Fan rotor for a turbomachine or a test engine

1. A fan rotor for a turbomachine, the rotor comprising a disk carrying blades having roots that are engaged in substantially axial grooves in the outer periphery of the disk, and a substantially frustoconical annular spinner mounted by jaw-clutching on the disk, upstream from the blades, the spinner having a substantially radial inner annular rim that is scalloped or crenellated and that comprises solid portions alternating with gap portions and that, in the assembled position, is received in an outer annular groove of the disk that is defined upstream by a substantially radial outer annular rim that is scalloped or crenellated, wherein the inner annular rim of the spinner is connected at its outer periphery to a substantially cylindrical wall that is designed to deform in the event of a fan blade being broken or lost, and wherein the gap portions in the inner annular rim of the spinner include substantially radial notches for increasing the flexibility in bending of the solid portions of said annular rim.

2. A rotor according to claim 1 , wherein, in the assembled position, residual axial clearance exists between the annular rims of the disk and of the spinner so as to allow the cylindrical wall of the spinner to deform.

3. A rotor according to claim 1 , including inter-blade platforms mounted on the disk between the blades, each platform including an upstream rim engaged in an annular groove of the spinner and opening out substantially axially in a downstream direction.

4. A rotor according to claim 1 , wherein the spinner has a radial wall including orifices for passing screws for fastening to an annular flange of the disk or on an annular flange of an intermediate shroud fitted on the disk and fastened thereto.

5. A rotor according to claim 4 , wherein the radial wall of the spinner is formed on an upstream end portion of the spinner.

6. A turbomachine, including a fan rotor according to claim 1 .

7. A test engine, including a fan rotor according to claim 1 .

8. A substantially frustoconical annular spinner for a fan rotor according to claim 1 , wherein the spinner includes a radial wall at its upstream end and an internal annular rim at its downstream end, the annular rim being scalloped or crenellated, comprising solid portions alternating with gap portions presenting substantially radial notches or recesses, the annular rim being connected to the spinner by a substantially cylindrical wall that is deformable.

9. A spinner according to claim 8 , including an annular groove at its downstream end, the groove opening out axially away from its radial wall.