CHASSIS FOR RAIL VEHICLES

Description

[0001] The invention relates to a chassis for rail vehicles comprising a chassis frame, at least one drive motor, at least one gearbox and at least one first wheelset, which is rotatably coupled to the chassis frame, wherein the at least one drive motor is connected to the chassis frame and wherein, for the purpose of transmitting torque from the at least one drive motor via the at least one gearbox to the at least first wheelset, the at least one drive motor is coupled to the at least one gearbox and the at least one gearbox is coupled to the at least first wheelset.

[0002] Rail vehicles are subject to stringent requirements regarding energy efficiency, environmental compatibility, and the impact on infrastructure (e.g., track bed). Running gear is an essential component of a rail vehicle. Lightweight construction measures in the design and manufacturing of running gear make a significant contribution to meeting these requirements.

[0003] Reducing the unsprung mass of running gear, i.e., the mass of components such as wheelsets that load the track without a mechanical decoupling spring effect, is of great importance in order to relieve the track and reduce track damage and wear.

[0004] In this context, brake discs mounted on wheelsets should also be mentioned, which, due to their high masses (up to 130 kg per brake disc), account for a large proportion of the unsprung masses of chassis.

[0005] For example, WO 2020 / 169567 A1 is known from the prior art, which describes a lightweight wheelset for the running gear of a rail vehicle with a plurality of wheelset axle sections detachably connected to each other and to form a wheelset axle. The wheelset axle has a cavity which can be filled with a fluid for damage detection.

[0006] Furthermore, WO 2022 / 023214 A1 discloses a fluidic monitoring device for a wheelset of a railway vehicle's bogie. A sensor device is provided on one end face of the wheelset to determine fluid mass losses in a cavity within the wheelset.

[0007] Furthermore, WO 2021 / 244971 A1 describes a chassis for a rail vehicle in which a drive motor is connected to a chassis frame and to a wheelset-bearing chassis component, e.g. to a gearbox.

[0008] From EP 0308616 B1 a chassis for a rail vehicle is known, wherein a brake disc is arranged on a hollow shaft and the hollow shaft is connected to the wheelset by means of a articulated coupling.

[0009] The aforementioned approaches, in their known forms, have the disadvantage that no design solutions relating to chassis brakes are apparent with regard to reducing unsprung mass.

[0010] The invention is based on the objective of providing a chassis that is further developed compared to the prior art and includes a chassis brake arrangement that contributes to a reduction in the unsprung mass of the chassis.

[0011] According to the invention, this problem is solved by a chassis according to claim 1, in which at least one brake disc is connected to a transmission shaft of the at least one transmission, and at least one brake actuator, which can be brought into contact with the at least one brake disc, is connected to a transmission housing of the at least one transmission. This measure allows a brake disc on the first wheelset to be omitted or the number of brake discs on the first wheelset to be reduced. This significantly reduces wheelset mass. If the chassis has primary suspension between the first wheelset and the chassis frame, then mechanical decoupling of the brake disc from the first wheelset is achieved, since the transmission is coupled to the drive motor and the drive motor is connected to the chassis frame.The brake actuator is connected to the gearbox housing, resulting in a compact and therefore space-saving arrangement of the drive motor, gearbox, and brake. This space-saving arrangement allows the use of a large-diameter, lightweight tubular wheelset with a correspondingly high area moment of inertia.

[0012] Further advantageous embodiments of the chassis according to the invention are set out in the dependent claims.

[0013] For example, it is advantageous if at least one brake actuator is structurally connected to another component of the chassis or other chassis components other than the gearbox housing only indirectly, via the gearbox housing.

[0014] This results in a concentrated application of drive and braking torques to the chassis frame. Braking torques are not applied to the chassis frame independently of the application of drive torques, as the brake actuator has no direct structural connection to the chassis frame.

[0015] A preferred solution is achieved when at least one drive motor is designed as an asynchronous motor. Asynchronous motors are suitable for high speeds. By operating at a high motor speed, a lower motor torque level can be used to achieve a defined motor power output, since motor speed and torque are factors in a known formula for determining motor power. Reducing the motor torque level allows the drive motor to be made more compact and lighter. A compact drive motor can, for example, result in a smaller overall height, which can reduce the floor height of a car body under which the running gear may be located, simplify cable routing in the running gear area, and / or simplify the car body structure.

[0016] It is also helpful if at least the first wheelset has a tubular wheelset axle.

[0017] This measure results in a reduction of wheelset mass while maintaining high strength in the first wheelset. Together with other measures mentioned above, this can enable a reduction in total chassis mass of approximately 10% and a reduction in unsprung chassis mass of approximately 20%.

[0018] The wheelset axle can, for example, be designed as a forged or drawn tube.

[0019] Fluid-based detection of faults or damage to the first wheelset is made possible if the wheelset axle is sealed for filling with a fluid.

[0020] The fluid could be, for example, compressed air.

[0021] In connection with the fluid-based detection of faults or damage to the first wheelset, it is advantageous if at least one first sensor for determining fluid mass losses in a cavity of the wheelset axle is connected to the first wheelset.

[0022] This measure allows, for example, cracks or unintentionally forming openings in the wheelset axle to be detected by observing fluid leaking from the axle. This increases safety. Repairs or replacements of the wheelset axle can then be organized in a timely manner.

[0023] Fluid mass losses can be determined, for example, by measuring the fluid's pressure using a pressure sensor or by taking combined pressure and temperature measurements of the fluid using a pressure sensor and a temperature sensor, etc.

[0024] A further advantageous solution is achieved if the wheelset axle is bolted to a first wheel and a second wheel of at least the first wheelset.

[0025] This eliminates the need for a press fit between the first and second wheels on the one hand, and the wheelset axle on the other. Swapping the first and second wheels can be done with simple assembly tools (e.g., a torque wrench). A wheelset press or induction heating ovens (for creating the press fit) are not required.

[0026] A modular first wheelset, in which individual parts can be exchanged separately, is achieved if the wheelset axle has at least a first shaft part, a second shaft part and a third shaft part, wherein the first shaft part is arranged between the first wheel and the second wheel, wherein the second shaft part and the third shaft part are arranged outside an area bounded by the first wheel and the second wheel, and wherein the first shaft part is connected to the first wheel and the second wheel, the second shaft part to the first wheel and the third shaft part to the second wheel.

[0027] In connection with the modular first wheelset, it is advantageous if at least the first wheel is connected to the first shaft part and the second shaft part by means of screws, wherein the screws are arranged to be guided from the second shaft part through the first wheel into the first shaft part.

[0028] This measure can reduce the number of connecting elements required between the first wheel on the one hand and the first shaft section and the second shaft section on the other.

[0029] According to the invention, a compact drive train is achieved when a drive shaft of the at least one drive motor is coupled to the transmission shaft, wherein the transmission shaft is coupled to a first gear which is connected to the at least first gear set.

[0030] In this context, it is particularly helpful if the drive shaft is aligned parallel or approximately parallel to a transverse axis of the chassis.

[0031] This measure increases the available installation space budget perpendicular to the chassis transverse axis, which can be used, for example, to increase the diameter of the first wheelset.

[0032] The invention will now be explained in more detail using an exemplary embodiment.

[0033] It shows, for example: Fig. 1: A schematic plan view of a section of an exemplary embodiment of a chassis according to the invention with a lightweight wheel set, wherein a brake disc is connected to a transmission shaft and a brake actuator is connected to a transmission housing.

[0034] A in Fig. 1 The schematic plan shown depicts a section of an exemplary embodiment of a chassis according to the invention for a rail vehicle. The chassis comprises a chassis frame 1, a first drive-brake arrangement comprising a drive motor 2 designed as a high-speed asynchronous motor, a clutch 3, a gearbox 4 with a high gear ratio, and a chassis brake coupled to the gearbox 4, as well as a structurally, technically, and functionally identical drive-brake arrangement, in Fig. 1 The second drive-brake arrangement (not shown) is also included. Furthermore, the chassis comprises a first wheelset 5 and a... Fig. 1 The second wheelset (not shown) is rotatably coupled to the chassis frame 1 via a first wheelset guide device with a first wheelset bearing 6, which is enclosed by a first wheelset bearing housing 8, and via a second wheelset guide device with a second wheelset bearing 7, which is enclosed by a second wheelset bearing housing 9. The second wheelset is rotatably coupled to the chassis frame 1 according to the same principle.

[0035] The chassis frame 1 is additionally connected to the first wheelset bearing housing 8 via a first primary spring 10 and to the second wheelset bearing housing 9 via a second primary spring 11. The chassis frame 1 is further connected to two additional primary springs, which are located in Fig. 1 The wheelset (not shown) is connected to the second wheelset. The chassis frame 1 is thus primarily sprung and connected to the first wheelset 5 and the second wheelset. The chassis is connected to the first wheelset 5 and the second wheelset via a first secondary spring 13 connected to a cross member 12 of the chassis frame 1 and a second secondary spring 14, also connected to the cross member 12 of the chassis frame 1. Fig. 1 coupled to the car body of the rail vehicle, which is not shown.

[0036] The drive motor 2 is connected to the cross member 12 via a first motor mount 15 and a second motor mount 16. The gearbox 4 is connected to the cross member 12 via a gearbox housing 17 and a torque arm 18. For torque transmission from the drive motor 2 via the gearbox 4 to the first wheelset 5, the drive motor 2 is coupled to the gearbox 4 and the gearbox 4 to the first wheelset 5 via the coupling 3.

[0037] For this purpose, a drive shaft 19 of the drive motor 2 is coupled to the transmission shaft 20 via the coupling 3, the transmission shaft 20 being coupled to a first gear 21, which is connected to the first gear set 5. The first gear 21 is meshed with a second gear 22 connected to the transmission shaft 20.

[0038] The drive shaft 19 and the transmission shaft 20 are aligned parallel to a chassis transverse axis 23.

[0039] The gearbox housing 17 encloses the first gear 21 and the second gear 22. The gearbox shaft 20 passes through the gearbox housing 17.

[0040] The second drive-brake arrangement is connected to the chassis frame 1 according to the same principle and coupled to the second wheelset.

[0041] Outside the gearbox housing 17, on a side of the gearbox 4 facing away from the drive motor 2 and the clutch 3, a brake disc 24 of the chassis brake is connected to the gearbox shaft 20. The brake disc 24 is connected in a Fig. 1 In the braking state shown, a first brake pad 25 and a second brake pad 26 of a brake actuator 27 of the running gear brake are brought into contact, thereby braking the running gear or the rail vehicle. In a Fig. 1 In the release state of the chassis brake not shown, the first brake pad 25 and the second brake pad 26 are released from the brake disc 24.

[0042] The brake actuator 27 is a pneumatic brake cylinder, which is operated via in Fig. 1 compressed air lines not shown with a Fig. 1 The compressed air supply system of the rail vehicle, which is also not shown, is pneumatically (i.e., not structurally) connected to a system in Fig. 1 The brake piston is not visible and acts on a rotatably mounted first brake lever 28 of the brake actuator 27, to which the first brake pad 25 is connected, and on a rotatably mounted second brake lever 29 of the brake actuator 27, to which the second brake pad 26 is connected. The first brake pad 25 and the second brake pad 26 are pivotable via the first brake lever 28 and the second brake lever 29.

[0043] The brake actuator 27 is connected to the gearbox housing 17 via a support arm 30. Beyond this connection to the gearbox housing 17, the brake actuator 27 is only indirectly, namely via the gearbox housing 17, structurally connected to a component of the chassis other than the gearbox housing 17, namely the chassis frame 1.

[0044] The first wheelset 5 is designed as a lightweight wheelset for a wheelset load of 13.5 t and has a tubular, thin-walled wheelset axle 31.

[0045] The wheelset axle 31 is bolted to a first wheel 32 and a second wheel 33 of the first wheelset 5 and comprises a first shaft section 34, a second shaft section 35, and a third shaft section 36, which are designed as drawn metal tubes. The first shaft section 34 is positioned between the first wheel 32 and the second wheel 33. The second shaft section 35 and the third shaft section 36 are located outside a region bounded by the first wheel 32 and the second wheel 33. The first shaft section 34 is connected to the first wheel 32 and the second wheel 33, the second shaft section 35 to the first wheel 32, and the third shaft section 36 to the second wheel 33.

[0046] The first wheel 32 is pushed onto the second shaft part 35, the second wheel 33 onto the third shaft part 36, but not pressed on.

[0047] The first wheel 32 is connected to the first shaft part 34 and the second shaft part 35 by means of a first screw 37, wherein the first screw 37 is arranged to be guided from the second shaft part 35 through the first wheel 32 into the first shaft part 34.

[0048] The second wheel 33 is connected to the first shaft part 34 and the third shaft part 36 by means of a second screw 38, wherein the second screw 38 is arranged to be guided from the third shaft part 36 through the second wheel 33 into the first shaft part 34.

[0049] Between the first wheel 32, the first shaft section 34 and the second shaft section 35, as well as between the second wheel 33, the first shaft section 34 and the third shaft section 36, further screws are arranged, which are in Fig. 1 are not visible.

[0050] The first screw 37, the second screw 38 and the subsequent screws are inserted into through holes in the first wheel 32, the second wheel 33, the second shaft part 35 and the third shaft part 36, as well as into blind holes in the first shaft part 34.

[0051] The first wheelset bearing 6 is connected to the second shaft section 35, the second wheelset bearing 7 to the third shaft section 36. The second shaft section 35 and the third shaft section 36 function as end sections of the first wheelset 5.

[0052] The wheelset axle 31 is sealed for filling with a fluid. Fig. 1 A cavity 39 of the wheelset axle 31 is filled with fluid, wherein the fluid is compressed air. Ventilation of the wheelset axle 31 can be carried out via an opening, tightly sealed with a closure 40, which is arranged at the end face of the third axle section 36.

[0053] The first wheelset 5 is connected to a first sensor 41 and a second sensor 42 for determining fluid mass losses in the cavity 39 of the wheelset axle 31, such as those that can occur, for example, in the event of a break in the wheelset axle 31. The first sensor 41 and the second sensor 42 are arranged at the center of an end face of the second axle section 35 and project into the cavity 39.

[0054] The first sensor 41 is designed as a pressure sensor, the second sensor 42 as a temperature sensor.

[0055] The pressures and temperatures of the fluid in the cavity 39 are measured by means of the first sensor 41 and the second sensor 42, and transmitted as pressure and temperature measurement signals via an antenna 43, which is connected to the second shaft section 35, the first sensor 41 and the second sensor 42, to an evaluation unit of a [device / system - context needed]. Fig. 1 Maintenance status not shown was transmitted.

[0056] However, according to the invention, it is also possible for the evaluation device to be arranged in the rail vehicle.

[0057] Based on the pressure measurement signals and the temperature measurement signals, fluid leaks from the cavity 39, i.e. fluid mass losses in the cavity 39, are detected in the evaluation unit, and based on the fluid leaks, any damage or defects of the first wheelset 5 are detected.

[0058] Based on the temperature measurement signals, temperature dependencies of the pressures are first compensated. For this purpose, a functional relationship between pressure and temperature according to Amontons' law with a reference temperature is stored in a database of the evaluation unit. The measured pressures and temperatures are inserted into this functional relationship, and temperature-compensated pressures are then determined using the reference temperature.

[0059] If the temperature-compensated pressures fall below a defined pressure threshold, this indicates a leak and thus damage or fault of the first wheelset 5, and a warning event (e.g., a message and / or a warning symbol, etc.) is generated in the evaluation unit.

[0060] The second wheelset is structurally and functionally identical to the first wheelset 5. List of designations

[0061] 1 Chassis frame 2 Drive motor 3 Clutch 4 Gearbox 5 First wheelset 6 First wheelset bearing 7 Second wheelset bearing 8 First wheelset bearing housing 9 Second wheelset bearing housing 10 First primary spring 11 Second primary spring 12 Crossmember 13 First secondary spring 14 Second secondary spring 15 First motor mount 16 Second motor mount 17 Gearbox housing 18 Torque arm 19 Drive shaft 20 Gearbox shaft 21 First gear 22 Second gear 23 Chassis transverse axle 24 Brake disc 25 First brake pad 26 Second brake pad 27 Brake actuator 28 First brake lever 29 Second brake lever 30 Support arm 31 Wheelset axle 32 First wheel 33 Second wheel 34 First shaft section 35 Second shaft section 36 Third shaft section 37 First screw 38 Second screw 39 Cavity 40 Closure 41 First sensor 42 Second sensor 43 Antenna

Claims

1. Chassis for rail vehicles with a chassis frame (1), at least one drive motor (2), at least one transmission (4) and at least one first wheelset (5), which is coupled to the chassis frame (1) in a rotatable manner, wherein the at least one drive motor (2) is connected to the chassis frame (1) and wherein in order to transmit torque from the at least one drive motor (2) via the at least one transmission (4) to the at least first wheelset (5), the at least one drive motor (2) is coupled to the at least one transmission (4) and the at least one transmission (4) is coupled to the at least first wheelset (5), wherein at least one brake actuator (27) which can be brought into contact with at least one brake disc (24) is connected to a transmission housing (17) of the at least one transmission (4), characterised in that the at least one brake disc (24) is connected to a transmission shaft (20) of the at least one transmission (4), and wherein, in order to achieve a compact drive train, a drive shaft (19) of the at least one drive motor (2) is coupled to the transmission shaft (20), wherein the transmission shaft (20) is coupled to a first gear wheel (21) which is connected to the at least first wheelset (5).

2. Chassis according to claim 1, characterised in that the at least one brake actuator (27) is only indirectly structurally connected via the transmission housing (17), beyond its connection to the transmission housing (17), to another component of the chassis or other components of the chassis other than the transmission housing (17).

3. Chassis according to claim 1 or 2, characterised in that the at least one drive motor (2) is embodied as an asynchronous motor.

4. Chassis according to one of claims 1 to 3, characterised in that the at least first wheelset (5) has a wheelset shaft (31) which is designed in the shape of a tube.

5. Chassis according to claim 4, characterised in that the wheelset shaft (31) is designed to be sealed in order to be filled with a fluid.

6. Chassis according to claim 5, characterised in that the fluid is compressed air.

7. Chassis according to claim 5 or 6, characterised in that at least one first sensor (41) is connected to the at least first wheelset (5) in order to determine fluid mass losses in a cavity (39) of the wheelset shaft (31).

8. Chassis according to one of claims 4 to 7, characterised in that the wheelset shaft (31) is screwed to a first wheel (32) and a second wheel (33) of the at least first wheelset (5).

9. Chassis according to claim 8, characterised in that the wheelset shaft (31) has at least a first shaft part (34), a second shaft part (35) and a third shaft part (36), wherein the first shaft part (34) is arranged between the first wheel (32) and the second wheel (33), wherein the second shaft part (35) and the third shaft part (36) are arranged outside of a region delimited by the first wheel (32) and the second wheel (33), and wherein the first shaft part (34) is connected to the first wheel (32) and the second wheel (33), the second shaft part (35) is connected to the first wheel (32) and the third shaft part (36) is connected to the second wheel (33).

10. Chassis according to claim 9, characterised in that at least the first wheel (32) is connected to the first shaft part (34) and the second shaft part (35) by means of screws, wherein the screws are arranged guided from the second shaft part (35) through the first wheel (32) into the first shaft part (34).

11. Chassis according to claim 9 or 10, characterised in that a first wheelset bearing (6) is connected to the second shaft part (35) and a second wheelset bearing (7) is connected to the third shaft part (36).

12. Chassis according to one of claims 1 to 11, characterised in that the drive shaft (19) is aligned parallel or approximately parallel to a chassis transverse axis (23).

13. Chassis according to one of claims 1 to 12, characterised in that the drive shaft (19) is coupled to the transmission shaft (20) via a coupling (3).

14. Chassis according to one of claims 1 to 13, characterised in that the chassis frame (1) is connected with a primary spring-loaded suspension to the at least first wheelset (5).