Drive system for cable transport installation

Abstract

The invention relates to a drive system (1) for driving a cable of a cable transport installation, the drive system (1) comprising a brushless motor (10) which comprises a fixed main shaft (11), a stator (13) and a rotor (30); the drive system (1) further comprising a pulley (60) comprising a drive armature (61) for driving the cable of the transport installation, the pulley (60) being rotatably mounted relative to the main shaft (11) and being directly attached to the rotor (30) of the brushless motor (10). The invention also relates to a cable transport installation comprising such a drive system (1). Figure 1

Description

Title of the invention: Drive system for cable transport installation Technical field of the invention

[0001] The present invention relates to the field of cable transport and more particularly to the field of ski lifts, such as for example chairlifts or cable cars. State of the art

[0002] Generally speaking, a cable transport installation is a motorized means of transport, mechanically guided by a rack or a cable forming a transport track on which a vehicle capable of transporting loads or people moves. Such a type of transport installation is advantageously used to overcome an obstacle, and / or to allow the load to be transported on a relatively steep slope.

[0003] To climb this slope, the vehicles of a ski lift (equipment, seats, cabins, trains, poles or more rudimentary skips) use the traction of the cable to which they are attached.

[0004] In order to set the cable in motion, it is known to use a motorization system coupled to a pulley which drives the cable. Historically, motorization systems were composed of three main elements: a motor (generally electric), a pulley, and a reducer to convert the rotational speed of the motor into a torque to drive the pulley.

[0005] Although these solutions are satisfactory in that they allow cable transport installations to be motorized, they generally consume a lot of energy and generate significant noise pollution, particularly due to the high rotation speed of the motor.

[0006] Gearless motorization solutions have therefore been developed in which a rotating shaft allows a connection between the rotating elements of the motor and the pulley. These solutions are interesting because they allow the rotation speed of the motor to be reduced, which reduces the noise generated by the motorization of the transport installation. However, the transmission shaft is a coupling part between the motor and the pulley which requires more maintenance. It is also a massive element which must be rotated by the motor, which contributes to increasing the energy consumption of the transport installation.

[0007] There is therefore a need to find a cable drive system that is silent, has reduced power consumption, while guaranteeing a good mechanical resistance to limit maintenance of the coupling parts between the motor and the pulley.

[0008] Object of the invention

[0009] The present invention aims to propose a solution which responds to all or part of the aforementioned problems.

[0010] This object can be achieved by implementing a drive system for driving a cable of a cable transport installation, the drive system comprising: - a brushless motor comprising: a fixed main shaft extending along a main axis; at least one stator comprising a cylindrical stator skirt extending axially around the main axis, said stator skirt housing coils; and at least one rotor arranged between the stator skirt and the main shaft, said rotor being rotatably mounted relative to the main shaft and comprising permanent magnets, the rotor being configured to be set in motion; at least one radial bearing configured to allow rotational mounting of the rotor relative to the main shaft; an electronic control system configured to supply electrical energy to the coils; and a pulley comprising a drive armature intended to drive the cable of the transport installation, the pulley having a geometry of revolution around the main axis and being rotatably mounted relative to the main shaft, the pulley being arranged coaxially with the rotor and fixed directly to the rotor of the brushless motor.

[0011] The arrangements described above make it possible to propose a drive system in which no element is interposed between the rotor of the brushless motor and the pulley used to drive the cable of the cable transport installation. The transfer of the motor torque is therefore optimized, and makes it possible to set the pulley in motion with minimal power, which saves energy.

[0012] It is therefore well understood that there is a rigid connection between the pulley and the rotor of the brushless motor. In other words, the pulley and the rotor of the brushless motor are in a built-in connection.

[0013] The drive system may further have one or more of the following features, taken alone or in combination.

[0014] According to one embodiment, the at least one radial bearing is a rolling bearing.

[0015] According to one embodiment, the at least one radial bearing is configured to allow the rotational mounting of the pulley relative to the main shaft.

[0016] Thus, the radial bearing makes it possible to guide the pulley around the main axis.

[0017] According to one embodiment, the at least one radial bearing comprises a proximal bearing configured to allow rotational mounting of the pulley on the main shaft and a distal bearing configured to allow rotational mounting of the rotor on the main shaft.

[0018] According to one embodiment, the proximal bearing is a ball joint bearing.

[0019] According to one embodiment, the distal bearing is a rigid bearing.

[0020] According to one embodiment, the proximal bearing and the distal bearing are coaxial.

[0021] According to one embodiment, the proximal bearing and the distal bearing are offset. axially along the main axis.

[0022] In this way, it is possible to carry out rotational guidance around the main shaft at the rotor, and at the pulley.

[0023] Furthermore, the use of a spherical bearing at the proximal bearing makes it possible to limit the stresses applied to the bearing, which makes its fatigue life longer, while allowing the pulley to be mounted in rotation relative to the main shaft in combination with the distal bearing.

[0024] According to one embodiment, the pulley comprises a cylindrical attachment skirt extending from the drive frame of the pulley around the main shaft, the attachment skirt having an attachment end portion, the attachment skirt being directed towards the rotor and attached to the rotor at the attachment end portion.

[0025] In this way, it is possible to spatially offset the brushless motor from the pulley, which makes it easier to access the brushless motor, particularly for maintenance operations.

[0026] According to one embodiment, the drive system comprises an access walkway arranged radially in line with the pulley fixing skirt.

[0027] Such an access gateway allows a user to directly access the stator for maintenance operations.

[0028] According to one embodiment, the fixing skirt has a diameter counted radially from the main axis which is substantially equal to a diameter of the rotor counted radially from the main axis.

[0029] Thus, it is possible to ensure better rotational synchronization of the pulley and the rotor. Furthermore, the diameter match is important because it allows the pulley and the rotor to be superimposed on each other, which makes the system more compact.

[0030] In other words, the pulley mounting skirt and the rotor have the same diameter.

[0031] By “substantially” we mean “within 5%”.

[0032] According to one embodiment, at least one element selected from the fixing skirt and the rotor comprises a fixing shoulder, said fixing shoulder projecting from said at least one element, and being configured to allow direct fixing of the fixing skirt to the rotor by means of fixing agents.

[0033] Thus it is possible to improve the direct fixing of the rotor on the pulley.

[0034] For example, the rotor includes a mounting shoulder projecting from the rotor toward the main shaft, and the mounting skirt includes a mounting shoulder projecting from the mounting skirt toward the main shaft.

[0035] According to one embodiment, the fixing shoulder(s) comprise a fixing opening configured to allow the passage of fixing agents.

[0036] According to one embodiment, the fixing agents are bolts.

[0037] According to one embodiment, the fixing skirt and the rotor are bolted together with the other, for example via the fixing shoulders.

[0038] According to one embodiment, the brushless motor comprises a distal end wall extending from the main shaft perpendicular to the main axis, and having a geometry of revolution about the main axis, the stator skirt extending from said distal end wall.

[0039] In other words, the distal end wall covers the stator at a portion of the main shaft opposite the pulley. Thus, the distal end wall prevents the penetration of parasitic elements into the brushless motor.

[0040] According to one embodiment, the distal end wall and the main shaft are fixed directly to each other.

[0041] Thus it is possible to have better mechanical resistance of the assembly.

[0042] According to one embodiment, the stator skirt is attached directly to the distal end wall.

[0043] According to one embodiment, the distal end wall and the main shaft form a single piece. In other words, the main shaft is integral with the distal end wall.

[0044] The mechanical resistance of the assembly thus formed is even better.

[0045] According to one embodiment, the pulley has an external diameter of between 5 m and 8 m, and in particular between 6 m and 7 m.

[0046] Thus, the drive system is suitable for the transport of people, for example for a chairlift or a cable car. Indeed, a sufficiently large external pulley diameter allows two vehicles to pass over the entire transport track of the transport installation.

[0047] According to one embodiment, the external diameter of the pulley is substantially equal to 6.30 m.

[0048] According to one embodiment, the external diameter of the pulley is substantially equal to 6.75 m.

[0049] According to one embodiment, the brushless motor comprises at least two stators stacked along the main axis and around the main shaft, the electronic control system being configured to individually and selectively power the coils of each stator.

[0050] Thus, it is possible to adapt the power supplied by the motor according to the number of stators, or the number of stator stages supplied with electrical energy.

[0051] According to one embodiment, the brushless motor comprises at least two rotors, one rotor being associated with each of the stators of the brushless motor, said rotors forming a stack of rotors along the main axis and around the main shaft, each rotor being attached directly to the or each adjacent rotor in said stack of rotors.

[0052] Thus, each rotor rotates the other rotors in the stack of rotors, which makes it possible to maintain a nested structure between the rotors and the pulley, while allowing selective actuation of the stators to provide the desired drive torque. This makes it possible to adapt the torque transmitted by the brushless motor to the user's power demand.

[0053] Generally, the pulley is attached directly to the lower rotor of the rotor stack. In other words, the pulley is attached to the rotor of the rotor stack that is closest to the pulley.

[0054] The aim of the invention can also be achieved by implementing a cable transport installation comprising: - a traction cable extending along a transport track; - a drive system of the type described above and configured to drive the traction cable; and - at least one vehicle configured to be moved by the traction cable along the transport track.

[0055] The arrangements described above make it possible to propose a transport installation in which the power required to move the vehicle along the transport route is reduced.

[0056] Brief description of the drawings

[0057] Other aspects, aims, advantages and characteristics of the invention will appear better on reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the appended drawings in which:

[0058] [Fig.l] [Fig.l] is a schematic sectional view of a drive system according to a particular embodiment of the invention.

[0059] [Fig.2] [Fig.2] is a schematic view of a perspective section of a drive system according to another particular embodiment of the invention. Detailed description

[0060] In the figures and in the remainder of the description, the same references represent identical or similar elements. In addition, the different elements are not shown to scale so as to enhance the clarity of the figures. Furthermore, the different embodiments and variants are not mutually exclusive and can be combined with each other.

[0061] As illustrated in Figures 1 and 2, the invention relates to a drive system 1 for driving a cable of a cable transport installation. The invention also relates to such a cable transport installation (not shown) comprising a traction cable which extends along a transport track. This traction cable is driven by a pulley 60 of the drive system 1, and is capable of moving at least one vehicle along the transport track. For example, such a transport installation is a chairlift, or a gondola.

[0062] The drive system 1 firstly comprises a brushless motor 10 comprising a fixed main shaft 11 extending along a main axis denoted “X”, and at least one stator 13. It is possible for the drive system 1 to comprise a plurality of stators 13 stacked along the main axis X and around the main shaft 11. [Fig.l] illustrates in particular an embodiment in which the brushless motor 10 comprises three stacked stators 13.

[0063] Each stator 13 comprises a cylindrical stator skirt 15 extending axially around the main axis X. By "cylindrical" is meant a surface defined by a straight line called a generator passing through a variable point describing a closed plane curve, called a director curve, the generator keeping a fixed direction. More particularly, the stator skirt 15 may be contained between two straight cylindrical surfaces each having a generator having a direction parallel to the main axis X and resting on circular director curves, the difference between the radii of the circular director curves being substantially equal to a greater thickness of the stator skirt 15.

[0064] The stator skirt 15 of the stator 13 houses coils 17. [Fig. 1] illustrates the positioning of the coils 17 on a portion of the stator 13. However, not all of the coils 17 have been shown so as not to overload the reading of the figures. It is however well understood that the coils 17 may be present over the entire circumference of the stator 13, and on each of the stator skirts 15.

[0065] The brushless motor 10 may also include a distal end wall 19 extending from the main shaft 11 perpendicular to the main axis X. The distal end wall 19 generally has a geometry of revolution around the main axis X, and covers the stator 13 at a portion of the main shaft 11 opposite the pulley 60. For example, the distal end wall 19 has a general disc shape. The stator skirt 15 may extend from said distal end wall 19, and towards the pulley 60, for example by projecting from a periphery of the distal end wall 19. Thus, the distal end wall 19 makes it possible to prevent the penetration of parasitic elements inside the brushless motor 10. According to one embodiment, the distal end wall 19 and the main shaft 11 are fixed directly to each other. Thus it is possible to have better mechanical strength of the assembly.It is also possible that the stator skirt 15 is attached directly to the distal end wall 19.

[0066] Advantageously, the distal end wall 19 and the main shaft 11 can form a single piece. In other words, the main shaft 11 is made of the same material as the distal end wall 19. The mechanical strength of the assembly thus formed is even better.

[0067] The brushless motor 10 also comprises at least one rotor 30 disposed between the stator skirt 15 and the main shaft 11. The brushless motor 10 may comprise at least two rotors 30. In this case, said rotors 30 may form a stack of rotors 30 along the main axis X and around the main shaft 11, each rotor 30 being attached directly to the or each adjacent rotor 30 in said stack of rotors 30. [Fig. 1] illustrates an embodiment in which the brushless motor 10 comprises three rotors, and [Fig. 2] illustrates an embodiment in which the brushless motor 10 comprises a single rotor 30. Moreover, when the description refers to a “stator” 13 or a “rotor” 30, it is understood that the same arrangements may apply to a plurality of stators 13 or to a plurality of rotors 30. Generally a rotor 30 is associated with each stator 13 of the brushless motor 10.The rotor stack structure 30 allows each rotor 30 to rotate the other rotors 30 of the rotor stack 30. This allows a nested structure to be maintained between the rotors 30 and the pulley 60, while allowing selective actuation of the stators 13 to provide the desired drive torque. This allows the torque transmitted by the brushless motor 10 to be adapted to the user's power demand. As can be seen in the figures, each rotor 30 may comprise a main wall of straight cylindrical shape, having a radius strictly less than a radius of the stator skirt 15 of the stator 13 with which said rotor 30 is associated.

[0068] Each rotor 30 is configured to be set in motion. For this, each rotor 30 is mounted to rotate relative to the main shaft 11 and comprises magnets permanent magnets 31. In order to set the rotor 30 in motion, the coils 17 of the stator 13 are powered by a variable electric current, and generate a rotating magnetic field. The permanent magnets 31 of the rotor 30 tend to follow this rotating magnetic field, which causes the rotor 30 to set in motion. [Fig.l] illustrates the positioning of the permanent magnets 31 on a part of the rotor 30. However, not all of the permanent magnets 31 have been shown so as not to overload the reading of the figures. It is however well understood that the permanent magnets 31 may be present over the entire circumference of the rotor 30.

[0069] Advantageously, each rotor 30 may comprise a fixing shoulder 51 projecting from the rotor 30, and in particular from the main wall of this rotor towards the main shaft 11. For example, each rotor 30 may comprise two fixing shoulders 51 offset from each other along a direction parallel to the main axis X. These two fixing shoulders 51 may project from the main wall of the rotor 30 at two ends of the main wall. Thus, it is possible to use these fixing shoulders 51 to fix the rotor 30 to the adjacent rotors 30 of the stack of rotors 30 and / or to the pulley 60. The fixing shoulders 51 may further comprise a fixing opening configured to allow the passage of fixing agents 53. For example, the fixing agents 53 are bolts.

[0070] The drive system 1 also comprises at least one radial bearing 40 configured to allow the rotor 30 to be mounted for rotation relative to the main shaft 11 around the main axis X, for example a rolling bearing. As can be seen in the figures, the at least one radial bearing 40 may comprise a distal bearing 43 configured to allow the rotor 30 to be mounted for rotation on the main shaft 11. According to one embodiment, the distal bearing 43 is a rigid bearing.

[0071] As can be seen in the figures, the at least one radial bearing 40 can also be configured to allow the pulley 60 to be mounted in rotation relative to the main shaft 11. Thus, the radial bearing 40 makes it possible to guide the pulley 60 around the main axis X. For this, it is possible for the at least one radial bearing 40 to comprise a proximal bearing 41 configured to allow the pulley 60 to be mounted in rotation on the main shaft 11. Generally, the proximal bearing 41 and the distal bearing 43 are coaxial, and are axially offset along the main axis X. In this way, it is possible to guide it in rotation around the main shaft 11 at the rotor 30, and at the pulley 60. Furthermore, the proximal bearing 41 can be a spherical bearing.The use of a spherical bearing at the proximal bearing 41 makes it possible to limit the stresses applied to the bearing, which makes its fatigue life longer, while allowing the pulley 60 to be mounted in rotation relative to the main shaft 11 in combination with the bearing. distal 43

[0072] The drive system 1 further comprises an electronic control system 50 configured to supply the coils 17 with electrical energy, and more particularly with alternating electric current. The electronic control system 50 is therefore configured to control the rotation speed of the rotor 30 as a function of said alternating electric current. In the case where the drive system 1 comprises several stators 13, it may be provided that the electronic control system 50 is configured to individually and selectively supply the coils 17 of each stator 13. Thus, it is possible to adapt the power supplied by the motor as a function of the number of stators 13, or the number of stator stages 13 supplied with electrical energy.

[0073] Finally, the drive system 1 comprises the pulley 60 which comprises a drive armature 61 intended to drive the cable of the transport installation. The pulley 60 has a geometry of revolution around the main axis X and is rotatably mounted relative to the main shaft 11. The pulley 60 is arranged coaxially with the rotor 30 and fixed directly to the rotor 30 of the brushless motor 10. It is therefore clearly understood that there is a rigid connection between the pulley 60 and the rotor 30 of the brushless motor 10. In other words, the pulley and the rotor of the brushless motor are in a built-in connection. In the case of a cable transport installation of the chairlift or gondola type adapted for transporting people, the pulley 60 generally has an external diameter d60 of between 5 m and 8 m, and in particular between 6 m and 7 m.Indeed, a sufficiently large external diameter d60 of pulley 60 allows two vehicles to cross over the entire transport route of the transport installation. According to a first variant, the external diameter d60 of the pulley 60 is substantially equal to 6.30 m. According to a second variant, the external diameter d60 of the pulley 60 is substantially equal to 6.75 m.

[0074] According to the embodiment illustrated in [Fig. 1], the pulley 60 is attached directly to the lower rotor 30 of the rotor stack 60. In other words, the pulley 60 is attached to the rotor of the rotor stack 30 which is closest to the pulley 60.

[0075] The pulley 60 may comprise a cylindrical fixing skirt 63 extending from the drive frame 61 of the pulley 60 around the main shaft 11. The fixing skirt 63 may comprise a fixing end portion 65 directed towards the rotor 30 and fixed to the rotor 30. In this way, it is possible to spatially offset the brushless motor 10 from the pulley 60, which makes it easier to access the brushless motor 10, in particular for maintenance operations. The fixing skirt 63 may have a diameter d63 counted radially from the main axis X which is substantially equal to a diameter d30 of the rotor 30 counted radially from the main axis X. Thus, it is possible to guarantee better rotational synchronization of the pulley 60 and the rotor 30. Furthermore, the diameter match d63, d30 is important because it allows the pulley 60 and the rotor 30 to be superimposed on each other, which makes the system more compact. In other words, the fixing skirt 63 of the pulley 60 and the rotor 30 have the same diameter. By "substantially" is meant "within 5%".

[0076] In the same way as for the rotor 30, it is possible for the fixing skirt 63 to comprise a fixing shoulder 51 projecting from said fixing skirt 63 towards the main shaft 11. This fixing shoulder 51 is configured to allow the direct fixing of the fixing skirt 63 to the rotor 30 by means of fixing agents 53. Thus it is possible to improve the direct fixing of the rotor 30 on the pulley 60. Advantageously, the fixing shoulder 51 comprises at least one fixing opening configured to allow the passage of the fixing agents 53. For example, the fixing agents 53 are bolts. Thus, the fixing skirt 63 and the rotor 30 are bolted together, for example via the fixing shoulders 51.

[0077] The drive system 1 may also comprise an access walkway 3 arranged radially in line with the fixing skirt 63 of the pulley 60. Such an access walkway 3 allows a user to directly access the stator 13, for maintenance operations.

[0078] All of the arrangements previously described make it possible to propose a drive system 1 in which no element is interposed between the rotor 30 of the brushless motor 10 and the pulley 60 used to drive the cable of the cable transport installation. The transfer of the motor torque is therefore optimized, and makes it possible to set the pulley 60 in motion with minimal power, which makes it possible to save energy.

Claims

Claims

1. A drive system (1) for driving a cable of a cable transport installation, the drive system (1) comprising: • a brushless motor (10) comprising: • a fixed main shaft (11) extending along a main axis (X); • at least one stator (13) comprising a cylindrical stator skirt (15) extending axially around the main axis (X), said stator skirt (15) housing coils (17); and • at least one rotor (30) arranged between the stator skirt (15) and the main shaft (11), said rotor (30) being rotatably mounted relative to the main shaft (11) and comprising permanent magnets (31), the rotor (30) being configured to be set in motion; • at least one radial bearing (40) configured to allow the rotor (30) to be rotatably mounted relative to the main shaft (11);• an electronic control system (50) configured to supply the coils (17) with electrical energy; and • a pulley (60) comprising a drive armature (61) intended to drive the cable of the transport installation, the pulley (60) having a geometry of revolution around the main axis (X) and being rotatably mounted relative to the main shaft (11), the pulley (60) being arranged coaxially with the rotor (30) and fixed directly to the rotor (30) of the brushless motor (10).;

2. A drive system (1) according to claim 1, wherein the at least one radial bearing (40) is configured to allow rotational mounting of the pulley (60) relative to the main shaft (11).

3. A drive system (1) according to any one of claims 1 or 2, wherein the pulley (60) comprises a cylindrical attachment skirt (63) extending from the drive frame (61) of the pulley (60) around the main shaft (11), the attachment skirt (63) having an attachment end portion (65), the attachment skirt (63) being directed towards the rotor (30) and fixed to the rotor (30) at the fixing end portion (65).

4. Drive system (1) according to claim 3, comprising an access walkway (3) arranged radially in line with the fixing skirt (63) of the pulley (60).

5. Drive system (1) according to any one of claims 3 or 4, wherein the fixing skirt (63) has a diameter (d63) counted radially from the main axis (X) which is substantially equal to a diameter (d30) of the rotor (30) counted radially from the main axis (X).

6. A drive system (1) according to any one of claims 3 to 5, wherein at least one element selected from the attachment skirt (63) and the rotor (30) comprises a attachment shoulder (51), said attachment shoulder (51) projecting from said at least one element, and being configured to allow direct attachment of the attachment skirt (63) to the rotor (30) via attachment agents (53).

7. A drive system (1) according to any one of claims 1 to 6, wherein the brushless motor (10) comprises a distal end wall (19) extending from the main shaft (11) perpendicular to the main axis (X), and having a geometry of revolution about the main axis (X), the stator skirt (15) extending from said distal end wall (19).

8. A drive system (1) according to claim 7, wherein the distal end wall (19) and the main shaft (11) are fixed directly to each other.

9. Drive system (1) according to any one of claims 1 to 8, in which the pulley (60) has an external diameter (d60) of between 5 m and 8 m, and in particular between 6 m and 7 m.

10. Drive system (1) according to any one of claims 1 to 9, wherein the brushless motor (10) comprises at least two stators (13) stacked along the main axis (X) and around the main shaft (11), the electronic control system (50) being configured to individually and selectively power the coils (17) of each stator (13).

11. Drive system (1) according to claim 10, wherein the brushless motor (10) comprises at least two rotors (30), one rotor (30) being associated with each of the stators (13) of the brushless motor (10), said rotors (30) forming a stack of rotors (30) along the axis main shaft (X) and around the main shaft (11), each rotor (30) being attached directly to the or each adjacent rotor (30) in said rotor stack (30).

12. Cable transport installation comprising: • a traction cable extending along a transport track; • a drive system (1) according to any one of claims 1 to 11 configured to drive the traction cable; and • at least one vehicle configured to be moved by the traction cable along the transport track.

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