Electromechanical assembly for a braking system of a rail vehicle, control system for the electromechanical assembly, and braking system comprising an electromechanical assembly and a control system

Abstract

An electromechanical assembly (100) for a braking system of a rail vehicle (200) is disclosed, the electromechanical assembly (100) including a flywheel (101) configured to store kinetic energy, the kinetic energy stored in the flywheel (101) being sufficient to actuate the electromechanical assembly (100) and cause the braking system to perform at least one of an emergency brake, a service brake, or a parking brake operation. Also disclosed are a control system for the electromechanical assembly (100) for a braking system of a rail vehicle (200), and the braking system (200) for the rail vehicle.

Description

[Technical Field]

[0001] The present invention relates generally to the field of railway braking systems, and more particularly, the present invention relates to an electromechanical assembly for a braking system of a railway vehicle, a control system for the electromechanical assembly, and a braking system including the electromechanical assembly and the control system. [Background technology]

[0002] In rail transport systems, known braking systems generate braking force using compressed air appropriately injected into brake cylinders, the compressed air being generated by one or more compressors.

[0003] The technology for generating compressed air is known to have several drawbacks, including: The overall efficiency of the compressor is very low, well below 50%, which means it consumes a huge amount of non-recoverable energy. Compressors are a source of noise to both the passenger and external environments and require significant soundproofing. The compressor is a source of vibration that is transmitted to the vehicle body, causing additional vibration and noise in the passenger environment. The compressor, its support frame, and the soundproofing enclosure for passive noise reduction have huge masses of several hundred kilograms, which constitute a further energy inefficiency when calculating the energy required to accelerate a rail vehicle. Compressor maintenance cycles are relatively frequent, intrusive and, above all, costly. Compressed air brake systems also require the use of dryers to remove moisture from the compressed air. The maintenance cycles for these dryers are characterized by frequent, intrusive, and costly maintenance. Furthermore, compressed air brake systems require a reservoir for storing the compressed air and piping for distributing the compressed air. The addition of both the reservoir and piping adds cost, bulk, and weight.

[0004] A preferred known alternative solution is represented by the use of electromechanical braked actuators to replace the current compressed air actuators.

[0005] Electromechanical brake actuators generally have one or more electric motors integrated into the actuator and mechanical elements that perform two primary functions: - Applying and releasing braking energy Loading the springs with sufficient energy to apply at least one autonomous brake in the event of a loss of electrical energy or an emergency brake being requested. This function is necessary because electronic control of one or more motors is not considered sufficiently safe.

[0006] For example, European Patent No. 0334434, entitled "Preferred Electromechanical Brake Unit for Railway Vehicles," discloses an electromechanical assembly using two electric motors. The first electric motor is a primary electric charge motor used to keep a spiral spring permanently loaded. The second electric motor is an electric control motor that acts on a mechanism capable of extracting a portion of the energy stored in the spring and converting that energy into a force that is transmitted to a lever of the electromechanical assembly to effect braking. In the absence of electricity to the electric control motor, this mechanism is configured to automatically extract the energy stored in the spiral spring and convert it into a braking force.

[0007] A second example is EP 3271602 "BRAKE ACTUATOR". The actuator disclosed therein uses a single electric motor which, depending on the configuration of the associated internal mechanism, may alternatively load a spring with the necessary stored energy to apply at least one emergency brake in the event of an emergency braking request or a sudden power failure.

[0008] Other known documents relating to electromechanical braking systems for rail vehicles disclose systems based on the use of springs to store the energy required for at least one emergency brake in the event of a sudden power failure. A drawback of systems based on the use of springs is that it is not possible to adjust the force exerted by the springs. In effect, the springs provide the entire stored force when activation of the springs is required. This poses a risk to passenger safety, as the force exerted by the springs used to brake the rail vehicle may cause a sudden acceleration when the springs are activated.

[0009] Furthermore, because the actual weight of a rail car varies with, for example, the number of passengers, the spring action may not be adjustable as a function of the actual weight of the rail car. Summary of the Invention [Problem to be solved by the invention]

[0010] It is therefore an object of the present invention to provide an electromechanical assembly for braking railway vehicles that has an energy storage system that can be used on demand, that has less abrupt energy release and is safer than known systems.

[0011] According to one aspect of the present invention, the above and other objects and advantages are achieved by an electromechanical assembly for braking of a railway vehicle having the features defined in claim 1, a control system for an electromechanical assembly for a braking system of a railway vehicle having the features defined in claim 9, and a braking system having the features defined in claim 18. Preferred embodiments of the invention are defined in the dependent claims, the content of which should be understood as an essential part of this description. [Brief explanation of the drawings]

[0012] Next, functional and structural features of some preferred embodiments of an electro-mechanical assembly for braking a railway vehicle according to the present invention, a control system for the electro-mechanical assembly for braking a railway vehicle according to the present invention, and a brake system comprising the electro-mechanical assembly and control system according to the present invention will be described in detail with reference to the accompanying drawings. [Figure 1] FIG. 1 shows an embodiment of an electromechanical assembly for braking a rail vehicle according to the present invention. [Figure 2] FIG. 2 shows the application of the electromechanical assembly of FIG. 1 in a first embodiment of a braking system for a rail vehicle. [Figure 3] FIG. 3 shows the application of the electromechanical assembly of FIG. 1 in a second embodiment of a braking system for a rail vehicle. [Figure 4A] FIG. 4A shows the application of the electromechanical assembly of FIG. 1 in a third embodiment of a braking system for a rail vehicle. [Figure 4B] FIG. 4B shows the application of the electromechanical assembly of FIG. 1 in a fourth embodiment of a braking system for a rail vehicle. [Figure 5] FIG. 5 is a graph showing the trend in the force that the ends of a linear actuator of an electromechanical assembly must exert as the distance between the ends is changed. [Figure 6] FIG. 6 shows a further embodiment of an electromechanical assembly for braking rail vehicles according to the invention. [Figure 7] FIG. 7 shows a control system for an electromechanical assembly for braking a railway vehicle according to the present invention. [Figure 8] FIG. 8 shows a further embodiment of an electromechanical assembly for braking rail vehicles according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Before describing several embodiments of the present invention in detail, it should be clear that the present invention is not limited in its application to the details of construction and arrangement of parts set forth in the following specification or illustrated in the drawings. The present invention is capable of other embodiments and may in fact be practiced or constructed in various ways. Also, it is to be understood that the phraseology and terminology are for the purpose of description and should not be regarded as limiting. The words "include," "comprise," or variations thereof mean the inclusion of the elements described below and equivalents thereof, as well as additional elements and equivalents thereof.

[0014] In a first embodiment, an electro-mechanical assembly 100 for a braking system of a rail vehicle includes a flywheel 101 configured to accumulate kinetic energy. The kinetic energy stored in the flywheel is sufficient to actuate the electro-mechanical assembly and cause the braking system to perform at least one of an emergency brake, a service brake, or a parking brake operation. Referring initially to FIG. 1 , in one embodiment, the electro-mechanical assembly 100 may further include a first electric motor 107, a primary transmission shaft 103 rotatably connected to the first electric motor 107, a secondary transmission shaft 109, first engagement means 108 configured to rotatably couple the secondary transmission shaft 109 to the primary transmission shaft 103, and locking means 111 coupled to the secondary transmission shaft 109. The locking means 111 is configured to stop rotation of the secondary transmission shaft 109.

[0015] The electromechanical assembly 100 may further include a linear actuator 131 capable of extension or retraction movement from a first retracted position to a second extended position. In the first retracted position, the two ends 104, 105 of the linear actuator 131 are positioned at a first distance dis1. In the second extended position, the two ends 104, 105 of the linear actuator 131 are positioned at a second distance dis2 that is greater than the first distance dis1. The linear actuator 131 is configured to operate a brake system.

[0016] Further, the electromechanical assembly 100 may include a transmission mechanism 133 interposed between the secondary transmission shaft 109 and the linear actuator 131 configured to convert rotational motion of the secondary transmission shaft 109 into linear motion of the linear actuator 131.

[0017] In this embodiment, the flywheel 101 is rotatably connected or rotatably connectable to the primary transmission shaft 103 .

[0018] The flywheel 101 may be accelerated to and maintained at a suitable speed by at least one first electric motor 107 via a primary transmission shaft 103. Preferably, the speed is related to the flywheel's moment of inertia, I, according to the energy formula E=½·I·ω 2 The linear actuator 131 may be controlled, for example, using one or more electrical commands generated by the control unit 720. Based on the electrical commands, the energy stored by the flywheel 101 may be extracted to modify the length L between its ends 104, 105. The ends 104, 105 may slide, for example, horizontally on their axis 106.

[0019] As shown in FIG. 6, the primary transmission shaft 103 may be directly rotatably connected to the flywheel 101 .

[0020] However, as shown in FIG. 8, the primary transmission shaft 103 may be rotatably connectable to the flywheel 101 by means of second engagement means 114 .

[0021] In any case, the first engaging means 108 may be an electromechanical or electromagnetic clutch. If there is a second engaging means 114, the second engaging means 114 may also be an electromechanical or electromagnetic clutch. The locking means 111 shown in Figures 6 and 8 may be an electromechanical or electromagnetic brake device.

[0022] In the embodiment shown in Figure 8, the primary transmission shaft 103 may be rotatably connected to the flywheel 101 by means of second engagement means 114. In this case, the first electric motor 107 The primary transmission shaft 103 is rotated in a first direction d1, and the rotation of the primary transmission shaft 103 in the first direction d1 increases the distance L between the ends (104, 105) of the linear actuator 131; The primary transmission shaft 103 may be rotated in a second direction d2 opposite to the first direction d1, and the rotation of the primary transmission shaft 103 in the second direction d2 may be configured to reduce the distance L between the ends (104, 105) of the linear actuator 131.

[0023] When the first electric motor 107 rotates the primary transmission shaft 103 in the second direction d2, the second engagement means 114 disconnects the primary transmission shaft 103 from the flywheel 101. In this way, the kinetic energy stored in the flywheel 101 is not discharged by the rotation of the primary transmission shaft 103.

[0024] Reference is now made to FIG. 6. In the embodiment shown in FIG. 6, the second engagement means 114 is not required. The first electric motor 107 is configured to rotate the primary transmission shaft 103 in a first direction d1. Rotation of the primary transmission shaft 103 in the first direction increases the distance between the ends 104, 105 of the linear actuator 131. However, in this embodiment, the electro-mechanical assembly 100 includes a second electric motor 112 coupled to the secondary transmission shaft 109. The second electric motor 112 is configured to rotate the secondary transmission shaft 109 in a second direction d2 opposite to the first direction d1. Thus, rotation of the secondary transmission shaft 109 in the second direction decreases the distance between the two ends 104, 105 of the linear actuator 131.

[0025] In this embodiment, in use, the first electric motor 107 may maintain a continuous supply of kinetic energy to the primary transmission shaft 103, thereby maintaining rotation of the primary transmission shaft 103 and thereby continuously storing kinetic energy within the flywheel 101.

[0026] 6 and 8, the electromechanical assembly 100 may include at least one force sensor means 134 arranged to measure the force applied by the linear actuator 131. The force sensor means 134 may, for example, be coupled to one of the ends 104, 105 of the linear actuator 131. The force sensor means 134 may, for example, be a load cell type sensor or a strain gauge type sensor.

[0027] Reference is now made to Figure 7. The present invention further relates to a control system for an electromechanical assembly 100 for a braking system of a rail vehicle according to any of the previous embodiments.

[0028] The control system includes a controller 720 arranged to control the operation of at least the first electric motor 107 , the first engaging means 108 and the locking means 111 .

[0029] The control system further comprises power supply means 701 connected at an input to a power supply source 702 and arranged to provide a stabilized voltage at an output, and first electric power converter means 706 connected to the first electric motor 107 and configured to supply energy to the first electric motor 107 in order to convert the stabilized voltage at the output of the power supply means 701.

[0030] The first power conversion means 706 is further configured to provide a regulated voltage by converting a variable voltage generated by at least the first electric motor 107 when rotated by the flywheel 101.

[0031] Furthermore, the control system further comprises control means 708 for controlling the power supply of the one control unit 720. The means 708 for controlling the power supply of the one control unit 720 are configured to supply energy to at least the control unit 720 from the regulated voltage at the output of the power supply means 701 or from the regulated voltage provided by the first power conversion means 706.

[0032] When the electromechanical assembly 100 is configured according to an embodiment that further includes a second electric motor 112 in addition to the first electric motor 107, the control system may include a second power conversion means 707 connected to the second electric motor 112. The second power conversion means 707 is configured to supply energy to the second electric motor 112 by converting a regulated voltage at the output to the power supply means 701. The second power conversion means 707 is further configured to provide a regulated voltage by converting a variable voltage generated by the second electric motor 112 when rotated by the flywheel 101.

[0033] The control means 708 of the power supply of one control unit 720 may be configured to supply energy to at least the control unit 720 from the regulated voltage at the output of the power supply means 701, from the regulated voltage supplied by the first power conversion means 706, or from the regulated voltage supplied by the second power conversion means 707.

[0034] Referring again to Figure 6, in the embodiment shown in Figure 6, two electric motors are provided. A controller 720 may be arranged to receive a brake force request signal 712. If the brake force request signal 712 indicates a force increase request to the ends 104, 105 of the linear actuator 131, the controller 720 may: deactivating the locking means 111 connected to the secondary transmission shaft 109; A secondary transmission shaft 109 is provided to be rotatably connected to the primary transmission shaft 103 via a first engagement means 108 . In this way, rotation to the primary transmission shaft 103 may be generated by at least the kinetic energy stored by the flywheel 101. The rotation of the primary transmission shaft 103 may be transmitted to the secondary transmission shaft 109, thereby changing the distance between the two ends 104, 105 of the linear actuator 131 and reducing the energy at the ends 104, 105 of the linear actuator 131.

[0035] Continuing with reference to Figure 6, in the embodiment shown in Figure 6, two electric motors are provided. When the braking force request signal 712 indicates a request for reduced energy to the two ends 104, 105 of the linear actuator 131, the control unit 720: deactivating the locking means 111 connected to the secondary transmission shaft 109; Rotatably decoupling the secondary transmission shaft 109 from the primary transmission shaft 103 via the first engagement means 108; A second electric motor 112 may be provided to activate and rotate the secondary transmission shaft 109 in a second direction of shaft rotation d2 opposite to the first direction of shaft rotation d1.

[0036] Thus, rotation on the secondary transmission shaft 109 may be generated by the second electric motor 112, thereby changing the distance between the two ends 104, 105 of the linear actuator 131 and reducing the force at the ends 104, 105 of the linear actuator 131. Continuing with reference to the embodiment shown in FIG. 6, the embodiment shown in FIG. 6 includes two electric motors. When the controller 720 detects a power supply anomaly from the power source 702, the rotation on the primary transmission shaft 103 generated by the kinetic energy stored by the flywheel 101 may be transmitted to the first electric motor 107. The kinetic energy transmitted by the flywheel 101 may be converted into electrical energy by the control system. The converted electrical energy is used by the control system to power the controller 720 of the control system.

[0037] Reference is now made to Figure 8. In the embodiment shown in Figure 8, there is only one electric motor (first electric motor 107). A controller 720 may further be provided to receive a brake force request signal 712. If the braking force request signal 712 indicates a request for increased force on the ends 104, 105 of the linear actuator 131, the control unit 720: deactivating the locking means 111 connected to the secondary transmission shaft 109; A secondary transmission shaft 109 is rotatably connected to the primary transmission shaft 103 via a first engagement means 108; A second engagement means 114 may be provided to rotatably couple the flywheel 101 to the primary transmission shaft 103 .

[0038] In this way, rotation on the primary transmission shaft 103 may be generated by at least the kinetic energy stored by the flywheel 101. The rotation of the primary transmission shaft 103 may be transmitted to the secondary transmission shaft 109, which may change the distance between the two ends 104, 105 of the linear actuator 131 and reduce the force at the ends 104, 105 of the linear actuator 131.

[0039] Continuing with reference to Figure 8, in the embodiment shown in Figure 8, only one electric motor (first electric motor 107) is provided. When a reduction in force is required at the two ends 104, 105 of the linear actuator 131, the control unit 720: deactivating the locking means 111 connected to the secondary transmission shaft 109; The primary transmission shaft 103 is rotatably connected to the secondary transmission shaft 109 via the first engagement means 108, using the second engagement means 114 to rotatably decouple the primary transmission shaft 103 from the flywheel 101; The first electric motor 107 may be provided to be activated to rotate the primary transmission shaft 103 in a second direction of shaft rotation d2 opposite to the first direction of shaft rotation d1.

[0040] Rotation of the secondary transmission shaft 109 generated by the first electric motor 107 may change the distance between the ends 104, 105 of the linear actuator 131 to reduce the force at the ends 104, 105 of the linear actuator 131.

[0041] Referring again to Figure 8, in the embodiment shown in Figure 8, only one electric motor (first electric motor 107) is provided. When the control unit 720 detects a power supply abnormality in the power supply 702, the control unit 720 the secondary transmission shaft 109 is rotatably disconnected from the primary transmission shaft 103 via the first engagement means 108; A second engagement means 114 may be provided to rotatably couple the flywheel 101 to the primary transmission shaft 103 .

[0042] The rotation generated by the kinetic energy stored by the flywheel 101 on the primary transmission shaft 103 may then be transferred to the first electric motor 107. As a result, the kinetic energy transferred by the flywheel 101 may be converted into electrical energy by the control system. The converted electrical energy may then be used by the control system to power a controller 720 of the control system.

[0043] Referring now to both the embodiment of Figure 6 and the embodiment of Figure 8, when the brake force request signal 712 indicates a force maintenance request to the two ends 104, 105 of the linear actuator 131, the control unit 720: By disconnecting the first engaging means 108, the secondary transmission shaft 109 is rotatably disconnected from the primary transmission shaft 103, A locking means 111 coupled to the secondary transmission shaft 109 may be activated to stop the rotation of the secondary transmission shaft 109, maintaining a constant distance between the ends 104, 105 of the linear actuator 131 and maintaining a constant force on the ends 104, 105 of the linear actuator 131.

[0044] 2, 3, 4a and 4b, the present invention further relates to a braking system 200 for a railway vehicle. The braking system 200 comprises an electromechanical assembly 100 for braking a railway vehicle according to any of the above-described embodiments, a control system according to any of the above-described embodiments, and braking means 204, 205 arranged to apply a braking force directly or indirectly to at least one wheel of the railway vehicle. The application of the braking force is controlled by the operation of a linear actuator 131.

[0045] 2, the braking system 200 may include a lever system 203 interposed between the linear actuator 131 and the braking means. The lever system 203 is connected to the two ends 104, 105 of the linear actuator 131 and may control the braking force that can be applied to the wheels of the rail vehicle as a function of the distance between the two ends 104, 105 of the linear actuator 131.

[0046] According to a first embodiment of integration in Fig. 2, the electromechanical assembly 100 is inserted inside a classical system of levers 201, 202, 203 which, by extending the ends 104, 105 of the linear actuator 131 in the direction 210, presses braking means 204, 205, including for example pad holders and associated brake pads, against a brake disc 206, applying a braking force to the brake disc 206.

[0047] Continuing to refer to Figure 2, as the distance between the two ends 104, 105 of the linear actuator 131 decreases, the braking force applied by the braking means may increase, and as the distance between the two ends 104, 105 of the linear actuator 131 increases, the braking force applied by the braking means may decrease.

[0048] According to a second embodiment of the integration shown in FIG. 3 , the electromechanical assembly 100 is inserted inside a brake caliper. With the electromechanical assembly 100 inserted inside the brake caliper, the ends 104, 105 move in a direction 310 and apply a braking force to the brake disc 206 by directly acting on the pad holder and associated brake pads (brake means 204, 205). As shown in FIG. 3 , the braking force applied by the brake means 204, 205 may decrease as the distance between the two ends 104, 105 of the linear actuator 131 decreases. Also, the braking force applied by the brake means 204, 205 may increase as the distance between the two ends 104, 105 of the linear actuator 131 increases.

[0049] According to a third embodiment of the integration in Fig. 4, the electromechanical assembly 100 is inserted into the classical system of levers 401, 402 that make up the mechanism of the braking system known as a TBU (tread brake unit). Then, by extending the ends 104, 105 of the linear actuator in the direction 210, a shoe holder and associated brake shoe 403 is pressed against the wheel 404, applying a braking force to the wheel 404.

[0050] Further description and practical examples of the use of the electromechanical assembly, the control system for the electromechanical assembly, and the braking system including the electromechanical assembly and the control system for the electromechanical assembly are detailed below.

[0051] 5 illustrates, for example, the trend of the braking force that the ends 104, 105 of the linear actuator 131 must apply as the distance L between the ends 104, 105 changes, with respect to the embodiment of the configuration shown in FIG. 2. The distance L has an initial value L0 corresponding to the rest state of the electromechanical assembly 100. In this state, the brake pads (brake means 204, 205) are each located at a distance A / 2 from the brake disc 206. To move the brake pads (brake means 204, 205) toward the brake disc 206, or to travel the distance A between L0 and L1, a minimum force F1 is required that exceeds the energy of the springs adequate to keep the brake pads (brake means 204, 205) away from the brake disc 206 in the rest state.

[0052] Subsequently, an increase in the force applied to the ends 104, 105 of the linear actuator 131 causes a flexure S of the levers 201, 203 as far as their resilience allows, up to a maximum value of distance L=L2, corresponding to a maximum force Fmax.

[0053] By way of example and non-exclusive values, the characteristics of a pneumatic brake actuator are: A=3 mm, S=4 mm, F1=1 KN, Fmax=80 KN. The minimum duration for application of maximum force Fmax may be 1 second.

[0054] To produce an electromechanical assembly 100 with the above characteristics, an electric motor is used to apply a force F(L), which should be delivered, either directly or through a reducer, to the ends 104, 105 of the linear actuator 131 at a speed of 4 mm per second near the limit of L2, with a peak force of 80 kN. Since power P [W] = F [N] * V [m / s], at the maximum force Fmax, the electric motor should have available power Pmax = 80 kN · 0.004 m / 1 S = 320 W, which is the net value of all friction and inefficiencies in the mechanism in 102 shown in Figure 2.

[0055] The size of a brushless motor with the power mentioned above is not suitable for this application.

[0056] The energy required for an electromechanical assembly according to the present invention having the above characteristics to apply a braking cycle corresponds to the area of ​​the triangle with vertices L1, L2 and Fmax, i.e., energy E [J] = 0.004 m * 80000 N / 2 = 160 J.

[0057] A value of 160 J of energy E may be provided, for example, by a motor capable of delivering 80 W for 2 seconds.

[0058] Continuing with reference to Figure 1, in Figure 1, an industrial electric motor 107 of 80 W and 6000 RPM and a radius of 50 mm and a height of 50 mm, i.e., inertia i = 4.3 E -3 kg m 2 For example only and not for limitation, if a brass flywheel 101 (density 8.73) having a .gtoreq.1.0001 ...

[0059] Maintaining a large margin of stored energy has several advantages.

[0060] The first advantage is that if an unexpected failure of the first electric motor 107 occurs during the first brake, there will still be enough energy available for at least the second brake, so that in the event of a simultaneous power outage of all vehicle brake units, there remains some possibility of applying an emergency brake that can safely stop the vehicle by employing the strategy described below.

[0061] A second advantage is that in the event of a simultaneous power outage of all brake units of the vehicle, the first electric motor 107 can be used as a generator to convert part of the kinetic energy stored in the flywheel 101 into electrical energy to be returned to the microprocessor control system (not shown), so that the electrical energy consumption required by the microprocessor control system to complete emergency braking typically does not exceed 10 W or 10 J / s.

[0062] A third advantage is that if the first electric motor 107 loses power during braking and its rotational speed is reduced by only 10%, the next emergency braking operation will be performed with a brake application time that is reduced by 10%. A 10% reduction in brake application time is usually within an acceptable range.

[0063] For example, the size of an industrial motor capable of delivering 80 W at a rotational speed of 6000 RPM is quite small, and in any case, much smaller than the size of a 320 W motor required for direct use with respect to the size of the flywheel mentioned above.

[0064] Obviously, if the acceleration time of the flywheel 101 increases, i.e., if the vehicle's mission profile proves that the average time between two complete brakings is much longer than the designed acceleration time, the power and size of the first electric motor 107 may be further reduced. Similarly, the mass of the flywheel may be reduced to keep the stored energy constant and increase the rotational speed. The energy equation is advantageous because by doubling the rotational speed, the flywheel moment of inertia may be reduced by a factor of four.

[0065] A general advantage of solutions based on kinetic energy storage is that, whereas direct motors must provide very high peak power at the expense of high peak currents, storage systems only require the power required to maintain the flywheel 101 at a constant speed once steady state is reached. This means that only the power required to overcome the friction of the bearings or to recover the energy used for braking, i.e., the power required for the action to be performed in time, is needed. In this case, the current required is much lower than with direct motors, reducing dissipation losses and allowing for smaller diameter conductors.

[0066] An example use of the electromechanical brake actuator (electromechanical assembly 100) embodiment described above and shown in FIG. 6 is detailed below.

[0067] The primary transmission shaft 103 connects the rotor 610 of the first electric motor 107, the flywheel 101 and the first engagement means .

[0068] Considering that the first engaging means 108 is an electromechanical clutch, a first rotating element 604 is provided connected to the first primary transmission shaft 103 .

[0069] The secondary transmission shaft 109 connects the first engagement means 108 (specifically, the second rotating element 607 of the first engagement means 108), the transmission mechanism 133, a rotor 611 of the second electric motor 112, and the locking means 111. The locking means 111 may be an electromechanical brake and may include a rotating element 613 coupled to the secondary transmission shaft 109. The transmission mechanism 133 may include a first element 608 that performs an input element function of the mechanical reducer.

[0070] 6 using a mechanical mass symbol (the mass symbol of the body 616 of the electromechanical assembly 100), the body of the first electric motor 107, the body of the second electric motor 112 and the second element of the electromechanical brake (fixed element 615) are mechanically constrained to the body 616 of the electromechanical assembly 100. The first engaging means 108 (i.e. the electromechanical clutch) and the locking means 111 (i.e. the electromechanical brake) may be, for example but not limited to, an electromagnetic type.

[0071] The electromechanical clutch is a known industrial component and has two functional states. In the first state, the rotating elements (first rotating element 604 and second rotating element 607) are coupled to one another. In this way, the primary transmission shaft 103 and the secondary transmission shaft 109 are mechanically constrained so that the flywheel 101 can transfer stored kinetic energy to the elements constrained to the primary transmission shaft 103. In the second state, the rotating elements 604 and 607 are decoupled from one another. In this way, the primary transmission shaft 103 and the secondary transmission shaft 109 are mechanically released, allowing the first electric motor 107 to return the flywheel 101 to a steady rotational speed. The diagram of the first engaging means 108 (i.e., the clutch in FIG. 6) is merely a functional diagram and, in practice, can take various forms while maintaining the described functionality without changing it.

[0072] The electromechanical brake is a known industrial component with two functional states. In the first state, the rotating element 613 and the fixed element 615 are coupled to each other. Thus, the secondary transmission shaft 109 is mechanically constrained to the body 616 of the electromechanical assembly 100 and cannot rotate. In the second state, the rotating element 613 and the fixed element 615 are decoupled from each other. Then, under energy transmission by the second electric motor 112 or the flywheel 101, the first engaging means 108 (i.e., the electromechanical clutch) couples the primary transmission shaft 103 and the secondary transmission shaft 109 to each other, allowing the secondary transmission shaft 109 to rotate freely. The illustration of the locking means 111 (i.e., the electromechanical brake) in FIG. 6 is merely a functional illustration and can, in practice, take various forms without changing the described function.

[0073] A second output element 617 (e.g., a mechanical reducer) of the transmission mechanism 133 may be connected to the linear actuator 131 using a tertiary transmission shaft 619. The linear actuator 131 may include a screw 618 and a screw 618 and nut screw 618′ system. Rotation of the tertiary transmission shaft 619 varies the distance L between the ends 104, 105 of the linear actuator 131.

[0074] The force sensor means 134 may be positioned on the mechanical path between the ends 104, 105 of the linear actuator 131 so as to measure the force F(L) applied by the linear actuator 131 as the distance L between the ends 104, 105 changes.

[0075] An embodiment based on a control system 700 for an electromechanical assembly according to the present invention will now be described.

[0076] The power supply means 701 is, for example, a power supply device, and is supplied by a power source 702, typically a vehicle battery. The power supply means 701 provides a stabilized power voltage between conductors 703, 704.

[0077] Power conversion means 706, 707 are connected to conductors 703, 704 assigned to the power supplies of the first electric motor 107 and the second electric motor 112, respectively.

[0078] The control means 708 of the power supply of the control unit 720 is further connected to the conductors 703,704.

[0079] The power conversion means 706, 707 may be, for example, but not limited to, a three-phase inverter.

[0080] The first electric motor 107 and the second electric motor 112 may be, for example, but are not limited to, brushless motors.

[0081] An energy storage device 705 may be coupled to the conductors 703, 704 to perform the function of temporary storage of electrical energy that may be regenerated by the first electric motor 107 and / or the second electric motor 112 via power conversion means 706, 707.

[0082] The first electric motor 107 and / or the second electric motor 112 may generate at least one angular position signal 709, 710, respectively, via power conversion means 706, 707, or both, arranged to be received by a controller 720. It is known in the art that motor control systems developed according to the state of the art can derive motor angular velocity information over time from the motor angular position variation information.

[0083] The control unit 720 may further receive a force signal 711 from the force sensor means 134, a brake force request signal 712, an emergency brake request signal 724, and a weight signal 718. The brake force request signal 712 indicates the braking force requested from the electro-mechanical assembly 100. The weight signal 718 indicates the weight being exerted on the bogie or body of the rail vehicle with which the electro-mechanical assembly 100 is associated.

[0084] The control unit 720 may generate control signals 713, 714 to activate and deactivate the first engaging means 108 (ie, the electromechanical clutch) and the locking means 111 (ie, the electromechanical brake), respectively.

[0085] Additionally, the controller 720 may generate one or more control signals 715, 716 for the power conversion means 706, 707 to control the speed and / or direction of the first electric motor 107 and / or the second electric motor 112, respectively, and thereby control the direction of electrical energy to / from the first electric motor 107 and / or the second electric motor 112.

[0086] The following is one example of the operation and interaction between the control system 700 and the electromechanical assembly 100.

[0087] As shown in FIG. 2, the electromechanical assembly 100 is initially assumed to be in a rest position, ie the braking means 204, 205 are each at a distance A / 2 from the brake disc 206.

[0088] When the control system is powered on, the controller 720 acts on at least one control signal 715 to cause the first electric motor 107 to rotate at a steady-state rotation speed, causing the flywheel 101 to store design kinetic energy, such as, but not limited to, 10 times the kinetic energy required to complete a braking cycle.

[0089] Continuing with reference to Figure 5, in the presence of a request received by the brake force request signal 712 (request for force value F3), the control unit 720 acts on a control signal 713 to cause the first engagement means 108 (i.e., the electromechanical clutch) to mechanically connect the primary transmission shaft 103 and the secondary transmission shaft 109. Furthermore, the control unit 720 acts on a control signal 714 to cause the locking means 111 (i.e., the electromechanical brake) to disconnect the secondary transmission shaft 109 from the body 616 of the electromechanical assembly 100.

[0090] Thus, the rotation of the primary transmission shaft 103 transfers the energy stored by the flywheel 101 to the secondary transmission shaft 109 with a possible speed reduction factor corresponding to the reduction factor of the transmission mechanism 133 and, if the transmission mechanism 133 acts as a mechanical speed reducer, a torque amplification factor corresponding to the inverse of the reduction factor of the transmission mechanism 133.

[0091] Because the product (area) of the minimum force F1 and the distance A is negligibly small relative to the area of ​​the triangle defined by the product of L1, L2, and Fmax, the distance L between the ends 104, 105 of the linear actuator 131 increases while moving through the range between L0 and L1 without actually absorbing much energy.

[0092] 2 reaches position L1, which corresponds to the position where the two distances A / 2 are again set to 0, the braking means 204, 205 (i.e., brake pads) reach the surface of the brake disc 206 and the force F(L) starts to increase, the value of which F(L) is reported by the force sensor means 134 to the control unit 720 via the force signal 711.

[0093] If the force signal 711 indicates that the force value F3 has been reached within the tolerances defined by the design, the control unit 720 acts on a control signal 713 to cause the first engagement means 108 (i.e., the electromechanical clutch) to mechanically disengage the primary transmission shaft 103 from the secondary transmission shaft 109. Furthermore, the control unit 720 acts on a control signal 714 to cause the locking means 111 (i.e., the electromechanical brake) to connect the secondary transmission shaft 109 to the body 616 of the electromechanical assembly 100.

[0094] In this way, the electromechanical assembly 100 maintains the force value F3 stable until a new request is made to change the braking force value.

[0095] As mentioned above, in the phases associated with the application of a positive force, the control unit 720 may utilize the contribution of the second electric motor 112. Concurrently with the act of coupling the primary transmission shaft 103 to the secondary transmission shaft 109, the control unit 720 may activate the second electric motor 112 using the control signal 716 to rotate in the same direction as the flywheel 101, or may provide additional torque to the secondary transmission shaft 109 by reducing the extraction of energy from the flywheel 101 or by increasing the application speed.

[0096] If there is a force reduction request from F3 to F2 by the brake force request signal 712, the control unit 720 acts on the control signal 714 to cause the locking means 111 (i.e. the electromechanical brake) to disconnect the secondary transmission shaft 109 from the body of the electromechanical assembly 100, allowing the secondary transmission shaft 109 to rotate freely. Needless to say, the primary transmission shaft 103 and the secondary transmission shaft 109 are disconnected from each other via the first engagement means 108.

[0097] Simultaneously with the deactivation of the locking means 111 (ie the electromechanical brake), the control unit 720 activates the second electric motor 112 to rotate in the opposite direction to the flywheel 101 .

[0098] If the force value F3 (force level) is higher than the frictional force of the transmission mechanism 133 and the frictional force of the linear actuator 131 (i.e., the frictional force of the mechanical chain between the end portions 104, 105 and the secondary transmission shaft 109), in other words, if they form a reversible mechanical chain, the secondary transmission shaft 109 will try to rotate autonomously in the opposite direction to the flywheel 101. In this case, if the rotational speed is higher than the expected force release gradient, the second electric motor 112 will be used as a brake by the control unit 720 and will convert the excess kinetic energy stored in the storage element (energy storage device 705) into electrical energy.

[0099] If the force value F3 (force level) is lower than the frictional force of the transmission mechanism 133 and the frictional force of the linear actuator 131 (i.e., the frictional force of the mechanical chain between the ends 104, 105 and the secondary transmission shaft 109), in other words, if the mechanical chain is irreversible, the secondary transmission shaft 109 will tend to remain stable in its current position. In this case, the second electric motor 112 is used by the control unit 720 to start and maintain the rotation of the secondary transmission shaft 109 at a value that ensures the required brake force release gradient. The second electric motor 112 must have a minimum torque that is at least equal to or greater than the static release frictions of the mechanical chain between the ends 104, 105 of the linear actuator 131 and the transmission shaft 606.

[0100] If the force signal 711 indicates that the force value F2 has been reached within the tolerances defined by the design, the control unit 720 acts on the control signal 714 to cause the locking means 111 (i.e. the electromechanical brake) to connect the secondary transmission shaft 109 to the body 616 of the electromechanical assembly 100. At the same time, the control unit 720 deactivates the second electric motor 112. In this way, the electromechanical assembly 100 maintains the force value F2 stable until a new request to change the force value is made.

[0101] If the brake force request signal 712 indicates a force reduction request to reduce F2 to 0 Newtons (i.e., a request to completely release the brake force), the control unit 720 operates exactly as in the previous case, except that when the force signal 711 reaches the level of force F=0 Newtons, the control unit 720 maintains the second electric motor 112 active and the locking means 111 (i.e., the electromechanical brake) inactive, and starts measuring the change in distance L, which corresponds to the change in angular position measured based on the angular position signal 710. When this change in distance L reaches distance A, the control unit 720 acts on the control signal 714 to cause the locking means 111 (i.e., the electromechanical brake) to connect the secondary transmission shaft 109 to the main body of the electromechanical assembly 100. At the same time, the control unit 720 deactivates the second electric motor 112. In this way, the electromechanical assembly 100 keeps the position of the braking means 204, 205 (ie the pad holders) stable at a distance A / 2 from the brake disc 206 until a new force value is required.

[0102] It is equally possible that the control unit 720 may permanently maintain the activation state of the first electric motor 107 during all the steps described above to preserve the amount of energy stored in the flywheel 101.

[0103] As disclosed instead in WO2019042860, in addition to the above-mentioned advantages, the present invention has the advantage of not requiring a specific device for implementing the parking brake. In fact, by selecting the locking means 111 (i.e., an electromechanical brake of electromagnetic nature and inverse type), i.e., in the absence of electrical energy, the electromechanical brake connects the secondary transmission shaft 109 to the mechanical mass (body 616) of the electromechanical assembly 100, so that the previously applied force can be permanently maintained even if electrical energy is subsequently not supplied or, for example, when the vehicle is parked for a long period of time. As an alternative to using the locking means 111 (i.e., an electromechanical brake), a design in which a mechanical chain, i.e., a first input element 608 of a mechanical reduction gear 609, runs between the ends 104, 105 of the linear actuator 131 and the secondary transmission shaft 109 to permanently maintain the parking brake force is sufficient. When the first input element 608 of the mechanical reduction gear 609 is provided, it is not possible to reverse the rotation of the secondary transmission shaft 109, even in the complete absence of electrical energy, since the mechanical chain is irreversible (i.e., any force applied externally to the ends 104, 105 of the linear actuator 131 has a maximum value Fmax).

[0104] If the power supply 702 fails, the power supply means 701 uses a signal 717 to notify the control unit 720 of the fact that the power supply 702 has failed.

[0105] The control unit 720 acts on the control signal 715 to immediately convert the first electric motor 107 into a controlled generator.

[0106] In fact, as known to those skilled in the art, the first power conversion means 706 reverses the direction of the current by absorbing the required amount of energy from the first electric motor 107, i.e. by converting part of the kinetic energy stored in the flywheel 101 into electrical energy. The required amount of energy is the amount of energy required to keep the control unit 720 active. By way of example only, it is appropriate to compare the power of approximately 10 W required by a typical electronic control unit with the pre-calculated power that can be supplied by the flywheel 101 for the following reasons: this comparison makes it clear that the extraction of energy equivalent to 10 W is negligible compared to the mechanical energy remaining in the flywheel during the time it takes to complete the final braking, and is furthermore required for the electromechanical assembly 100 to complete the final braking.

[0107] This last solution is highly advantageous when compared to other solutions such as those disclosed in WO2019042841.

[0108] In the case of WO2019042841, the energy storage system must not only ensure the storage of energy necessary to complete the final braking, but also ensure flawless operation within the temperature range stipulated by railway regulations, i.e., -40°C to +85°C, and a service life compatible with the maintenance cycle achieved by a comparable electro-pneumatic braking system, i.e., a service life of 10 years. Furthermore, if the energy storage system disclosed in WO2019042841 is a battery, it is known to those skilled in the art that it is complicated to determine the amount of charge stored in this energy storage system at an appropriate safety level, typically SIL4, which is appropriate for emergency braking according to the EN50126 and EN50129 standards.

[0109] In the present invention, the flywheel 101 not only acts as a facilitator in the application of force by significantly reducing the size of the second electric motor 112, but also as a reservoir of kinetic energy that can be converted to electrical energy to accomplish a final emergency or parking brake application. The amount of energy stored in the flywheel 101 is easily monitored and certified by a simple measurement of the speed of the flywheel 101 derived from the angular position signal 709 by the control unit 720.

[0110] A signal 725 generated by the control unit 720 generates an alarm for a system external to the braking system when the amount of energy stored in the flywheel 101 reaches a minimum safety threshold.

[0111] It should be clarified that the energy storage device 705 does not require any sizing to accomplish braking, but only serves as a temporary buffer for the electrical energy reconverted by the first power conversion means 706 and for immediate reuse by the control system 700 to manage any final emergency or parking brake.

[0112] In the event of a failure of the control unit 720, there is a possibility that the energy stored in the flywheel 101 could be completely transferred to the secondary transmission shaft 109 via the first engaging means 108 (i.e., the electromechanical clutch). This would clearly risk damaging at least one mechanical element in the mechanical chain extending from the ends 104, 105 of the linear actuator 131 to the flywheel 101. To remedy the above problem, it is sufficient to set the friction coefficient of the first engaging means 108 (i.e., the electromechanical clutch) so that the frictional force associated with the braking force is slightly greater than the force required to apply the maximum braking force Fmax. In this way, the electromechanical clutch functions as a mechanical fuse. Those skilled in the art know that industrial electromechanical clutches suitable for performing the function of an electromechanical clutch have a functional life measurable in the range of several million joules dissipated during engagement and disengagement phases. In the present case, as described above as an example, the flywheel 101 stores an amount of power on the order of 1,000 joules. In this case, the electromechanical clutch acts as a temporary fuse element, but is not damaged in a way that would disable subsequent operation.

[0113] The presence of a further weight signal 718 at the input of the control unit 720 indicates the weight bearing on the bogie with which the electromechanical assembly is associated. The weight signal 718 enables the control unit 720 to calculate the force value to be applied as a function of the weight value provided by the weight signal 718 in order to provide the maximum braking force possible without exceeding the available grip force. This makes it possible to carry out the braking procedure even in the event of a power failure.

[0114] In the above description of the dynamic behavior of the braking system, the assumption is made that the instantaneous state of the first engaging means 108 (i.e., the electromechanical clutch) and the instantaneous state of the locking means 111 (i.e., the electromechanical brake) are switched. In reality, the aforementioned device has a physical actuation time of about several hundred milliseconds, and the friction force continuously transitions from a null value to a nominal operating value. This means that during simultaneous switching, a problem can arise in that the energy of the flywheel 101, which is charged with kinetic energy, is transferred to the mechanical mass (body 616) of the electromechanical assembly 100 via the secondary transmission shaft 109 for a short period of time, precisely about 100 milliseconds.

[0115] One solution is typically to preload the memory of the controller 720 with the nominal delay times of the components, typically supplied by the manufacturer. The nominal delay times are used by the control module to appropriately command one or more of the engaging means 108 (i.e., electromechanical clutch) and locking means 111 (i.e., electromechanical brake), thereby avoiding actuation crossing.

[0116] In fact, during their functional life, both electromechanical brakes and electromechanical clutches undergo a gradual wear of the clutch material, modifying the mechanical gap and lengthening or shortening the reaction time depending on the functional structure of the components.

[0117] To remedy this situation, the control unit 720 may receive information regarding the magnitude and direction of the currents flowing from / to the first electric motor 107 and / or the second electric motor 112 by means of signals 721, 722. These currents indicate the torques experienced by the motors and thus indicate, for example, the fact that either the locking means 111 (i.e., electromechanical brake) is interposed at the appropriate time before or after deactivating the second electric motor 112, or before opening the engaging means 108 (i.e., electromechanical clutch). Furthermore, the activation and deactivation of the electromechanical brake and the electromechanical clutch cause fluctuations in the speed of the first electric motor 107 and / or the second electric motor 112.

[0118] By correlating the command times to the electromechanical brake and electromechanical clutch with variations in electric motor current and speed, the controller 720 can correct the aforementioned switching times initially preloaded into its non-volatile memory to minimize mechanical stress and wear on the electromechanical brake and electromechanical clutch.

[0119] Referring now to Figure 5, it can be assumed that there exists a force field below Fmot that allows the second electric motor 112 to operate automatically in applying and releasing the required braking force. Fmot depends on the size of the second electric motor 112 and the frictional force of the mechanical chain extending from the ends 104, 105 of the linear actuator 131 to the secondary transmission shaft 109.

[0120] To further limit mechanical stress and wear on the electromechanical brake and electromechanical clutch, when the braking force field is less than Fmot, the control unit 720 may activate the electromechanical brake only when the rotational speed of the second electric motor 112 reaches zero. Furthermore, when the braking force field is less than Fmot, the control unit 720 may activate the electromechanical clutch (i.e., the engaging means 108) only when the rotational speed of the second electric motor 112 reaches the motor rotational speed.

[0121] In the following, an example of the use of the electromechanical brake actuator (electromechanical assembly 100) according to the embodiment described above and shown in FIG. 8 will be described.

[0122] The tertiary transmission shaft 802 connects the flywheel 101 and the second engagement means 114. For example, the second engagement means 114 is an electromechanical clutch, and a first rotating element 804 of the second engagement means 114 is connected to the tertiary transmission shaft 802.

[0123] The primary transmission shaft 103 is connected to the first engagement means 108. For example, the first engagement means 108 is an electromechanical clutch. The first rotational element 805 is connected to the primary transmission shaft 103, a rotor 807 of the first electric motor 107, and the second engagement means 114 (i.e., a second rotational element 809 of the second engagement means 114). In this embodiment, only one electric motor, the first electric motor 107, is provided in the electromechanical assembly 100, and a second electric motor 112 is not provided. The secondary transmission shaft 109 connects the second rotational element 810 of the first engagement means 108 to the drive mechanism (transmission mechanism 133) and the locking means 111. If the locking means 111 is an electromechanical brake, the secondary transmission shaft is connected to the rotational element 815 of the electromechanical brake.

[0124] As shown in FIG. 8 by the symbol for mechanical mass 818 (the mass of the body of the electromechanical assembly 100), the body of the first electric motor 107 and the locking means 111 are mechanically constrained to the body of the electromechanical assembly 100.

[0125] The first engaging means 108, the second engaging means 114 (ie, electromechanical clutch) and the locking means 111 (ie, electromechanical brake) may be, for example but not limited to, electromagnetic.

[0126] Analyzing the operation of the second engaging means 114 in detail and considering an example in which the second engaging means 114 is an electromechanical clutch, this electromechanical clutch is a known industrial component with two functional states. In the first state, the rotating element 804 and the rotating element 805 are coupled to each other. As a result, the tertiary transmission shaft 802 and the primary transmission shaft 103 are mechanically constrained so that the flywheel 101 can transfer its stored kinetic energy to the primary transmission shaft 103. The first electric motor 107 can then transfer kinetic energy to the flywheel 101. In the second state, the rotating element 804 and the rotating element 805 are decoupled from each other. In this way, the tertiary transmission shaft 802 and the primary transmission shaft 103 are mechanically released, allowing the flywheel 101 to rotate freely due to its own inertia.

[0127] Analyzing the operation of the first engaging means 108 in detail and considering an example where the first engaging means 108 is an electromechanical clutch, this electromechanical clutch is a known industrial component with two functional states. In the first state, the rotating elements 809 and 810 are coupled to each other, thereby mechanically constraining the primary transmission shaft 103 and the secondary transmission shaft 109 so that the first electric motor 107 and the flywheel 101 can transfer kinetic energy to the transmission mechanism 133. When the transmission mechanism 133 is a mechanical reducer and the rotating elements 804, 805 of the first electromechanical clutch 803 are coupled, kinetic energy is transferred to the first element 812 of the mechanical reducer.

[0128] In the second state, the rotating element 809 and the rotating element 810 are decoupled from each other, thus mechanically disengaging the primary transmission shaft 103 and the secondary transmission shaft 109, and the secondary transmission shaft 109 is free.

[0129] The illustration of the electromechanical clutch (first engaging means 108 and second engaging means 114) in Figure 8 is purely functional. In reality, the electromechanical clutch (first engaging means 108 and second engaging means 114) can take on a variety of forms while maintaining its functionality without any functional changes as described above.

[0130] Analyzing the operation of the locking means 111 in detail and considering an example where the locking means 111 is an electromechanical brake, this is a known industrial component with two functional states. In the first state, the rotating element 815 and the mechanical mass 818 (the body of the electromechanical assembly 100) are coupled together. In this way, the secondary transmission shaft 109 is mechanically constrained to the body of the electromechanical assembly 100 and prevented from rotating. In the second state, the rotating element 815 and the mechanical mass 818 (the body of the electromechanical assembly 100) are decoupled from each other, allowing the secondary transmission shaft 109 to rotate freely.

[0131] The diagram of the electromechanical brake (locking means 111) shown in Figure 8 is purely functional, and in fact can take many forms while maintaining the disclosed functionality without changing it.

[0132] Analyzing the operation of the transmission mechanism 133 in detail and considering an embodiment in which the transmission mechanism 133 is a mechanical reducer, the second element 813 of the mechanical reducer is connected to a screw and nut screw system 820 by means of a quaternary transmission shaft 821. Rotation of the quaternary transmission shaft 821 varies the distance L between the ends 104, 105 of the linear actuator 131. For example, but not limited to, a force sensor means 134 may be disposed between the two ends 104, 105 of the linear actuator 131 to measure the force F(L) applied by the electromechanical assembly 100 as the distance L varies. In FIG. 7 , a power supply means 701 (e.g., a power supply) is powered by a power source 702, typically a vehicle battery. The power supply means 701 provides a stabilized power supply voltage between conductors 703, 704.

[0133] The first power conversion means 706 is connected to the conductors 703, 704. In this embodiment, only one first electric motor 107 is provided. The first power conversion means 706 is assigned to the power supply of the first electric motor 107.

[0134] The control means 708 of the power supply of the control unit 720 is further connected to the conductors 703,704.

[0135] The first electric motor 107 may be, for example, but is not limited to, a brushless motor. The first power conversion means 706 may be, for example, but is not limited to, a three-phase inverter.

[0136] The energy storage device 705 performs the function of an accumulator for any electrical energy regenerated by the first electric motor 107 via the first power conversion means 706 .

[0137] The first electric motor 107 generates an angular position signal 709 which is intended for the first power conversion means 706 and the control unit 720, respectively. It is prior art that motor control systems developed according to the state of the art are able to derive angular velocity information of the motor from information about the angular position variations over time.

[0138] The control unit 720 further receives a force signal 711 from the force sensor means 134 and a brake force demand signal 712 indicative of the force demanded from the electromechanical assembly.

[0139] The control unit 720 generates control signals 713, 723, 714 to activate and deactivate the second engaging means 114, the first engaging means 108 and the locking means 111, respectively.

[0140] Additionally, the control unit 720 generates a control signal 715 for the first power conversion means 706 to control the speed and direction of the first electric motor 107 .

[0141] The operation and interaction between the control system 700 and the electromechanical assembly 100 will now be described in detail.

[0142] 2, the electromechanical assembly 100 is initially assumed to be in a rest position, i.e. the braking means 204, 205 (i.e. the pad holders) are each assumed to be located at a distance A / 2 from the brake disc 206.

[0143] When the control system is powered on, the controller 720 activates the second engagement means 114 connecting the tertiary transmission shaft 802 to the primary transmission shaft 103 and starts the first electric motor 107 to a steady state speed using a control signal 715. The steady state rotational speed is the speed at which the flywheel 101 has stored its design kinetic energy, or, for example, but not limited to, ten times the energy required to complete a braking cycle.

[0144] 5. In the presence of a demand from the braking force demand signal 712 (demand for force value F3), the control unit 720 acts on the control signals 713, 723, and 714. The control signal 713 thereby causes the second engagement means 114 to mechanically connect the tertiary transmission shaft 802 to the primary transmission shaft 103. The control signal 723 causes the first engagement means 108 to mechanically connect the primary transmission shaft 103 to the secondary transmission shaft 109. The control signal 714 causes the locking means 111 to disconnect the secondary transmission shaft 109 from the main body (mechanical mass 818) of the electromechanical assembly 100.

[0145] In this manner, the rotation of the tertiary transmission shaft 802 and the rotation of the primary transmission shaft 103 transfer the energy of the flywheel 101 to the secondary transmission shaft 109. The rotation of the secondary transmission shaft 109 may therefore transfer the energy of the flywheel 101 to the quaternary transmission shaft 821 with a possible speed reduction factor corresponding to the speed reduction factor of the transmission mechanism 133, which may act as a mechanical reducer, and with a possible torque amplification factor corresponding to the speed reduction factor of the transmission mechanism 133 (i.e., the mechanical reducer).

[0146] Since the product (area) of the minimum force F1 and the distance A is negligibly small relative to the area of ​​the triangle determined by the product of L1, L2, and Fmax, the distance L between the ends 104, 105 of the linear actuator 131 actually increases by moving along the portion between L0 and L1 without consuming a large amount of energy.

[0147] 2, the brake means 204, 205 (i.e., the brake pads) reach the surface of the brake disc 206, and the force F(L) begins to increase, and the value of the force F(L) is then reported by the force sensor means 134 to the control unit 720 via the force signal 711.

[0148] If the force signal 711 indicates that the force value F3 has been reached within the tolerances defined by the design, the control unit 720 acts on the control signals 723 and 714. The control signal 723 causes the first engagement means 108 to mechanically disconnect the primary transmission shaft 103 from the secondary transmission shaft 109. The control signal 714 causes the locking means 111 to connect the secondary transmission shaft 109 to the mechanical mass 818 (the main body of the electromechanical assembly 100).

[0149] In this way, the electromechanical assembly 100 maintains the force value F3 stably until a new request to change the force value is made. The control unit 720 keeps the second engagement means 114 active so that the first electric motor 107 can continue to keep the flywheel 101 rotatable.

[0150] When there is a force reduction request from F3 to F2 via brake force request signal 712, control unit 720 acts on control signals 714, 713, and 723. Control signal 714 causes locking means 111 to disconnect secondary transmission shaft 109 from mechanical mass 818 (the main body of electro-mechanical assembly 100), allowing secondary transmission shaft 109 to rotate freely. Control signal 713 causes second engagement means 114 to disconnect tertiary transmission shaft 802 from primary transmission shaft 103, causing first electric motor 107 to rotate at a different speed than flywheel 101. Control signal 723 causes first engagement means 108 to connect primary transmission shaft 103 to secondary transmission shaft 109, activating first electric motor 107 to rotate in the opposite direction to flywheel 101.

[0151] If the force value F3 (force level) is greater than the friction force of the mechanical chain from the ends 104, 105 of the linear actuator 131 to the secondary transmission shaft 109, the secondary transmission shaft 109 will try to rotate autonomously in the opposite direction to the flywheel 101. In this case, if the rotation speed is higher than the expected force release gradient, the first electric motor 107 will be used by the control unit 720 as an electromechanical brake and will convert the excess kinetic energy into electrical energy that is stored in the storage element (energy storage device 705).

[0152] If the force value F3 (force level) is less than the frictional force of the mechanical chain from the ends 104, 105 of the linear actuator 131 to the secondary transmission shaft 109, the secondary transmission shaft 109 will tend to remain stable at its current position. In this case, the first electric motor 107 is used by the module control unit 720 to start and maintain rotation of the secondary transmission shaft 109 at a value that ensures the required brake force release gradient. The first electric motor 107 must have a minimum torque that is at least greater than the static friction in the released state of the mechanical chain from the ends 104, 105 of the linear actuator 131 to the secondary transmission shaft 109.

[0153] When the force signal 711 indicates that the force value F2 has been reached within the tolerances defined by the design, the control unit 720 acts on the control signals 723 and 714. The control signal 723 causes the first engaging means 108 to disconnect the primary transmission shaft 103 from the secondary transmission shaft 109. The control signal 714 causes the locking means 111 to connect the secondary transmission shaft 109 to the main body (mechanical mass 818) of the electromechanical assembly 100. In this way, the electromechanical assembly 100 maintains the force value F2 stably until a new request to change the force value is made. At the same time, the control unit 720 of the control device acts on the control signals 713 and 715. The control signal 713 causes the second engaging means 114 to connect the tertiary transmission shaft 802 to the primary transmission shaft 103. The control signal 715 causes the first electric motor 107 to return the flywheel 101 to a steady rotational speed and recharge the kinetic energy lost during braking.

[0154] If there is a demand from the brake force demand signal 712 to reduce the force from F2 to 0N (i.e. to fully release the brake force), the control unit 720 behaves exactly as in the previous case, except that if the force signal 711 indicates that the force F=0N level has been reached, the control unit 720 keeps the first electric motor 107 active and the locking means 111 inactive and starts measuring the change in distance L, which corresponds to the change in angular position measured based on the angular position signal 710. When the change in distance L reaches distance A, the control unit 720 acts on the control signal 714 to cause the locking means 111 to connect the secondary transmission shaft 109 to the body of the electromechanical assembly 100. In this way, the electromechanical assembly 100 stably maintains the position of the brake actuator (i.e. the position of the pad holder (brake means 204, 205) at a distance A / 2 from the brake disc 206) until a new force value is required. Similar principles to those of the electromechanical assemblies disclosed in the previous embodiments are valid for the electromechanical assembly now disclosed, relating to how to apply the parking brake, how to convert kinetic energy into electrical energy for final emergency braking or parking braking, and how to compensate for the switching delays of the two electromechanical clutches 803, 811 and the electromechanical brakes.

[0155] The disclosed transmission mechanism 133 may be obtained by, for example, but not limited to, connecting two or more gears, a gear and worm screw connection, or connecting one or more planetary gearboxes in series.

[0156] The control unit 720 may include at least one microprocessor or at least one programmable circuit of the FPGA, Gate Array, or ASIC type, or may include both.

[0157] Various aspects and embodiments of the electromechanical assembly according to the present invention and of the control system for the electromechanical assembly according to the present invention have been described in detail. It is understood that each embodiment can be combined with any other embodiment. Furthermore, the present invention is not limited to the described embodiments, but may be modified within the scope defined by the appended claims.

Claims

1. 1. An electromechanical assembly for a braking system of a rail vehicle, comprising: a flywheel adapted to store sufficient kinetic energy to operate the electromechanical assembly to cause the brake system to perform at least one emergency brake application, service brake application, or parking brake application; 1. An electromechanical assembly comprising:

2. a first electric motor; a primary transmission shaft rotatably connected to the first electric motor; A secondary transmission shaft; first engagement means for rotatably connecting the secondary transmission shaft to the primary transmission shaft; a locking means coupled to the secondary transmission shaft for preventing rotation of the secondary transmission shaft; a linear actuator provided to actuate the braking system, a linear actuator extendable from a first retracted position in which two ends of the linear actuator are at a first distance to a second extended position in which the two ends of the linear actuator are disposed at a second distance greater than the first distance; a transmission mechanism interposed between the secondary transmission shaft and the linear actuator and configured to convert rotation of the secondary transmission shaft into linear motion of the linear actuator; Further comprising:

2. The electromechanical assembly of claim 1, wherein the flywheel is rotatably connected or connectable to the primary transmission shaft.

3. the primary transmission shaft is rotatably connectable to the flywheel by a second engagement means; the first electric motor Rotating the primary transmission shaft in a first direction; rotating the primary transmission shaft in a second direction opposite to the first direction; It is set up as follows: rotation of the primary transmission shaft in the first direction increases the distance between the two ends of the linear actuator; rotation of the primary transmission shaft in the second direction decreases the distance between the two ends of the linear actuator; 3. The electromechanical assembly of claim 2, wherein said second engaging means disconnects said primary transmission shaft from said flywheel when said first electric motor rotates said primary transmission shaft in said second direction.

4. the first electric motor is configured to rotate the primary transmission shaft in a first direction; rotation of the primary transmission shaft in the first direction increases the distance between the two ends of the linear actuator; the electromechanical assembly including a second electric motor coupled to the secondary transmission shaft; the second electric motor is configured to rotate the secondary transmission shaft in a second direction opposite to the first direction; 3. The electromechanical assembly of claim 2, wherein the rotation of the secondary transmission shaft in the second direction decreases the distance between the two ends of the linear actuator.

5. The electromechanical assembly of claim 4 , wherein the first electric motor is continuously powered to rotate the primary transmission shaft to continuously store kinetic energy in the flywheel.

6. The electromechanical assembly of claim 3 , wherein one or both of the first engaging means and the second engaging means comprises an electromechanical or electromagnetic clutch.

7. 3. The electromechanical assembly of claim 2, wherein the locking means comprises an electromechanical brake or an electromagnetic brake.

8. 3. An electromechanical assembly according to claim 2, comprising at least one force sensor means arranged to measure the force exerted by said linear actuator.

9. A control system for an electromechanical assembly of a braking system, comprising: the electromechanical assembly a flywheel arranged to store sufficient kinetic energy to operate the electromechanical assembly for at least one emergency brake application, service brake application or parking brake application of the brake system; Equipped with The control system a control arranged to control operation of at least the first electric motor, the first engaging means and the locking means of said electromechanical assembly; Equipped with the first engagement means is provided to rotatably couple a primary transmission shaft rotatably connected to the first motor to a secondary transmission shaft; the locking means is coupled to the secondary transmission shaft and is provided to stop rotation of the secondary transmission shaft; The control system further comprises: power supply means connected at an input to the power supply and arranged to output a regulated voltage; a first power conversion means connected to the first electric motor and configured to supply energy to the first electric motor by converting the regulated voltage at the output of the power supply means; a first power conversion means further configured to provide a regulated voltage by converting a variable voltage generated by at least the first electric motor when rotatably driven by the flywheel; and - control means for supplying power to said control unit, said control means being arranged to supply energy to at least said control unit from said regulated voltage present at the output of said power supply means or by said regulated voltage provided by said first power conversion means; A control system comprising:

10. The control system, second power conversion means connected to a second electric motor of the electromechanical assembly and configured to convert the regulated voltage present at the output of the power supply means to supply energy to the second electric motor coupled to the secondary transmission shaft of the electromechanical assembly; Further comprising: the second power conversion means is further configured to provide a regulated voltage by converting a variable voltage generated by the second electric motor when rotatably driven by the flywheel; 10. The control system of claim 9, wherein the control means for supplying power to the control unit is configured to supply energy to at least the control unit from the regulated voltage present at the output of the power supply means, by the regulated voltage provided by the first power conversion means, or by the regulated voltage provided by the second power conversion means.

11. The electromechanical assembly comprising: a linear actuator provided to actuate the braking system, a linear actuator extendable from a first retracted position in which two ends of the linear actuator are at a first distance to a second extended position in which the two ends of the linear actuator are disposed at a second distance greater than the first distance; Further comprising: the control unit is configured to receive a braking force request signal; when the brake force demand signal indicates a demand for an increase in force at the two ends of the linear actuator, the control unit: deactivating the locking means coupled to the secondary transmission shaft; a first engagement means for rotatably connecting the secondary transmission shaft to the primary transmission shaft; The rotation of the primary transmission shaft is generated at least by the kinetic energy stored by the flywheel, 10. The control system of claim 9, wherein the rotation of the primary transmission shaft is transmitted to the secondary transmission shaft to change the distance between the two ends of the linear actuator and reduce the force at the two ends of the linear actuator.

12. when the brake force demand signal indicates a demand for a reduction in force at the two ends of the linear actuator, the control unit deactivating the locking means coupled to the secondary transmission shaft; disconnecting the secondary transmission shaft from the primary transmission shaft via the first engaging means so that the secondary transmission shaft is rotatable; activating a second electric motor of the electro-mechanical assembly coupled to the secondary transmission shaft to rotate the secondary transmission shaft in a second direction of rotation of the secondary transmission shaft opposite the first direction of rotation of the primary transmission shaft; It is set up as follows:

12. The control system of claim 11, wherein rotation about the secondary transmission shaft is generated by the second electric motor to change the distance between the two ends of the linear actuator and reduce the force at the two ends of the linear actuator.

13. When the control unit detects a power supply abnormality from the power supply, rotation of the primary transmission shaft generated by the kinetic energy stored by the flywheel is transmitted to the first electric motor; the kinetic energy transmitted by the flywheel is converted into electrical energy by the control system; The control system of claim 10 , wherein the converted electrical energy is used by the control system to power the control unit of the control system.

14. The electromechanical assembly comprising: a linear actuator provided to actuate the braking system, a linear actuator extendable from a first retracted position in which two ends of the linear actuator are at a first distance to a second extended position in which the two ends of the linear actuator are disposed at a second distance greater than the first distance; Further comprising: the control unit is configured to receive a braking force request signal; when the brake force demand signal indicates a demand for an increase in force at the two ends of the linear actuator, the control unit: deactivating the locking means coupled to the secondary transmission shaft; The secondary transmission shaft is rotatably connected to the primary transmission shaft via the first engagement means, rotatably connecting the flywheel to the primary transmission shaft via second engagement means of the electromechanical assembly; It is set up as follows: rotation of the primary transmission shaft is generated by the kinetic energy stored by at least the flywheel; 10. The control system of claim 9, wherein the rotation of the primary transmission shaft (103) is transmitted to the secondary transmission shaft to change the distance between the two ends of the linear actuator and reduce the force at the two ends of the linear actuator.

15. When a decrease in the force at the two ends of the linear actuator is desired, the control unit: deactivating the locking means coupled to the secondary transmission shaft; The secondary transmission shaft is rotatably connected to the primary transmission shaft via the first engagement means; disconnecting the primary transmission shaft from the flywheel via the second engagement means so that the primary transmission shaft is rotatable; activating the first electric motor to rotate the primary transmission shaft in a second direction of rotation of the primary transmission shaft opposite the first direction of rotation of the primary transmission shaft; It is set up as follows:

15. The control system of claim 14, configured such that the rotation of the secondary transmission shaft generated by the first electric motor changes the distance between the two ends of the linear actuator to reduce the force at the two ends of the linear actuator.

16. When the control unit detects a loss of power from the power supply, the control unit disconnecting the secondary transmission shaft from the primary transmission shaft via the first engagement means so that the secondary transmission shaft is rotatable; the flywheel is rotatably connected to the primary transmission shaft via the second engagement means; It is set up as follows: rotation of the primary transmission shaft generated by the kinetic energy stored by the flywheel is transmitted to the first electric motor; the kinetic energy transmitted by the flywheel is converted into electrical energy by the control system; The control system of claim 14 , wherein the converted electrical energy is used by the control system to provide the power to the control unit of the control system.

17. When the brake force demand signal indicates a demand for maintaining force at the two ends of the linear actuator, the control unit: disconnecting the first engagement means to disconnect the secondary transmission shaft so that the secondary transmission shaft is rotatable from the primary transmission shaft; activating the locking means coupled to the secondary transmission shaft to stop the rotation of the secondary transmission shaft, keeping the distance between the two ends of the linear actuator constant, and keeping the force at the two ends of the linear actuator constant; 12. The control system of claim 11, wherein:

18. 1. A braking system for a rail vehicle, comprising: an electromechanical assembly for braking the railcar, the electromechanical assembly comprising a flywheel arranged to store kinetic energy sufficient to operate the electromechanical assembly for at least one emergency brake application, service brake application or parking brake application of the braking system; a control system for the electromechanical assembly; braking means arranged to apply a braking force directly or indirectly to at least one wheel of the railway vehicle; Equipped with the application of the braking force is controlled by extension and retraction of a linear actuator of the electromechanical assembly; the linear actuator is extendable from a first retracted position in which two ends of the linear actuator are at a first distance to a second extended position in which the two ends of the linear actuator are disposed at a second distance greater than the first distance; A braking system, characterized in that the linear actuator is arranged to operate the braking system.

19. a lever system interposed between said linear actuator and said braking means; The lever system connected to the two ends of the linear actuator; controlling the braking force applied by the braking means as a function of the distance between the two ends of the linear actuator; 20. The braking system of claim 18, wherein:

20. The braking force applied by the braking means is increasing as the distance between the two ends of the linear actuator decreases and decreasing as the distance between the two ends of the linear actuator increases; Or, The braking force applied by the braking means is 20. The braking system of claim 18, wherein the force increases as the distance between the two ends of the linear actuator increases and decreases as the distance between the two ends of the linear actuator decreases.

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