Speed ratio qs
The speed ratio is an important factor to avaluate optimal grinding process parameters. This factor refers to the ratio between the peripheral speeds of grinding wheel and workpiece (control wheel). In centerless grinding the control wheel drives the workpiece, and therefore, the surface sapeeds of control wheel and workpiece are identical. |
Aim for the following values:
| Rough grinding: |
60 to 80 |
| Finish grinding: |
80 to 120 |
| qs < 50: |
danger of chatter marks |
| qs > 120: |
danger of burning |
| Example for setting a speed ratio of |
qs = 70 |
| Given: |
grinding wheel surface speed |
vc = 45 m/s |
|
Control wheel diameter |
dcw = 300 mm |
| Required: |
surface speed of control wheel |
vcw in m/s |
|
rpm of control wheel |
ncw (rpm) |
| vcw = |
vc
qs = 45 m/s / 70 = 0.64 m/s |
|
| ncw = |
(vcw x 1000 x 60) / n x dcw = 40 rpm |
| |
