Cooling jacket including a groove unit through which cooling medium passes, stator including a cooling jacket, and rotary electric machine including a cooling jacket
A cooling jacket capable of improving production efficiency. The cooling jacket includes a tubular main body having a first end face and a second end face, and a groove unit defining a flow channel of a cooling medium successively disposed axially on an outer periphery of the main body. The cooling jacket includes no portion located radially outward from a bottom of the groove unit between a first end portion of the groove unit located on the axial rear side of the main body and the first end face of the main body.
1. A cooling jacket on a radial outside of a stator of a rotary electric machine, the cooling jacket comprising:
a tubular main body including a first end face of one axial side and a second end face of the other axial side; and
a groove unit defining a flow channel of a cooling medium, the groove unit being successively disposed axially on an outer periphery of the main body,
wherein the cooling jacket includes no portion located radially outward from a bottom of the groove unit between a first end portion of the groove unit on the one axial side of the main body and the first end face of the main body and between a second end portion of the groove unit on the other axial side of the main body and the second end face of the main body,
wherein the groove unit is a multi-thread groove successively extended axially on the main body in a spiral manner.
2. The cooling jacket according to claim 1 , comprising a cylindrical outer peripheral region having an outer radius equal to or smaller than a radial distance between the bottom of the groove unit and a center axis of the main body, the region being located between the first end portion of the groove unit and the first end face of the main body.
3. The cooling jacket according to claim 1 , comprising a cylindrical outer peripheral region having an outer radius equal to or smaller than a radial distance between the bottom of the groove unit and a center axis of the main body, the region being located between a second end portion of the groove unit on the other axial side of the main body and the second end face of the main body.
4. The cooling jacket according to claim 1 , wherein the groove unit is formed by hobbing.
5. A stator comprising the cooling jacket according to claim 1 .
6. A rotary electric machine comprising the stator according to claim 5 .
7. A method for producing a cooling jacket on a radial outside of a stator of a rotary electric machine, the method comprising steps of: preparing a tubular main body including a first end face of one axial side and a second end face of the other axial side; rotating the main body around a center axis of the main body; pressing a rotating hob against an outer periphery of the main body; and moving the rotating hob axially relative to the main body between a first end portion of the one axial side of the main body and a second end portion of the other axial side of the main body to form a groove unit defining a flow channel of a cooling medium, the groove unit being a multi-thread groove successively extending axially on the outer periphery of the main body in a spiral manner.
8. The production method according to claim 7 , further comprising step of cutting the main body from the first end face of the main body to a predetermined axial position before pressing the rotating hob, in order to form a cylindrical outer peripheral region having an outer radius equal to or smaller than a radial distance between the bottom of the groove unit and the center axis of the main body.
9. The production method according to claim 7 , further comprising a step of cutting the main body from the first end face of the main body to a predetermined axial position after forming the groove unit, in order to form a cylindrical outer peripheral region having an outer radius of equal to or smaller than a radial distance between the bottom of the groove unit and the center axis of the main body.
10. The cooling jacket according to claim 1 , wherein the groove unit extends to at least either the first end face or the second end face of the main body.