Deceleration mechanism

1. A deceleration mechanism, comprising:

a driving device; and

a transmission assembly, comprising:

a driving member connected to the driving device; and

a first driven assembly;

a second driven assembly;

a first transmission member connecting the driving member to the first driven assembly, and driven by the driving device, and rotating the first driven assembly; and

a second transmission member connecting the first driven assembly to the second driven assembly, and driven by the first driven assembly, and rotating the second driven assembly, wherein the second driven assembly comprises a transmission portion, the second transmission member coils on the first driven assembly, and opposite ends of the second transmission member are fixed on the transmission portion, the second driven assembly further defines a through hole extending through the transmission portion, the driving member extends through the through hole of the second transmission portion.

2. The deceleration mechanism of claim 1 , wherein the rotational axis of the first driven assembly is substantially parallel to the rotational axis of the driving member.

3. The deceleration mechanism of claim 2 , wherein the first driven assembly comprises a driven shaft and at least one driven wheel; wherein the first transmission member coils around the driving member, and opposite ends of the first transmission member coil on the at least one driven wheel.

4. The deceleration mechanism of claim 3 , wherein the second transmission member coils on the driven shaft of the first driven assembly.

5. The deceleration mechanism of claim 1 , wherein the transmission portion of the second driven assembly is substantially fan-shaped.

6. The deceleration mechanism of claim 3 , wherein the at least one driven wheel comprises two driven wheels arranged around at the opposite ends of the driven shaft; the second transmission member coils on the driven shaft, between the driven wheels; and the first transmission member coils on the driving member, each end of the first transmission member winding around on one driven wheel.

7. The deceleration mechanism of claim 3 , wherein the at least one driven wheel defines a receiving slot in which the first transmission member is coiled.

8. The deceleration mechanism of claim 7 , wherein the receiving slot of the at least one driven wheel is a spiral slot comprising a plurality of windings; the first transmission member is coiled in parts of the windings of the receiving slot, and the number of windings of the receiving slot receiving the first transmission member is less than the number of the windings of the receiving slot remaining.

9. The deceleration mechanism of claim 1 , wherein the transmission portion of the second driven assembly defines a receiving slot receiving a portion of the second transmission member.

10. The deceleration mechanism of claim 1 , wherein the first transmission member and the second transmission member are wire cables.

11. The deceleration mechanism of claim 1 , wherein the first transmission member and the second transmission member are steel coils.

12. The deceleration mechanism of claim 1 , wherein the transmission assembly further comprises a plurality of fixing assemblies fixing the first transmission member to the first driven assembly and the second transmission member to the second driven assembly.

13. A deceleration mechanism, comprising:

a driving device; and

a transmission assembly, comprising:

a driving member connected to the driving device;

a first driven assembly;

a second driven assembly;

a first transmission member coiling around the driving member and the first driven assembly; and

a second transmission member coiling around the first driven assembly and the second driven assembly, wherein the driving device rotates the driving member, the driving member rotates the first driven assembly, and the first driven assembly rotates the second driven assembly, the second driven assembly comprises a transmission portion, the second transmission member coils on the first driven assembly, and opposite ends of the second transmission member are fixed on the transmission portion, the second driven assembly further defines a through hole extending through the transmission portion, the driving member extends through the through hole of the second transmission portion.

14. The deceleration mechanism of claim 13 , wherein the rotational axis of the first driven assembly is substantially parallel to the rotational axis of the driving member.

15. The deceleration mechanism of claim 14 , wherein the first driven assembly comprises a driven shaft and at least one driven wheel arranged around the driven shaft; the first transmission member coils around the driving member, opposite ends of the first transmission member coil on the at least one driven wheel.

16. The deceleration mechanism of claim 15 , wherein the second transmission member coils on the driven shaft of the first driven assembly.

17. The deceleration mechanism of claim 15 , wherein the at least one driven wheel defines a receiving slot in which the first transmission member is coiled.

18. The deceleration mechanism of claim 17 , wherein the receiving slot of the at least one driven wheel is a spiral slot comprising a plurality of windings; the first transmission member is coiled in parts of the windings of the receiving slot, and the number of windings of the receiving slot receiving the first transmission member is less than the number of the windings of the receiving slot remaining.