US-12618435-B2 - Glide bearing assembly

US12618435B2US 12618435 B2US12618435 B2US 12618435B2US-12618435-B2

Abstract

The disclosure relates to a load-handling device for lifting and moving storage containers stacked in a storage structure. The load-handling device includes a body mounted on a first set of wheels to engage a first set of parallel tracks and a second set of wheels to engage with a second set of parallel tracks. A direction-change assembly is configured to raise or lower the first and second sets of wheels with respect to the body to engage one of the first or second sets of wheels with the parallel tracks and disengage the other of the first or second sets of wheels from the parallel tracks. A glide bearing assembly includes a bearing element including a sliding surface defining a contact line along which the direction-change assembly moves with respect to the body when raising or lowering the first and second sets of wheels.

Inventors

Alexandros MATSAGKOS
Arvid HÄLLJE

Assignees

OCADO INNOVATION LIMITED

Dates

Publication Date: 20260505
Application Date: 20220525
Priority Date: 20210525

Claims (13)

1 . A load-handling device for lifting and moving storage containers stacked in a storage structure having a first set of parallel rails or tracks, and a second set of parallel rails or tracks extending substantially perpendicularly to the first set of rails or tracks, in a substantially horizontal plane to form a grid with a grid pattern including a plurality of grid spaces, wherein the grid is supported by a set of uprights to form a plurality of vertical storage locations beneath the grid for containers to be stacked between, and to be guided by, the uprights in a vertical direction through the plurality of grid spaces, the load-handling device comprising: a body mounted on a first set of wheels configured to engage with a first set of parallel tracks, and a second set of wheels configured to engage with a second set of parallel tracks; a direction-change assembly configured to raise or lower the first and second sets of wheels with respect to the body to engage one of the first or second sets of wheels with the parallel tracks and disengage the other of the first or second sets of wheels from the parallel tracks; and a glide bearing assembly including: a bearing element including a sliding surface defining a contact line along which the direction-change assembly moves with respect to the body when raising or lowering the first and second sets of wheels; and a removable cartridge configured to hold the bearing element in position between the body and the direction-change assembly, wherein the body or the direction-change assembly includes a bearing mount configured to receive the cartridge.
2 . A load-handling device according to claim 1 , wherein the body or the direction-change assembly comprises: a bore through which the cartridge can be accessed.
3 . A load-handling device according to claim 2 , wherein the bore is divergent in a direction of the cartridge.
4 . A load-handling device according to claim 1 , wherein the cartridge is configured to be removed from the body or the direction-change assembly in a direction of the contact line.
5 . A load-handling device according to claim 1 , wherein the glide bearing assembly comprises: a retaining plate securable to the body or the direction-change assembly so as to hold the cartridge in position with respect to the body or the direction-change assembly.
6 . A load-handling device according to claim 5 , wherein the glide bearing assembly comprises: a fastener extending through the retaining plate and the cartridge.
7 . A load-handling device according to claim 1 , wherein the cartridge comprises: a manual adjustment mechanism configured to adjust a position of the bearing element relative to the cartridge.
8 . A load-handling device according to claim 1 , wherein the cartridge is marked according to its size for identification.
9 . A load-handling device according to claim 1 , wherein the bearing element has a cylindrical shape.
10 . A load-handling device according to claim 1 , wherein the bearing element has a triangular prism shape.
11 . A load-handling device according to claim 10 , wherein the contact line is located at an apex of the bearing element.
12 . A load-handling device according to claim 1 , wherein the bearing element is made of polytetrafluoroethylene.
13 . A glide bearing assembly configured for a load-handling device having a body mounted on a first set of wheels configured to engage with a first set of parallel tracks, and a second set of wheels configured to engage with a second set of parallel tracks; and a direction-change assembly configured to raise or lower the first and second sets of wheels with respect to the body to engage one of the first or second sets of wheels with the parallel tracks and disengage the other of the first or second sets of wheels from the parallel tracks, the glide bearing assembly comprising: a bearing element including a sliding surface defining a contact line along which a direction-change assembly will move with respect to a body when raising or lowering first and second sets of wheels of the load-handling device; and a removable cartridge configured to hold the bearing element in position between the body and the direction-change assembly.

Description

The invention relates to a glide bearing assembly and in particular a guide bearing assembly for a load-handling device. BACKGROUND GB2520104A (Ocado Innovation) describes a system in which stacks of containers are arranged within a storage structure that supports load-handling devices. The load-handling devices each cover one grid space of the storage structure, thus allowing high density of load handlers and thus high throughput of a given size system. The robotic load-handling devices are controllably moved around the top of the storage structure on a track system forming a grid. Each load-handling device is configured to lift a bin from the stack, the container being lifted containing inventory items needed to fulfil a customer order. The container is then carried to a pick station where the required inventory item may be manually removed from the bin and placed in a delivery container, the delivery container forming part of the customer order, and being manually filled for dispatch at the appropriate time. It is beneficial to reduce the weight of each load-handling device. These benefits extend, not only to the device itself in terms of reduced capital and operating expenses, but also to the infrastructure around the device, such as the storage structure and track system. However, in order to ensure that light weight load-handling devices will serve their design purposes and remain functional for a desired service life, it is important to minimise any harmful vibrations that may, over time, compromise its structural integrity. It is against this background that the invention was devised. SUMMARY Accordingly, there is provided, in a first aspect, a load-handling device for lifting and moving storage containers stacked in a storage structure comprising a first set of parallel rails or tracks and a second set of parallel rails or tracks extending substantially perpendicularly to the first set of rails or tracks in a substantially horizontal plane to form a grid pattern comprising a plurality of grid spaces, wherein the grid is supported by a set of uprights to form a plurality of vertical storage locations beneath the grid for containers to be stacked between and be guided by the uprights in a vertical direction through the plurality of grid spaces, the load-handling device comprising a body mounted on a first set of wheels configured to engage with the first set of parallel tracks and a second set of wheels configured to engage with the second set of parallel tracks; a direction-change assembly configured to raise or lower the first and second sets of wheels with respect to the body to engage one of the first or second set of wheels with the parallel tracks and disengage the other of the first or second set of wheels from the parallel tracks; and, a glide bearing assembly comprising a bearing element comprising a sliding surface defining a contact line along which the direction-change assembly moves with respect to the body when raising or lowering the first and second sets of wheels. Using a sliding surface to provide an area of contact between the direction-change assembly and the body reduces noise and vibration when the direction-change assembly moves with respect to the body when compared to conventional bearing assemblies which use a rolling bearing element. The glide bearing assembly further comprises a removable cartridge configured to hold the bearing element in position between the body and the direction-change assembly, wherein the body or the direction-change assembly comprises a bearing mount configured to receive the cartridge. This arrangement provides two advantages. Firstly, from a maintenance perspective, it provides for a straightforward removal and replacement of the bearing elements without the need to disassemble other parts of the bot. Secondly, the provision of removable cartridges enables one to compensate for changes in the dimensions of a contact surface for the glide bearing assembly (e.g., the diameter of a guide shaft or the like). In order to provide smooth, reliable movements during a direction-change manoeuvre; movements that are repeatable over time, and largely free of noise and vibrations, a precise fit between the contact surface and glide bearing assembly is essential. That is to say, the distance between the contact surface and glide bearing assembly must be precise as any variations from the nominal dimensions of the contact surface could have damaging consequences. In order to allow for these variations, differently sized cartridges can be installed that compensate for any changes to the nominal dimensions of the contact surface. So differently sized removable cartridges can be selected according to the dimensions of the contact surface, preventing inaccuracies therebetween, and lessening any noise and vibrations resulting from a direction-change manoeuvre. Compensating for departures from the nominal dimensions of the contact surface cannot be made so easily with