蜗轮剃齿刀是高精度蜗轮的最后精加工刀具。蜗轮剃齿刀一般可使蜗轮加工精度提高一级。
蜗轮剃齿刀是在蜗杆的两侧螺旋面作出许多容屑槽。其前刀面通过剃齿刀轴线的为阿基米德蜗杆剃齿刀,前刃面在螺纹法向截面上的为法向直廓蜗杆剃齿刀。
蜗轮剃齿刀容屑槽分为通槽式和闭槽式两种,前者齿数较少,制造容易,后者齿数多,适于高精度蜗轮加工,一般蜗轮剃齿刀与工作蜗杆是在同一蜗杆磨床上磨削侧螺纹面。
蜗轮剃齿刀的刀齿后面是一条后角为零度的刃带,当加工铸铁蜗轮时,刃带宽度为0.35~0.4mm;加工铜蜗轮时,刃带宽度为0.15~0.2mm。
蜗轮剃齿刀的齿顶不参加工作,一般比工作蜗杆的齿顶高增大0.1mx(mx为蜗杆槽数)(见图5-68)。
蜗轮剃齿刀的制造精度,可按表3-140高精度蜗轮滚刀的制造公差选取。
表3-140 普通蜗轮滚刀的制造公差
序号 |
项目 |
精度等级 |
模数mm |
>0.5~1 |
>1~2.25 |
>2.25~4 |
>4~6 |
>6~8 |
>8~10 |
1 |
孔径偏差 |
AA、A |
H5(GB1801—79) |
B、C |
H5(GB1801—79) |
2 |
轴台径向圆跳动或带柄滚刀支承部分的径向圆跳动 |
AA |
8 |
10 |
10 |
10 |
10 |
15 |
A |
12 |
20 |
20 |
20 |
20 |
20 |
B |
15 |
20 |
20 |
20 |
20 |
20 |
C |
20 |
30 |
30 |
30 |
30 |
30 |
3 |
轴台端面圆跳动或带柄滚刀支承端面的圆端面 |
AA |
5 |
8 |
8 |
8 |
10 |
10 |
A |
8 |
10 |
10 |
20 |
20 |
20 |
B |
12 |
20 |
20 |
20 |
20 |
20 |
C |
15 |
20 |
20 |
25 |
25 |
25 |
4 |
最大齿距偏差 |
AA |
±5 |
±8 |
±8 |
±10 |
±12 |
±12 |
A |
±8 |
±10 |
±10 |
±15 |
±15 |
±25 |
B |
±12 |
±15 |
±15 |
±25 |
±25 |
±35 |
C |
±20 |
±25 |
±40 |
±40 |
±40 |
±40 |
5 |
多头蜗轮滚刀的相邻齿距差 |
AA |
8 |
12 |
12 |
15 |
18 |
18 |
A |
12 |
15 |
15 |
25 |
25 |
40 |
B |
18 |
25 |
25 |
40 |
40 |
50 |
C |
30 |
40 |
60 |
60 |
60 |
60 |
6 |
任意三个齿距长度内最大的齿距累积误差 |
AA |
±8 |
±12 |
±12 |
±15 |
±18 |
±18 |
A |
±12 |
±15 |
±15 |
±25 |
±25 |
±40 |
B |
±18 |
±25 |
±25 |
±40 |
±40 |
±50 |
C |
±30 |
±40 |
±60 |
±60 |
±60 |
±60 |
7 |
齿形误差 |
AA |
5 |
8 |
10 |
12 |
15 |
20 |
A |
8 |
12 |
15 |
18 |
25 |
30 |
B |
12 |
18 |
25 |
30 |
35 |
40 |
C |
20 |
30 |
50 |
70 |
70 |
70 |
8 |
刀齿前刀面的径向性 |
AA |
20 |
30 |
40 |
50 |
60 |
80 |
A |
25 |
40 |
50 |
70 |
90 |
120 |
B |
35 |
60 |
80 |
110 |
140 |
170 |
C |
50 |
90 |
120 |
150 |
200 |
250 |
9 |
到齿前端面与内孔轴线的平行度(直槽滚刀) |
AA |
16 |
30 |
40 |
40 |
50 |
65 |
A |
20 |
35 |
45 |
50 |
60 |
70 |
B |
25 |
45 |
55 |
65 |
80 |
90 |
C |
30 |
45 |
55 |
65 |
80 |
90 |
10 |
容屑槽周节的最大累积误差 |
AA |
25 |
35 |
40 |
50 |
50 |
60 |
A |
25 |
35 |
40 |
50 |
50 |
60 |
B |
30 |
35 |
40 |
50 |
60 |
70 |
C |
30 |
35 |
40 |
50 |
60 |
70 |
11 |
刀齿的径向圆跳动(直槽滚刀) |
AA |
20 |
20 |
20 |
30 |
40 |
40 |
A |
25 |
30 |
30 |
40 |
40 |
50 |
B |
30 |
40 |
50 |
60 |
60 |
80 |
C |
40 |
50 |
70 |
70 |
70 |
90 |
12 |
刀齿的径向圆跳动(螺旋槽滚刀) |
单头 |
AA |
20 |
20 |
20 |
30 |
40 |
40 |
A |
25 |
30 |
30 |
40 |
40 |
50 |
B |
30 |
40 |
50 |
60 |
60 |
80 |
C |
40 |
50 |
70 |
70 |
70 |
90 |
多头 |
AA |
30 |
30 |
30 |
45 |
60 |
60 |
A |
35 |
45 |
45 |
60 |
60 |
70 |
B |
40 |
60 |
70 |
80 |
80 |
100 |
C |
50 |
70 |
90 |
90 |
90 |
110 |
13 |
外径锥度(直槽滚刀) |
AA |
20 |
30 |
30 |
40 |
40 |
50 |
A |
20 |
30 |
30 |
40 |
40 |
50 |
B |
30 |
40 |
40 |
45 |
45 |
50 |
C |
40 |
80 |
80 |
120 |
120 |
120 |
14 |
外径锥度(螺旋槽滚刀) |
单头 |
AA |
25 |
40 |
40 |
50 |
50 |
60 |
A |
30 |
40 |
40 |
50 |
50 |
60 |
B |
40 |
50 |
50 |
55 |
55 |
60 |
C |
50 |
90 |
90 |
130 |
130 |
130 |
多头 |
AA |
30 |
50 |
50 |
60 |
60 |
70 |
A |
40 |
50 |
50 |
60 |
60 |
70 |
B |
50 |
60 |
60 |
65 |
65 |
70 |
C |
60 |
100 |
100 |
140 |
140 |
140 |
15 |
齿厚偏差 |
AA |
±12 |
±20 |
±25 |
±30 |
±40 |
±50 |
A |
±12 |
±20 |
±25 |
±30 |
±40 |
±50 |
B |
±12 |
±20 |
±25 |
±30 |
±40 |
±50 |
C |
±20 |
±30 |
±40 |
±50 |
±60 |
±70 |
16 |
外径偏差 |
AA |
+0.15m①
-0.10m |
+0.25m
-0.15m |
+0.3m
-0.2m |
A |
B |
C |
±0.15m |
±0.3m |
±0.5m |
17 |
容屑槽的导程误差(螺旋槽滚刀) |
|
容屑槽螺旋角βk |
βk≤10° |
βk>10° |
AA |
1.5%Pk |
1%Pk |
A |
2%Pk |
1.5%Pk |
B |
2.5%Pk |
2%Pk |
C |
3%Pk |
2.5%Pk |