US-12618437-B2 - Ball spline device, automated guided vehicle and stereoscopic warehouse system

US12618437B2US 12618437 B2US12618437 B2US 12618437B2US-12618437-B2

Abstract

A ball spline device includes a spline shaft, the outer side wall provided with raceway grooves extending in the axial direction, each raceway groove comprising, a first groove section and a second groove section, and the width of the second groove section being greater than that of the first groove section; a spline nut coaxially fitted over the spline shaft; and first rolling bodies. When the spline nut is located at a first position, the first rolling bodies are located in the first groove sections and in constraint fit with the first groove sections; and when the spline nut is located at a second position, the first rolling bodies are located in the second groove sections, such that the spline nut and the spline shaft have a preset movement amount in the circumferential direction. Further provided are an automated guided vehicle and a stereoscopic warehouse system.

Inventors

Chen Liu
Zongjing YU
Guoku SONG
Xu Liu

Assignees

Beijing Jingdong Qianshi Technology Co., Ltd.

Dates

Publication Date: 20260505
Application Date: 20210311
Priority Date: 20200922

Claims (12)

1 . An automated guided vehicle, comprising a ball spline device, a wheel and a drive member, wherein the ball spline device, comprises: a spline shaft, an outer side wall of which is provided with a raceway groove extending along an axial direction, the raceway groove comprising a first groove section and a second groove section communicated along the axial direction, a width of the second groove section being greater than a width of the first groove section; a spline nut, coaxially sleeved outside the spline shaft; and a first rolling body, movably disposed in the raceway groove along the axial direction, so as to achieve relative movement of the spline nut and the spline shaft; wherein when the spline nut is in a first position, the first rolling body is in the first groove section and cooperates with the first groove section in a constrained manner, so as to cause synchronous rotation of the spline nut and the spline shaft; and when the spline nut is in a second position, the first rolling body is in the second groove section, so that there is a predetermined gap in a circumferential direction between the spline shaft and the spline nut; wherein the wheel is coaxially mounted to the spline nut, the drive member is configured to provide drive power for the rotation of the spline shaft, and the spline nut comprises: an inner nut, sleeved outside the spline shaft and connected with the wheel; an outer nut, sleeved outside the inner nut, the outer nut is provided with a flange structure, and the outer nut is connected with a support frame disposed on the automated guided vehicle by means of the flange structure; and a second rolling body, movably disposed between the inner nut and the outer nut along the circumferential direction, so as to enable relative rotation of the inner nut and the outer nut; wherein the first rolling body is disposed between the inner nut and the raceway groove.
2 . The automated guided vehicle according to claim 1 , wherein the raceway groove further comprises a transition groove section, the transition groove section connected between the first groove section and the second groove section, and configured to guide the first rolling body to switch between the first groove section and the second groove section.
3 . The automated guided vehicle according to claim 2 , wherein both side walls of the transition groove section are bevels, and have a distance therebetween gradually increasing from the first groove section to the second groove section.
4 . The automated guided vehicle according to claim 1 , wherein there are two first groove sections, the second groove section is located in the middle region of the spline shaft along the axial direction, and both ends of the second groove section are communicated with the two first groove sections, respectively.
5 . The automated guided vehicle according to claim 1 , wherein a first end of the spline shaft has a first mounting portion configured to connect to a drive member that provides power to the rotation of the spline shaft; and a second end of the spline shaft has a second mounting portion configured to be connected with an external first transmission member.
6 . The automated guided vehicle according to claim 1 , further comprising: two first seal members, disposed between the spline nut and the spline shaft and located at two ends of the spline nut along the axial direction; wherein the first rolling body is located between the two first seal members.
7 . The automated guided vehicle according to claim 6 , further comprising: two second seal members, disposed between the inner nut and the outer nut and located at two ends of the outer nut along the axial direction, wherein the second rolling body is located between the two second seal members.
8 . The automated guided vehicle according to claim 1 , wherein a first end of the spline shaft has a first mounting portion, the drive member is in drive connection with the first mounting portion, and a second end of the spline shaft has a second mounting portion; the automated guided vehicle further comprises a first transmission member, the first transmission member connected to the second mounting portion and configured to cooperate with an external second transmission member.
9 . The automated guided vehicle according to claim 8 , wherein when the spline nut is in the second position, the first transmission member is configured to be adjusted to cooperate with the second transmission member while a position of the wheel remains unchanged.
10 . The automated guided vehicle according to claim 8 , wherein the automated guided vehicle is configured to have a walking mode and a moving mode when the spline nut is in the first position; wherein in the walking mode, the automated guided vehicle is configured to drive rotation of the wheel through driving the spline shaft by the drive member to achieve walking; and in the moving mode, the automated guided vehicle is configured to drive rotation of the first transmission member through driving the spline shaft by the drive member, so as to achieve movement through cooperation of the first transmission member and the second transmission member.
11 . A stereoscopic warehouse system, comprising: a stereoscopic warehouse, having a plurality of layers of storage positions and provided with a second transmission member which comprises a vertical rack; and an automated guided vehicle according to claim 1 , comprising a first transmission member which comprises a gear, a first end of the spline shaft having a first mounting portion, the drive member being in drive connection with the first mounting portion, and a second end of the spline shaft having a second mounting portion connected to the gear; wherein when the spline nut is in the second position, the gear is configured to be adjusted to cooperate with the second transmission member while a position of the wheel is unchanged.
12 . The stereoscopic warehouse system according to claim 11 , wherein the automated guided vehicle is configured to have a walking mode and a moving mode when the spline nut is in the first position; in the walking mode, the automated guided vehicle is configured to drive rotation of the wheel through driving the spline shaft by the drive member to achieve walking; and in the moving mode, the automated guided vehicle is configured to drive motion of the gear along the rack through driving the spline shaft by the drive member to achieve movement in the vertical direction, so as to reach storage positions in different layers.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a U.S. National State Application under 35 U.S.C. § 371 of International Application No. PCT/CN2021/080165, filed Mar. 11, 2021, which itself is based on and claims priority to Chinese Application No. 202011004699.0, filed on Sep. 22, 2020, the disclosure of both of which are hereby incorporated into the present disclosure in their entireties. TECHNICAL FIELD The present disclosure relates to the technical field of mechanical transmission, in particular to a ball spline device, an automated guided vehicle and a stereoscopic warehouse system. BACKGROUND A ball spline is a component having a raceway groove machined on a spline shaft and a steel ball, on a spline nut, cooperating with the raceway groove on the spline shaft, so that the spline nut can move along the axial direction on the spline shaft and also can transmit torque and force. The raceway on the spline shaft of the ball spline at present cooperates with the steel ball in a constrained manner in the whole length, so that the spline shaft and the spline nut have a strict transmission ratio, and when the spline shaft is required to rotate by a small angle relative to the spline nut in the application process, it is difficult for the ball spline structure at present to achieve this function. SUMMARY According to a first aspect of the present disclosure, a ball spline device is provided, including: a spline shaft, the outer side wall of which is provided with a raceway groove extending along the axial direction, the raceway groove includes a first groove section and a second groove section communicated along the axial direction, a width of the second groove section being greater than a width of the first groove section;a spline nut, coaxially sleeved outside the spline shaft; anda first rolling body, movably disposed in the raceway groove along the axial direction, so as to achieve relative movement of the spline nut and the spline shaft;wherein when the spline nut is in a first position, the first rolling body is in the first groove section, and cooperates with the first groove section in a constrained manner, so as to cause synchronous rotation of the spline nut and the spline shaft; and when the spline nut is in a second position, the first rolling body is in the second groove section, so that there is a predetermined gap in a circumferential direction between the spline shaft and the spline shaft. In some embodiments, the raceway groove further includes a transition groove section, the transition groove section connected between the first groove section and the second groove section, and configured to guide the first rolling body to switch between the first groove section and the second groove section. In some embodiments, both side walls of the transition groove section are bevels, and have a distance therebetween gradually increasing from the first groove section to the second groove section. In some embodiments, the second groove section is located in the middle region of the spline shaft along the axial direction, and both ends of the second groove section are provided with the first groove section. In some embodiments, a plurality of groups of raceway grooves are disposed along the circumferential direction, each group of the raceway grooves including two spaced raceway grooves, and a circumferential spacing between two adjacent groups of raceway grooves being greater than that between two adjacent raceway grooves in the same group. In some embodiments, a first end of the spline shaft has a first mounting portion configured to connect to a drive member that provides power to the rotation of the spline shaft; and a second end of the spline shaft has a second mounting portion configured to be connected with an external first transmission member. In some embodiments, the present disclosure further includes: two groups of first seal members, disposed between the spline nut and the spline shaft and located at two ends of the spline nut along the axial direction;wherein the first rolling body is located between the two groups of first seal members. In some embodiments, the spline nut includes: an inner nut, sleeved outside the spline shaft;an outer nut, sleeved outside the inner nut; anda second rolling body, movably disposed between the inner nut and the outer nut along the circumferential direction, so as to enable relative rotation of the inner nut and the outer nut;wherein the first rolling body is disposed between the inner nut and the raceway groove. In some embodiments, the present disclosure further includes: two groups of second seal members, disposed between the inner nut and the outer nut and located at two ends of the outer nut along the axial direction;wherein the second rolling body is located between the two groups of second seal members. According to a second aspect of the present disclosure, an automated guided vehicle is provided, including: the ball spline device i