| radio of roll | 1.051034 |
| machine position | 0 |
| first-order spiral motion coefficient (mm.rad-1) | 0 |
| machine root angle (°） | 69.5114 |
| radial (mm) | 365.8539 |
| workhead offset (mm) | 0 |
For the spiral bevel gear pair of the gyratory crusher, to determine the reasonable adjustment parameters of the gear cutting machine tool, the tooth surface modification function, and the tooth surface contact
analysis and tooth surface loading contact analysis functions of the KIMoS software are fully utilized. By modifying the first-order and second-order modification parameters of the tooth surface, the modification amount of the pinion tooth surface can be changed, including the modification amount of the pressure angle, the modification amount of the helix angle, the modification amount of the tooth length curvature, and the modification amount of the tooth height curvature. Then, through the tooth surface contact analysis function module and the tooth surface loading contact analysis function module, the size, direction, and position of the meshing contact area of the gear pair at different working places were observed. When the contact areas of other working parts meet the design requirements, the corresponding adjustment parameters of the gear-cutting machine can be output.
Picture D is the meshing contact area of the tooth surface between the concave surface of the small wheel and the convex surface of the large wheel at different working positions obtained after several corrections and adjustments. Picture E is the tooth surface loading meshing contact area of the small wheel’s concave surface and the large wheel’s convex surface at different working positions when the gear pair is fully loaded. It can be seen from pictures D and E that no matter whether it is a light load or full load, the meshing contact area of the tooth surface is located in the tooth surface, and there is no edge contact. Tables 2 and 3 are the machine tool adjustment parameters calculated by the software for cutting/grinding large and small wheels, respectively.
| Item | convexity | concave |
| tool cutting-edge inclination (°） | 0 | 0 |
| swivel angle(°） | 0 | 0 |
| horizontal gear position allowance （mm） | -8.8828 | 5.1404 |
| main aspects scroll position (°） | 44.3687 | 47.1233 |
| center scroll position (°） | 57.3778 | 57.0879 |
| small end scroll position (°） | 68.2155 | 68.3026 |
| radio of roll | 3.149442 | 3.343870 |
| machine position | 2.2465 | -1.6214 |
| first-order spiral motion coefficient (mm.rad-1) | -4.965134 | 19.314835 |
| machine root angle (°） | 15.6783 | 15.6783 |
| radial (mm) | 353.3600 | 376.3734 |
| workhead offset (mm) | 0.2368 | 0.3119 |
Gear cutting
Based on the above software design and calculation results, Chamol has carried out the actual gear cutting of the bevel gear &pinion gear on the H2000C CNC spiral bevel gear milling machine and the thermal post-grinding of the bevel gear &pinion gear on the H2000G CNC spiral bevel gear grinding machine Tooth finishing. The contact area inspection was carried out on the H2000T CNC spiral bevel gear inspection machine. As shown in Figure 6, the gear pair’s actual contact area is consistent with the software analysis results, which meets the requirements of the gyratory crusher manufacturer. The gear pair has been put into practical application.
