Patent ID: 11866256
Assignee: WALMART APOLLO, LLC
Field: Mechanical elements (Mechanical engineering)
Classification: CPC B  F | IPC B

Claim 11:
12. An order fulfilment system, comprising:
a multilevel storage structure having storage locations in different levels, and a vertical or inclined passage passing between the different levels, the passage comprising a linear drive mount along its length; and
a mobile robot configured to travel between the levels in the passage, the mobile robot having:
a motor mounted within the mobile robot, the motor comprising a first spline;
a shaft having a second spline, the shaft configured to be rotated about an axis of rotation by the motor by the first spline of the motor exerting force on the second spline of the shaft, the shaft further configured to be extended axially along the axis of rotation;
a drive gear mounted on an end of the shaft, the drive gear configured to move into engagement with the linear drive mount upon extension of the shaft;
wherein the first and second splines are configured to prevent jamming of the drive gear against the linear drive mount when the drive gear moves into engagement with the linear drive mount upon extension of the shaft by providing rotational play between the first and second splines, the rotational play allowing a degree of free rotation of the drive gear relative to the linear drive mount.