High-voltage electrical network switch blade lubrication device

Abstract

A lubrication device (18) for knives (14) of switches (12) of the high voltage electrical network is proposed, the device (18) being intended to be mounted on a terminal effector (20), the device (18) comprising: a container (24) adapted to contain grease; a worm screw (26) adapted to be driven in rotation about a longitudinal axis; a piston head (28) arranged to move linearly in the container (24) in response to the rotation of the worm screw (26), the piston head (28) being dimensioned to exert pressure on the grease inside the container (24) and push the grease towards an outlet (38) of the container (24); and a lubrication nozzle (30) comprising an inlet (50) for fluid communication with the outlet (48) of the container (24) and an outlet (52) comprising a brush (54), the brush (54) being adapted to apply grease from the container (24) to the knives (14). Figure 3

Description

Title of the invention: Lubrication device for high-voltage electrical network switch blades technical field

[0001] This disclosure relates to the field of high-voltage electrical network maintenance. More specifically, this disclosure relates to a device for lubricating switch blades of said electrical network and a method for applying grease to switch blades of such an electrical network. Prior art

[0002] A high-voltage electrical circuit is commonly equipped with a switch. The electrical circuit is designed to transmit current in a distribution network, from a voltage source to the consumer. The switch allows the current flowing through the circuit to be interrupted or established by opening or closing the circuit.

[0003] Classically, the switch comprises two knives, or contacts, mutually movable between a junction position, corresponding to the closure of the circuit, and a gapping position, corresponding to the opening of the circuit.

[0004] To ensure the proper functioning and durability of the switches, it is necessary to regularly lubricate the blades. Such lubrication reduces mechanical wear due to repeated friction of the blades when the switch is opened or closed, improves electrical conductivity by ensuring good contact between the blade surfaces, protects against corrosion by forming a barrier against moisture, and prevents the occurrence of electrical arcs when the switch is opened or closed.

[0005] Typically, blade lubrication is carried out by specialized maintenance teams, following strict procedures. First, the line on which the switch is installed is shut off. Since the switches are located high up on poles or pylons, it is necessary to use aerial work platforms, ladders, or to climb directly onto the structures via safety cable systems to access the blades. The grease is then applied manually by the teams.

[0006] However, such lubrication is inefficient in terms of the time and resources required. Working at height requires specialized equipment such as aerial work platforms and safety systems, increasing the complexity and intervention time. In addition, teams must take safety precautions to avoid any risk of contact with knives in which a residual charge may remain.

[0007] There is therefore a need to improve the lubrication of the knives in order to make this operation simpler and more efficient. Summary

[0008] A device for lubricating the knives of high-voltage electrical network switches is proposed, the device being intended to be mounted on a terminal effector, the device comprising: - a container suitable for holding grease; - a worm screw adapted to be driven in rotation around a longitudinal axis; - a piston head arranged to move linearly within the container in response to the rotation of the screw, the piston head being sized to exert pressure on the grease inside the container and push the grease towards an outlet in the container; and - a grease nozzle comprising a fluid communication inlet with the container outlet and a brush outlet, the brush being adapted to apply grease from the container onto the knives.

[0009] Thus, the device can be used to lubricate the blades of switches located at height using a robotic arm, without requiring excessive time and resources. It is possible to lubricate the blades from the ground by controlling the robotic arm on which the device is mounted. Lubrication can also be carried out without interrupting the power supply. Such lubrication is simple, quick, and requires few material resources.

[0010] Optionally, a retaining ring can be attached to one end of the worm gear located away from the piston head. The retaining ring is adapted to drive the worm gear in rotation around the longitudinal axis by being connected to a remote motor. Thus, mounting the device on the robotic arm can be simple and easily reversible – the retaining ring can, for example, cooperate with a quick-release hook.

[0011] Optionally, the container may have a capacity greater than 400 mL. Such a capacity makes it possible to limit the frequency of refilling the container with grease.

[0012] Optionally, the brush may have a shape adapted for lubricating the switch blades, for example, a brush shape or a circular shape. This allows the grease to be applied evenly to the surface of the blades, avoiding any risk of over- or under-lubrication, which could impair the proper functioning of the blades.

[0013] According to another aspect, a terminal effector is proposed, configured to allow the device to be mounted on a robotic arm, the terminal effector comprising: - a fixed part intended to be mounted on the robotic arm; - A moving part extending from the fixed part, the moving part being mounted for rotation on the fixed part around a second longitudinal axis, the moving part being adapted to be secured to the worm gear of the lubrication device to drive the worm gear in rotation. Such a terminal effector allows for efficient transmission of the rotational motion from the terminal effector to the worm gear. The lubrication device can be of simplified construction, not requiring its own motor or power source.

[0014] Optionally, the moving part may include a hook that is axially movable about the second longitudinal axis between a deployed position in which the hook protrudes from the moving part to allow it to be secured with the mounting ring of the lubrication device, and a retracted position in which the hook is housed within the moving part, so that the worm gear of the lubrication device, when mounted on the moving part, extends into the moving part. Thus, the attachment of the lubrication device is quick and easily reversible, while ensuring a rigid connection between the parts. When the parts are assembled, any separation or relative movement between them is prevented.

[0015] Optionally, a motor can be housed in the fixed part, and a rotor of the motor is connected to the moving part to drive the moving part in rotation. The lubrication device can be entirely without a motor or internal power source. The lubrication device can be relatively lightweight, thus improving the stability of the device mounted on the robotic arm.

[0016] According to another aspect, an aerial switch lubrication assembly is proposed comprising the lubrication device and the terminal effector, the moving part of the terminal effector being integral with the worm screw.

[0017] Optionally, the assembly may further include a fixed sleeve extending between a proximal end fitted onto the fixed part of the end effector and a distal end fixed to a mounting portion of the lubrication device. This improves the rigidity of the assembly.

[0018] According to another aspect, a method is proposed for applying grease to the knives of a high-voltage electrical network switch using the assembly, the assembly being mounted on the end of a robotic arm, the method comprising: - activating a motor of the terminal effector, by a remote operator,; - drive in rotation, by the motor, the moving part of the terminal effector and, by extension, the worm gear of the lubrication device mounted on the moving part; - move, via the worm screw, the piston head of the lubrication device towards the outlet of the container to push the grease towards the brush of the lubrication device; - to control, by the operator, the robotic arm so as to move the brush of the lubrication device by applying grease to the switch blade.

[0019] Such a method can be easily implemented by an operator located on the ground, without requiring additional material resources. Brief description of the drawings

[0020] Other features, details and advantages will become apparent from reading the detailed description below and from analyzing the accompanying drawings, in which: Fig. 1

[0021] [Fig.1] schematically illustrates a perspective view of switches mounted in a high voltage electrical circuit, according to one embodiment. Fig. 2

[0022] [Fig.2] schematically illustrates a perspective view of a lubrication assembly which can be implemented for lubricating the switches of [Fig.1], according to one embodiment. Fig. 3

[0023] [Fig.3] schematically illustrates an exploded perspective view of a device greasing of the entire [Fig.2], according to one embodiment. Fig. 4

[0024] [Fig.4] schematically illustrates a perspective view of a terminal effector of the whole of [Fig.2], according to one embodiment. Fig. 5

[0025] [Fig. 5] schematically illustrates a side view of a fixing sleeve that can to be implemented throughout [Fig.2], according to an embodiment. Fig. 6

[0026] [Fig.6] illustrates a flowchart of a method for greasing knives of switches, according to one embodiment. Description of the implementation methods

[0027] Figure 1 illustrates a switch 10 mounted in a high-voltage electrical circuit 12. In what follows, the term "high voltage" (HV) is used in its usual sense, namely that the term "high voltage" refers to a voltage that is between 1 kV and 50 kV. Such an electrical circuit 12 is intended to transmit current in a distribution network.

[0028] It should be noted that such a high-voltage electrical circuit 12 generally comprises three phases, i.e., it is three-phase. Thus, the electrical circuit 12 may include three switches 10, as shown in [Fig. 1]. Each switch 10 can be associated with one of the phases of the electrical circuit 12.

[0029] The switch 10 comprises two fixed terminals connected by one or more movable blades 14. The blades 14 are movable contacts that allow the electrical circuit to be closed or opened by connecting or disconnecting the two fixed terminals. When closed, they allow current to flow; when open, they interrupt the circuit 12 and isolate the relevant section.

[0030] A lubrication assembly 16 for the knives 14 is described below, with reference to Figures 2 to 5. The assembly 16 is intended to be mounted on a robotic arm (not shown). Such a mounting allows the lubrication operation to be performed by remote control of the robotic arm. An operator can thus perform the operation from the ground. It is not necessary to disconnect the power line to carry out the lubrication operation.

[0031] As seen in [Fig.2], the lubrication assembly 16 comprises a lubrication device 18, an end effector 20 and a mounting sleeve 22. The lubrication device 16 is adapted to be mounted on the end effector 20, itself adapted to be fixed to the robotic arm, and the mounting sleeve 22 makes the assembly 16 rigid.

[0032] The lubrication device 18, more clearly visible in [Fig.3], is described first. The lubrication device 18 comprises a container 24, a worm screw 26, a piston head 28 and a lubrication nozzle 30.

[0033] The container 24 has a symmetrical external shape of revolution, with a median axis denoted A. The container 24 is cylindrical and has a circular cross-section. The container 24 includes, in particular, a body 32, forming an internal chamber 34 for holding the grease, and a lid 36 screwed onto the body 32 to close the internal chamber 34. The container 24 further includes an outlet 38, coaxial with the median axis A, provided here on the lid 36, allowing the passage of grease from the internal chamber 34 of the container 24 to the grease nozzle 30.

[0034] The container 24 has the capacity to hold a volume of grease greater than 400 mL. Therefore, the container has a diameter greater than 70 mm, preferably 77 mm, and a length, measured along axis A, greater than 80 mm, preferably 86 mm. This capacity makes it possible to limit the frequency of refilling the container with grease while also limiting the overall weight of the lubrication device—excessive weight that could compromise the stability of the device when mounted on the robotic arm.

[0035] The grease is for example a conductive grease or a lubricant designed for electrical conditions and high temperatures.

[0036] The auger 26 extends along a longitudinal axis, between a first axial end external to the container 24 and a second axial end inside the container 24. For this purpose, a bottom of the container includes an opening adapted for the passage of the auger 26. The auger 26 is configured to be driven in rotation around the longitudinal axis, here the longitudinal axis being coincident with the axis A of the container 24.

[0037] In the illustrated example, the worm screw 26 comprises a hollow cylinder 40 having an internal thread, and a threaded rod 42 configured to cooperate with the internal thread of the hollow cylinder 40. The hollow cylinder 40 is configured to rotate about the longitudinal axis, causing a linear displacement of the threaded rod 42 along this axis.

[0038] The lubrication device 18 may, for example, include a retaining ring 44, the retaining ring 44 serving as a means of transmitting a rotational movement from a motor provided in the terminal effector 20 to the worm gear 26, for example to the hollow cylinder 40. The retaining ring 44 has an annular, or ring-like, shape provided at the first axial end of the worm gear 26 to be inserted into a hook of the terminal effector 20, as will be described in more detail later.

[0039] The piston head 28 is arranged in the container 24, for example by being inserted into the container 24 before the lid 36 is screwed onto the body 32 of the container. The piston head 28 extends radially from the median axis A to the walls delimiting the internal chamber of the container 24.

[0040] The piston head 28 is mechanically connected to the worm screw 26, so that the piston head 28 moves linearly along the axis A in response to the rotation of the worm screw 26. Thus, when the worm screw 26 rotates, the piston head 28 can push the grease contained in the container 24 towards the outlet 38 of the container 24.

[0041] In particular, in the illustrated example, the piston head 28 is integral with the threaded rod 42 of the worm screw 26, so that the piston head 28 moves linearly along the axis A of the container 24 in response to the rotation of the hollow cylinder 40 of the worm screw 26.

[0042] Furthermore, as can be seen in [Fig. 3], the piston head 28 may include two grooves 44 located on the radially external wall of the piston head 28, the grooves 46 being diametrically opposed with respect to the axis A. The grooves 44 are configured to cooperate with two ribs 46 of the container 24. The ribs 46 extend axially along the internal wall of the container 24. Thus, the grooves 44 of the piston head 28 and the ribs 46 of the container 24 can guide the linear movement of the piston head 28 within the container 24.

[0043] The grease nozzle 30 is mounted on the container 24, at the outlet 38 of the container 24. For example, the outlet 38 of the container may be delimited by a threaded collar 48 configured to cooperate with a threaded internal wall (not visible) of the grease nozzle 30. The grease nozzle 30 mounted on the outlet of the container forms a grease passage from the internal chamber 34 of the container 24, through an inlet 50 of the grease nozzle 30 to an outlet 52 of the grease nozzle 30.

[0044] The grease nozzle 30 has a frustoconical external shape between the inlet 48 and the outlet 50. When the grease nozzle 30 is fixed to the container 24, the axis of the grease nozzle 30 coincides with the median axis A of the container 24. Thus, the grease pushed into the container by the piston head 28 can be pushed through the grease passage to the outlet 50 of the grease nozzle 30.

[0045] The outlet 50 of the grease nozzle 30 includes a brush 52. The brush 52 can take any shape suitable for applying the grease from the container 24 to the knives 14. For example, here, the brush 52 has a circular shape, but the brush 52 could also have other shapes, such as a paintbrush shape. The brush 52 allows for a homogeneous application of the grease from the container 24 to the surface of the knives.

[0046] The terminal effector 20 configured to connect the lubrication device 18 described above to a robotic arm is described below, with reference to [Fig.4].

[0047] The end effector 20 comprises a fixed part 54 and a moving part 56. The fixed part 54 is configured to be received on one end of a robotic arm. The moving part 56 is configured to transmit a rotary motion from the end effector 20 to the lubrication device 18 when mounted on the end effector 20.

[0048] The fixed part 54 has a symmetrical external shape of revolution, with a median axis denoted B. When the lubrication device 18 is mounted on the end effector 20, the axis B coincides with the longitudinal axis of the worm gear 26 and the median axis A of the container 24. The fixed part 54 may include, at a first axial end, one or more annular ribs 58 allowing the fixed part 54 to be fixed to the robotic arm. The movable part 56 is rotatably mounted on the second axial end of the fixed part 54.

[0049] One or more motors (not visible) can be housed in the fixed part 54 to drive the worm screw 26 in rotation. In particular, a rotor of a motor can be attached to the moving part 56, adapted to be attached to the fixing ring 44 of the lubrication device 18 to drive the worm screw 26 in rotation.

[0050] The moving part 56 extends in line with the fixed part 54. The moving part 56 is mounted in rotation on the fixed part 54, around a second longitudinal axis, coinciding with the axis B.

[0051] The movable part 56 comprises a cylinder 60 and a retractable hook 62, which is axially movable within the cylinder 60 between a deployed position and a retracted position. In the deployed position, the hook 62 protrudes from the free end of the cylinder 60, away from the fixed part 54. The hook 62 can thus engage with the retaining ring 44 of the lubrication device 18. In the retracted position, the retractable hook 62 is located in the vicinity of the fixed part 54. Thus, when the device The lubrication 18 is attached to the retractable hook 62, the worm screw 26 extends in the hollow cylinder 60. The rigidity of the rotating assembly comprising the moving part 56 and the worm screw 26 is thereby improved.

[0052] As shown in [Fig. 4], the hook 62 can, in particular, be a quick-release hook. The retaining ring 44 of the lubrication device 18 can be inserted into a curved section of the hook 62, and the hook 62 can then be closed by pressing on the curved section. The lubrication device is thus temporarily secured and can be easily and quickly changed by an operator.

[0053] Furthermore, the fixing sleeve 22 is configured to secure the fixed part 54 of the terminal effector 20 and a fixing portion 64 of the lubrication device 18. The fixing portion 64 of the lubrication device 18 may, for example, be located in the vicinity of the container 24. The fixing sleeve 22 makes it possible to stiffen the lubrication assembly 16.

[0054] The fixing sleeve 22 can, for example, fit onto the fixed part 54 of the terminal effector 20 at a proximal end 66 of the fixing sleeve 22. In particular, the sleeve 22 includes one or more internal grooves (not visible) adapted to cooperate with axial ribs 68 formed on the fixed part 54 of the terminal effector 20, to secure the fixing sleeve 22 and the fixed part 54.

[0055] The retaining sleeve 22 can also be fitted onto the retaining portion 64 of the lubrication device 18, at a distal end of the sleeve 22. For example, the retaining portion 64 may be rectangular, and a distal end 70 may have a hollow rectangular shape with a cross-section corresponding to that of the retaining portion 64, allowing for a fit based on complementary shapes. The retaining sleeve 22 can be fitted onto the retaining portion 64 when the retaining ring is secured to the retractable hook 62 and the hook 62 is moved to the retracted position.

[0056] As seen in [Fig.5], the fixing sleeve 22 may include slots 72 extending axially along the fixing sleeve to lighten the fixing sleeve 22. The slots 72 may be regularly distributed angularly around the main axis of extension of the sleeve 22. The fixing sleeve is thus relatively light.

[0057] A method for applying grease to switch blades is described below, with reference to [Fig.6]. In this method, the grease fitting 18 is fixed to the terminal effector 20, and the terminal effector 20 is mounted on a robotic arm.

[0058] The method includes activating 100, by a remote operator, a motor of the terminal effector 20. The operator can, for example, activate the motor from the ground, at a distance from the switch positioned at a height. Operator safety is improved.

[0059] The method comprises rotating the moving part 56 of the end effector 20 and the worm gear 26 attached to the moving part 56 by the motor. The method further comprises moving the piston head 28 within the container 24 by means of the worm gear 26 to push the grease towards the brush 54 of the lubrication nozzle 30. These two steps require no action from the operator and are a consequence of the mechanical connection between the parts of the assembly. The operator is passive during these steps, facilitating the lubrication operation.

[0060] The method further includes controlling 400, by an operator, the movement of the robotic arm to move the brush 54 on the surface of the knife 14 while applying grease.

[0061] The lubrication process is simple and safe for operators.

Claims

Demands

1. Lubrication device (18) for knives (14) of switches (12) of the high voltage electrical network, the device (18) being intended to be mounted on a terminal effector (20), the device (18) comprising: - a container (24) adapted to contain grease; - a worm screw (26) adapted to be driven in rotation about a longitudinal axis; - a piston head (28) arranged to move linearly in the container (24) in response to the rotation of the worm screw (26), the piston head (28) being dimensioned to exert pressure on the grease inside the container (24) and push the grease towards an outlet (38) of the container (24); and - a grease nozzle (30) comprising an inlet (50) in fluid communication with the outlet (48) of the container (24) and an outlet (52) comprising a brush (54), the brush (54) being adapted to apply grease from the container (24) to the knives (14).

2. Lubrication device (18) according to claim 1, in which a fixing ring (44) is fixed to one end of the worm (26) distant from the piston head (28), the fixing ring (44) being adapted to drive the worm (26) in rotation about the longitudinal axis by being attached to a remote motor.

3. Lubrication device (18) according to claim 1 or 2, wherein the container (24) has a capacity greater than 400 mL.

4. Lubricating device (18) according to any one of the preceding claims, wherein the brush (54) has a shape adapted for lubricating knives (14), for example a brush shape or a circular shape.

5. A terminal effector (20) configured to allow the mounting of the lubrication device (18) according to any one of claims 1 to 4 on a robotic arm, the terminal effector (20) comprising: - a fixed portion (54) for mounting on the robotic arm; - a movable portion (56) extending in line with the fixed portion (54), the movable portion (56) being rotatably mounted on the fixed portion (54) about a second longitudinal axis, the movable portion being adapted to be joined with the worm screw (26) of the lubrication device (18) to drive the worm screw (26) in rotation.

6. Terminal effector (20) according to claim 5, in combination with claim 2, wherein the moving part (56) comprises a hook (62) movable axially about the second longitudinal axis between a deployment position in which the hook (62) protrudes from the moving part (56) to allow its attachment to the fixing ring (44) of the lubrication device (18) and a retracted position in which the hook (62) is housed in the moving part (56) so that the worm screw (26) of the lubrication device (18), when mounted on the moving part (56), extends into the moving part (56).

7. Terminal effector (20) according to claim 5 or 6, wherein a motor is housed in the fixed part (54), and a rotor of the motor is connected to the moving part (56) to drive the moving part (56) in rotation.

8. Assembly (16) for lubricating switches (12) of the high voltage electrical network comprising the lubrication device (18) according to any one of claims 1 to 4 and the terminal effector (20) according to any one of claims 5 to 7, the moving part (56) of the terminal effector (20) being integral with the worm screw (26).

9. Assembly (16) according to claim 8, further comprising a fixed fixing sleeve (22) extending between a proximal end (66) fitted onto the fixed part (54) of the terminal effector (20) and a distal end (70) fitted onto a fixing portion (64) of the lubrication device (18).

10. Method of applying grease to knives (14) of a switch (10) of the high voltage electrical network using the assembly (16) according to any one of claims 8 or 9, the assembly (16) being mounted on the end of a robotic arm, the method comprising: - activating a motor of the terminal effector (20), by a remote operator, - driving in rotation, by the motor, the moving part (56) of the terminal effector (20) and, by extension, the worm gear (26) of the lubrication device (18) mounted on the moving part (56); - move, via the worm screw (26), the piston head (28) of the lubrication device (16) towards the outlet (38) of the container (24) to push the grease towards the brush (54) of the lubrication device (18); - to control, by the operator, the robotic arm so as to move the brush (54) of the lubrication device (18) by applying grease to the knife (14) of the switch (10).

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