WO2022193060A1

WO2022193060A1 - Pressure relief component, gearbox and robot

Info

Publication number: WO2022193060A1
Application number: PCT/CN2021/080761
Authority: WO
Inventors: Xiaodong Cao; Yun HA; Hui Yu
Original assignee: Abb Schweiz Ag
Priority date: 2021-03-15
Filing date: 2021-03-15
Publication date: 2022-09-22
Also published as: CN116888388A

Abstract

A pressure relief component, a gearbox and a robot. The pressure relief component (100) for a gearbox (200) comprises: a body (101) arranged to close an internal chamber (201) of the gearbox (200) and comprising a groove (1011), the groove (1011) formed on a side of the body (101) adjacent to the internal chamber (201) to form a cavity (1013) in the body (101), wherein the cavity (1013) is in fluid communication with a pressure source providing a predetermined pressure; and an elastic member (102) arranged at an opening of the groove (1011) to isolate the cavity (1013) from the internal chamber (201), the elastic member (102) adapted to deform in response to a pressure difference between the cavity (1013) and the internal chamber(201). With the pressure relief component (100), when the pressure within the internal chamber (201) is increased during the operation of the gearbox (200), the elastic member (102) will deform towards the cavity (1013) because the pressure within the cavity (1013) remains basically constant. The deformation of the elastic member (102) towards the cavity (1013) will increase the volume of the internal chamber (201) and thus reduce the pressure within the internal chamber (201) according to the relationship between the volume and pressure. In this way, the pressure relief component (100) can efficiently reduce the pressure within the internal chamber (201), thereby improve the sealing performance.

Description

PRESSURE RELIEF COMPONENT, GEARBOX AND ROBOT

FIELD

Embodiments of the present disclosure generally relate to a gearbox of a robot, and more specifically, to a pressure relief component for a gearbox.

BACKGROUND

Robots are 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 reduction ratio requirements, a gearbox or a reducer needs 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.

Lubricant such as oil and/or grease is usually provided in the gearbox to provide lubrication for the gears and other components. Besides the lubrication function for the individual elements to substantially reduce friction, lubricant in the gearbox can also cool the heated subassemblies as well as mitigate and attenuate gear strokes. In addition, it reduces vibration, protects against corrosion, and keeps everything clean. Lubricant is usually located in an internal chamber of the gearbox to provide lubrication to the various components around the internal chamber. Lubricant usually fills roughly half of the internal chamber.

SUMMARY

Embodiments of the present disclosure provide a pressure relief component for a gearbox, an associated gearbox and a robot.

In a first aspect, a pressure relief component for a gearbox is provided. The pressure relief component comprises a body arranged to close an internal chamber of the gearbox and comprising a groove, the groove formed on a side of the body adjacent to the internal chamber to form a cavity in the body, wherein the cavity is in fluid communication with a pressure source providing a predetermined pressure; and an elastic member arranged at an opening of the groove to isolate the cavity from the internal chamber, the elastic member adapted to deform in response to a pressure difference between the cavity and the internal chamber.

With the pressure relief component according to embodiments of the present disclosure, when the pressure within the internal chamber is increased during the operation of the gearbox, the elastic member will deform towards the cavity in the body because the pressure within the cavity remains basically constant. The deformation of the elastic member towards the cavity will increase the volume of the internal chamber and thus reduce the pressure within the internal chamber according to the relationship between the volume and pressure. In this way, the pressure relief component can efficiently reduce the pressure within the internal chamber, thereby improving the sealing performance of the gearbox.

In some embodiments, the body further comprises at least one through hole formed on a side of the body away from the internal chamber to allow the cavity to be in fluid communication with the external environment providing a standard atmospheric pressure. In this way, the cavity may remain in communication with the external environment in a simple way.

In some embodiments, the groove comprises at least one annular groove centered on an axis of a main shaft of the gearbox. As a result, the pressure within the internal chamber can be further reduced due to a large deformable portion of the elastic member.

In some embodiments, the elastic member comprises a deformable portion of an initial shape in a cross section of the groove and adapted to deform in response to the pressure difference, the initial shape selected from a group consisting of the following: a flat shape, a curved shape, a zigzag shape, or a rectangular shape. In this way, the elastic member can be manufactured more flexibly.

In some embodiments, the elastic member further comprises a coupling portion arranged around the deformable portion and adapted to be coupled to the groove by a tight fit or bonding. In this way, the elastic member can be attached to the groove more easily.

In some embodiments, the deformable portion and the coupling portion are integrally formed. As a result, the elastic member can have a higher strength.

In some embodiments, the at least one through hole comprises a plurality of through holes evenly arranged on the body in a circumferential direction. This arrangement can facilitate the fluid commination of the cavity with the external environment.

In some embodiments, the elastic member is made of an oleophobic material and/or a gas-permeable material. In this way, the volume of the internal chamber is significantly increased, thereby reducing the pressure therein more effectively to further improve the sealing performance.

In some embodiments, the pressure relief component is an input or output flange for the gearbox or at least a part of a robot arm coupled to the gearbox. This arrangement makes the arrangement of the pressure relief component more flexible and more applicable.

In a second aspect of the present disclosure, a gearbox is provided. The gearbox comprises a pressure relief component as mentioned in the first aspect.

In a third aspect of the present disclosure, a robot is provided. The robot comprises at least one robot arm coupled to the gearbox as mentioned in the above second aspect.

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 the same components.

FIG. 1 shows a side sectional view of a gearbox in the prior art;

FIG. 2 shows a side sectional view of a gearbox according to embodiments of the present disclosure;

FIG. 3 shows an enlarged view of part A as shown in FIG. 2;

FIG. 4 shows a side sectional view of a gearbox according to embodiments of the present disclosure;

FIG. 5 shows an enlarged view of part B as shown in FIG. 4;

FIG. 6 shows a side sectional view of a gearbox according to embodiments of the present disclosure; and

FIG. 7 shows an enlarged view of part C as shown in FIG. 6.

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.

Various parts such as gears and bearings in a gearbox need lubricant to ensure the smooth and reliable operation of the gearbox. FIG. 1 shows a side sectional view of a gearbox in the prior art. As shown in FIG. 1, lubricant used for the gearbox is usually located in an internal chamber 201’ inside the gearbox 200’ and occupies roughly half of the volume of the internal chamber 201’, while the other half is occupied by air. The internal chamber 201’ is typically enclosed by a housing for receiving gears and bearings and end part (s) arranged at one or both ends of the housing. The end parts 100’ may be an end flange or a part of a robot arm coupled to the gearbox. During the operation of a gearbox, due to factors such as friction between the various components, the temperature in the lubricant and the components will increase, which will increase the volume of the lubricant and air, resulting in an increased pressure in the internal chamber.

The increased pressure will deteriorate the sealing system of the gearbox used for the internal chamber. For example, under normal circumstances, the pressure that the sealing system can withstand is a predetermined value or range. When the pressure of the internal chamber is greater than this value or range, the sealing system may fail, causing lubricant to leak out and thus causing a series of serious problems.

In order to at least partially address the above and other potential problems, embodiments of the present disclosure provide a pressure relief component 100 for a gearbox 200 to efficiently reduce the pressure within the internal chamber 201 during the operation of the gearbox 200, thereby improving the sealing performance of the gearbox 200. Now some example embodiments will be described with reference to FIGs. 2-7.

FIG. 2 shows a side sectional view of a gearbox 200 according to embodiments of the present disclosure and FIG. 3 shows an enlarged view of part A as shown in FIG. 2. As shown in FIGs. 2 and 3, generally, the pressure relief component 100 according to embodiments of the present disclosure comprises a body 101 and an elastic member 102. The body 101 may be an end flange or a part of a robot arm coupled to the gearbox 200 as mentioned above. That is, the concept of the present disclosure can be realized by modifying the end flange of the existing gearbox 200 or the robot arm coupled to the gearbox 200, thereby effectively reducing the excessive pressure in the internal chamber 201 of the existing gearbox 200 during operation and thereby improving the sealing performance of the gearbox 200.

In the following, embodiments of the present disclosure will be described mainly by taking the body 101 as an end flange as an example. It is to be understood that embodiments where the body 101 comprises other components such as robot arms are similar, and will not be described separately in the following.

The body 101 is arranged to close the internal chamber 201 which is sealed by means of a dynamic seal and static seal means. The dynamic seal and the static seal means constitute a sealing system for the internal chamber 201 and can ensure the sealing performance under a certain pressure within the internal chamber 201. As mentioned above, when the pressure of the internal chamber is greater than a predetermined value or range, the sealing system may fail. To effectively reduce the internal pressure within the internal chamber 201 so as to ensure the sealing performance, according to embodiments of the present disclosure, some minor improvements are made to the body 101.

Specifically, the body 101 is formed with a groove 1011 on a side of the body 101 adjacent to the internal chamber 201. In this way, a cavity 1013 is formed by the groove 1011 in the body 101. In some embodiments, the groove 1011 may be an annular groove 1011 centered on an axis of a main shaft of the gearbox 200. It is to be understood that this is merely illustrative, without suggesting any limitation as to the scope of the present disclosure. In some alternative embodiments, the groove 1011 may also be a straight groove 1011, a curved groove 1011 or a bent groove 1011 formed on the body 101. In some further alternative embodiments, the groove 1011 may also comprise one or more blind holes of round or oval or any other suitable shape.

The cavity 1013 is in fluid communication with a pressure source providing a predetermined pressure. In this way, the pressure within the cavity 1013 will be maintained at the predetermined pressure. For example, in some embodiments, to simplify the structure of the pressure relief component 100, the pressure source may be the external environment providing a standard atmospheric pressure. That is, in some embodiments, the cavity 1013 may be in fluid communication with the external environment providing a standard atmospheric pressure. In this case, the pressure within the cavity 1013 will remain basically constant, i. e., one atmosphere.

In some embodiments, this can be achieved by forming at least one through hole 1012 on a side of the body 101 away from the internal chamber 201. For example, in some embodiments, the at least one through hole 1012 may comprise a plurality of through holes 1012 evenly arranged on the body 101 in circumferential direction to facilitate the fluid commination of the cavity 1013 with the external environment. Furthermore, it is to be understood that the through hole 1012 may also be formed in other suitable sides of the body 101 as long as the through hole 1012 can fluidly communicate the cavity 1013 with the external environment.

The elastic member 102 is arranged at an opening of the groove 1011 to isolate the cavity 1013 from the internal chamber 201. In this way, the volume, contents and pressure in the internal chamber 201 and the cavity 1013 are isolated from each other. The elastic member 102 can deform when there is pressure difference between the internal chamber 201 and the cavity 1013.

In this way, when the pressure within the internal chamber 201 is increased during the operation of the gearbox 200, the elastic member 102 will deform towards the cavity 1013, for example, from position “a” to position “b” , as shown in FIG. 3, because the pressure within the cavity 1013 remains basically constant. The deformation of the elastic member 102 towards the cavity 1013 will increase the volume of the internal chamber 201. Experiments have shown that this increase in volume of the internal chamber 201 will cause the pressure therein to be reduced significantly. The reduced pressure within the internal chamber 201 is very important to maintain the effectiveness of the sealing system. In this way, the sealing performance of the gearbox 200 can be ensured.

Furthermore, the pressure difference will also directly affect the amount of deformation of the elastic member 102. That is, the greater the pressure in the internal chamber 201, the greater the amount of deformation, and the better the effect of reducing the pressure of the internal chamber 201. In this way, the pressure relief component 100 can efficiently reduce the pressure within the internal chamber 201, thereby further improving the sealing performance.

Moreover, it can be seen from the above that the idea of the present disclosure can effectively reduce the pressure within the internal chamber 201 by making little modification to the existing gearbox 200. Further, the pressure relief component 100 according to embodiments of the present disclosure can also be applied to various types of gearboxes 200, such as hat-type or cup-type gearboxes 200. In addition, the pressure relief component 100 according to embodiments of the present disclosure can work no matter which orientation the gearbox 200 is in. That is to say, no matter whether the main shaft of the gearbox 200 is vertical, horizontal or inclined, the pressure relief component 100 can effectively reduce the pressure within the internal chamber 201. Further, according to the principle of the present disclosure, no matter which way the gearbox 200 and the driving device such as a motor or the like are connected, for example, direct connection, belt connection, gear connection, etc., the pressure relief effect of the pressure relief component 100 will not be affected.

In addition, it should also be understood that the above embodiments where the pressure source comprises the external environment are merely illustrative, without suggesting any limitation as to the scope of the present disclosure. Other suitable arrangements are also possible. For example, in some alternative embodiments, the pressure source in communication with the cavity 1013 may also be any other suitable pressure source that provides a suitable pressure or a variable pressure.

For example, in some embodiments, the pressure source may provide a variable pressure. Specifically, when the assembly of the gearbox 200 is just completed, the pressure source can provide a pressure greater than a predetermined pressure, so that the pressure in the cavity 1013 is greater, and the elastic member 102 will be deformed toward the internal chamber 201 at this time. During the operation of the gearbox 200, the pressure provided by the pressure source may be reduced to thus reduce the pressure within the cavity 1013, thereby promoting the deformation of the elastic member 102 toward the cavity 1013 and further ensuring the effect of reducing the pressure in the internal chamber 201.

In some embodiments, the elastic member 102 may just comprise a deformable portion 1021, as shown in FIGs 2 and 3. The deformable portion 1021 may be deformed in response the pressure difference between the internal chamber 201 and the cavity 1013 as mentioned above. The deformable portion 1021 may be of an initial shape in a cross section of the groove 1011 before deformation, which may be selected from a group consisting of the following: a flat shape, a curved shape, a zigzag shape or a rectangular shape.

For example, as shown in FIGs. 2 and 3, the deformable portion 1021 may be directly attached to the opening of the groove 1011 for example by bonding or the like. The initial shape of the deformable shape may be a curved shape. It is to be understood that this is merely for illustration, without suggesting any limitation as to the scope of the present disclosure. Any other suitable structure or arrangement of the elastic member 102 is also possible.

FIGs. 4-7 show possible variations of the elastic member 102. As shown in FIGs. 4-7, in some embodiments, besides a deformable portion 1021, the elastic member 102 may further comprise a coupling portion 1022 arranged around the deformable portion 1021 to facilitate the attachment of the elastic member 102 to the groove 1011. For example, with the coupling portion 1022, the elastic member 102 can be attached to the opening of the groove 1011 by coupling the coupling portion 1022 to the groove 1011 by a tight fit, bonding or the like. In this way, the installation of the elastic member 102 in the groove 1011 can be simplified and more reliable.

In some embodiments, the deformable portion 1021 and the coupling portion 1022 may be integrally formed for example by molding. For example, the deformable portion 1021 and the coupling portion 1022 may be integrally made of silicone or rubber such as nitrile butadiene rubber, fluorine rubber or any other suitable material. In some alternative embodiments, the deformable portion 1021 and the coupling portion 1022 may also be formed separately and assembled together for example by bonding or the like.

Furthermore, as shown in FIGs. 4 and 5, in some embodiments, the initial shape of the deformable portion 1021 before deformation may also be substantially a rectangular shape. When there is a pressure difference between the internal chamber 201 and the cavity 1013 during the operation of the gearbox 200, the elastic member 102 may deform from a state shown in FIGs. 4 and 5 to a state shown in FIGs. 6 and 7. In this way, the volume of the internal chamber 201 is significantly increased, thereby reducing the pressure therein more effectively to further improve the sealing performance of the gearbox 200.

In some embodiments, the elastic member 102 may be made of an oleophobic material to prevent lubricant such as oil or grease from adhering to the surface of the elastic member 102 and affecting the deformation performance. Alternatively or additionally, in some embodiments, the elastic member 102 may also be made of a gas-permeable material which allows passage of gas but prevents passage of the lubricant. In this way, the high-pressure gas in the internal chamber 201 may pass though the elastic member 102 to further reduce the pressure in the internal chamber 201.

According to other aspects of the present disclosure, a gearbox 200 comprising the pressure relief component 100 as mentioned above and a robot comprising the gearbox 200 are provided. The robot comprises at least one robot arm coupled to the gearbox 200 as mentioned above. With the pressure relief component 100 according to embodiments of the present disclosure, the sealing performance of the gearbox 200 can be significantly improved and thus prolong the service life of the gearbox 200 and the robot.

It should be appreciated that the above detailed embodiments of the present disclosure are only for exemplifying or explaining principles of the present disclosure and do not limit the present disclosure. Therefore, any modifications, equivalent alternatives and improvements, 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 pressure relief component for a gearbox, comprising:

a body (101) arranged to close an internal chamber (201) of the gearbox and comprising a groove (1011) , the groove (1011) formed on a side of the body (101) adjacent to the internal chamber (201) to form a cavity (1013) in the body (101) , wherein the cavity (1013) is in fluid communication with a pressure source providing a predetermined pressure; and

an elastic member (102) arranged at an opening of the groove (1011) to isolate the cavity (1013) from the internal chamber (201) , the elastic member (102) adapted to deform in response to a pressure difference between the cavity (1013) and the internal chamber (201) .
The pressure relief component of claim 1, wherein the body (101) further comprises at least one through hole formed on a side of the body (101) away from the internal chamber (201) to allow the cavity to be in fluid communication with external environment providing a standard atmospheric pressure.
The pressure relief component of claim 1, wherein the groove (1011) comprises at least one annular groove (1011) centered on an axis of a main shaft of the gearbox.
The pressure relief component of claim 1, wherein the elastic member (102) comprises:

a deformable portion (1021) of an initial shape in a cross section of the groove (1011) and adapted to deform in response to the pressure difference, the initial shape selected from a group consisting of the following: a flat shape, a curved shape, a zigzag shape, or a rectangular shape.
The pressure relief component of claim 4, wherein the elastic member (102) further comprises:

a coupling portion (1022) arranged around the deformable portion and adapted to be coupled to the groove (1011) by a tight fit or bonding.
The pressure relief component of claim 5, wherein the deformable portion (1021) and the coupling portion (1022) are integrally formed.
The pressure relief component of claim 2, wherein the at least one through hole (1012) comprises a plurality of through holes (1012) evenly arranged on the body (101) in a circumferential direction.
The pressure relief component of claim 1, wherein the elastic member (102) is made of an oleophobic material and/or a gas-permeable material.
The pressure relief component of claim 1, wherein the pressure relief component is an input or output flange for the gearbox or at least a part of a robot arm coupled to the gearbox.
A gearbox, comprising a pressure relief component of any of claims 1-9.
A robot, comprising at least one robot arm coupled to a gearbox of claim 10.