Vehicle drive, in particular for a rail vehicle

Abstract

A drive device comprises a mechanical coupling device (19) mechanically coupling a drive shaft (18) and an axle, comprising:-a hub (28) integral with the shaft (18),-a gear (30) connected to the shaft (18) by a pivot member,-a slider (32) integral in rotation with the hub (28) and movable in translation along the hub (28) between an engaged position of the slider (32) with the gear (30) and a retracted position of the gear (30), -an electromagnetic actuator (42) which, when activated, exerts a first force which displaces the slider (32) towards its engaged position, and-restoring elastic means (44) which restore the slider (32) towards its retracted position, which exerts a second force which displaces the slider (32) towards its retracted position, the second force being smaller than the first force.

Description

Technical Field

[0001] The present application relates to a vehicle drive device, which is particularly used for a rail vehicle. Background Art

[0002] Such a drive device comprises an electric motor, in particular a permanent magnet motor, which is connected to the wheels of the vehicle in order to drive these wheels in rotation.

[0003] In the event of a power failure to the motor, in particular an electrical failure in or upstream of the motor or an electrical disconnection of the motor, the motor connected to the wheel is still driven in rotation by the inertia of the wheel. This driving of the unpowered motor can generate an arc, which can damage the motor and / or its surroundings, or even cause a fire. Summary of the invention

[0004] The invention aims in particular to remedy this problem by proposing a drive device that allows avoiding the generation of arcs in the event of a power failure of the motor.

[0005] To this end, the object of the present invention is a vehicle drive device, in particular for a rail vehicle, comprising an electric motor powered by an electric circuit and driving a drive shaft intended to be coupled to an axle of the vehicle, the drive device comprising a mechanical coupling device of the drive shaft to said axle, characterised in that the coupling device comprises:

[0006] – a wheel hub, which is integral with the drive shaft,

[0007] – a gear, which is connected to the drive shaft via a pivot connection,

[0008] - a slide which surrounds the hub and is integral in rotation with the hub, the slide being movable in translation along the hub parallel to the drive shaft between an engaged position in which the slide engages with the gear and is thus connected in rotation with the gear, and a retracted position in which the slide is retracted from the gear,

[0009] an electromagnetic actuator, powered by the circuit, configured to apply a first force that displaces the slider towards its engaged position when it is activated, and

[0010] - Restoration elastic means, which restore the slide towards its retracted position, which exerts a second force displacing the slide towards its retracted position, the second force being less than the first force.

[0011] The sleeve is held in the engaged position by an electromagnetic actuator. Since the electromagnetic actuator is powered by the same circuit as the motor and in particular by the same electrical energy source, in the event of a fault in the circuit, the electromagnetic actuator is deactivated and the sleeve is no longer subjected to the force of the restoring elastic means, which drives the sleeve towards its retracted position.

[0012] The motor is thus mechanically disconnected from the wheel, thus avoiding the risk of an electric arc in the motor.

[0013] The drive device according to the present invention may further include one or more of the following features, which may be employed alone or in any technically possible combination.

[0014] The drive device comprises short-circuit detection means, located in the circuit and / or in the motor, and control means for the electromagnetic actuator, configured to deactivate the electromagnetic actuator when the detection means detects a short circuit.

[0015] The slider comprises a disk table extending perpendicularly to the drive shaft and a generally cylindrical sleeve coaxial with the drive shaft, the sleeve surrounding the hub and being rotatably connected to the hub, and the electromagnetic actuator is arranged facing the disk table to apply a first force to the disk table.

[0016] The disk table is fixed in rotation and movable in translation parallel to the axis of the drive shaft, and the sleeve is movable in rotation relative to the disk table and is integral in translation with the disk table.

[0017] The drive means comprise direct or indirect measurement means of the speed of the gear and means for operating the motor so that, before coupling the slide to the gear, the speed difference between the hub and the gear is less than a predetermined speed, for example less than 100 rpm.

[0018] The drive comprises a synchronizing device carried by the gear and intended to reduce the speed difference between the gear and the slide.

[0019] - The synchronizing device comprises a first part integral with the gear wheel and a second part mounted on the first part and movable relative to the first part, each of the first and second parts comprising respective teeth adapted to cooperate with complementary teeth provided on the slide, and the first and second parts being arranged so that the slide engages on the teeth of the second part before the teeth of the first part.

[0020] The drive device comprises a gearbox which kinematically connects the gear to the axle.

[0021] The invention also relates to a vehicle, in particular a rail vehicle, characterized in that it comprises a drive device as defined above. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The different aspects and advantages of the invention will become apparent on reading the following description, given by way of non-limiting example only, and with reference to the accompanying drawings, in which:

[0023] [ Figure 1 ] Figure 1 is a schematic diagram showing a driving device according to the present invention;

[0024] [ Figure 2 ] Figure 2 Schematically shows Figure 1 The details show Figure 1 A coupling device for a drive device;

[0025] [ Figure 3 ] Figure 3 According to the example of the embodiment Figure 2 A partial perspective view of a coupling device;

[0026] [ Figure 4 ] Figure 4 yes Figure 3 A cross-sectional view of the coupling device in a first coupling configuration;

[0027] [ Figure 5 ] Figure 5 is a coupling device in a second disengaged configuration similar to Figure 4 's view;

[0028] [ Figure 6 ] Figure 6 is a perspective view of a detail of the coupling device. DETAILED DESCRIPTION

[0029] Figure 1 Schematically shown is a drive device 10 for a vehicle, and in particular for a rail vehicle. The rail vehicle may be of any possible type, such as a high-speed train, a tram, a subway or the like.

[0030] In the case of a rail vehicle, the drive device 10 is preferably arranged on a motor truck of the rail vehicle. More particularly, the motor truck comprises at least one motorized axle 24 which is driven in rotation by the drive device 10 .

[0031] The drive device 10 comprises an electric motor 12 , for example a permanent magnet motor, which is powered by an electrical circuit 14 .

[0032] The circuit 14 is of conventional type and electrically connects the electric motor 12 to at least one source of electrical energy via electrical connection means and power electronics. The source of electrical energy may be formed by at least one pantograph cooperating with contact wires and / or at least one battery carried on the vehicle. For example, the circuit 14 may be simultaneously connected to at least one pantograph and to at least one battery, the circuit 14 being configured to switch from one source of energy to another, depending on the situation, for example, depending on the track section on which the vehicle is travelling.

[0033] The electric motor 12 generally includes a stator and a rotor. An output shaft 16 is rotationally integral with the rotor.

[0034] The output shaft 16 is usually connected in rotation to the drive shaft 18, for example by means of a coupling 20. The output shaft 16 and the drive shaft 18 may be coaxial or, as a variant, may have axes of rotation that are radially offset and / or, in another variant, angled with respect to each other.

[0035] The drive device 10 also comprises a drive device 22 which connects the drive shaft 18 to at least one axle 24 of the vehicle and in particular to a motorized axle of a bogie carrying the drive device (called "motorized bogie"). The axle 24 carries the wheels of the vehicle (not shown) in a conventional manner. The drive device 22 according to the invention also comprises a coupling device 19 which couples the drive shaft 18 to the drive device 22.

[0036] In the case of a vehicle comprising a plurality of motorized bogies and / or a plurality of motors, the vehicle preferably comprises a plurality of drive devices 10. For example, each drive device 10 is associated with a different axle 24 or, as a variant, with a plurality of axles 24. Furthermore, the circuit 14 may be at least partially common to a plurality of electric motors 12.

[0037] The drive unit 22 also typically includes a mechanical gear mechanism box 26 that includes a gear mechanism that connects the drive shaft 18 to the axle 24 .

[0038] The present invention provides for allowing disengagement of the output shaft 16 and the drive shaft 18 as described below.

[0039] To this end, Figure 2 The coupling device 19 shown in more detail in FIG. 1 comprises a hub 28 integral with the drive shaft 18, a gear 30 mounted around the drive shaft 18 and connected to the drive shaft 18 via a pivot connection, and a slide 32 capable of connecting or disconnecting the hub 28 and the gear 30 from each other.

[0040] The gear 30 is coaxial with the drive shaft 18 and can rotate freely relative to the drive shaft 18 as long as no other elements interfere with its connection.

[0041] According to the embodiment considered, the toothed wheel 30 carries directly or indirectly the grooved outer surface 36. In the embodiment described, the grooved outer surface 36 is carried indirectly by the toothed wheel 30 via mechanical synchronization means 38, which will be described in more detail later.

[0042] Note that the gear 30 also includes teeth 39 that cooperate with one of the gears in the gear box 26 .

[0043] The slider 32 itself surrounds the hub 28 and is at least partially connected to the hub 28 in terms of rotation, such as by a key connection or by a toothed fit. For example, the slider 32 has a grooved inner surface 40 that cooperates with the grooved outer surface 34 of the hub 28.

[0044] In the example depicted, the slider 32 comprises a disc table 32A extending perpendicularly to the drive shaft 18 and a generally cylindrical sleeve 32B coaxial with the drive shaft 18. The sleeve 32B surrounds the hub 28 and is rotationally connected thereto.

[0045] According to an embodiment, the disk table 32A is rotationally fixed and translationally movable parallel to the axis of the drive shaft 18. The sleeve 32B is rotationally movable relative to the disk table 32A and translationally integral with the disk table 32A.

[0046] The sleeve 32B can be translated along the hub 28 parallel to the drive shaft 18 between an engaged position in which the sleeve 32B is engaged with the gear 30 (i.e., the grooved inner surface 40 cooperates with the grooved outer surface 36) and a retracted position in which the sleeve 32B is retracted from the gear 30 (so that the grooved inner surface 40 does not cooperate with the grooved outer surface 36).

[0047] The joint position is as follows Figure 4 As shown and the retracted position is as Figure 5 shown.

[0048] The coupling device 19 includes an electromagnetic actuator 42 (also called an electromagnet), which is powered by the circuit 14 and is configured to apply a first force to the slider 32 and in particular the disk table 32A arranged to face the electromagnetic actuator 42 when the electromagnetic actuator 42 is activated, so as to displace the slider 32 toward its engagement position.

[0049] The electromagnetic actuator 42 is preferably monostable, ie it assumes only one stable state, in which it remains as long as it is actuated.

[0050] The coupling device 19 further comprises a restoring elastic mechanism 44 which restores the slider 32 towards its retracted position by applying a second force smaller than the first force to the slider 32 and in particular the disk table 32A to displace the slider 32 towards its retracted position.

[0051] Thus, when the electromagnetic actuator 42 is activated, the first force is greater than the second force and is in the opposite direction, and the slide 32 is maintained in its engaged position.

[0052] like Figure 4 As shown, when the slider 32 is in its engaged position, the grooved inner surface 40 cooperates with the outer surface 36 and the sleeve 32B remains rotationally connected to the hub 28. Thus, the hub 28 and the gear 30 are rotationally connected. In other words, the gear 30 is thus rotationally connected to the drive shaft 18. Thus, the gear 30 drives the axle 24 via the drive device 22 in a manner known per se.

[0053] It is designed as the normal operating position. The actuator 42 is activated and the slider 32 couples the gear 30 to the hub 28 so that normal mechanical power transmission occurs between the drive shaft 18 and the shaft 24 .

[0054] In contrast, when the electromagnetic actuator 42 is deactivated, the slide 32 is subjected only to the second force and the slide 32 therefore enters its retracted position in which it remains until a possible reactivation of the electromagnetic actuator 42 .

[0055] like Figure 5 As shown, when the slider 32 is in its retracted position, it does not cooperate with the gear 30. The gear 30 connected to the axle 24 is then free to rotate relative to the drive shaft 18. This therefore allows the motor to be disengaged from the wheel, in particular in the event of an electrical failure, as described below.

[0056] It is therefore apparent that by deactivating the electromagnetic actuator 42 , the motor can be disconnected from the wheels in a simple, direct and effective manner.

[0057] This can happen in a variety of situations.

[0058] In the simplest case of an electrical fault in the circuit 14, for example due to a large short circuit in the circuit 14 or the electric motor 12 or for example due to an interruption in the power supply for whatever reason, the motor 12 is no longer powered and should be disengaged from the wheel to avoid arcing, as described above. Since the electromagnetic actuator 42 is powered by the same circuit 14 as the motor 12, the electromagnetic actuator 42 and the motor 12 are de-energized at the same time. The electromagnetic actuator 42, which is de-energized, no longer exerts the first force on the sleeve 32, which therefore changes to the retracted position, thereby de-energizing the drive shaft 18 from the axle.

[0059] Thus, the vehicle can continue its journey using the mechanically isolated motor 12 .

[0060] In a preferred embodiment of the invention, the drive device 10 comprises short-circuit detection means 46 for detecting short circuits in the circuit 14 and / or in the motor 12. These short-circuit detection means 46 allow the above-described situations to detect short circuits that do not lead to a complete interruption of the power supply. Such short-circuit detection means are known per se and therefore will not be described in detail, the electronics expert knowing how to implement such detection means.

[0061] Therefore, the drive device 10 comprises control means 48 of the electromagnetic actuator 42, which are configured to deactivate the electromagnetic actuator 42 when the detection means 46 detects a short circuit. Therefore, these control means 48 are advantageously connected to the detection means 46 to receive a signal in the event of a short circuit.

[0062] When the control device 48 deactivates the electromagnetic actuator 42 , the electromagnetic actuator 42 no longer applies the first force to the slider 32 , which causes the slider 32 to shift to the retracted position, thereby decoupling the drive shaft 18 from the vehicle axle.

[0063] The invention can also be used to manage changes in the power supply section of a rail vehicle. This is the case, for example, when the rail vehicle changes from a section powered by a contact grid to a section without power supply, in which case the vehicle changes from contact grid power supply to battery power supply. This situation can be considered in an alternative way in any situation where a change in the power supply occurs.

[0064] In order to change the power supply sector completely safely, it is preferred to disconnect the motor from the wheel before the sector change in order to connect it again after the sector change. Therefore, the control device 48 deactivates the electromagnetic actuator before the sector change and reactivates it after the sector change. These actions can be carried out automatically by means of the guidance system or beacon of the vehicle, which then transmits the sector change signal to the control device. As a variant, these actions are carried out manually by the driver of the vehicle.

[0065] However, it is noted that in the case of a connection when the vehicle is moving, either when the power supply section changes or due to a weightless short circuit, the hub 28 and the gear 30 rotate at different speeds, making it preferable to synchronize them so as to be able to connect them in rotation via the slide 32.

[0066] To this end, the drive device 10 preferably comprises means for measuring the speed of the gear wheel 30. For example, the means for measuring the speed of the gear wheel 30 allow an indirect measurement to be carried out, in particular by measuring the speed of the axle 24 by means of a conventional measuring device 50 for measuring the speed of the axle 24. Since the speed of the gear wheel 30 is related to the speed of the axle 24, it is calculated from the speed of the axle 24.

[0067] As a variant, drive device 10 comprises means for direct measurement of the speed of toothed wheel 30 .

[0068] By knowing the speed of the gear 30, the rotation speed of the drive shaft 18 is varied by influencing the motor 12 to be as close as possible to this rotation speed of the gear 30. This variation of the rotation of the drive shaft 18 is achieved by a conventional steering system of the motor 12.

[0069] For example, the motor 12 is steered so that the speed difference between the hub 28 and the gear 30 is less than 100 rpm (revolutions per minute). However, a more precise motor steering system may be provided to further reduce the speed difference.

[0070] According to the described embodiment, the drive device 10 comprises, as described above, a synchronization device 38. The synchronization device allows the speed difference to be further reduced after it has been reduced to less than 100 rom.

[0071] exist Figure 4 and 5 The synchronizing device 38 visible in the figure comprises, for example, a first part 38A integral with the gear 30 and a second part 38B mounted on and movable relative to the first part 38A and capable of synchronizing its rotational speed with the rotational speed of the first part 38A. Each of the first part 38A and the second part 38B comprises teeth, the teeth of the first part 38A forming the second grooved outer surface 36. The first part 38A and the second part 38B are arranged so that the sleeve 32B engages on the teeth of the second part 38B before the teeth of the first part 38A.

[0072] In other words, the second portion 38B allows the absorption of the energy required for synchronization of the rotational speeds of the components to be coupled, and the sleeve 32B engages the first portion 38A only when the rotational speed of the sleeve 32B is synchronized with that of the first portion 38A by means of the second portion 38B.

[0073] The synchronizing device 38 is known per se, so that the person skilled in the art will know its implementation. For example, the synchronizing device 38 is of the Borg-Warner type, described in particular in the document "BM5668 Engineer Technique" on gearbox synchronization.

[0074] According to a preferred embodiment, the teeth of the second portion 30B are shaped to facilitate engagement with and retraction of the sleeve 32B.

[0075] For this reason, Figure 6 As shown, in the view along the radial direction, each tooth portion 52 in the tooth is flared, which expands away from the sleeve 32B in the displacement direction of the sleeve 32B. Therefore, the space between two adjacent tooth portions 52 is larger at the mouth for accommodating the sleeve 32B.

[0076] It should be noted that the present invention is not limited to the above-described embodiments, and various complementary modifications may be made without departing from the scope of the claims.

Claims

1. A vehicle drive device (10), in particular for a rail vehicle, comprising an electric motor (12) powered by an electric circuit (14) and driving a drive shaft (18) for coupling to an axle (24) of the vehicle, the drive device (10) comprising a mechanical coupling device (19) of the drive shaft (18) to the axle (24), characterized in that: The mechanical connection device (19) comprises: - a hub (28) integral with the drive shaft (18), - a gear (30) connected to the drive shaft (18) via a pivot connection, a slide (32) which surrounds the hub (28) and is integrally rotatable with it, the slide (32) being movable in translation along the hub (28) parallel to the drive shaft (18) between an engaged position in which the slide (32) is engaged with the gear (30) and is thus rotationally connected to the gear (30) and a retracted position in which the slide (32) is retracted from the gear (30), an electromagnetic actuator (42), powered by said circuit (14), configured to apply, when activated, a first force causing said slide (32) to displace towards its engaged position, and - a restoring elastic device (44) which restores the slide (32) towards its retracted position, which applies a second force which displaces the slide (32) towards its retracted position, the second force being less than the first force.

2. The drive device (10) according to claim 1 comprises a short circuit detection device (46) which detects a short circuit in the electric circuit (14) and / or the electric motor (12); and a control device (48) for the electromagnetic actuator (42) which is configured to deactivate the electromagnetic actuator (42) when the detection device (46) detects a short circuit.

3. The drive device (10) according to claim 1, wherein: The sliding member (32) includes a disk table (32A) extending perpendicularly to the drive shaft (18) and a generally cylindrical sleeve (32B) coaxial with the drive shaft (18), the sleeve (32B) surrounding the hub (28) and connected to the hub (28) in terms of rotation, and the electromagnetic actuator (42) is arranged to face the disk table (32A) to apply the first force to the disk table (32A).

4. The drive device (10) according to claim 1 comprises a direct or indirect measuring device for measuring the speed of the gear (30) and a control device for the motor (12), so that before the slider (32) is connected to the gear (30), the speed difference between the hub (28) and the gear (30) is less than a predetermined speed, for example, less than 100 rpm.

5. Drive device (10) according to claim 4, comprising a synchronization device (38) carried by the gear (30) for reducing the speed difference between the gear (30) and the slide (32).

6. The drive device (10) according to claim 5, wherein: The synchronization device (38) includes a first part (38A) integral with the gear (30) and a second part (38B) mounted on the first part (38A) and capable of moving relative to the first part (38A), each of the first part (38A) and the second part (38B) including corresponding teeth for cooperating with complementary teeth provided on the sliding member (32), and the first part (38A) and the second part (38B) are arranged so that the sliding member (32) engages with the teeth of the second part (38B) before the teeth of the first part (38A).

7. The drive device of claim 1, comprising a gear mechanism box (26) kinematically connecting the gear (30) to the axle (24).

8. A vehicle, in particular a track vehicle, characterized in that: It comprises a drive device according to any one of the preceding claims.

Images