Rotor shaft for use in an aerating device

1. A rotor shaft for use in an aerating device for a ground, wherein the rotor shaft comprises at least one connecting disc which extends transversely of the axis of the rotor shaft and on which at least two knives are arranged, wherein each knife is provided with two knife connecting holes and is connected between the connecting disc and a connecting ring, wherein the connecting disc and the connecting ring are provided with knife connecting holes which coincide with the knife connecting holes of the knives, wherein bolts are arranged through the coinciding knife connecting holes in order to connect the connecting disc, the knives and the connecting ring, wherein the connecting ring is constructed from at least two ring sectors which together form the connecting ring, and a ring sector is connected to two knives and extends therebetween.

2. The rotor shaft as claimed in claim 1 , wherein the ring sectors are uniform.

3. The rotor shaft as claimed in claim 1 , wherein each ring sector is provided close to the outer ends with a knife connecting hole.

4. The rotor shaft as claimed in claim 1 , wherein the knife connecting holes for a single knife are located at different radial distances, wherein a ring sector is provided with at least one protrusion for accommodating a knife connecting hole.

5. The rotor shaft as claimed in claim 1 , further comprising ring sector-shaped filling members between the knives, wherein a filling member has a form such that it fills on the one hand the space between the connecting disc and the connecting ring and on the other the space between two knives, wherein a filling member is provided with at least one filling member connecting hole and wherein the connecting ring and connecting disc are provided with filling member connecting holes which coincide with the filling member connecting holes of the filling members, wherein bolts are arranged through the coinciding filling member connecting holes in order to connect the connecting disc, the filling members and the connecting ring.

6. The rotor shaft as claimed in claim 5 , wherein the filling members and the knives form a continuous annular structure in the connected state, wherein the knives are held in form-fitting manner between the filling members, the connecting disc and the connecting ring.

7. The rotor shaft as claimed in claim 5 , wherein a knife is provided with a recess which forms a contact surface with a normal with a component in the radial direction, wherein a filling member is provided with a projection with a form complementary to the contact surface of the recess.

8. The rotor shaft as claimed in claim 7 , wherein the projection is arranged at an outer end of a filling member.

9. The rotor shaft as claimed in claim 5 , wherein the filling member connecting holes have a diameter differing from that of the knife connecting holes.

10. An aerating device for a ground, comprising:

a frame;

moving means arranged on the frame for the purpose of moving the aerating device in a direction of movement over a surface for working;

a drive; and

a rotor shaft as claimed in claim 1 operatively connected to the drive for the purpose of rotating the rotor shaft.

11. The aerating device as claimed in claim 10 , further comprising a housing which protects at least the rotor shaft, wherein the housing is provided with a hatch which is arranged hingedly on the housing for the purpose of making the rotor shaft accessible.

12. The rotor shaft as claimed in claim 1 , wherein the connecting ring comprises three ring sectors.

13. The rotor shaft as claimed in claim 5 , wherein the rotor shaft comprises three ring sector-shaped filling members.

14. The rotor shaft as claimed in claim 5 , wherein a ring sector of connecting ring wholly overlaps the filling member.

15. The rotor shaft as claimed in claim 5 , wherein the ring sector-shaped filling members have a thickness in the direction of the axis of the rotor shaft equal to a thickness an end of a knife.