WO2021046795A1

WO2021046795A1 - Robot, connection assembly and assembly method thereof

Info

Publication number: WO2021046795A1
Application number: PCT/CN2019/105607
Authority: WO
Inventors: Bin Liu; Xiaodong Cao
Original assignee: Abb Schweiz Ag
Priority date: 2019-09-12
Filing date: 2019-09-12
Publication date: 2021-03-18

Abstract

A connection assembly for connecting a motor to a gearbox is provided. The connection assembly comprises a sealing housing coupled to the gearbox to form a cavity for receiving a lubricant to lubricate an input of the gearbox; and an intermediate member arranged to at least partially pass through the gearbox or the sealing housing to connect an output of the motor to the input of the gearbox for transmission. With the sealing housing to from a cavity and the intermediate member for connecting the output of the motor to the input of the gearbox, the lubricant would not leak into the motor, thus improving the stability and service life of the motor and even the robot. Furthermore, the motor and/or the gearbox can be removed from or installed on each other in an easier way, for example, merely by decoupling the motor from the intermediate member without the need to dump and refill the lubricant.

Description

ROBOT, CONNECTION ASSEMBLY AND ASSEMBLY METHOD THEREOF

FIELD

Embodiments of the present disclosure generally relate to a robot as well as a connection assembly for connecting a motor to a gearbox of the robot.

BACKGROUND

Robots are now widely used automation mechanisms that increase operational efficiency and accuracy. A robot typically comprises robot arm links and joints. The robot arm link can be driven to rotate or move by a motor arranged in the joint or a base. To meet the requirements of the reduction ratio, a gearbox is needed to be arranged between the motor and the robot arm links to be driven. The gearbox is a device that uses gears and gear trains to provide speed and torque conversions from a rotating power source to another device.

Usually, as a precision component by external suppliers with different material and processing, the gearbox is separated from robot structure manufacturing, which is further connected on the robot structure in the following assembly process. Such separated gearbox and structure designs require connection interfaces and occupy space. Furthermore, for some gearboxes, such as rotary vector (RV) gearbox, at least one gear as an input of the RV gearbox is located outside of the gearbox, and needs to be lubricated during operation to meet its transmission performance and extend service life. In this event, at least a part, such as an output of the motor coupled to the input of gearbox needs to be immersed in the lubricant for lubricating the input of gearbox. As a result, the lubricant may leak into the motor and cause damage to the motor.

SUMMARY

To address or at least partially address the above and other potential problems, embodiments of the present disclosure provide a connection assembly for connecting a motor to a gearbox of the robot.

In a first aspect, a connection assembly for connecting a motor to a gearbox is provided. The connection assembly comprises a sealing housing coupled to the gearbox and defining a cavity for receiving a lubricant to lubricate an input of the gearbox; and an intermediate member at least partially passing through the gearbox or the sealing housing to connect an output of the motor to the input of the gearbox for transmission.

With the sealing housing to from a cavity and the intermediate member for connecting the output of the motor to the input of the gearbox, the lubricant would not leak into the motor, thus improving the stability and service life of the motor and even the robot. Furthermore, the motor and/or the gearbox can be removed from or installed on each other in an easier way, for example, merely by decoupling the motor from the intermediate member without the need to dump and refill the lubricant.

In some embodiments, the intermediate member comprises an internal spline part adapted to be coupled to the output of the motor to rotate with the output; and a gear shaft coupled to the internal spline part and the input of the gearbox for transmission. In this way, the assembly difficulty and cost may be further reduced.

In some embodiments, the internal spline part is arranged adjacent to an end of the gearbox away from the input of the gearbox, and the intermediate member at least partially passes through the gearbox and a coupling end of the intermediate member away from the internal spline part is coupled to the input. With this arrangement, the connection assembly can be more compact.

In some embodiments, the connection assembly further comprises a rotary sealing member arranged between the intermediate member and the gearbox. As a result, the sealing effect may be further improved.

In some embodiments, the internal spline part is arranged adjacent to the input, and the intermediate member at least partially passes through the sealing housing and a coupling end of the intermediate member away from the internal spline part is coupled to the input. With this arrangement, the connection assembly may be achieved in an easier way and can be applied on the conventional motor or gearbox to reduce the maintenance cost.

In some embodiments, the connection assembly further comprises a rotary sealing member arranged between the sealing housing and the intermediate member. As a result, the sealing effect may be further improved.

In some embodiments, the internal spline part and the gear shaft are coaxial. In this way, the volume occupied by the connection assembly may be further reduced with a further improved transmission performance.

In some embodiments, the coupling end comprises external teeth for coupling with at least one gear as the input of the gearbox. In this way, the connection assembly can be applied to a gearbox, such as a rotary vector gearbox with at least one gear as the input, to improve the transmission performance while reducing maintenance costs.

In second aspect, a robot is provided. The robot comprises a joint, a connection assembly as mentioned in the first aspect and a robot arm link coupled to the joint and driven to rotate via the connection assembly.

In some embodiments, a sealing housing of the connection assembly is integrated in the joint or the robot arm link.

In third aspect, an assembly method of a connection assembly is provided. The assembly method comprises providing a sealing housing coupled to the gearbox to form a cavity for receiving a lubricating medium to lubricate an input of the gearbox; and arranging an intermediate member to pass through the gearbox or the sealing housing to couple an output of the motor to the input of the gearbox for transmission.

It is to be understood that the Summary is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objectives, features and advantages of the present disclosure will become more apparent through more detailed depiction of example embodiments of the present disclosure in conjunction with the accompanying drawings, wherein in the example embodiments of the present disclosure, same reference numerals usually represent same components.

FIG. 1 shows a sectional side view and a perspective view of a traditional gearbox;

FIG. 2 shows a sectional side view of a traditional power unit comprising a motor connected with a gearbox;

FIG. 3 shows a sectional side view of a gearbox with a connection assembly according to embodiments of the present disclosure;

FIG. 4 shows a sectional side view of a power unit comprising a motor connected to a gearbox via a connection assembly according to embodiments of the present disclosure;

FIG. 5 shows a perspective view of a gearbox with a connection assembly according to embodiments of the present disclosure; and

FIG. 6 shows a flowchart illustrating an assembly method of a connection assembly according to embodiments of the present disclosure.

Throughout the drawings, the same or similar reference symbols are used to indicate the same or similar elements.

DETAILED DESCRIPTION

The present disclosure will now be discussed with reference to several example embodiments. It is to be understood these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the present disclosure, rather than suggesting any limitations on the scope of the subject matter.

As used herein, the term “comprises” and its variants are to be read as open terms that mean “comprises, but is not limited to. ” The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The terms “first, ” “second, ” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be comprised below. A definition of a term is consistent throughout the description unless the context clearly indicates otherwise.

For some gearboxes, such as rotary vector (RV) gearboxes 300’ , at least one gear as an input 301’ is located outside of the gearbox, which needs to be lubricated during operation to meet its transmission performance and extend service life, as shown in FIG. 1. In this event, at least a part, such as an output 201’ of a motor 200’ coupled to the input 301’ of the gearbox 300’ needs to be immersed in the lubricant for lubricating the input 301’ of gearbox 300’ , as shown in FIG. 2. With the operation of the motor, sealing means arranged in the motor may be worn out. As a result, the lubricant may leak into the motor and cause damage to the motor 200’ .

Furthermore, in the conventional connection assembly, as shown in FIG. 2, the space for receiving the lubricant is formed by parts of motor 200’ and gearbox 300’ with a cylindered housing 101’a rranged therebetween. In this event, when the motor needs to be disassembled from or assembled to the gearbox, for example, during the maintenance of the power unit of a robot, the lubricant in the space needs to be released first. When the motor is reassembled to the gearbox, the lubricant needs to be refilled.

It can be seen that the conventional power unit is time-consuming and labor-intensive in maintenance, and also causes a large amount of lubricant waste, resulting in a significant increase in maintenance costs.

In order to solve or at least partly solve the above problems, embodiments of the present disclosure provide a connection assembly 100 for connecting an output 201 of a motor 200 to an input 301 of a gearbox 300. Now some example embodiments will be described with reference to FIGS. 3-5.

FIG. 3 shows a sectional side view of a gearbox 300 with a connection assembly 100; FIG. 4 shows a sectional side view of a power unit comprising a motor 200 connected to a gearbox 300 via a connection assembly 100; and FIG. 5 shows a perspective view of a gearbox 300 with a connection assembly 100.

As shown, the connection assembly 100 according to embodiments of the present disclosure comprises a sealing housing 101 and an intermediated member 102. The sealing housing 101 can form a cavity 1011 with the gearbox 300 when being coupled to the gearbox 300. The cavity 1011 is used to receive lubricant for lubricating the input 301 of the gearbox 300.

That is, contrast to the conventional solutions, the cavity 1011 for receiving the lubricant is formed by the sealing housing 101 and the gearbox 300, without the motor 200. This arrangement allows that the motor 200 can be disassembled or reassembled without releasing or refilling the lubricant, which will be discussed further below, thereby improving the maintenance efficiency.

The intermediate member 102 of the connection assembly 100 acts as a transmission part to transmit torque and movement from the output 201 of the motor 200 to the input 301 of the gearbox 300. Specifically, the intermediate member 102 is arranged to at least partially pass through the gearbox 300 or the sealing housing 101 to connect the output 201 of the motor 200 to the input 301 of the gearbox 300 for the transmission.

With the sealing housing to form a cavity and the intermediate member for connecting the output of the motor to the input of the gearbox, on the one hand, the input 201 of the motor 200 is completely isolated from the lubricant. As a result, the lubricant would not leak into the motor, thus improving the stability and service life of the motor 200 and even the robot.

On the other hand, as mentioned above, the cavity 1011 for receiving the lubricant is formed by the sealing housing 101 and the gearbox 300 without the motor 200. In this way, the motor 200 can be removed from the gearbox 300 in an easier way, for example, merely by decoupling the motor 200 from the intermediate member 102 without the need to release and refill the lubricant. As a result, the maintenance efficiency may be improved with reduced maintenance costs.

In some embodiments, the intermediate member 102 may comprise an internal spline part 1021 and a gear shaft 1022. The internal spline part 1021 is used to be coupled to the output 201 of the motor 200 to rotate with the output 201. For example, the internal spline part 102 may comprise an internal spline that can be engaged with an external spline arranged on the output 201 coaxially. In this way, when the motor 200 needs to be removed from the gearbox 300, the user only needs to pull out the motor 200 without performing other operations, which significantly improves maintenance efficiency and reduces maintenance costs.

It should be understood that the above embodiments where the internal spline part 1021 is coupled to the output 201 of the motor 200 coaxially are merely for illustration, without suggesting any limitation as to the scope of the present application. Any suitable structures or arrangements are possible. In some alternative embodiments, the axes of internal spline part 1021 and the output 201 of the motor 200 may also be parallel to each other but not coincident. For example, the internal spline part 1021 may have external teeth that can be engaged with the output 201 of the motor 200.

A distal end of the internal spline part 102 away from the output 201 is fixed to the gear shaft 1022, as shown in FIGS. 3 and 4. Specifically, in some embodiments, the distal end of the internal spline part 102 may be coupled to the gear shaft 1022 with splines. For example, the distal end of the internal spline part 102 may have an internal spline arranged therein. In the meantime, one end of the gear shaft 1022 may comprise an external spline that can be engaged with the internal spline arranged on the distal end of the internal spline part 102. This arrangement allows the intermediate member to be assembled more easily.

It should be understood that the above embodiments are merely for illustration, without suggesting any limitation as to the scope of the present application. Any suitable structures or arrangements are possible. For example, in some alternative embodiments, the distal end may also be coupled to the gear shaft 1022 by interference fit, adhesion, welding or the like. In some further alternative embodiments, the internal spline part 1021 and the gear shaft 1022 may also be integrally formed.

In some embodiments, a coupling end of the gear shaft 1022 away from the internal spline part 102 may have teeth. The teeth can be engaged with the input 301 of the gearbox 300. In this way, the movement and torque can be transmitted from the output 201 of the motor 200 to the input 301 of the gearbox 300.

As mentioned above, the intermediate member 102 at least partially passes through the gearbox 300 or the sealing housing 101 to connect an output 201 of the motor 200 to the input 301 of the gearbox 300. This arrangement allows the gearbox 300 to be coupled to the motor in two different ways.

Specifically, in some embodiments, as shown in FIG. 4, the input 301 of the gearbox 300 may be arranged away from the motor 200. In those embodiments, the gearbox 300 may be of a hollow structure and the internal spline part 1021 is arranged adjacent to an end of the gearbox 300 away from the input 301 of the gearbox 300. The hollow structure of the gearbox 300 allows the intermediated member 102 to at least partially pass through the gearbox 300. In this way, the coupling end of the intermediate member 102 away from the internal spline part can be coupled to the input 301 of the gearbox 300.

With this arrangement, the combination of the motor 200 and the gearbox 300 may be more compact. In this event, to enhance the seal, a rotary sealing member 103 may be placed between the components that are relatively rotatable, for example, between the intermediate member 102 and the gearbox 300, as shown in FIG. 4. The rotary sealing member 103, which typically has a deformable structure, is a kind of dynamic sealing member that can withstand the alternating pressure on both sides when the components are relatively rotating.

In some embodiments, as for the components that have no relative motion, a common seal, such as O-ring may be placed therebetween. For example, the O-ring may be placed between the sealing housing 101 and the gearbox 300 to enhance the seal therebetween.

In some embodiments, a flange 104 may be arranged between the motor 200 and the gearbox 300 to facilitate the arrangement of the motor and the gearbox 300. The flange 104 allows a more strengthen the connection between the motor 200 and the gearbox 300. In the case where the motor 200 has a structure that can be assembled well with the gearbox 300, the flange 104 may be omitted.

The above describes the case where the output 301 of the gearbox 300 is away from the motor 200. In some embodiments, the output 301 of the gearbox 300 may also be adjacent to the motor 200. In those embodiments, the internal spline part 1021 is arranged adjacent to the input 301 of the gearbox 300. In the meantime, the intermediate member 102 at least partially passes through the sealing housing 101 with the coupling end being coupled to the input 301.

This arrangement allows a more easy assembly of the motor 200 and the gearbox 300. There is no need to modify the motor 200 and gearbox 300, but only the sealing housing 101 is coupled to the gearbox 300. In those embodiments, different from the example as shown in FIG. 4, a through hole may be formed on the sealing housing 101. The intermediate member 102 may be inserted into the cavity 1011 via the through hole with the coupling end being coupled to the input 301.

Similar to the embodiments as shown in FIG. 4, to enhance the seal, a rotary sealing member may be placed between the components that are relatively rotatable, i.e., between the intermediate member 102 and the sealing housing 101. For example, the rotary sealing member may be arranged in the through hole or around the perimeter of the through hole.

The connection assembly 100 as described above can be used in a robot. Embodiments of the present disclosure further provide a robot comprising a joint, a connection assembly 100 as mentioned above and a robot arm link. The robot arm link is coupled to the joint and driven to rotate by the motor 200 via the connection assembly 100. With the connection assembly 100, the maintenance efficiency for the robot may be significantly improved.

In some embodiments, the sealing housing 101 of the connection assembly 100 may be a part of the robot arm link or the joint. That is, the sealing housing 101 may be integrated in the joint or the robot arm link. This can further improve the integration of the robot, reduce the size of the robot, and facilitate the miniaturization of the robot.

Embodiments of the present disclosure further provide an assembly method of the above mentioned connection assembly 100. FIG. 6 shows a flowchart 600 illustrating an assembly method of a connection assembly 100. As shown, in block 610, a sealing housing 101 is provided. The sealing housing is coupled to the gearbox 300 to form a cavity for receiving a lubricating medium to lubricate an input 301 of the gearbox 300.

In block 620, an intermediate member 102 is arranged to pass through the gearbox 300 or the sealing housing 101 to couple an output 201 of the motor 200 to the input 301 of the gearbox 300 for transmission. With the sealing housing to form a cavity and the intermediate member for connecting the output of the motor to the input of the gearbox, the lubricant would not leak into the motor, thus improving the stability and service life of the motor and even the robot. Furthermore, the motor and/or the gearbox can be removed from or installed on each other in an easier way, for example, merely by decoupling the motor from the intermediate member without the need to dump and refill the lubricant.

It should be appreciated that the above detailed embodiments of the present disclosure are only to exemplify or explain principles of the present disclosure and not to limit the present disclosure. Therefore, any modifications, equivalent alternatives and improvement, etc. without departing from the spirit and scope of the present disclosure shall be comprised in the scope of protection of the present disclosure. Meanwhile, appended claims of the present disclosure aim to cover all the variations and modifications falling under the scope and boundary of the claims or equivalents of the scope and boundary.

Claims

A connection assembly (100) for connecting a motor (200) to a gearbox (300) , comprising:

a sealing housing (101) coupled to the gearbox (300) and defining a cavity (1011) for receiving a lubricant to lubricate an input (301) of the gearbox (300) ; and

an intermediate member (102) at least partially passing through the gearbox (300) or the sealing housing (101) to connect an output (201) of the motor (200) to the input (301) of the gearbox (300) for transmission.
The connection assembly (100) of claim 1, wherein the intermediate member (102) comprises:

an internal spline part (1021) adapted to be coupled to the output (201) of the motor (200) to rotate with the output (201) ; and

a gear shaft (1022) coupled to the internal spline part (1021) and the input (301) of the gearbox (300) for transmission.
The connection assembly (100) of claim 2, wherein the internal spline part (1021) is arranged adjacent to an end of the gearbox (300) away from the input (301) of the gearbox (300) , and

the intermediate member (102) at least partially passes through the gearbox (300) , and a coupling end of the intermediate member (102) away from the internal spline part (1021) is coupled to the input (301) .
The connection assembly (100) of claim 3, further comprising a rotating sealing member (103) arranged between the intermediate member (102) and the gearbox (300) .
The connection assembly (100) of claim 2, wherein the internal spline part (1021) is arranged adjacent to the input (301) , and

the intermediate member (102) at least partially passes through the sealing housing (101) , and a coupling end of the intermediate member (102) away from the internal spline part (1021) is coupled to the input (301) .
The connection assembly (100) of claim 5, further comprising a rotating sealing member arranged between the sealing housing (101) and the intermediate member (102) .
The connection assembly (100) of claim 2, wherein the internal spline part (1021) and the gear shaft (1022) are coaxial.
The connection assembly (100) of claim 3 or 5, wherein the coupling end comprises external teeth for coupling with at least one gear as the input (301) of the gearbox (300) .
A robot (400) , comprising:

a joint;

a connection assembly (100) of any of claims 1-8; and

a robot arm link coupled to the joint and driven to rotate via the connection assembly (100) .
The robot (400) of claim 9, wherein a sealing housing (101) of the connection assembly (100) is integrated in the joint or the robot arm link.
An assembly method of a connection assembly (100) , comprising:

providing a sealing housing (101) coupled to the gearbox (300) to form a cavity for receiving a lubricating medium to lubricate an input (301) of the gearbox (300) ; and

arranging an intermediate member (102) to pass through the gearbox (300) or the sealing housing (101) to couple an output (201) of the motor (200) to the input (301) of the gearbox (300) for transmission.