| 摘要 |
PROBLEM TO BE SOLVED: To reduce pulsation of extrusion velocity.SOLUTION: A gear pump extruder includes a pair of extrusion gears disposed in a casing thereof and the extrusion gear comprises a single helical gear or a double helical gear. When one pitch of the extrusion gear is divided equally into n (n is equal to or larger than 10) pieces of radial-direction planes extending radially from the shaft center j of the extrusion gear and tooth space areas, each of which is an area of a tooth space on each of the cross sections being the radial-direction planes of the extrusion gear, are defined as Si (i=1-n), an area difference &Dgr;S(=Smax-Smin) being a difference between the maximum tooth space area Smax and the minimum tooth space area Smin is equal to 0.5% or smaller than the mean value (&Sgr;Si/n) of the tooth space areas Si. |
