A New Study on the Parameter Relationships of Planetary Roller Screws

Table 1

List of the parameters used in the present study.

Parameter	Symbol	Unit	Value
Effective diameter of screw (right hand)	𝑑𝑠	mm	30
Starts	𝑛𝑠=𝑛𝑛		5
Pitch	p	mm	2
Helix angle	𝛽0	°	6.056
Contact angle	𝛼0	°	45
Effective diameter of roller (right hand)	𝑑𝑟	mm	10
Effective diameter of nut (right hand)	𝑑𝑛	mm	50
External diameter of nut thread	𝐷𝑛	mm	51.2
Tooth number of the roller thread	𝜏		20
Number of rollers	𝑁0		10
Orbital diameter of roller	𝑑𝑚	mm	40
Radius of effective ball	𝑅	mm	7.0711
Rolling coefficient of friction	𝑓𝑔		0.005
Sliding coefficient of friction	𝑓ℎ		0.05
Loss coefficient of energy	𝛾		0.007
Young’s modulus	𝐸𝑠,𝐸𝑛	Pa	210 × 10^9
Poisson’s ratio	𝜇𝑠,𝜇𝑛		0.3