Device for determining oil leaks and robot using the same

Abstract

Embodiments of the present disclosure provide an apparatus for determining oil leakage of a gear box (201) and an associated robot. The apparatus comprises a base (101) arranged between the gear box (201) and a motor (202) coupled to the gear box, the base (101) being made of a functional oil-absorbing material so that a volume of the base (101) changes when the base (101) contacts oil; a signal generator (102) coupled to the base (101) and configured to cause a change in an electrical signal or a physical property of the signal generator (102) in response to the change in the volume of the base (101); and a controller (103) coupled to the signal generator (102) and configured to detect the change in the electrical signal or the physical property and determine oil leakage in response to the aforementioned detection of the change in the electrical signal or the physical property. By using the apparatus, the user is informed or the motor (202) is stopped before oil leaks into the motor (202). The robot using the apparatus can be operated more safely.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure generally relate to robots, and more particularly to an apparatus for determining oil leakage of a gear box used in a robot joint. BACKGROUND

[0002] Robots are widely used automated mechanisms that increase operational efficiency and accuracy. A robot generally includes a robot arm and joints. The robot arm can be rotated or moved by a motor provided in the joint or base. To meet the requirement of a reduction ratio, a gear box needs to be arranged between the motor and the robot arm to be driven. The gear box is a device that uses gears and gear trains to provide speed and torque conversion from a rotating power source to another device.

[0003] Oil is generally provided in the gear box for lubricating the gears and other components. In addition to the lubricating function of the individual elements to significantly reduce friction, the oil in the gear box can also cool the heat-generating sub-components and reduce and weaken the gear stroke. In addition, it can also reduce vibration, prevent corrosion, and keep everything clean.

[0004] For robot applications, the motor is generally coupled to the gear box, with the shaft of the motor extending into the oil cavity of the gear box. The aging of the seal used to seal the oil cavity can cause problems in preventing the oil in the oil cavity from entering the motor, thereby adversely affecting the operation of the motor. SUMMARY

[0005] Embodiments of the present disclosure provide an apparatus for determining oil leakage of a gear box and associated robots to at least partially address the above-mentioned problems and other potential problems.

[0006] In a first aspect, an apparatus for determining oil leakage of a gear box is provided. The apparatus includes a base arranged between the gear box and a motor coupled with the gear box, the base being made of a functional oil-absorbing material such that a volume of the base changes when the base contacts oil; a signal generator coupled to the base and configured to cause a change in an electrical signal or a physical property of the signal generator in response to the change in the volume of the base; and a controller coupled to the signal generator and configured to detect the change in the electrical signal or the physical property and determine the oil leakage in response to the detection of the change in the electrical signal or the physical property.

[0007] With the apparatus according to embodiments of the present disclosure, the user is already aware of the oil leakage or the motor has already been stopped before the oil leaks into the motor. In this case, the user can only need to replace the damaged or aged seal ring to restore the robot joint to a normal operating state. In this way, maintenance costs can be reduced. More importantly, the robot using the apparatus according to embodiments of the present disclosure can be operated more safely.

[0008] In some embodiments, the device further comprises a housing arranged on the stationary portion of the motor and comprising a recess for receiving the base. In this way, the device can be more easily mounted on the motor.

[0009] In some embodiments, the signal generator comprises a signal cable coupled to the controller and comprising a first portion and a second portion that are disconnected; a first electrode connected to the first portion; and a second electrode connected to the second portion, wherein at least one of the first electrode and the second electrode is arranged on the base and adapted to electrically contact the housing in response to a change in volume of the base, thereby connecting the first portion and the second portion such that the controller detects an electrical signal. This arrangement can facilitate the determination of oil leakage from the gear box.

[0010] In some embodiments, both the first electrode and the second electrode are arranged on the base and adapted to electrically contact different portions of the housing in response to a change in volume of the base. This arrangement can facilitate the mounting of the device on the motor, thereby improving the efficiency of the mounting.

[0011] In some embodiments, the different portions of the housing that contact the first electrode and the second electrode are electrically conductive. This arrangement can ensure the generation of an electrical signal by the signal generator, thereby improving the reliability of the device.

[0012] In some embodiments, the first electrode is arranged on the base and the second electrode is arranged on the housing, and the first electrode is adapted to electrically contact the housing in response to a change in volume of the base. This arrangement can facilitate the maintenance of the device, thereby improving the efficiency of the maintenance.

[0013] In some embodiments, the functional oil-absorbing material comprises an oil-swelling rubber.

[0014] In some embodiments, the physical property comprises at least one of volume, temperature, color, or hardness.

[0015] In some embodiments, the housing comprises a wire slot adapted to arrange at least one of the first and second portions of the signal generator therein. As a result, the cable arranged in the wire slot will not be easily damaged, thereby improving the reliability of the device.

[0016] In some embodiments, the device further comprises a radial seal arranged between the rotatable portion of the motor and the housing. The radial seal can provide additional sealing protection.

[0017] In some embodiments, the device further comprises an additional sleeve arranged on the rotatable portion and adapted to rotate with the rotatable portion. This arrangement can improve the adaptability of the device.

[0018] In a second aspect, a robot is provided. The robot comprises at least one joint and at least one device according to the first aspect described above.

[0019] It is to be understood that the Summary is not intended to identify key or essential features of embodiments of the disclosure, nor is it intended to be used to limit the scope of the disclosure. Other objects, features, and advantages of the disclosure will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which like reference characters designate the same parts throughout the drawings.

[0021] Figure 1 a cross-sectional view of an apparatus for determining oil leakage of a gearbox arranged between a gearbox and a motor according to an embodiment of the present disclosure is shown;

[0022] Figure 2 an exploded view of an apparatus according to an embodiment of the present disclosure is shown;

[0023] Figure 3 a top view of a motor having an apparatus according to an embodiment of the present disclosure is shown;

[0024] Figure 4 a perspective view of a portion of an apparatus according to another embodiment of the present disclosure is shown; and

[0025] Figure 5 a partial cross-sectional view of a motor having an apparatus according to another embodiment of the present disclosure is shown.

[0026] Throughout the drawings, same or similar reference numerals are used for same or similar elements. DETAILED DESCRIPTION

[0027] The present disclosure will now be discussed with reference to several example embodiments. It is to be understood that discussion of these embodiments is merely provided for the purposes of enabling a person of ordinary skill in the art to better understand and thereby implement the present disclosure, and is not intended to imply any limitation of the scope of the subject matter.

[0028] As used herein, the term “includes” and its variants are to be read to be analogous to an open term that means “comprising, but not limited to.” The term “based on” is to be understood as “based, at least in part, on.” The terms “a” and “an” are to be understood as meaning “at least one” The term “another” is to be understood as meaning “at least one other.” The terms “first,” “second,” etc. can refer to different or the same objects. Other explicit and implicit definitions can be included below. The definition of a term is consistent throughout the specification unless otherwise explicitly provided by context.

[0029] Gearboxes and motors are commonly used components in robot joints. The motor usually includes a brake mechanism to quickly reduce the rotational speed of the arm of the joint or to hold the arm of the joint in place. The gearbox is usually provided with an oil cavity for containing oil to lubricate the various elements to significantly reduce friction and achieve other necessary functions. In order to make the joint more compact, the shaft of the motor is usually inserted into the oil cavity to engage with the gears arranged in the oil cavity.

[0030] A seal is provided around the motor shaft to prevent oil from entering the motor. However, in the case of long-time operation, the seal around the motor shaft can fail due to long-term wear, which will cause oil to enter the motor. The oil entering the motor will accelerate the aging of the insulation components in the motor. Moreover, more importantly, once the oil enters the brake mechanism of the motor, there is a risk of failure of the brake mechanism, which can lead to a major accident. For example, if the brake mechanism of the motor for stopping or holding the second and third arms fails, the third arm can slip due to the failure of the brake mechanism, which can damage the surrounding equipment and / or threaten personnel safety.

[0031] A conventional solution to prevent oil from entering the motor is to adopt a double-seal structure including two seals. A detection hole is provided between the two seals for the operator to observe the oil leaking through one of the seals adjacent to the oil cavity. If oil is observed through the detection hole, it means that at least one of the two seals is damaged, and the motor or the double-seal structure needs to be replaced in time. However, there is currently no way to know whether the motor wrapped inside the joint has leaked oil.

[0032] To at least partially solve the above and other potential problems, embodiments of the present disclosure provide an apparatus for determining a gearbox oil leak. Figure 1 A cross-sectional view of an apparatus 100 for determining an oil leak of a gearbox 201 arranged between the gearbox 201 and a motor 202 of the gearbox 201 is shown; and Figure 2 An exploded view of the apparatus 100 according to embodiments of the present disclosure is shown.

[0033] As shown, the apparatus 100 for determining an oil leak of the gearbox 201 generally comprises a base 101, a signal generator 102, and a controller 103. The base 101 is arranged between the gearbox 201 and a motor 202 connected to the gearbox 201. The base 101 is made of a functional oil-absorbing material, which changes its volume when in contact with oil. For example, in some embodiments, the functional oil-absorbing material comprises an oil-swollen rubber. That is, the base 101 can be made of an oil-swollen rubber. Oil-swollen rubbers are a class of polymeric functional oil-absorbing materials that mainly comprise a rubber matrix and a lipophilic functional group or lipophilic component. The base 101 made of an oil-swollen rubber can swell when in contact with oil. The swollen base 101 can act as another seal to prevent oil from entering the motor 202. Alternatively, in some embodiments, the base 101 can also shrink when in contact with oil.

[0034] It is of course understood that the embodiment in which the functional oil-absorbing material comprises an oil-swollen rubber is for illustrative purposes only and does not limit the scope of the present disclosure in any way. Other suitable materials that can change their volume when exposed to or in contact with oil are also possible. For example, in some alternative embodiments, the functional oil-absorbing material can also comprise a polymeric material, such as a resin that swells when exposed to oil.

[0035] The base 101 is arranged such that, when an oil leak of the gearbox 201 occurs, the oil will first contact the base 101. Thus, if the base 101 swells, it means that the base 101 is in contact with oil from the gearbox 201. To make the swelling of the base 101 easier to be electronically detected, the signal generator 102 is provided, which is coupled to the base 101. The signal generator 102 can cause an electrical signal or a change in its physical properties in response to the volume change of the base 101. For example, in some embodiments, at least one physical property of the signal generator 102 can change, such as volume, temperature, color, or hardness, when the volume of the base 101 changes.

[0036] For example, in some embodiments, the temperature of the signal generator 102 can change when the volume of the base 101 changes. The change in temperature can be detected by the controller 103. That is, a temperature change that exceeds a threshold value indicates that the base 101 is in contact with oil. Thus, the controller 103 can determine an oil leak of the gearbox 201. Alternatively or additionally, the signal generator 102 can also change color or hardness when the base 101 swells.

[0037] It should be appreciated that the above examples regarding the change in physical property are for illustrative purposes only and are not intended to imply any limitation on the scope of the present disclosure. Any structure or material can be used as the signal generator 102 as long as it can change its detectable or observable physical property when the base 101 is inflated. For example, in some embodiments, the signal generator 102 can shrink or be squeezed to reduce the volume when the base 101 is inflated.

[0038] Alternatively or additionally, as mentioned above, the signal generator 102 can also cause an electrical signal to be detected by the controller 103. The electrical signal, which can be easier to detect than the change in physical property, can then be detected by the controller 103. Upon detecting the electrical signal, the controller 103 can determine the oil leak of the gear box 201. In some embodiments, the electrical signal can be a current signal or a voltage signal. In some embodiments, the electrical signal can also refer to a change in the current or voltage signal, such as a rising or falling edge of the current. For example, the electrical signal can refer to a current signal that drops from a certain value to zero or rises from zero to a certain value.

[0039] Upon determining the oil leak, the user can be notified or warned in various ways. For example, in some embodiments, an indicator such as a light can be coupled to the signal generator 102. When the electrical signal is generated in response to the volume change of the base 101, the light can automatically turn on to notify the user of the oil leak. In some alternative embodiments, a color change of the signal generator 102 can be observed by the user in response to the volume change of the base 101 to indicate the oil leak of the gear box 201. That is, if the user observes that the color of the signal generator 102 has changed, it means that the oil leak has occurred.

[0040] The above description indicates that the oil leak can be more intuitively observed. Of course, it should be appreciated that other methods can also notify the user of the determined oil leak. For example, when the controller 103 determines that the oil leak of the gear box 201 has occurred, the controller 103 can push a notification or warning of the oil leak to an external device, such as a cell phone used by the user, directly or indirectly through other controllers 103. Alternatively or additionally, the controller 103 can also be configured to stop the motor 202 upon determining the oil leak before notifying or warning the user. In some embodiments, the controller 103 can be a controller of a robot using the apparatus 100. In some alternative embodiments, the controller 103 can also be a controller independent of the robot controller.

[0041] In this way, the user can be informed or the motor 202 can be stopped before the oil leaks into the motor 202. In this case, the user can only need to replace the damaged seal ring to restore the robot joint to a normal operating state. In this way, the maintenance cost can be reduced. More importantly, the robot using the apparatus 100 according to the embodiments of the present disclosure can be operated more safely.

[0042] In some embodiments, as shown in FIG. 1, the device 100 can further include a housing 104 arranged on the fixed part of the motor 202. The housing 104 includes a recess 1041 for accommodating the base 101. Thus, the device 100 can be easily installed between the motor 202 and the gear box 201. Figures 1-3

[0043] To achieve the above-mentioned function of generating an electrical signal when the volume of the base 101 changes, in some embodiments, as shown in FIG. 2, the signal generator 102 can include a signal cable 1021 and two electrodes. For ease of discussion, the two electrodes will be referred to as a first electrode 1024 and a second electrode 1025, respectively. Figure 2 4 The signal cable 1021 includes two parts, i.e., a first part 1022 and a second part 1023. The first electrode 1024 is connected to the first part 1022, and the second electrode 1025 is connected to the second part 1023. At least one of the first electrode 1024 and the second electrode 1025 is arranged on the base 101 and can electrically contact the housing 104 in response to a change in the volume of the part to connect the first part 1022 and the second part 1023, so that the controller 103 can detect the electrical signal. To ensure that the electrodes contact the housing 104 when oil leakage occurs, at least one of the first electrode 1024 and the second electrode 1025 can include a plurality of sub-electrodes. The sub-electrodes of the first electrode 1024 or the second electrode 1025 are electrically conductive.

[0044] In some embodiments, as shown in FIG. 2, both the first electrode 1024 and the second electrode 1025 are arranged on the base 101. For example, each of the first electrode 1024 and the second electrode 1025 can include three or four or more sub-electrodes, which can be uniformly arranged on the base 101. In these embodiments, the first electrode 1024 is arranged on the inner surface of the base 101, and the second electrode 1025 is arranged on the outer surface of the base 101. In some alternative embodiments, the first electrode 1024 and the second electrode 1025 can also be embedded in the base 101, which has a part protruding from the inner surface and the outer surface, respectively.

[0045] In some embodiments, as shown in FIG. 2, both the first electrode 1024 and the second electrode 1025 are arranged on the base 101. For example, each of the first electrode 1024 and the second electrode 1025 can include three or four or more sub-electrodes, which can be uniformly arranged on the base 101. In these embodiments, the first electrode 1024 is arranged on the inner surface of the base 101, and the second electrode 1025 is arranged on the outer surface of the base 101. In some alternative embodiments, the first electrode 1024 and the second electrode 1025 can also be embedded in the base 101, which has a part protruding from the inner surface and the outer surface, respectively. Figure 2

[0046] ​​​When the base 101 is placed in the recess 1041 of the housing 104 and has not yet expanded, at least one of the first and second electrodes 1024 and 1025 does not contact the housing 104. When oil leakage of the gear box 201 occurs and the oil contacts the base 101, the base 101 will expand to cause the first and second electrodes 1024 and 1025 to contact different portions of the housing 104. In this way, the first and second portions 1022 and 1023 of the signal cable 1021 can be connected through the first and second electrodes 1024 and 1025 and the housing 104. With the connection of the first and second portions 1022 and 1023, there will be a current flowing through the signal cable 1021, which can be implemented in an appropriate manner.

[0047] For example, in some embodiments, one of the first and second portions 1022 and 1023 can be connected to a power source and a resistor. When the gear box 201 has no oil leakage, the signal cable 1021 is disconnected and no current flows therein. When oil leakage occurs and the oil contacts the base 101, the base 101 expands to cause the first and second electrodes 1024 and 1025 to contact the housing 104, and then the signal cable 1021 is conductive. In this way, a current will flow in the signal cable 1021 and can be detected by the controller 103.

[0048] In some alternative embodiments, the physical property of the signal generator 102 can include the resistance of the signal cable 1021. When the signal cable 1021 is disconnected, its resistance is infinite. When the signal cable 1021 is turned on by connecting the first and second portions 1022 and 1023 due to oil leakage, the resistance of the signal cable 1021 becomes zero or other non-infinite values. Upon detecting the change in the resistance of the signal cable 1021, the controller 103 can determine that oil leakage has occurred.

[0049] Of course, it should be understood that the above-described embodiments in which both the first and second electrodes 1024 and 1025 are arranged on the base 101 are for illustrative purposes only, and are not intended to imply any limitation on the scope of the present disclosure. Other arrangements or structures are also possible.

[0050] For example, in some alternative embodiments, as Figure 4 and 5As shown, the first electrode 1024 is arranged on the base 101 and the second electrode 1025 is arranged on the housing 104. When the base 101 is placed in the recess 1041 of the housing 104 and has not yet swelled, the first electrode 1024 does not contact the housing 104. The first and second portions of the signal cable 1021 are disconnected. When oil leakage of the gear box 201 occurs and the oil contacts the base 101, the base 101 will generate swelling, which will cause the first electrode 1024 to contact the housing 104. In this way, the first portion 1022 and the second portion 1023 of the signal cable 1021 can be connected through the first electrode 1024 and the second electrode 1025 and the housing 104. Therefore, the controller 103 can detect the electrical signal and the change in the physical property of the signal generator 102, thereby determining the oil leakage.

[0051] In some embodiments, the entire portion of the housing 104 can be made of metal to ensure that the signal cable 1021 conducts electricity when the electrodes contact the housing 104. In some alternative embodiments, only the portions of the housing 104 that will contact the first electrode 1024 and / or the second electrode 1025 are conductive. For example, these portions of the housing 104 can be made conductive by arranging metal wires, sheets or tabs. Therefore, other portions of the housing 104 can be made of non-metal to reduce the cost and weight of the device 100.

[0052] In some embodiments, as shown in Figure 1 and Figure 5 The device 100 can further include a radial seal 105 between the rotatable portion (e.g. the shaft of the motor 202) and the housing 104. The radial seal 105 can provide additional sealing protection for the oil cavity of the gear box 201. Due to the radial seal 105, the oil leaked from the gear box 201 will be first prevented from leaking to the outside of the device 100 without affecting the motor 202. Even if the radial seal 105 is damaged, the oil leakage can be detected in time before it enters the motor 202. Only the seal of the gear box 201 and the radial seal 105 of the device 100 need to be replaced, without the need to replace the motor 202 or the entire joint, which can significantly reduce the cost.

[0053] In some embodiments, as shown in Figure 1 and 5 To improve adaptability, the device 100 can further include an additional sleeve 106. The additional sleeve 106 can be arranged on the rotatable portion, e.g. the shaft of the motor 202, and can rotate with the rotatable portion. In these embodiments, the radial seal 105 is arranged between the additional sleeve 106 and the housing 104. In this way, the device 100 can be applied to various rotatable portions of the motor 202 regardless of their structure. Therefore, the device 100 can be applied to various motors, which significantly improves the adaptability of the device 100.

[0054] To facilitate the arrangement of the signal cable 1021, in some embodiments, the housing 104 can include a wire slot 1042. The wire slot 1042 allows at least one of the first portion 1022 and the second portion 1023 to be arranged therein. In this way, the signal cable 1021 arranged in the wire slot 1042 can be protected from being damaged, thereby improving the reliability of the device 100.

[0055] According to other aspects of the present disclosure, a robot is provided. The robot includes at least one joint and at least one device 100 as described above. Using the device 100 according to embodiments of the present disclosure, oil leakage of the gear box 201 can be determined in time before affecting the performance of the motor 202. In this way, the reliability of the robot is improved.

[0056] It should be understood that the above detailed description of the present disclosure is only for illustration or explanation of the principles of the present disclosure, not for limiting the present disclosure. Therefore, any modification, equivalent replacement and improvement, etc. shall be included in the protection scope of the present disclosure without departing from the spirit and scope of the present disclosure. Meanwhile, the appended claims of the present disclosure are intended to cover all the variants and modifications or equivalents of the scope and boundaries of the claims.

Claims

1. An apparatus for determining an oil leak in a gearbox (201), comprising: A base (101) is disposed between the gearbox (201) and the motor (202) coupled to the gearbox (201), the base (101) being made of a functional oil-absorbing material such that the volume of the base (101) changes when the base (101) comes into contact with oil; The housing (104) is disposed on the fixed portion of the motor (202) and includes a groove (1041) for receiving the base (101). A signal generator (102), coupled to the base (101) and configured to cause a change in the electrical signal or physical properties of the signal generator (102) in response to a change in the volume of the base (101); and A controller (103), coupled to the signal generator (102) and configured to detect the change in the electrical signal or the physical property, and to determine the oil leak in response to the detection of the change in the electrical signal or the physical property. The signal generator (102) mentioned above includes: The signal cable (1021) is coupled to the controller (103) and includes a disconnected first portion (1022) and a second portion (1023). The first electrode (1024) is connected to the first portion (1022); and The second electrode (1025) is connected to the second part (1023). At least one of the first electrode (1024) and the second electrode (1025) is disposed on the base (101) and adapted to electrically contact the housing (104) in response to the change in the volume of the base (101), thereby connecting the first part (1022) and the second part (1023) so that the controller (103) detects the electrical signal.

2. The device according to claim 1, wherein both the first electrode (1024) and the second electrode (1025) are disposed on the base (101) and adapted to electrically contact different portions of the housing (104) in response to the change in the volume of the base (101).

3. The device according to claim 2, wherein the different portions of the housing (104) that contact the first electrode (1024) and the second electrode (1025) are conductive.

4. The apparatus according to claim 1, wherein the first electrode (1024) is disposed on the base (101) and the second electrode (1025) is disposed on the housing (104), and The first electrode (1024) is adapted to make electrical contact with the housing (104) in response to the change in the volume of the base (101).

5. The device according to any one of claims 1 to 4, wherein the functional oil-absorbing material comprises oil-swellable rubber.

6. The apparatus according to any one of claims 1 to 4, wherein the physical property includes at least one of volume, temperature, color or hardness.

7. The device according to any one of claims 1 to 4, wherein the housing (104) comprises: The cable tray (1042) is adapted to accommodate at least one of the first portion (1022) and the second portion (1023).

8. The apparatus according to any one of claims 1 to 4, further comprising: A radial seal (105) is disposed between the rotatable portion of the motor and the housing (104).

9. The apparatus according to claim 8, further comprising: An additional sleeve (106) is arranged on the rotatable portion and is adapted to rotate together with the rotatable portion.

10. A robot comprising: At least one joint; and At least one device according to any one of claims 1 to 9, wherein the device is arranged on the at least one joint.

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