Rotor for kneading, kneading machine, and method for manufacturing rotor for kneading

1. A rotor for kneading comprising:

a tubular rotor shaft that has a pipe accommodating part having a first end portion which has a blocking part, a second end portion which is an opening, and an inner surface;

a blade part that is integrally and spirally formed around the tubular rotor shaft and extends outward from the tubular rotor shaft;

an insertion member that is accommodated inside the pipe accommodating part and that includes a cooling medium inlet which is an opening and a tip opening portion which is located in the pipe accommodating part such that a space is provided between the tip opening portion and the blocking part; and

a filling body that is provided in a recessed part which is formed at a position where the blade part is provided on the inner surface of the pipe accommodating part of the tubular rotor shaft, and that is made from a material having a higher thermal conductivity than a material from which the tubular rotor shaft and the blade part are made,

wherein the filling body includes a cooling medium contact surface that is configured to come into contact with a cooling medium, and a blade part contact surface that is in contact with the recessed part,

wherein the cooling medium contact surface is spirally formed around the tubular rotor shaft, and the cooling medium contact surface extends toward a circumferential direction of the tubular rotor shaft as going toward an end in an axial direction of the tubular rotor shaft, and

wherein a cooling surface is formed by the inner surface of the pipe accommodating part and the cooling medium contact surface.

2. The rotor for kneading according to claim 1 , further comprising:

fins that are formed on the cooling medium contact surface of the filling body and protrude toward a center axis of the tubular rotor shaft.