EP4627232A1

EP4627232A1 - Device for separating impurities from the oil filling of gearboxes and/or bearing boxes, especially industrial robots, method of separation

Info

Publication number: EP4627232A1
Application number: EP23841046.8A
Authority: EP
Inventors: ubomír ILE KO
Original assignee: Erobot JSA
Current assignee: Erobot JSA
Priority date: 2022-11-30
Filing date: 2023-11-24
Publication date: 2025-10-08
Also published as: KR20250121343A; SK9823Y1; WO2024116039A1; SK500952022U1

Abstract

A device includes an oil pump (1) with an electric engine (2), an input and output oil piping (9), an element (5) for separation of impurities and an independent, removable electric power source (3) for propulsion of the pump (1 ). The pump (1 ), the element (5) for the separation of the impurities and the independent electric power source (3) can be placed in a single body (4) that is designed for a connection to the construction of the machine or industrial robot. The electric power source (3) is a battery and/or accumulator, preferably rechargeable accumulator with DC voltage, which allows for flexible deployment of the device even on the moving parts and arms of the machines, manipulators and industrial robots. The element (5) for the separation of the impurities is a filtration element, preferably with removeable filtration insert. The advantage of the device is the decrease of the environmental burden, which decreases the overall consumption of the oil during industrial maintenance.

Description

DEVICE FOR SEPARATING IMPURITIES FROM THE OIL FILLING OF GEARBOXES AND/OR BEARING BOXES, ESPECIALLY INDUSTRIAL ROBOTS, METHOD OF SEPARATION

Field of technoloqv

The invention concerns separation and removal of impurities from the oil in gearboxes and/or bearing boxes, especially from the oil filling of gearboxes and/or bearing boxes and modules of industrial robots and manipulators. The subject matter of the technical solution is also the method of separation of the impurities and similar undesired mechanical particles from the box with oil filling, which in the operational regime serves the purpose of lubrication of moving parts and/or of cooling.

Prior state of the art

Gearboxes and bearing boxes of industrial robots and manipulators have oil filling which serves the purpose of lubricating and cooling of the moving parts. The oil filling is replaced in planned maintenance intervals so that the sudden failure of the robot on the production line is prevented. The maintenance operations usually require stopping of the whole production process, and the change of oil produces a waste which must be further ecologically processed.

The increase of the durability of the oil in industrial robots can be partially achieved pursuant to publication W02012000539A1 , which discloses the insertion of absorption device in the lubricating robot’s gearbox. The absorption device can absorb only humidity, but it has only low influence on the durability of oil polluted by mechanical impurities.

General solutions of bearing boxes are known, which have their own pressure oil system with pumping of the oil, which allows to include filtration element in the circuit. Such solution is difficult to use with industrial robots and manipulators where small dimensions and weights of gear and bearing modules are required. The filtration of the oil in case of industrial robots is known in case of hydraulic performance circuits which move arms and joints, for example pursuant to publication KR920005146; however, filtration of the gear oils in kinematic modules with relatively low amount of oil filling is not common. Usually, oil is filtered in car gears, mainly automatic gears, such as pursuant to EP0995535A2, which, however, addresses different technical problems since all lubricated components are placed in a common box, and oil circuits here fulfill both performance and control function.

Patent file JP2016196087A discloses the system with the oil state sensors in the gearbox of the robot, which improves the diagnostic of the state of the oil filling and planning of the maintenance, but it does not solve the removal of impurities from the oil filling. Publication KR920005146B1 discloses the device with the hydraulic pump and filter, by means of which the impurities can be removed from the gear of the robot. In case of multi-axis robots, such device causes problems with difficulty and reliability, and it leads to lower allowed load of the robot in the operation.

These problems are partially addressed by publication WO2019111232 which discloses the connection of oil fillings in multiple gear and/or bearing modules into a common circuit in which there is a filtration element for removal of impurities from oil, aside from pump. The pump and filtration element can be placed by the basis of the robot, where the dimensions and weight present no problem. In this invention, it is necessary to connect the oil fillings of multiple gear and/or bearing modules by piping, and it is especially preferable solution in case of production of new robots. But there is further solution desired and not known, which will simplify the maintenance of already produced and installed robots, which will shorten the maintenance time and the which will lower the production of waste. The new solution should be simple to install and service, and it should be usable independently of the surrounding infrastructure of the workplace.

Essence of the invention

The device according to invention is defined in claims 1 to 20 and the method according to the invention is defined in claims 21 to 24. The deficiencies in the prior art are significantly remedied by the device for separation of the impurities from the oil filling of the gearboxes and/or bearing boxes, mainly boxes of the industrial robots, where the box is equipped by the input and output oil opening according to this technical solution, which essence lies in the fact that it includes an oil pump with electric engine, the input and output of the oil, the element for separation of the impurities, and the independent and/or portable electric power source for propulsion of the electric engine of the pump, whereby the oil pump and the element for separation of impurities can be placed in a single body which is designed for connection to the construction carrying the gearbox and/or the bearing box, or to the construction of the industrial robot, and the input and output oil piping of the device is designed for connection to the input and output oil opening in the gearbox and/or bearing box. The device preferably includes at least one flexible oil piping. The connection of the device with the oil filling of the box can be indirect, too, for example in such a way that the oil filling of the box flows through the external oil vessel and the device is connected to the vessel in such a way that it filters the oil in an independent circuit in which the oil flows from the vessel to the device and subsequently, after purification, it flows back into the vessel.

The element for separation of impurities from the oil is preferably a filtration element with the removable filtration insert or centrifugal separator or any other element designed for separation of impurities and other undesired mechanical particles. It is preferable if the filtration element has an insert with separation size 0,5 mm to 1 pm, preferably 5 to 10 pm. The term impurities in this file denotes any alien substance in the oil filling, mainly metal particles, splinters, solidified clots, and so on. The independent source of the electric power can in some of the preferable arrangements be placed in the body of the device together with other elements of the device, or it can be separated and connected with the body of the device by means of a connector or a cable.

The element for separation of the impurities can include filtration element, preferably removable filtration element, and also bypass valve for protection during the clotted filtration element. A pressure sensor which can assess the permeability of the element can be part of the element for separation of impurities. The element for separation of impurities can also include elements known in the filtration systems.

The device includes input and output of oil, but it would suffice for the connection to the box if only a single flexible oil piping is used in situation where the body of the device is connected directly to the opening of the box by screw with a channel for guiding the oil from the box to the device. The second branch of the circuit is realized by the flexible oil piping which connects the device with the second opening in the box, whereby this can be on the other side of the box, too. In the specific case where the device is precisely designed for the shape and dimensions of a specific box, the full oil piping in form of pipes or hoses needs not to be part of the device, and the device can be connected by its oil input and output directly to the input and output oil opening in the box.

The significant feature of the proposed technical solution is the arrangement with its own source of electric power to propel the oil pump. The independent source of the electric power will be battery and/or accumulator, preferably rechargeable accumulator. Especially preferably, a single removable accumulator inserts or multiple removable accumulator inserts are used, as in the electric hand tools. In such arrangement, multiple accumulator cells are connected into a circuit and placed in the removable casing with the contacts on the outer surface of the casing, which is designed for insertion into a slot with respective electric contacts. The term “independent portable electric power source” in this text means a source which is portable, and which one can manipulate with, during the common maintenance of the device, whereby it will be possible to carry it in a single hand. It will be a source in form of an electric energy storage; it is not a source in form of an electric energy generator, for example generator with a combustion engine. Typical forms of such electric power source according to this invention are accu packs used with accumulator hand tools (accu tool). However, they can also be typical lead accumulators, such as gel accumulators able to function in any position.

Disclosed basic arrangement significantly simplifies the use of the device. Thanks to its own electric power source, no connection to the electrical network is necessary during the maintenance of the gearbox or bearing box. The connection to the electrical network is basically always available within the vicinity of e g. industrial robot, but the connection to the moving parts, such as moving arms of the industrial robot, is in principle impossible - it would rule out the free movement of individual axes, respectively. The proposed technical solution allows for the device to connect to any gearbox and/or bearing box and the industrial robot still has full freedom of movement. The device can be deployed in such a way that the separation of the impurities takes place during common operation of the machine or industrial robot, respectively. Even in case the separation of impurities takes place during maintenance stop of the machine or industrial robot, it is preferably to move the parts of the machine, or arms of the industrial robot, so that the movement of the inner parts of the gear or bearing flows out the impurities to the oil circulating through the device according to this technical solution. The own electric power source, mainly in form of DC voltage from a rechargeable accumulator, allows high operational and movement freedom to the device, and ability to work without taking the electric power from the system within the production line.

Body of the device is adjusted for attachment to the construction of the machine or to the construction of the industrial robot, for example by means of connecting plate with the openings or by means of a sleeve or by means of a hanging eye or by means of a magnet, straps, suction cup, and so on. In general, it is possible that the device with such connecting possibilities is only freely placed on the machine or by the machine or on the base of the industrial robot or in its vicinity. A solution is also possible where during the first maintenance with us of the device according to this invention the box or the module or the arm of the robot are equipped by a holder, a hook, a hinge, on which the device is then attached.

In a preferable arrangement the input and output openings of the box are equipped by hydraulic couplings to connect the hoses of the device with the box. In such case, the input and output oil piping of the device is equipped by respective endings in order to connect to the oil filling of the box. It suffices for the cooperation of the device according to this solution with the machine or the industrial robot if the input and output opening of the box is equipped by hydraulic couplings, for example in such a way that the blanking nuts of the openings in the box are removed and hydraulic couplings are screwed in their place, whereby they also fulfill the role of closure unless a corresponding counterpart from the device side is connected to these couplings. At the same time, the direct connection of the device is possible, where the opening in the device and the opening in the box are connected by a hollow screw. The use of the hydraulic couplings in a box of the industrial robot is not necessary, since the box can during the installation be rotated to the position where the oil does not flow out from the openings in the box. At the axes of the robot which do not allow for such rotation, or in case of static machines, the hoses with plugs can be connected to the openings, whereby the plugs are demounted in the position where the end of the hose is higher than the level of the oil in the box.

The device according to this technical solution allows for autonomous cleaning of the oil filling without the need for change of the oil itself, which significantly decreases the amount of waste. It is also important that the device can pump the oil even during the movement of the machine or industrial robot, respectively, where the inside of the box is washed more effectively and the impurities from the mechanical parts of the gear or the bearing flow into the oil filling, and they are subsequently pumped into the separation element.

It is possible to use this device together with the connection of oil fillings of multiple boxes of the industrial robot, as disclosed in the earlier inventions of the applicant of this technical solution. In such arrangement the oil filling of at least two boxes is connected with the oil piping into a common circuit. The connection can be permanent in the preferable arrangement, not only for the period of maintenance.

In one of the preferable arrangements the device is equipped by sensors of the oil’s features and/or sensors of the state of the element for separation of impurities and/or pressure sensors and/or flow sensors. The device can have a control unit which assesses and controls the state of the oil pumping, controls the pressure and flow of the oil, and assesses the permeability of the element for separation of impurities. It is also preferable if the device has contactless communication module for the connection with the control and display element. This allows one to control the device remotely, or control multiple devices in a single operation at the same time. The contactless module can be Wi-Fi or Bluetooth module with various protocols. A smartphone, notebook, desktop computer, tablet or similar device with contactless communication channel can be used as control and display element.

The device can be part of a set which includes also at least one spare rechargeable accumulator, charger and control and display element in the form of a mobile phone. The set is stored in a portable case.

Deficiencies in the prior art are remedied by a new method of separation of the impurities from the oil filling of gearboxes and/or bearing boxes, mainly boxes of industrial robots, too, where the oil filling is pumped in a closed circuit through an element for separation of impurities placed outside the box according to this technical solution, whose essence lies in the fact that the oil is pumped through oil pump which is propelled by the portable electric power source. It is preferable if the electric energy with DC voltage is supplied from a rechargeable accumulator.

In a preferable arrangement the pumping of the oil is at least partially realized during the operation of the machine or movement of the industrial robot. It is also preferable if the period of the pumping is set according to the volume of the oil in the respective box, for example, in order to achieve at least 5 times exchange of the volume of the box, and at the same time the quality of the oil at the output from the device is measured. If the pumping of the oil is realized during common operation of the machine, for example robot, it is preferable if the device contains fresh or filtered oil in the amount which roughly corresponds to the volume in the circuit within the device, preferably volume including the oil in the piping. That basically means that the device is not launched dry, but that it is filled with oil in such a way that during the pumping of the oil from the box there is no significant decrease in the oil level in the box, which could cause lubrication problems during operation.

Significant advantages of the proposed invention are increase and reliability of the strained gears and bearings. A significant advantage is also the reducing of the environmental burden, where the overall consumption of the oil is decreased. A significant advantage of the proposed invention is also high flexibility of the application; the device and method according to this technical solution can be used with already installed industrial robots, whereby the small adjustment of the gearbox or bearing module or the box need not to be supplied with anything else, or adjusted in any way.

Description of drawings

The invention is further disclosed by means of drawings 1 to 4. The depicted schemas of connection, the ratio of depiction and the depicted robot are only examples and cannot be interpreted as limiting the scope of protection.

Figures 1 to 3 schematically depicted the connection of the device into variously structured oil circuits of gearboxes of the industrial robot. The dotted line suggests an interface of the removable accumulator, which is adjusted for being pulled out of the slot of the device. In the middle of the drawings 1 to 3, a robot with axes a1 to a6 is depicted for illustration purposes. The second filter of the circuit without the position mark depicts thick filter, such as sifter for protection of the oil pump.

On figure 1 at the top, there is a connection where the oil fillings of three gearboxes of a robot for three different axes are connected. By means of couplings the device is connected to an oil pump. Figure 1 , at the bottom left corner, depicts simple connection of the device to a single gearbox of the robot (axis a1). On the right in figure 1 , there are two connected axes - a3, a2. Figure 2 depicts the connection where six axes a1 to a6 are mutually connected in series, one after another, by means of oil piping. The oil in the common oil filling can be purified by an independent bypass branch which is depicted on the left bottom, and/or by a direct branch, which is depicted on the right and produces the flowing of the oil in connected oil pipings. The electric power source for the propulsion of the pump on the right side is not depicted as separable from the device, but it still holds that it is independent and portable, that is, portable together with the body of the device. In this branch a filtration element can be placed, too (it is not depicted on fig. 2), or this branch can only ensure the flow of the oil in the circuit with multiple boxes.

Figure 3 is a schema of connection of six boxes of the robot in axes a1 to a6, without independent branch with the oil.

Figure 4 is a view of the body of the device and the display element. On the left, in the lower part, there are couplings for the guiding of the oil protruding from the body.

Examples of realization

Example 1

In this example according to figures 1 to 4 the pump 1, the electric engine 2, the element 5 for separation of impurities, and the slot for insertion of the electric power source 3, placed in a common body 4. The body 4 has metal sheathing and it is adjusted for common rough treatment in the industrial environment. On one side the body 4 is equipped by connecting connectors for connection of the input and output flexible piping 9. At the end of the piping 9, there are hydraulic quick couplings, which are designed for connection with couplings 7 on the box 6.

Each box 6 has one input and one output opening designed for pumping the oil filling to the circuit. In this example, the electric power source 3 is accumulator with DC voltage of 12V, which is removable from the slot in the body 4. The body 4 has a compact shape, whereby it collates most of the elements in the device except for connecting piping 9. The control of the pump 1 , and the gathering of the data from the sensors, are connected with the control unit, to which a communication module 8 is connected by a Bluetooth channel.

The element 5 for separation of impurities is a filter with the filtration insert with density of 5 to 10 μm. Use of the device also prevents the situations where new oil is wrongly specified during the oil exchange. During the filtration by means of the device, the original oil specification is maintained, only the contaminating substances are removed from the oil.

The tests have confirmed that during the summary flow of the oil in the device in amount that corresponds to two times the volume of the oil filling in the respective 6 there is 50% decrease in the volume of impurities. If the flow is eight times the volume, the decrease of impurities reaches 95%.

An accumulator in the casing which is used in accumulator tool by a particular producer is used as an electric power source 3, whereby the available casing, slot and connector are used.

Example 2

In this example the device has distributed structure, the oil pump 1 and the electric engine 2 form a single whole which is designed for connection to the arm of the robot by means of two adjustable straps. The element 5 for separation of impurities is adjusted for independent attachment to the box 6 or also to the arm of the robot. The electric power source 3 is placed as an independent element by the leg of the robot, but it can also be connected to the arm of the robot. The electric power source 3 is connected by a cable with the electric engine 2.

Industrial applicability

Industrial applicability is obvious. According to this invention it is possible to industrially and repeatedly produce and use device for separation of impurities from the oil filling of the gearboxes or bearing boxes of various machines, manipulators and industrial robots. List of symbols

1 - pump

2 - electric engine 3 - electric power source

4 - body

5 - element for separation of impurities

6 - box

7 - coupling 8 - communication module

9 - piping

M - engine a1 to a6 - individual axes of the industrial robot

Claims

PATENT CLAIMS 1.A device for a separation of impurities from an oil filling of gearboxes and/or bearing boxes, mainly boxes of industrial robots, where the box (6) is equipped by an input and output oil opening, where the oil filling is designed for lubricating and/or cooling moving parts in the gearbox (6) and/or the bearing box (6), which includes an oil pump (1) with an electric engine (2), an elemeng (5) for the separation of the impurities, and an input and output oil piping (9), which is designed for connection to the input and the output oil opening in the gearbox (6) and/or the bearing box (6), is characterized by the fact, that it includes an independent electric power source (3) which is connected to the electric engine (2) of the pump (1).

2.The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according to the claim 1 is characterized by the fact, that the electric power source (3) is a battery and/or a rechargeable accumulator.

3.The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according to the claim 2 is characterized by the fact, that the electric power source (3) is placed in a casing with a connecting connector on an outer side of the casing, and the casing is adjusted for an insertion into or pulling out of a slot of the device; preferably the slot is part of a body (4).

4.The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according any of the claims 1 to 3 is characterized by the fact, that the pump (1 ) with the electric engine (2) and/or the element (5) for the separation of the impurities are placed in the body (4) which is designed for a connection to the gearbox (6) and/or bearing box (6) and/or for the connection to a construction carrying the gearbox (6) and/or bearing box (6) and/or for the connection to the construction of the industrial robot.

5.The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according to the claim 4 is characterized by the fact, that the electric power source (3) is part of the body (4) of the device.

6. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according to the claim 1 or 2 is characterized by the fact, that the electric power source (3) is connected with the device or with the electric engine (2) by means of a connector or a cable.

7. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according any of the claims 1 to 6 is characterized by the fact, that the element (5) for the separation of the impurities is a filtration element, preferably with a removable filtration insert.

8. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according to the claim 7 is characterized by the fact, that the filtration element has a filtration size 0,5 mm to 1 μm, preferably 5 to 10 μm.

9. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according any of the claims 1 to 8 is characterized by the fact, that it includes an oil pressure sensor.

10. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according any of the claims 1 to 9 is characterized by the fact, that it includes an oil flow sensor.

11. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according any of the claims 1 to 10 is characterized by the fact, that it includes an oil temperature sensor.

12. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according any of the claims 1 to 11 is characterized by the fact, that it includes a ferromagnetic particles sensor.

13. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according any of the claims 1 to 12 is characterized by the fact, that it includes a bypass pressure valve and a pressure sensor for measuring a permeability of the filtration element.

14. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according any of the claims 3 to 13 is characterized by the fact, that the body (4) and/or the piping (9) are equipped by hydraulic couplings (7).

15. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according any of the claims 1 to 14 is characterized by the fact, that it includes a control unit.

16. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according to the claim 15 is characterized by the fact, that it includes at least one diagnostic element connected with the control unit.

17. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according to the claim 15 or 16 is characterized by the fact, that it has a communication module (8), preferably wireless communication module, especially preferably the communication module (8) with Wi-Fi or Bluetooth.

18. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according any of the claims 15 to 17 is characterized by the fact, that it includes a control and display element, preferably on form of a tablet or smartphone with a respective software.

19. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according any of the claims 1 to 18 is characterized by the fact, that it is composed into a portable case together with another electric power source (3) and a charger.

20. The device for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes according any of the claims 1 to 19 is characterized by the fact, that it is equipped by the connector on the outside for supplying of the electric engine (2) with an electric energy, preferably with DC voltage.

21. A method for a separation of impurities from an oil filling of gearboxes and/or bearing boxes, mainly the boxes of industrial robots, where the oil filling is designed for lubricating and/or cooling moving parts in the gearbox (6) and/or the bearing box (6), and where the oil filling is pumped in a close circuit through an element (5) placed outside the box (6), is characterized by the fact, that an oil is pumped by a pump (1) which is propelled by a separable electric power source (3).

22. The method for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes, mainly the boxes of the industrial robots according to the claim 21 is characterized by the fact, that the oil is pumped at least partially during an operation of a machine where the operation is accompanied by a movement of components inside the box (6), preferably during the movement of an arm in an axis of the industrial robot with the respective box (6).

23. The method for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes, mainly the boxes of the industrial robots according to the claim 21 or 22 is characterized by the fact, that the oil is pumped in order to achieve an oil exchange in an amount that is at least twice a volume of the oil in the respective box (6), preferably in the amount that is at least four times the volume of the oil in the respective box (6), especially preferably in the amount that is at least eight times the volume of the oil in the respective box (6).

24. The method for the separation of the impurities from the oil filling of the gearboxes and/or the bearing boxes, mainly the boxes of the industrial robots according to any of the claims 21 to 23 is characterized by the fact, that a flow of the oil changes in order to achieve a dynamic effect of washing of the impurities by means of the oil in the box (6).