Container handling vehicle with direct drive on elevating axle, associated method, and system

Abstract

To provide a force transmission assembly.SOLUTION: The invention provides an automatic storage and collection system. The system comprises a container handling vehicle having a transportation mechanism for transportation of a vehicle on a rail system and an elevating assembly for picking up a storage container to a position above the minimum height of the transportation mechanism from a storage column. The elevating assembly comprises: an elevating frame capable of being connected to the storage container; a first elevating shaft and a second elevating shaft; two elevating elements; a motor drive assembly having at least a first motor; and a force transmission assembly for rotatably connecting the first and second elevating shafts via a force transmission element.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an automated storage and retrieval system, a container handling vehicle that can operate on the automated storage and retrieval system, and a method of operating the automated storage and retrieval system. [Background technology]

[0002] FIG. 1 discloses a framework 1 of a typical prior art automated storage and retrieval system, and FIGS. 2A-2C disclose different container handling vehicles 9 of such a system.

[0003] The framework 1 comprises a number of upright members 2 and a number of horizontal members 3 supported by the upright members 2. The members 2, 3 may typically be made from metal, for example extruded aluminium profiles.

[0004] Framework structure 1 defines a storage grid 4 comprising storage columns 5 arranged in rows, within which storage columns 5 store storage containers 6, also known as bins, that are stacked one on top of the other to form stacks 7. Each storage container 6 may typically hold multiple product items (not shown), and the product items within a storage container 6 may be the same or may be different product types depending on the application. Framework structure 1 prevents horizontal movement of stack 7 of storage containers 6 and guides vertical movement of the containers 6, but typically does not otherwise support the storage containers 6 when stacked.

[0005] Rail system 8 is arranged in a grid pattern across the tops of storage columns 5, and a plurality of container handling vehicles 9 are operated on rail system 8 to raise and lower storage containers 6 from and into storage columns 5, and to transport storage containers 6 above storage columns 5. Rail system 8 comprises a first set of parallel rails 10 arranged to guide movement of container handling vehicles 9 in a first direction X across the top of frame structure 1, and a second set of parallel rails 11 arranged perpendicular to first set of rails 10 to guide movement of container handling vehicles 9 in a second direction Y that is perpendicular to first direction X. Rail system 8 thus defines a grid column 12 above which container handling vehicles 9 can move laterally above storage columns 5, i.e., in a plane that is parallel to the horizontal XY plane.

[0006] Each container handling vehicle 9 includes a vehicle body 13 and first and second sets of wheels 14, 15 that enable lateral movement of the container handling vehicle 9, i.e., movement in the X and Y directions. In Figure 2A, two wheels in each of the sets 14, 15 are visible, while in Figures 2B and 2C, only two wheels in one of the sets of wheels 14 are visible. The first set of wheels 14 is arranged to engage two adjacent rails of the first set of rails 10, and the second set of wheels 15 is arranged to engage two adjacent rails of the second set of rails 11. Each set of wheels 14, 15 can be raised and lowered so that the first set of wheels 14 and / or the second set of wheels 15 can be engaged with the respective set of rails 10, 11 at any one time.

[0007] Each container handling vehicle 9 also includes a lifting device 16 (see FIGS. 2B and 2C) for vertical transportation of storage containers 6, e.g., raising and lowering storage containers 6 from and into storage columns 5. The lifting device may be arranged inside the body 13 (as in FIG. 2A) or outside the body 13 (as disclosed in FIGS. 2B and 2C). The lifting device 16 may include a lifting frame 18 adapted to engage with the storage container 6, which can be lowered from the vehicle body 13 such that the position of the lifting frame relative to the vehicle body 13 can be adjusted in a third direction Z that is orthogonal to the first direction X and the second direction Y.

[0008] Conventionally, and for purposes of this application, Z=1 identifies the top layer of grid 4, i.e., the layer immediately below rail system 8, Z=2 the second layer below rail system 8, Z=3 the third layer, etc. In the embodiment disclosed in FIG. 1, Z=8 identifies the bottom layer of grid 4. Consequently, by way of example and using the Cartesian coordinate system X, Y, Z shown in FIG. 1, a storage container identified as 7' in FIG. 1 may be said to occupy grid location or cell X=10, Y=2, Z=3. A container handling vehicle 9 may be said to travel within layer Z=0, and each grid column may be identified by its X and Y coordinates.

[0009] Each container handling vehicle 9 comprises a storage compartment or space for receiving and storing the storage containers 6 as they are transported across the grid 4. The storage space may comprise a cavity (FIG. 2A) centrally arranged within the vehicle body 13, for example, as described in International Publication No. WO 2014 / 090684 A1 (the contents of which are incorporated herein by reference). Alternatively, the storage compartment or space can be arranged on the side of the body, as disclosed in FIGS. 2B and 2C, i.e., the container handling vehicle may have a cantilever structure, as described in International Publication No. 317366 (the contents of which are also incorporated herein by reference).

[0010] The container handling vehicle 9 may have a footprint 22 (see FIG. 4), i.e., an extent in the X and Y directions that is approximately equal to the lateral or horizontal extent of the grid column 12, i.e., the extent of the grid column 12 in the X and Y directions, as described, for example, in International Publication No. WO 2015 / 193278 A1, the contents of which are incorporated herein by reference. Alternatively, the container handling vehicle 9 may have a footprint that is greater than the lateral extent of the grid column 12, as disclosed, for example, in International Publication No. WO 2014 / 090684 A1.

[0011] The rail system 8 may be a single rail system, as shown in Figure 3. Alternatively, the rail system 8 may be a dual rail system, as shown in Figure 4, thus allowing a container handling vehicle 9 having a footprint 22 generally corresponding to the lateral extent of a grid column 12 to travel along that row, even though another container handling vehicle 9 is positioned above the grid column adjacent to that row of grid columns.

[0012] In a storage grid, the majority of the grid columns 12 are storage columns 5, i.e., grid columns where storage containers are stored in stacks. However, the grid typically has at least one grid column that is not used to store storage containers, but that provides a location where a container handling vehicle can drop off and / or pick up a storage container so that the storage container can be accessed from outside the grid or transported to an access station where it can be transferred out of or into the grid. Within the art, such a location is typically referred to as a "port," and the grid column in which the port is located may be referred to as a port column.

[0013] Grid 4 of Figure 1 includes two port columns 19 and 20. The first port column 19 may be, for example, a dedicated drop-off port column where container handling vehicles 9 may drop off storage containers to be transported to an access or transfer station (not shown), and the second port column 20 may be a dedicated pickup port column where container handling vehicles 9 may pick up storage containers that have been transported to grid 4 from an access or transfer station.

[0014] An access station may typically be a sorting or stockpiling station where product items are removed from or placed into a storage container. At a sorting or stockpiling station, the storage container is typically never removed from the automated storage and retrieval system, but is returned to the grid once accessed. Ports can also be used to transfer storage containers off or into the grid, for example, to transfer the storage container to another storage facility (e.g., to another grid or to another automated storage and retrieval system), to a transport vehicle (e.g., a train or lorry), or to a production facility.

[0015] A conveyor system comprising conveyors is typically employed to transport storage containers between the port and the access station.

[0016] If the port and the access station are located at different elevations, the conveyor system may include a lifting device for transporting the storage containers vertically between the port and the access station.

[0017] The conveyor system may be arranged to transfer storage containers between different grids, for example as described in International Publication No. WO2014 / 075937A1, the contents of which are incorporated herein by reference.

[0018] WO 2016 / 198467 A1 (the contents of which are incorporated herein by reference) discloses an example of a prior art access system having a conveyor belt (FIGS. 5a and 5b of WO 2016 / 198467 A1) and a frame-mounted truck (FIGS. 6a and 6b of WO 2016 / 198467 A1) for transporting storage containers between a port and a workstation where an operator can access the storage containers.

[0019] When a storage container 6 stored within the grid 4 disclosed in FIG. 1 is accessed, one of the container handling vehicles 9 is commanded to retrieve the target storage container from its position within the grid 4 and transport it to the drop-off port 19. This operation involves moving the container handling vehicle 9 to a grid location above the storage column in which the target storage container is located, retrieving the storage container from the storage column using a lifting device (not shown) on the container handling vehicle, and transporting the storage container to the drop-off port 19. If the target storage container 6 is located deep within the stack 7, i.e., one or more other storage containers are positioned above the target storage container, the operation also involves temporarily moving the upper-positioned storage container prior to lifting the target storage container from the storage column. This step, sometimes referred to in the art as "locating," may be performed using the same container handling vehicle 9 subsequently used to transport the target storage container to the drop-off port 19 or using one or more other cooperating container handling vehicles. Alternatively, or in addition, the automated storage and retrieval system may have a container handling vehicle 9 specifically dedicated to the task of temporarily removing a storage container 6 from a storage column. Once the target storage container has been removed from the storage column, the temporarily removed storage container 6 can be repositioned in the original storage column. However, the removed storage container 6 may alternatively be relocated to another storage column.

[0020] When a storage container 6 is stored in a grid 4, one of the container handling vehicles 9 is commanded to pick up the storage container from a pickup port 20 and transport it to a grid location above the storage column where it is stored. After any storage container 6 positioned at or above the target location in the storage column stack is removed, the container handling vehicle 9 positions the storage container 6 in the desired location. The removed storage container may then be lowered back into the storage column or relocated to another storage column.

[0021] To monitor and control the automated storage and retrieval system, for example, to monitor and control the location of individual storage containers within grid 4, the contents of each storage container 6, and the movements of container handling vehicles 9 so that the desired storage containers can be delivered to the desired locations at the desired times without the container handling vehicles 9 colliding with each other, the automated storage and retrieval system typically includes a control system that is computerized and includes a database for tracking the storage containers.

[0022] Furthermore, in prior art lifting systems for container handling vehicles, the lifting assembly includes a mechanical motor that is mechanically connected to two separate lifting shafts via a gear and belt arrangement. Over time, the mechanical components will be subject to wear and tear that results in uneven / inclined lifting and lowering of storage containers.

[0023] It is therefore an object of the present invention to provide a lifting system for a container handling vehicle that provides more stable lifting and lowering of storage containers or storage bins.

[0024] More specifically, it is an object of the present invention to provide a lifting system for a container handling vehicle in which the lifting operation provides minimal relative movement of different lifting bands connected to the lifting frame so that the storage container or storage bin remains level with a plane that is substantially parallel to the horizontal plane during the entire vertical lifting operation.

[0025] It is a further object of the present invention to have less reliance on mechanical parts in the lift system as these are susceptible to wear and tear. [Prior art documents] [Patent documents]

[0026] [Patent Document 1] International Publication No. 2014 / 075937 [Patent Document 2] International Publication No. 2014 / 090684 [Patent Document 3] International Publication No. 2015 / 193278 [Patent Document 4] International Publication No. 2016 / 198467 Summary of the Invention [Means for solving the problem]

[0027] The invention is set forth in the independent claims, which describe alternatives of the invention.

[0028] The present invention provides an automated storage and retrieval system, comprising: 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 perpendicular to the first direction, the first and second sets of tracks forming a grid pattern in the horizontal plane, the grid pattern comprising a plurality of adjacent grid cells, each of the plurality of adjacent grid cells comprising a grid opening defined by a pair of adjacent tracks of the first set of tracks and a pair of adjacent tracks of the second set of tracks; a plurality of stacks of storage containers arranged in storage columns located below the rail system, each storage column located vertically below a grid opening; A container handling vehicle, a transport mechanism for transporting vehicles on a rail system; a lifting assembly for lifting the storage container from the storage column to a position above the minimum height of the transport mechanism; A container handling vehicle equipped with Equipped with The lifting assembly is a lifting frame connectable to the storage container; a first lift shaft and a second lift shaft of equal or nearly equal diameter, the first and second lift shafts being primarily parallel, and each of the first and second lift shafts being supported within an upper portion of the vehicle; two lifting elements extending from each of the lifting shafts to the lifting frame; a motor drive assembly including at least one motor, the at least one motor surrounding one of the lift shafts; a force transmission assembly rotatably connecting the first and second lift shafts via a force transmission element; The present invention relates to an automated storage and retrieval system comprising:

[0029] The first and second lift shafts are preferably of equal or nearly equal diameter, which provides similar angular velocities of the reel surfaces on the first and second lift shafts when the lift shafts are rotated, resulting in the lift frame being substantially horizontal during lifting and lowering (i.e., the lift frame being parallel to a horizontal plane during lifting and lowering).

[0030] The force transmission element of the force transmission assembly may be considered a timing belt that ensures that the first and second lifting shafts are synchronized. Alternatively, the force transmission element may comprise a drive belt. Alternatively, the force transmission assembly may comprise a belt in the form of a chain. Thus, the force transmission element may be any synchronizing device that ensures that the angular velocities of the reel surfaces of the first and second lifting shafts are matched, thereby ensuring that the lifting frame is lifted evenly, i.e., that the lifting frame is approximately parallel to a horizontal plane during lifting and lowering.

[0031] Common to all aspects of the system is that first and second elevator shaft wheels, each of which is connected for rotation with a respective elevator shaft; at least one other guide wheel; Force transmission elements forming a closed loop The existence of At least one of the other guide wheels is arranged inside the closed loop; the first or second lift shaft wheel contacts the inner surface of the force transmission element; The other of the first or second shafts contacts the outer surface of the force transmission element. In other words, one of the first or second lift shaft wheels is arranged inside the closed loop formed by the force transmission element, and the other of the first or second lift shaft wheels is arranged outside the closed loop formed by the force transmission element. Such an arrangement results in counter-rotation of the first lift shaft relative to the second lift shaft.

[0032] An electric motor may be arranged around the periphery of the lift shaft to provide power transmission, i.e., rotational movement, to the lift shaft. In one aspect, the lift shaft may form an integral part of the electric motor.

[0033] In one aspect, the force transmission element comprises an endless belt with an inner and outer surface, with the first elevator shaft contacting the inner or outer surface of the belt and the second elevator shaft contacting the other of the inner or outer surfaces of the belt. Alternatively, the force transmission element can comprise a Möbius strip. In all aspects, the force transmission assembly is configured such that the first and second elevator shafts rotate in opposite directions.

[0034] Thus, the force transfer assembly is arranged in a configuration that allows for counter-rotation, i.e., reverse rotation, of the first lift shaft relative to the second lift shaft.

[0035] The force transmission assembly may include a first lift shaft wheel connected for rotation with the first lift shaft, a second lift shaft wheel connected for rotation with the second lift shaft, and at least one guide wheel that presses an outer surface of the belt against one of the first or second lift shaft wheels, such that when one of the first or second lift shafts moves in a first rotational direction, the other of the first and second lift shafts moves in a second rotational direction opposite the first direction in both rotational directions. This counter-rotation ensures that the lift frame and any storage containers lifted by the lift frame are lifted substantially vertically with minimal horizontal movement during vertical lifting operations. Preferably, the first and second lift shafts and lifting elements are connected such that the lifting elements are wound onto the lift shafts from the outside. This ensures connection of the lifting elements within the end portions of the lifting frame (e.g., in or near corners) and ensures that the lifting frame is centered and moves only vertically (and not horizontally) relative to the first and second lifting shafts during the entire lifting sequence.

[0036] In one aspect, the force transmission elements may form a closed loop, with one of the first or second elevator shaft wheels arranged inside the closed loop and the other of the first or second elevator shaft wheels arranged outside the closed loop. Such a configuration facilitates the arrangement of vertical keyhole-shaped holes for mounting the shafts while also allowing for ease of maintenance.

[0037] In one aspect, the force transmission assembly includes a tensioning or tightening mechanism for initial tightening of the force transmission elements. The tensioning mechanism may include an eccentric tensioning mechanism including a tightening wheel with an axle that can be adjusted within an opening in the fixed bracket. The axle of the tightening wheel can thus be moved in different directions relative to the opening in the fixed bracket. The area of ​​the opening is therefore greater than the area occupied by the cross-section of the axle within the opening at all positions of the axle within the opening. Such a tensioning mechanism may be advantageous to further ensure that the force transmission assembly can provide synchronous operation of the first and second lift shafts. The force transmission elements are preferably made of a non-elastic material so that their lengths are fixed. When the force transmission elements are initially installed, proper tension is ensured using a tuning fork that measures the frequency of the force transmission elements. The frequency corresponds to a given tension. The tension in the force transmission elements is adjusted by moving the tightening wheel within the opening in the bracket, thereby adjusting the length of the force transmission elements, and therefore the tension in the force transmission elements. When the frequency of the force transmission element is within a predetermined frequency range, the clamping wheel is locked in this position by a suitable fastening element, such as a screw or bolt. Once locked in a dedicated position, the force transmission assembly (i.e., the force transmission element and guide wheel and / or clamping wheel) is theoretically adapted to operate for thousands of hours before having to be replaced, similar to a drive belt in a combustion engine in a car.

[0038] The tensioning wheel of the tensioning mechanism may be a guide wheel separate from the guide wheels used in the counter-rotation mechanisms of the first and second lifting shafts, or may be one of the guide wheels used in the counter-rotation of the first and second lifting shafts.

[0039] In one aspect, at least one motor comprises a brushless DC motor. Various types of brushless DC motors are known, including permanent magnet synchronous motors (which use permanent magnets) and switched reluctance motors (which do not use any permanent magnets).

[0040] The operating principles of permanent magnet synchronous brushless DC motors are known to those skilled in the art, as explained, for example, at https: / / en.wikipedia.org / wiki / Brushless_DC_electric_motor, and typically use one or more permanent magnets in the rotor and an electromagnet on the motor housing for the stator. A motor controller converts direct current to alternating current. This design is mechanically simpler than brushed motors because it eliminates the complexity of transferring power from outside the motor to the rotating rotor. The motor controller can sense rotor position via Hall-effect sensors or similar devices and precisely control the timing, phase, etc. of the current in the rotor coils to optimize torque, conserve power, regulate speed, and even apply some braking.

[0041] The operating principle of a switched reluctance motor is known to those skilled in the art and is available, for example, from Jin-Woo Ahn (2011), Switched Reluctance Motor, Torque Control, Prof. Moulay, available at http: / / cdn.intechweb.org / pdfs / 13717.pdf As described in Tahar Lamchich (Ed.), ISBN: 978-953-307-428-3, InTech, and R. Krishnan (2001), Switched reluctance motor drives: Modelling, Simulation, Analysis, Design and Applications; CRC Press.

[0042] In one aspect, the at least one motor comprises a rotary electric motor that converts direct current electrical energy into rotational energy for at least the first or second lift shaft.

[0043] In one aspect, at least one motor is a permanent magnet brushless DC motor, and the motor includes a stator arranged radially between a rotor magnet (on the radially outer side of the stator) and a first or second lift shaft (on the radially inner side of the stator). The stator may be fixed to a stator housing, which is connected to the housing of the container handling vehicle. The rotor magnet may be arranged on the inner side of a wheel rim surrounding the stator and connected for rotation with the first or second lift shaft such that the rotor magnet and the first or second lift shaft rotate together. The stator then rotates the rotor magnet, and thereby the lift shaft. The stator may, for example, be arranged at least partially, preferably completely, in the same plane of rotation as the motor housing and at least partially, preferably completely, within the container vehicle body. The term "plane of rotation" in this embodiment refers to a plane extending perpendicularly from the rotation axis of the lift shaft. The stator includes both windings and a yoke, with the stator field windings following the outer periphery of the wheel rim on which the rotor magnets are arranged.

[0044] In some aspects, the electric motor may be a reluctance motor with operating principles similar to the permanent magnet brushless DC motor described above, such as a switched reluctance motor including a stator element with multiple stator poles and a rotor element featuring multiple rotor poles connected to or part of a drive shaft, one of which is a lift shaft or forms part of the rotor element. The rotor element (or drive shaft) of the reluctance motor may be aligned with the centerline of the lift shaft or comprise part of one end of the lift shaft. Alternatively, the stator element may be arranged within the rotor element (or vice versa), and the rotor element may be arranged within the lift shaft as part of or operably connected to the lift shaft. This latter solution would free up the greatest amount of space within the vehicle body cavity.

[0045] In one aspect, the container handling vehicle includes means suitable for (at least indirectly) measuring electromotive force (emf) of at least one of the lift shafts, in signal communication with one of the stator and rotor, thereby enabling online rolling set-specific speed registration of the lifting motion during lifting. For example, a back-emf measurement circuit may be disposed in signal communication with at least one of the lift shafts. Hall sensors may be used alternatively or in combination.

[0046] In another aspect, the container handling vehicle further comprises means suitable for measuring acceleration of at least one of the first and second lift shafts, the means being in signal communication with the stator. Such means preferably comprises one or more piezoelectric sensors, e.g., PCB TM One or more inductive sensors may be used in place of or in combination with the piezoelectric sensors, including accelerometers from Piezotronics.

[0047] In one aspect, the motor drive assembly includes a second motor that surrounds the same lift shaft as the first motor, and the force transmission assembly includes a belt that transmits torque from the first or second lift shaft associated with the first and second motors to the other of the first or second lift shaft.

[0048] In one aspect, the motor drive assembly includes a second motor that is different from the first motor and surrounds the other of the first or second lift shafts, and the force transfer assembly includes a timing belt that provides synchronous movement of the first and second lift shafts relative to one another.

[0049] In one aspect, when using first and second motors, e.g., surrounding the same lift shaft or surrounding separate first and second lift shafts, the system further includes sensing means, such as a sensor, in each of the first and second motors that provides input to an encoder within each motor to determine the speed of each motor. Signals representing the speed of each motor are transmitted to a common control system, which operates the different motors to increase or decrease their speeds based on the signals. This can be advantageous as an additional force transmission element, for example, in situations where the load of a storage container is unevenly distributed, with the center of gravity of the storage container being more on one side than another (i.e., the center of gravity is not at the geometric center of the storage container bottom), resulting in uneven loads being received by the motors. The sensor may, for example, read an optical disk provided with some of the following:

[0050] In one aspect, the force transfer arrangement is configured to synchronize the rotation of the first lift shaft and the second lift shaft.

[0051] In one aspect, the rotational force of the motor drive assembly corresponds to the maximum intended weight of the storage container with the items, which may typically be between 2 and 50 kilograms.

[0052] In one aspect, the force transfer assembly includes a number of angle gears and a link shaft, the angle gears connected for rotation with each of the first and second elevator shafts, and the link shaft arranged between the angle gears of the first and second elevator gears.

[0053] The present invention further relates to a container handling vehicle for moving storage containers stacked in stacks within an automated storage and retrieval system, the container handling vehicle being configured to travel on a rail system above storage columns, and including a lifting assembly for picking up the storage containers from the storage columns to a position above a minimum height of a transport mechanism on the container handling vehicle; The lifting assembly is a lifting frame connectable to the storage container; a first lift shaft and a second lift shaft of equal or nearly equal diameter, the first and second lift shafts being primarily parallel, and each of the first and second lift shafts being supported within 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 including at least a first motor, the at least first motor surrounding one of the lift shafts; a force transmission assembly rotatably connecting the first and second lift shafts via a force transmission element; The automated storage and retrieval system may include 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 orthogonal to the first direction, the first and second sets of tracks forming a grid pattern in the horizontal plane, the grid pattern comprising a plurality of adjacent grid cells, each of the plurality of adjacent grid cells comprising a grid opening defined by a pair of adjacent tracks in the first set of tracks and a pair of adjacent tracks in the second set of tracks, and a plurality of stacks of storage containers arranged in storage columns located below the rail system, each storage column located vertically below a grid opening.

[0054] In one aspect of the container handling vehicle, the force transmission assembly includes an endless belt, a first lift shaft wheel connected for rotation with the first lift shaft, a second lift shaft wheel connected for rotation with the second lift shaft, and at least one guide wheel arranged such that when one of the first or second lift shaft moves in a first rotational direction, the other of the first and second lift shafts moves in a second rotational direction opposite the first direction. The endless belt forms a closed loop, and one of the first or second lift shaft wheel is arranged inside the closed loop and the other of the first or second lift shaft wheel is arranged outside the closed loop.

[0055] The container handling vehicle may have a central cavity or cantilever structure for receiving the storage container.

[0056] Further described is the use of a container handling vehicle as defined above for the storage and retrieval of storage containers within a storage system.

[0057] Further described is a method of operating an automated storage and retrieval system as defined above, including providing signals to different container handling vehicles operating within the system to store and retrieve storage containers from the stacks.

[0058] The invention further relates to the use of a container handling vehicle as described above for the storage and retrieval of storage containers in a storage system.

[0059] The present invention further relates to a method of operating an automated storage and retrieval system as described above, the method comprising providing signals to different container handling vehicles that operate within the system to store storage containers in stacks and retrieve storage containers from stacks.

[0060] The present invention further provides a method of operating a lifting assembly of a container handling vehicle, comprising: Arranging a motor drive assembly including at least a first motor to surround the first or second lift shaft of the lift system; connecting two lifting elements from each of the first and second lifting shafts to the lifting frame; rotationally coupling the first and second lift shafts to synchronize the lifting and lowering of opposite sides of the lift frame; using a lifting assembly for lifting the storage container from the storage column to a position above the minimum height of the transport mechanism on the container handling vehicle; The present invention relates to a method, including:

[0061] In one aspect of the method, the method further comprises: The method includes surrounding the second motor around the same first or second lift shaft as the first motor, or around the other of the first motor and the same first or second lift shaft.

[0062] The lifting elements are preferably electrically and signal conducting so that grippers on the lifting frame can be electronically operated to grip and hold storage containers. The lifting elements may be bands or other electrically and signal conducting means.

[0063] The lift shafts are preferably provided with a braking arrangement. The braking arrangement may be arranged on the inside or outside of the container vehicle housing and may be a locking pin, e.g., a ratchet mechanism, cooperating with a gear connected for rotation with the first or second lift shaft. In the locked position of the locking arrangement, the locking pin engages with the gear on the lift shaft, thereby preventing rotation of the gear (and therefore the lift shaft). In the released position of the locking arrangement, the locking pin is operated to a position out of engagement with the gear on the lift shaft, thereby allowing the lift shaft to rotate freely under any command from the motor.

[0064] Another advantage of the present invention over prior art solutions in which the drive system for the lifting device is based on a motor connected to the lifting shaft via gears is that it is an easier system to assemble as it has fewer parts and is less complex, in addition to a more reliable system with longer inspection intervals for the parts. Furthermore, when the motor operates directly on at least the first and / or second lifting shaft, a more efficient and precise lifting is achieved as the lifting shaft is momentarily influenced by the motor.

[0065] In one aspect, the housing of the container handling vehicle is integrally cast. The housing can be, for example, an integrally cast aluminum casing. Typically, according to prior art solutions, multiple thin metal plates are connected by screws or bolts. A monolithic casting eliminates the need for thin metal plates, thus reducing the number of screws used to connect the plates (typically, about 40 screws are used to connect the plates). Additionally, a monolithic casting results in less time being spent assembling the container handling vehicle because there are fewer parts to assemble.

[0066] In one aspect, there may be four lift elements, two from each of the first and second lift shafts.

[0067] In the following description, numerous specific details are introduced by way of example only, so as to provide a thorough understanding of embodiments of the claimed system, container handling vehicle, and method. However, those skilled in the art will recognize that these embodiments may be practiced without one or more of the specific details, or with other components, systems, etc. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring aspects of the disclosed embodiments. The present invention provides, for example, the following items. (Item 1) 1. An automated storage and retrieval system comprising: a rail system (8) comprising: a first set (10) of parallel tracks arranged in a horizontal plane (P) and extending in a first direction (X); and a second set (11) of parallel tracks arranged in the horizontal plane (P) and extending in a second direction (Y) perpendicular to the first direction (X), the first and second sets (10, 11) of tracks forming a grid pattern in the horizontal plane (P), the grid pattern comprising a plurality of adjacent grid cells, each of the plurality of adjacent grid cells comprising a grid opening (12) defined by a pair of adjacent tracks (10a, 10b) of the first set (10) of tracks and a pair of adjacent tracks (10a, 10b) of the second set (11) of tracks; a plurality of stacks (7) of storage containers (6) arranged in storage columns (5) located below the rail system (8), each storage column (5) being located vertically below a grid opening (12); A container handling vehicle (9), a transport mechanism (14, 15) for transporting the vehicle (9) on the rail system (8); a lifting assembly (24) for lifting a storage container (6) from said storage column (5) to a position above the minimum height of said transport mechanism (14, 15); A container handling vehicle (9) equipped with Equipped with The lifting assembly (24) a lifting frame (18) connectable to the storage container (6); a first lift shaft (25) and a second lift shaft (25), the first and second lift shafts (25, 26) being primarily parallel, each of the first and second lift shafts (25, 26) being supported within an upper portion of the vehicle (90); two lifting elements (25', 25''; 26', 26'') extending from each of the first and second lifting shafts (25, 26) to the lifting frame (18); a motor drive assembly comprising at least a first motor (30), said at least first motor (30) surrounding one of said lift shafts (25, 26); a force transmission assembly (32, 33', 33'', 33''', 33'''', 34, 35) that rotatably connects the first and second lift shafts (25, 26) via a force transmission element (32); An automated storage and retrieval system comprising: (Item 2) Item 1, an automated storage and retrieval system, wherein the force transmission element comprises an endless belt (32) with an inner surface and an outer surface, the first lifting shaft (25) contacting the inner surface or the outer surface of the belt, and the second lifting shaft (26) contacting the other of the inner surface or the outer surface of the belt (32). (Item 3) Item 3. The automated storage and retrieval system of item 2, wherein the force transmission assembly comprises: a first elevator shaft wheel (33') connected to rotate with the first elevator shaft (25) so that when one of the first or second elevator shaft (25, 26) moves in a first rotational direction, the other of the first and second elevator shafts (25, 26) moves in a second rotational direction opposite to the first direction in both rotational directions; a second elevator shaft wheel (33'') connected to rotate with the second elevator shaft (25); and at least one guide wheel (33''', 33'''') that presses the outer surface of the belt (32) against one of the first or second elevator shaft wheels (33', 33''). (Item 4) 4. The automatic storage and retrieval system according to any one of items 2 or 3, wherein the endless belt (32) forms a closed loop, one of the first or second lifting shaft wheels (33′, 33″) is arranged inside the closed loop, and the other of the first or second lifting shaft wheels (33′, 33″) is arranged outside the closed loop. (Item 5) 2. The automated storage and retrieval system of claim 1, wherein the force transmission assembly comprises a tensioning mechanism (34) for initial tightening of the force transmission element (32). (Item 6) 2. The automated storage and retrieval system of claim 1, wherein the at least one motor (30) comprises a brushless DC motor. (Item 7) Item 7. The automated storage and retrieval system of item 6, wherein the at least first motor (30) comprises a rotary electric motor that converts direct current electrical energy into rotational energy for the at least first or second lift shaft (25, 26). (Item 8) 8. The automated storage and retrieval system of any of the preceding items 1-7, wherein the motor drive assembly includes a second motor (30), the second motor (30) surrounding the same lift shaft (25, 26) as the first motor (30), and the force transmission assembly includes a belt that transmits torque from the first or second lift shaft (25, 26) associated with the first and second motors (30) to the other of the first or second lift shaft (25, 26). (Item 9) 8. The automated storage and retrieval system of any of the preceding items 1-7, wherein the motor drive assembly comprises a second motor (30) surrounding the other of the first or second lifting shafts (25, 26) that is different from the first motor (30), and the force transmission assembly comprises a timing belt that provides synchronous movement of the first and second lifting shafts (25, 26) relative to each other. (Item 10) Item 10. The automated storage and retrieval system of claim 1, wherein the rotational force of the motor-driven assembly corresponds to the maximum intended weight of the storage container (6) with items. (Item 11) Item 1, an automated storage and retrieval system, wherein the force transmission assembly comprises several angle gears and a link shaft, the angle gears connected for rotation with each of the first and second lifting shafts, and the link shaft arranged between the angle gears of the first and second lifting gears. (Item 12) a container handling vehicle (9) for moving storage containers (6) stacked in stacks within the automated storage and retrieval system (1), said container handling vehicle (9) configured to move on a rail system (8) above the storage columns (5); a lifting assembly (24) for lifting a storage container (6) from the storage column (5) to a position above the minimum height of the transport mechanism on the container handling vehicle (9); Equipped with The lifting assembly (24) a lifting frame (18) connectable to the storage container (6); a first lift shaft (25) and a second lift shaft (26), the first and second lift shafts (25, 26) being primarily parallel and each of the first and second lift shafts (25, 26) being supported within an upper portion of the vehicle (9); two lifting elements (25', 25''; 26', 26'') extending from each of the first and second lifting shafts (25, 26) to the lifting frame (18); a motor drive assembly comprising at least a first motor (30), said at least first motor (30) surrounding one of said lift shafts (25, 26); a force transmission assembly rotatably connecting the first and second lift shafts (25, 26) via a force transmission element (32); A container handling vehicle (9). (Item 13) the force transmission element (32) comprises an endless belt (32) with an inner surface and an outer surface, the first lift shaft (25) contacting the inner surface or the outer surface of the belt, and the second lift shaft (26) contacting the other of the inner surface or the outer surface of the belt (32); a first lift shaft wheel (33') connected to rotate with the first lift shaft (25), a second lift shaft wheel (33'') connected to rotate with the second lift shaft (25), and at least one guide wheel (33''', 33''''), such that when one of the first or second lift shaft (25, 26) moves in a first rotational direction, the other of the first and second lift shafts (25, 26) moves in a second rotational direction opposite to the first direction; Item 13. The container handling vehicle (9) according to item 12, wherein the endless belt (32) forms a closed loop, one of the first or second lift shaft wheels (33', 33'') is arranged inside the closed loop, and the other of the first or second lift shaft wheels (33', 33'') is arranged outside the closed loop. (Item 14) Use of a container handling vehicle according to item 12 or 13 for storing and retrieving storage containers (6) in a storage system. (Item 15) 12. A method of operating an automated storage and retrieval system according to items 1-11, comprising providing signals to different container handling vehicles (9) that operate within the system to store storage containers (6) in stacks (5) and retrieve storage containers from stacks (5). (Item 16) A method of operating a lifting assembly (24) of a container handling vehicle (9), comprising: arranging a motor drive assembly including at least a first motor (30) to surround the first or second lift shaft (25, 26) of the lift system (24); connecting two lifting elements (25', 25''; 26', 26'') from each of the first and second lifting shafts (25, 26) to the lifting frame (18); Rotationally coupling the first and second lifting shafts (25, 26) to synchronize the raising and lowering of opposite sides of the lifting frame (18); using a lifting assembly (24) for lifting a storage container (6) from a storage column (5) to a position above the minimum height of the transport mechanism on the container handling vehicle (9); A method comprising: (Item 17) Item 17. The method according to item 16, further comprising surrounding a second motor (30) around the same first or second lift shaft (25, 26) as the first motor (30) or around the other of the same first or second lift shaft (25, 26) as the first motor (30). [Brief explanation of the drawings]

[0068] The following drawings are included to facilitate understanding of the present invention.

[0069] [Figure 1] FIG. 1 is a perspective view of a grid with a rail system of a prior art automated storage and retrieval system. [Figure 2A] FIG. 2A is a perspective view of a first prior art container handling vehicle. [Figure 2B] FIG. 2B is a perspective view of a second prior art container handling vehicle. [Figure 2C] FIG. 2C is a side view of the second prior art container handling vehicle of FIG. 2B showing a lifting device, ie, an elevator, for lifting and / or lowering the storage containers. [Figure 3] FIG. 3 is a top view of a prior art single rail grid. [Figure 4] FIG. 4 is a top view of a prior art dual rail grid. [Figure 5-1] 5A and 5B are perspective views of a second container handling vehicle with an exemplary lifting assembly according to the present invention with one motor on each of the first and second lifting shafts, viewed from two different angles. [Figure 5-2] 5C and 5D are side views of a second container handling vehicle with an exemplary lifting assembly according to the present invention, viewed from two different sides. [Figure 5-3] FIG. 5E is a perspective view of a second container handling vehicle with one motor on each of the first and second lift shafts with an exploded view of an exemplary lift assembly according to the present invention. [Figure 6-1] 6A and 6B are side perspective views of a first container handling vehicle with an exemplary lifting assembly in accordance with the present invention. [Figure 6-2]6C and 6D are side views of a first container handling vehicle with an exemplary lifting assembly according to the present invention, viewed from two different sides. [Figure 6-3] Figures 6E and 6F are perspective and top views of the first container handling vehicle with two motors on the same lift shaft. [Figure 6-4] FIG. 6G is a perspective view of a first container handling vehicle with two motors on one of the lift shafts with an exploded view of an exemplary lift assembly in accordance with the present invention. [Figure 6-5] FIG. 6H is an upside-down view of the upper portion of a container handling vehicle according to the second embodiment. [Figure 7] 7A-7F are examples of different configurations of force transfer assemblies including guide wheels, lift shaft wheels, and force transfer elements that provide counter-rotation of the first and second lift shafts.

[0070] In the drawings, like reference numerals are used to denote like parts, elements, or features unless otherwise expressly stated or implicitly understood from the context. DETAILED DESCRIPTION OF THE INVENTION

[0071] In the following, embodiments of the present invention will be discussed in more detail, by way of example only, with reference to the accompanying drawings, in which: It will be understood, however, that the drawings are not intended to limit the invention to the subject matter depicted in the drawings; Furthermore, even if some of the features are described in relation to the system only, it will be clear that they are also valid in relation to the method and container handling vehicle, and vice versa, i.e., any feature described in relation to the method only is also valid in relation to the system and container handling vehicle;

[0072] FIG. 3 is a top view of a grid 4 with a rail system 8 of an automated storage and retrieval system. The grid 4 comprises a framework structure 1 including a plurality of upright members 2 (see FIG. 1 ) and a plurality of horizontal members 3 supported by the upright members. As is known in the art, the upright and horizontal members may typically be made of metal, such as extruded aluminum profiles. The top surface of the grid 4 has a rail system 8. The rail system 8 includes a first set of parallel tracks 10 arranged in a horizontal plane P and extending in a first direction X, and a second set of parallel tracks 11 arranged in the horizontal plane P and extending in a second direction Y perpendicular to the first direction X. The first and second sets of tracks 10, 11 form a grid pattern in the horizontal plane P including a plurality of adjacent grid cells, each including a grid opening 12 defined by a pair of adjacent tracks 10 a, 10 b of the first set of tracks 10 and a pair of adjacent tracks 11 a, 11 b of the second set of tracks 11. The exemplary grid opening 12 of Figures 3 and 4 is part of an overall rail system 8 (see Figure 1).

[0073] Figures 6A and 6B are perspective side views of a first container handling vehicle with a lifting assembly according to the present invention, and Figures 5A and 5B are perspective views of a second container handling vehicle with an exemplary lifting assembly according to the present invention, with one motor on each of the first and second lifting shafts, viewed from two different angles.

[0074] 5A and 5B, the container handling vehicle 9 comprises a transport mechanism exemplified as a first set of wheels 14 and a second set of wheels 15. The first set of wheels 14 and the second set of wheels are vertically oriented such that the container handling vehicle 9 is configured to move on the rail system 8 above the storage columns 5 in both the X and Y directions. Arranged on the upper portion of the container handling vehicle 9 is a lifting assembly 24 for picking up storage containers or bins 6 from the storage columns 5 to a position above the minimum height of the first and second sets of wheels 14, 15 on the container handling vehicle. The operation of the container handling vehicle 9 and the details of its configuration will not be described in more detail herein, as such container handling vehicles 9 are known. The lifting assembly 24 comprises a lifting frame 18 connectable to the storage container 6. The lifting frame 18 typically comprises several electrically operated grippers 38 (gripper details in FIGS. 5C and 5E ) arranged around the circumference of the lifting frame 18, which grip the storage containers 6 for lifting them and moving them between stacks 5, to a port, to another storage system, etc. Several guidance devices 39 are arranged on the underside and in the corners of the lifting frame 18 for guiding the lifting frame 18 relative to the storage containers 6. The lifting frame 18 is lowered into the stack and therefore has a cross-sectional area similar to that of a cell in the rail system 8.

[0075] The lift assembly 24 further includes a first lift shaft 25 and a second lift shaft 26 of equal or nearly equal diameter. The first and second lift shafts 25, 26 are arranged on opposite sides of the lift assembly and are primarily parallel. The first and second lift shafts 25, 26 are each supported within the upper portion of the vehicle 9. Two lift elements, e.g., belts 25′, 25″, 26′, 26″, extend from each of the first and second lift shafts 25, 26 to the lift frame 18 and are connected to the lift frame 18 at flexible element connections 37 for the lift elements (see FIG. 5E in detail). A motor drive assembly is connected to at least one of the first or second lift shafts 25, 26. In FIGS. 5A and 5B, the motor drive assembly includes two motors 30 surrounding the respective first and second lift shafts 25, 26. Force transmission assemblies 32, 33', 33'', 33''', 33'''', 35 rotatably connect the first and second lifting shafts 25, 26 via force transmission elements 32. A tensioning mechanism, shown as a tensioning wheel 34, may be provided for initial tensioning of the force transmission elements 32 to ensure proper force transmission and / or synchronization between the first and second lifting shafts 25, 26. Figures 5C and 5D are side views of a second container handling vehicle 9 with an exemplary lifting assembly according to the present invention, seen from two different sides.

[0076] FIG. 5E is a perspective view of a second container handling vehicle with one motor 30 on each of the first and second lift shafts 25, 26, along with an exploded view of an exemplary lift assembly according to one aspect of the present invention. Motor 30 is illustrated as a brushless DC motor of a reluctance motor type; however, other types of DC motors, as illustrated and described in the general section of the description, such as one or more permanent magnet motors or a combination of different brushless DC motors, can be used instead of or in addition to the disclosed reluctance motor type. The stator 21 in motor 30 seen in FIG. 5E is in the form of electrical windings 21 a wound around a yoke 21 b. However, those skilled in the art will understand that stator 21 and rotor 22 can be configured with stator magnets and rotor yokes / windings, respectively (in other embodiments of the present invention). The motor 30 includes a stator 21 radially arranged between a rotor magnet (on the radially outer side of the stator 21 inside the wheel rim 46) and a first or second lift shaft 25, 26 (on the radially inner side of the stator 21). The stator 21 is fixed to a stator housing 45, which is fixedly connected to the housing of the container handling vehicle 9. A rotor magnet (not shown) is arranged on the inner side of the wheel rim 46 surrounding the stator 21 and is rotationally connected to the first or second lift shaft 25, 26, for example, via a conical bearing 44 (detail of the conical bearing 44 in FIG. 6G), so that the rotor magnet and the first or second lift shaft 25, 26 rotate together. The stator 21, in turn, rotates the rotor magnet and thereby the lift shaft 25, 26. A protective cover 23 surrounds the wheel rim 46 and the stator 21.

[0077] FIG. 5E further discloses an example of how the lifting elements 25′, 26, 26′, 26″ are wound on reels around the first and second lifting shafts 25, 26, respectively. When the lifting shafts 25, 26 rotate, the reels rotate with the lifting shafts 25, 26, and depending on the direction of rotation, the lifting frame 18 is either raised or lowered. The lifting elements 25′, 25″, 26′, 26″ are preferably electrically conductive and signal conductive so that the grippers 38 in the lifting frame 18 can be electronically operated to grip and release bins or containers 6.

[0078] The force transmission assembly comprises several wheels 33', 33", 33'", 33'", 33"', including a first lift shaft wheel 33' and a second lift shaft wheel 33", which are arranged relative to one another such that when one of the first or second lift shafts 25, 26 moves in a first rotational direction, the other of the first and second lift shafts 25, 26 moves in a second rotational direction opposite the first direction in both rotational directions. The first lift shaft wheel 33' is connected for rotation with the first lift shaft 25, and the second lift shaft wheel 33" is connected for rotation with the second lift shaft 26, following any rotational movement of the first and second lift shafts 25, 26, respectively. At least one of the other guide wheels 33'" is arranged inside the closed loop (see details in Figures 7A-7F). Additionally, one of the first or second lift shaft wheels 33', 33" contacts the inner surface of the endless belt 32, and the other of the first or second lift shaft wheels 33', 33" contacts the outer surface of the endless belt 32, causing the first and second lift shaft wheels 33', 33" (and thus the first and second lift shafts 25, 26) to rotate in opposite directions. This opposite rotation ensures that the lift frame 18, and any storage containers lifted by the lift frame 18, are lifted substantially vertically with minimal horizontal movement during the vertical lifting operation. Preferably, the first and second lifting shafts 25, 26 and lifting elements 25′, 25″, 26′, 26″ are connected such that the lifting elements 25′, 25″, 26′, 26″ are wound onto the first and second lifting shafts 25, 26 from the outside (see detail of lifting elements 26′, 26″ in FIG. 5A , which discloses that the lifting elements 26′, 26″ extend onto the outside of the second lifting shaft 26). This ensures connection of the lifting elements 25′, 25″, 26′, 26″ within the end portions of the lifting frame 18 (e.g., in or near corners) and ensures that the lifting frame is centered and moves only vertically (no or minimal horizontal movement) relative to the first and second lifting shafts 25, 26 during the entire lifting sequence.

[0079] 5A and 5D, a brake arrangement 40 for the lift shafts is further disclosed. The brake arrangement is arranged on the inside of the container handling vehicle 9 (and can also be arranged on the outside of the container handling vehicle 9) and is disclosed as a locking pin 40' (FIG. 5A) that cooperates with a gear (illustrated as second lift shaft 33'' in FIG. 5D) connected for rotation with the first lift shaft 25. In the locked position of the locking arrangement 40, the locking pin 40' engages with the gear on the lift shaft 25, thereby preventing rotation of the gear (and thus the lift shafts 25, 26). In the released position of the locking arrangement 40, the locking pin 40' is operated to a position out of engagement with the gear on the lift shaft 25, thereby allowing the lift shaft to rotate freely under any command from the motor 30.

[0080] 6A and 6B are side perspective views of a first container handling vehicle with an exemplary lifting assembly in accordance with the present invention.

[0081] 6C and 6D are side views of a first container handling vehicle with an exemplary lifting assembly according to the present invention, viewed from two different sides.

[0082] FIG. 6E is a perspective view of the first container handling vehicle from above with two motors on the same lift shaft.

[0083] FIG. 6F is a top view of the first container handling vehicle with two motors on the same lift shaft.

[0084] FIG. 6G is a perspective view of a first container handling vehicle with two motors on one of the lift shafts with an exploded view of an exemplary lift assembly in accordance with the present invention.

[0085] FIG. 6H is an upside-down view of the upper portion of a container handling vehicle according to the second embodiment.

[0086] 6B and 6H, similar to FIG. 5A, a brake arrangement 40 for the lift shaft 25 is disclosed. The brake arrangement 40 is arranged on the exterior of the enclosure container handling vehicle 9 and may include a locking pin 40′, e.g., a ratchet mechanism, cooperating with a gear connected for rotation with the first lift shaft 25. In the locked position of the locking arrangement 40, the locking pin engages with the gear on the lift shaft 25, thereby preventing rotation of the gear (and thus the lift shaft 25). In the released position of the locking arrangement 40, the locking pin is operated to a position out of engagement with the gear on the lift shaft 25, thereby allowing the lift shaft to rotate freely under any command from the motor 30. Further, in FIG. 6H details of the supports for the lift shafts 25, 26 and brushes for power and signal communication to the lift elements for the first and second lift shafts 25′, 25″, 26′, 26″ arranged in the upper portion of the container handling vehicle (generally at 41). Furthermore, FIG. 6H shows details of a “keyhole” arrangement 36′, 36″ in the housing of the container handling vehicle for receiving the first and second lift shafts 25, 26. The keyhole arrangement comprises a recessed guide portion 36″ with a cross-sectional area approximately equal to the diameter of the first and second lift shafts 25, 26. Thus, the first and second lift shafts can be guided into an inner recess 36′ of slightly larger cross-sectional area than the recessed guide portion 36″. Once the individual lift shafts 25, 26 have entered the inner recess 36, supports 41' of substantially the same cross-sectional area as the inner recess 36' are disposed from each axial end of the individual lift shafts 25, 26, whereby the lift shafts 25, 26 are locked within the inner recess 36' by suitable fastening means such as threaded connections, screws or bolts 42 and prevented from escaping from the inner recess 36' through the recess guide 36''. When any repair or maintenance of the lift shafts is required, the fastening means 42 are unclamped, the supports 41' are removed and the lift shafts are free to be removed through the recess guide 36'.

[0087] Although the first and second container handling vehicles are different, one having a central hollow structure for receiving a storage container and the other having a cantilever structure for receiving a storage container, the lifting assembly 24 of the first container handling vehicle 9 is identical to the lifting assembly 24 described in connection with the second container handling vehicle 9. Therefore, the description of the features and functional operation of the lifting assembly 24 is the same for both container handling vehicles and will not be repeated.

[0088] 7A-7F illustrate examples of different configurations of force transmission assemblies that provide counter-rotation of the first and second elevator shafts 25, 26. As shown in all of the embodiments of FIGS. 7A-7F, common to all of the force transmission assemblies is the presence of first and second elevator shaft wheels 33', 33", at least one other guide wheel 33'", 33"", and a force transmission element 32 in the form of an endless belt forming a closed loop, each of which is connected for rotation with a respective elevator shaft 25, 26, with at least one other guide wheel 33'", 33"" arranged inside the closed loop. In addition, either the first or second elevator shaft wheel 33', 33" contacts the inner surface of the endless belt 32, while the other of the first or second elevator shaft wheel 33', 33" contacts the outer surface of the endless belt 32. This is achieved by arranging one of the first or second lift shaft wheels 33', 33" inside the closed loop formed by the force transmission element 32 and the other of the first or second lift shaft wheels 33', 33" outside the closed loop formed by the force transmission element 32. The mutual configuration of the first and second lift shaft wheels 33', 33", the guide wheels 33'", 33"", and the force transmission element 32 is such that the first and second lift shafts 25, 26 rotate in opposite directions (counter-rotating) (via the first and second lift shaft wheels 33', 33", respectively). The first and second lift shaft wheels 33', 33" are preferably arranged in the same horizontal plane to ensure horizontal stability during lifting. The guide wheels 33'", 33"" are arranged along the travel of the force transmission element 32 at fixed positions so that they provide a "change" in the travel direction of the force transmission element 32. The guide wheels 33''', 33'''' are arranged to correctly guide the force transmission element 32 onto the first and second lift shaft wheels 33', 33'', respectively, thereby allowing the first and second lift shaft wheels 33', 33'' (and therefore the lift shafts 25, 26) to rotate in opposite directions.

[0089] In the embodiment of FIG. 7A, one guide wheel 33''' is shown.

[0090] 7B-7F show some embodiments of a force transmission assembly comprising two guide wheels 33''', 33''''. The guide wheels 33', 33'' are arranged alternately along the path of the force transmission element 32 such that the first lift shaft wheel 31' is followed by the guide wheels 33''', 33'''' and the second lift shaft wheel 33'' is followed by the guide wheels 33''', 33'''' in both directions of travel of the force transmission element 32.

[0091] 7D, 7E, and 7F, an embodiment is disclosed that includes a tensioning wheel 34 for tensioning the force transmission element 32. The tensioning wheel 34 may be an eccentric tensioning mechanism, for example, including a rotatable guide wheel with an axle that can be adjusted within an opening in a fixed bracket. The location of the tensioning wheel 34 along the path of the force transmission element 32 is preferably at a location where the path length of the force transmission element 32 can be affected (i.e., the path of the force transmission element can be shortened or lengthened to add more tension or reduce tension in the force transmission element). The tensioning wheel 34 can be arranged inside (FIGS. 7D and 7F) or outside (FIG. 7E) of the closed loop formed by the force transmission element 32.

[0092] In the embodiment of Figures 7A-7C, a dedicated tensioning mechanism such as a tensioning wheel is shown; however, if a tensioning mechanism is required, one of the guide wheels 33''' or 33'''' may be the tensioning mechanism and can be replaced by tensioning wheel 34.

[0093] One or more of the aspects of the present invention provide advantages over the prior art, including the following. The efficiency of lifting and lowering storage containers between the container handling vehicle and the storage column is improved. The capacity of the storage system in terms of moving storage containers in less time is increased. The system compensates when the load on a storage container is unevenly distributed, with the center of gravity of the storage container being more on one side than another. The lift system is easier to assemble and maintain and has fewer parts than prior art solutions.

[0094] In the foregoing description, various aspects of the automated storage and retrieval system according to the present invention have been described with reference to illustrative embodiments. However, this description is not intended to be construed in a limiting sense. Various modifications and variations of the illustrative embodiments, and other embodiments of the system, that are apparent to those skilled in the art are deemed to be within the scope of the invention as defined by the following claims.

[0095] [Table 1]

Claims

1. An automated storage and retrieval system, comprising: Rail system and A container handling vehicle (9), a transport mechanism (14, 15) for transporting said vehicle (9) on said rail system (8); a lifting assembly (24) for lifting storage containers (6) from storage columns (5) arranged below the rail system to a position above the minimum height of the transport mechanisms (14, 15); A container handling vehicle (9) comprising: Equipped with The lifting assembly (24) a lifting frame (18) connectable to the storage container (6); a first lift shaft (25) and a second lift shaft (25), the first and second lift shafts (25, 26) being primarily parallel, each of the first and second lift shafts (25, 26) being supported within an upper portion of the vehicle (90); two lifting elements (25', 25''; 26', 26'') extending from each of the first and second lifting shafts (25, 26) to the lifting frame (18); a motor drive assembly comprising at least a first motor (30), said at least first motor (30) surrounding one of said lift shafts (25, 26); a force transmission assembly comprising two or more lift shaft wheels and at least one guide wheel, rotatably connecting the first and second lift shafts (25, 26) via a force transmission element (32); An automated storage and retrieval system comprising:

2. An automatic storage and retrieval system as described in claim 1, wherein the force transmission element comprises an endless belt (32) with an inner and outer surface, the first lifting shaft (25) contacting the inner surface or the outer surface of the belt, and the second lifting shaft (26) contacting the other of the inner surface or the outer surface of the belt (32).

3. The automatic storage and retrieval system of claim 2, wherein the force transmission assembly comprises a first lifting shaft wheel (33') connected to rotate with the first lifting shaft (25) and a second lifting shaft wheel (33'') connected to rotate with the second lifting shaft (25), so that when one of the first or second lifting shafts (25, 26) moves in a first rotational direction, the other of the first and second lifting shafts (25, 26) moves in a second rotational direction opposite to the first direction in both rotational directions, and the at least one guide wheel (33''', 33'''') is arranged to press the outer surface of the belt (32) against one of the first or second lifting shaft wheels (33', 33'').

4. An automatic storage and retrieval system as described in either claim 2 or 3, wherein the endless belt (32) forms a closed loop, one of the first or second lifting shaft wheels (33', 33'') is arranged inside the closed loop, and the other of the first or second lifting shaft wheels (33', 33'') is arranged outside the closed loop.

5. An automatic storage and retrieval system as described in any one of claims 1 to 4, wherein the force transmission assembly is provided with a tensioning mechanism (34) for initial tightening of the force transmission element (32).

6. An automatic storage and retrieval system as described in any one of claims 1 to 5, wherein at least one motor (30) comprises a brushless DC motor.

7. An automatic storage and retrieval system as described in Claim 6, wherein the at least first motor (30) comprises a rotary electric motor that converts direct current electrical energy into rotational energy for the at least first or second lifting shaft (25, 26).

8. An automatic storage and retrieval system as described in any one of claims 1 to 7, wherein the motor drive assembly includes a second motor (30) that surrounds the same lifting shaft (25, 26) as the first motor (30), and the force transmission assembly includes a belt that transmits torque from the first or second lifting shaft (25, 26) associated with the first and second motors (30) to the other of the first or second lifting shaft (25, 26).

9. An automatic storage and retrieval system as described in any one of claims 1 to 7, wherein the motor drive assembly includes a second motor (30) surrounding the other of the first or second lifting shafts (25, 26) different from the first motor (30), and the force transmission assembly includes a timing belt providing synchronous movement of the first and second lifting shafts (25, 26) relative to each other.

10. An automated storage and retrieval system as described in any of claims 1 to 9, wherein the rotational force of the motor-driven assembly corresponds to the intended maximum weight of the storage container (6) containing the items.

11. An automatic storage and retrieval system as described in claim 1, wherein the force transmission assembly comprises several angle gears and a link shaft, the angle gears connected to rotate with each of the first and second lifting shafts, and the link shaft arranged between the angle gears of the first and second lifting gears.

12. A container handling vehicle (9) for moving storage containers (6) in an automated storage and retrieval system (1), said container handling vehicle (9) configured to move on a rail system (8); a lifting assembly (24) for lifting a storage container (6) from a storage column (5) below said rail system to a position above the minimum height of the transport mechanism on said container handling vehicle (9); Equipped with The lifting assembly (24) a lifting frame (18) connectable to the storage container (6); a first lift shaft (25) and a second lift shaft (26), said first and second lift shafts (25, 26) being primarily parallel and each of said first and second lift shafts (25, 26) being supported within an upper portion of said vehicle (9); two lifting elements (25', 25''; 26', 26'') extending from each of the first and second lifting shafts (25, 26) to the lifting frame (18); a motor drive assembly comprising at least a first motor (30), said at least first motor (30) surrounding one of said lift shafts (25, 26); a force transmission assembly including two or more elevator shaft wheels and at least one guide wheel, the force transmission assembly rotatably connecting the first and second elevator shafts via a force transmission element; A container handling vehicle (9).

13. The force transmission element (32) comprises an endless belt (32) with an inner and an outer surface, the first lifting shaft (25) being in contact with the inner surface or the outer surface of the belt, and the second lifting shaft (26) being in contact with the other of the inner surface or the outer surface of the belt (32); a first lifting shaft wheel (33') connected to rotate with the first lifting shaft (25), a second lifting shaft wheel (33'') connected to rotate with the second lifting shaft (25), and the at least one guide wheel (33''', 33''''), such that when one of the first or second lifting shafts (25, 26) moves in a first rotational direction, the other of the first and second lifting shafts (25, 26) moves in a second rotational direction opposite to the first direction; 13. The container handling vehicle (9) according to claim 12, wherein the endless belt (32) forms a closed loop, one of the first or second lift shaft wheels (33′, 33″) is arranged inside the closed loop, and the other of the first or second lift shaft wheels (33′, 33″) is arranged outside the closed loop.

14. Use of a container handling vehicle as described in claim 12 or 13 for storing and retrieving storage containers (6) in a storage system.

15. A method of operating an automated storage and retrieval system as described in claims 1 to 11, comprising providing signals to different container handling vehicles (9), said different container handling vehicles (9) operating within said automated storage and retrieval system to store storage containers (6) in stacks (5) and retrieve storage containers from stacks (5).

16. A method for operating a lifting assembly (24) of a container handling vehicle (9), comprising: arranging a motor drive assembly including at least a first motor (30) to surround the first or second lift shaft (25, 26) of the lift assembly (24); connecting two lifting elements (25', 25''; 26', 26'') from each of the first and second lifting shafts (25, 26) to a lifting frame (18); rotationally coupling the first and second lift shafts (25, 26) via a force transmission assembly to synchronize the raising and lowering of opposite sides of the lift frame (18); using said lifting assembly (24) to lift a storage container (6) from a storage column (5) to a position above the minimum height of a transport mechanism on said container handling vehicle (9); wherein the force transmission assembly comprises two or more elevator shaft wheels, at least one guide wheel, and a force transmission element.

17. The method of claim 16, further comprising a second motor (30) surrounding the same first or second lifting shaft (25, 26) as the first motor (30), or the second motor (30) surrounding the other of the first or second lifting shaft (25, 26) as the first motor (30).

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