Container handling vehicle with direct drive on lifting axle(s), associated methods and system
An automated storage and retrieval system includes a plurality of stacks of storage containers arranged in storage columns, and a container handling vehicle. The container handling vehicle includes a transport mechanism for transport of the vehicle, and a lifting assembly for picking up storage containers from the storage columns. The lifting assembly includes: a lifting frame connectable to a storage container, a first lifting shaft and a second lifting shaft, the first and second lifting shafts being mainly parallel, and each of the first and second lifting shafts being supported in an upper portion of the vehicle, two lifting elements extending from each of the first and second lifting shafts to the lifting frame, and a motor drive assembly having at least one motor including a first motor, and a force transferring assembly rotatably connecting the first and second lifting shafts via a force transferring element.
1. An automated storage and retrieval system comprising:
a plurality of stacks of storage containers arranged in storage columns, and
a container handling vehicle comprising:
a transport mechanism for transport of the vehicle, and
a lifting assembly for picking up storage containers from the storage columns,
wherein the lifting assembly comprises:
a lifting frame connectable to a storage container,
a first lifting shaft and a second lifting shaft, the first and second lifting shafts being mainly parallel, and each of the first and second lifting shafts being supported in an upper portion of the vehicle,
two lifting elements extending from each of the first and second lifting shafts to the lifting frame, and
a motor drive assembly comprising at least one motor including a first motor, and a force transferring assembly rotatably connecting the first and second lifting shafts via a force transferring element,
wherein the force transferring element comprises an endless belt with an inner surface and an outer surface, and
wherein the first lifting shaft is in contact with one of the inner surface and the outer surface of the belt and the second lifting shaft is in contact with another of the inner surface and the outer surface of the belt.
2. The automated storage and retrieval system according to claim 1 , further comprises a rail system comprising a first set of parallel tracks arranged in a horizontal plane and extending in a first direction, and a second set of parallel tracks arranged in the horizontal plane and extending in a second direction which is orthogonal to the first direction, which first and second sets of parallel tracks form a grid pattern in the horizontal plane comprising a plurality of adjacent grid cells, each comprising a grid opening defined by a pair of neighboring tracks of the first set of parallel tracks and a pair of neighboring tracks of the second set of parallel tracks.
3. The automated storage and retrieval system according to claim 2 , wherein the force transferring assembly comprises a first lifting shaft wheel connected for rotation with the first lifting shaft and a second lifting shaft wheel connected for rotation with the second lifting shaft and at least one guide wheel urging the outer surface of the belt against one of the first or second lifting shaft wheels, such that when one of the first or second lifting shaft moves in a first rotational direction, the other of the first or second lifting shaft moves in a second rotational direction opposite the first rotational direction, in both rotational directions.
4. The automated storage and retrieval system according to claim 3 , wherein the endless belt forms a closed loop, and wherein one of the first or second lifting shaft wheels is arranged inside the closed loop and the other of the first or second lifting shaft wheels is arranged outside the closed loop.
5. The automated storage and retrieval system according to claim 1 , wherein the force transferring assembly comprises a tensioning mechanism for initial tightening of the force transferring element.
6. The automated storage and retrieval system according to claim 1 , wherein the at least one motor comprises a brushless DC motor.
7. The automated storage and retrieval system according to claim 6 , wherein the first motor comprises a rotary electrical motor converting direct current electrical energy into rotational energy of the first or second lifting shafts.
8. The automated storage and retrieval system according to claim 1 , wherein the motor drive assembly comprises a second motor, and wherein the force transferring assembly comprises a belt transferring torque from the first or second lifting shaft with the first and second motors to the other of the first or second lifting shaft.
9. The automated storage and retrieval system according to claim 1 , wherein the motor drive assembly comprises a second motor, and wherein the force transferring assembly comprises a timing belt providing synchronous movement of the first and second lifting shafts relative to each other.
10. The automated storage and retrieval system according to claim 1 , wherein a rotational force of the motor drive assembly corresponds to an intended maximum weight of the storage container with an item.
11. The automated storage and retrieval system according to claim 1 , wherein the force transferring assembly comprises a number of angular gears and a link shaft, wherein the angular gears are connected for rotation with each of the first and second lifting shafts and the link shaft is arranged between the angular gears of the first and second lifting shafts gears.
12. A method of operating the automated storage and retrieval system according to claim 1 , comprising providing signals to different container handling vehicles operating in the automated storage and retrieval system to store the storage containers in the stacks and retrieve the storage containers from the stacks.
13. A container handling vehicle for moving storage containers stacked in stacks within an automated storage and retrieval system, wherein the container handling vehicle is configured to move above storage columns and comprises:
a lifting assembly for picking up storage containers from the storage columns,
wherein the lifting assembly comprises:
a lifting frame connectable to a storage container,
a first lifting shaft and a second lifting shaft, the first and second lifting shafts being mainly parallel, each of the first and second lifting shafts being supported in an upper portion of the vehicle,
two lifting elements extending from each of the first and second lifting shafts to the lifting frame,
a motor drive assembly comprising at least a first motor, and
a force transferring assembly rotatably connecting the first and second lifting shafts via a force transferring element,
wherein the force transferring element comprises an endless belt with an inner surface and an outer surface, and
wherein the first lifting shaft is in contact with one of the inner surface and the outer surface of the belt, and the second lifting shaft is in contact with another of the inner surface and the outer surface of the belt.
14. The container handling vehicle according to claim 13 ,
wherein the force transferring element comprises a first lifting shaft wheel connected for rotation with the first lifting shaft and a second lifting shaft wheel connected for rotation with the second lifting shaft and at least one guide wheel, such that when one of the first and second lifting shafts moves in a first rotational direction, another of the first and second lifting shafts moves in a second rotational direction opposite the first rotational direction,
wherein the endless belt forms a closed loop, and
wherein one of the first and second lifting shaft wheels is arranged inside the closed loop and another of the first and second lifting shaft wheels is arranged outside the closed loop.
15. The container handling vehicle according to claim 13 , wherein the container handling vehicle is configured for storage and retrieval of the storage containers in a storage system.
16. A method of operating a lifting assembly of a container handling vehicle comprising:
arranging a motor drive assembly comprising at least a first motor,
connecting two lifting elements from each of a first lifting shaft and a second lifting shaft to a lifting frame, and
rotationally coupling the first and second lifting shafts, through a force transferring assembly,
wherein the force transferring assembly comprises an endless belt with an inner surface and an outer surface, and
wherein the first lifting shaft is in contact with one of the inner surface and the outer surface of the belt and the second lifting shaft is in contact with another of the inner surface and the outer surface of the belt, the force transferring assembly being configured to synchronize raising and lowering of opposite sides of the lifting frame, and using the lifting assembly for picking up storage containers from storage columns to a position above a lowest level of a transport mechanism on the container handling vehicle.