Mitsubishi Electronics MDS-D-SVJ3 ユーザーズマニュアル

7 - 13

In the machine which carries out the spindle’s acceleration/deceleration frequently (example: tapping 

center), short-time rating is frequently used, and a rise in temperature become significant on the spindle 

motor or drive unit. Thus, calculate the average output (P

AV

) from one cycle operation pattern and confirm 

that the calculated value is less than the continuous rating output of the selected spindle motor.

Continuous operation pattern (example)

  

  

P1 to P8

:Output

t1 to t8

:Time

t0

:One cycle operation time

1. Calculate acceleration/deceleration time by the accurate load inertia because even if the rotation 

speed is the same, acceleration/deceleration time varies with a tool or workpiece mounted to the 

spindle.

Refer to the section "Adjusting the acceleration/deceleration operation" (1) in Instruction Manual.

2. Calculation method of synchronous tapping 

The acceleration/deceleration number of times is twice, for forward run and reverse run are carried 

out in one machining. The output guideline is 50% of the short-time rating. The time is tapping time 

constant.

3. Calculation method of spindle synchronization

The output guideline is 70% of the short-time rating. The time is spindle synchronization time 

constant.

 

0

 

0

 

P3 

P2 

t1  t2  t3  t4  

t0  

P1 

P4 

P5 

P6 

P7 

P8 

t5  t6  t7  t8  

[1] 

[2] 

[3] 

[4] 

[5] 

[6] 

[7] 

[8] 

Motor
torque

Motor

speed

Time

Output during 
acceleration/deceleration(kw)
＝Short-time rating ×1.2

Accelera-
tion

Accelera-
tion

Decelera-
tion

Decelera-
tion

Cutting

Cutting

Stop

Stop

P

AV

 =

P1

2

·

t

1+P2

2

·

t2

+P3

2

·

t3

+P4

2

·

t4

+P5

2

·

t5

+P6

2

·

t6

+P7

2

·

t7

+P8

2

·

t8

t0

≧

Continuous rated output        One cycle operation pattern average output (P

AV

)