Rail vehicle transmission

Abstract

The invention relates to a railway vehicle transmission (1) comprising an output shaft (2) for coupling with drive wheels of a railway vehicle carrying the railway vehicle transmission (1), and a feed pump (11) comprising a piston (14), wherein the feed pump (11) draws lubricant and / or coolant from a reservoir (12) located vertically below the railway vehicle transmission (1) during translational stroke movements of the piston (14) and delivers it into a supply line (20). The piston (14) engages a stroke contour (26) which is rotationally fixed to the output shaft (2) and has a variable profile, whereby the stroke contour (26) converts a rotation of the output shaft (2) into the stroke movements of the piston (14) via its variable profile.Furthermore, the feed pump (11) is arranged at a radial distance to the output shaft (2) in the area of ​​the reservoir (12), wherein the stroke contour (26) is formed on an annular disk (23) which is fixed to the output shaft (2) and extends radially to the feed pump (11) to bridge the radial distance from the output shaft (2).

Description

[0001] The invention relates to a railway vehicle transmission comprising an output shaft, which is provided for coupling with drive wheels of a railway vehicle incorporating the railway vehicle transmission, and a feed pump comprising a piston, wherein, during translational stroke movements of the piston, the feed pump draws lubricant and / or coolant from a reservoir located vertically below the installation position of the railway vehicle transmission and delivers it into a supply line, wherein the piston engages a stroke contour which is rotationally fixed to the output shaft and has a variable profile, whereby the stroke contour, via its variable profile, converts a rotation of the output shaft into the stroke movements of the piston. The invention further relates to a railway vehicle drive train with the aforementioned railway vehicle transmission.

[0002] In gearboxes, bearings and gear meshes are typically supplied with lubricant and coolant to ensure adequate lubrication and cooling in their respective areas. The lubricant and coolant supplied is usually oil. Apart from immersion or spray lubrication, a feed pump is often used to supply the lubricant and coolant. This pump draws the lubricant and coolant from a reservoir and delivers it—usually via intermediate lines—to the supply area(s). Such a feed pump is often driven by a motor upstream of the gearbox.However, particularly in vehicle transmissions, operating situations arise where an output-side component of the transmission is towed while decoupled from the stationary input side, for example, when the vehicle is being towed or when the vehicle is only powered by part of its drive system. Since an input-side pump would not deliver any fluid in this case, resulting in a lack of or insufficient supply to the output-side components, some vehicle transmissions are equipped with output-side pumps, which are usually permanently connected to one of the output-side components of the transmission.

[0003] German patent application DE 10 2014 220 309 A1 discloses a vehicle transmission in which a feed pump is driven via an output shaft. The output shaft transmits torque from the drive of a vehicle containing the transmission to the drive wheels. A section of the output shaft is also provided with a stroke contour that has a variable profile. A piston of the feed pump, which is arranged radially adjacent to the output shaft and is connected to a lubricant reservoir via a supply line, engages this stroke contour. The stroke contour mechanically converts the rotation of the output shaft into stroke movements of the piston, causing the feed pump to draw lubricant from the reservoir and deliver it to a supply line.

[0004] From DE 1 757 482 U and US 3 618 712 A, a differential gear for a vehicle is known in which a pump driven via an eccentric stroke contour supplies a bearing of an input shaft of the respective differential gear with lubricant.

[0005] US Patent 4,352,301 A further discloses a differential gear for a vehicle, comprising a piston pump assembly driven by a stroke contour arranged on a final drive shaft of the differential gear. Lubricating components, including the bearings of the final drive shafts, are supplied by this piston pump assembly via long supply lines.

[0006] Starting from the prior art described above, the object of the present invention is to create a rail vehicle transmission in which a reliable supply via a feed pump is ensured even in the case of towing on the output side, and this should be achieved with the lowest possible manufacturing effort.

[0007] This problem is solved starting from the preamble of claim 1 in conjunction with its characterizing features. The subsequent dependent claims each describe advantageous embodiments of the invention. A vehicle drive train in which a rail vehicle transmission according to the invention is provided is further the subject of claim 9.

[0008] According to the invention, a railway vehicle transmission comprises an output shaft, which is designed for coupling with drive wheels of a railway vehicle carrying the transmission, and a feed pump comprising a piston. During translational stroke movements of the piston, the feed pump draws lubricant and / or coolant from a reservoir located vertically below the transmission in its installed position and delivers the lubricant and / or coolant into a supply line. The piston then strikes a stroke contour that is rotationally fixed to the output shaft and has a variable profile, whereby the stroke contour, through its variable profile, converts the rotation of the output shaft into the stroke movements of the piston.

[0009] The rail vehicle transmission according to the invention thus provides an output shaft, wherein this output shaft is connected to a transmission output in the rail vehicle transmission by being coupled to the drive wheels of a rail vehicle in the installed state of the rail vehicle transmission, in whose drive train the rail vehicle transmission according to the invention is arranged. Preferably, a permanent coupling with the drive wheels is established at the output shaft in the installed state of the rail vehicle transmission, so that rotations of the drive wheels also necessarily cause a rotation of the output shaft and vice versa.

[0010] The vehicle transmission according to the invention is a rail vehicle transmission, i.e., the vehicle transmission is intended for use in a motor vehicle designed as a rail vehicle. Most preferably, the rail vehicle is a passenger train.

[0011] The rail vehicle transmission according to the invention also includes a feed pump which, when driven, draws lubricant and / or coolant from a reservoir and delivers it to a supply line. In the vehicle transmission, the reservoir is located in a vertically downward-facing area when the transmission is installed, allowing lubricant and / or coolant to accumulate there. The lubricant and / or coolant delivered by the feed pump is, in particular, a liquid used for cooling or lubrication, or both, of at least one supply area of ​​the rail vehicle transmission. Oil is especially preferred as the lubricant and / or coolant.

[0012] For conveying the lubricant and / or coolant, the pump is equipped with a piston capable of translational stroke movements. These stroke movements occur primarily between bottom dead center and top dead center, with the suction of the lubricant and / or coolant from the reservoir being preferably achieved in one stroke direction between the piston's dead centers, while the displacement of the lubricant and / or coolant into the supply line is achieved in the other, opposite stroke direction between the piston's dead centers.

[0013] According to the invention, the pump is drivenly coupled to the output shaft by means of a rotationally fixed connection between the output shaft and a stroke contour, against which the pump piston also runs. Furthermore, the stroke contour has a variable profile, so that the piston running against the stroke contour and the combined rotation of the stroke contour with the output shaft mechanically converts the rotation of the output shaft into the translational stroke movements of the piston. The drive connection between the pump and the output shaft is thus designed like a cam mechanism, whereby a rotational movement of the output shaft is converted into a translational movement of the piston via the stroke contour.

[0014] Due to the permanent coupling of the piston's movement with the output shaft, the rail vehicle transmission according to the invention delivers fluid via the feed pump as soon as the output shaft rotates. Since this coupling is achieved purely mechanically by means of the stroke contour, rotation of the output shaft automatically results in the delivery of lubricant and / or coolant into the supply line, thus supplying at least one supply area of ​​the rail vehicle transmission. Therefore, in certain operating situations where, due to appropriate switching within the rail vehicle transmission, a connection to a drive side of the transmission is severed, but output-side drag occurs, the supply can still be achieved.Such an operating situation could involve, for example, towing the motor vehicle or operating the rail vehicle via a drive train of the rail vehicle that is parallel to the rail vehicle transmission.

[0015] The invention now comprises the technical teaching that the feed pump is arranged in the reservoir area at a radial distance from the output shaft. Furthermore, the stroke contour is formed on an annular disk which is rotationally fixed to the output shaft and extends radially from the output shaft to the feed pump to bridge the radial distance.

[0016] In other words, in the rail vehicle transmission according to the invention, the feed pump is arranged radially spaced from the output shaft and is located in the reservoir area, i.e., in a vertically downward-facing region of the rail vehicle transmission when installed. Furthermore, an annular disc is provided, which is attached to the output shaft with a rotationally fixed connection and bridges the radial distance between the output shaft and the feed pump by extending radially from its attachment point on the output shaft to the feed pump. The annular disc is also designed with a stroke contour and thus establishes the drive coupling between the output shaft and the feed pump by ensuring that the pump piston is in contact with the annular disc at its stroke contour.

[0017] This design of a rail vehicle transmission offers the advantage of enabling reliable drive of the feed pump via the output shaft using the intermediate annular disc. Furthermore, the feed pump can be easily positioned radially within the reservoir. The intermediate annular disc bridges the radial gap resulting from this placement, thus ensuring the feed pump is driven via the output shaft. Due to the feed pump's closer radial position to the reservoir, the suction line connecting the pump to the reservoir can be shortened or even eliminated entirely, reducing manufacturing costs. Additionally, the stroke contour no longer needs to be machined on the output shaft itself, but is instead defined by the annular disc.The latter can be achieved simply and with a further reduction in manufacturing effort. Furthermore, the feed pump can generally ensure reliable delivery of lubricant and / or coolant even at lower temperatures and the associated higher viscosity of the fluid. Overall, a rail vehicle transmission can be realized in which the rotation of an output shaft automatically and purely mechanically drives a feed pump located in the vicinity of a reservoir.

[0018] "Radial" refers to a direction in the diameter of the output shaft, while "axial" means a direction parallel to a rotation axis of the output shaft.

[0019] According to the invention, the ring disc is fixed to the output shaft in a rotationally fixed manner, which, within the scope of the invention, means that the ring disc is rigidly connected to the output shaft in the direction of rotation. Preferably, the ring disc, which is a separate component from the output shaft, is held firmly to the output shaft, at least in the direction of rotation, by means of fasteners, which are particularly in the form of screw connections.

[0020] According to one embodiment of the invention, the stroke contour is formed with a radially variable profile on an outer circumference of the ring disk, with the piston contacting the stroke contour radially. In this case, the piston then performs its translational stroke movements in a radial direction or radially oriented. Alternatively, within the scope of the invention, it would also be conceivable for the stroke contour to have an axially variable profile, with the stroke contour then being formed on an axial side of the ring disk. In this case, the piston would then contact the stroke contour axially and perform its translational stroke movements in an axial direction or axially oriented.

[0021] According to one embodiment of the invention, the stroke contour is formed by an eccentric section of the ring disk. In this case, the ring disk thus has an eccentrically designed section, which allows the variable path of the stroke contour to be implemented in a simple manner.

[0022] In one embodiment of the invention, the feed pump is located within the reservoir. This has the advantage that a suction line between the feed pump and the reservoir can be completely eliminated, since the feed pump is arranged directly in the reservoir and can thus draw lubricant and / or coolant directly from the reservoir. In particular, the feed pump is positioned with one suction side in a region of the reservoir that, in the installed position of the rail vehicle transmission, forms the lowest vertical point of the reservoir.

[0023] As an alternative to the aforementioned embodiment, the feed pump is located adjacent to the reservoir, with the feed pump and the reservoir being connected to each other via an intermediate suction line. This allows the inventive design to be easily retrofitted to an existing gearbox with only minor modifications, by providing the ring disk on the output shaft and also by placing the feed pump, which is in contact with the ring disk at its piston, in the area of ​​the reservoir.

[0024] According to the invention, the supply line extends from the feed pump into a region which, in the installed position of the rail vehicle transmission, lies vertically above at least one supply area. The supply line in this region has at least one outlet opening through which lubricant and / or coolant can be dispensed. According to the invention, the at least one supply area includes a bearing for the output shaft, and preferably, at least primarily, the supply of lubricant and / or coolant to the output shaft bearing is provided by means of exactly one supply line. This is particularly important when the output shaft is dragged on the output side, as it is essential to ensure an adequate supply to the output shaft bearing. According to the invention, the supply line runs axially overlapping and radially surrounding the annular disk. This allows the supply to be implemented in a compact installation space.

[0025] In a further embodiment of the invention, the piston is guided in a housing so as to be translationally displaceable and, together with the housing, defines a pressure chamber at its end face. A suction channel and a pressure channel open into this pressure chamber. The suction channel is connected to the reservoir and, at its opening in the pressure chamber, is provided with a first check valve that allows lubricant and / or coolant to flow from the suction channel into the pressure chamber and prevents backflow of lubricant and / or coolant from the pressure chamber into the suction channel. The pressure channel is connected to the supply line and has a second check valve at its opening in the pressure chamber. This second check valve allows lubricant and / or coolant to flow from the pressure chamber into the pressure channel and prevents backflow of lubricant and / or coolant from the pressure channel into the pressure chamber.This advantageously allows for the realization of a suitable setup in which the translational stroke movements of the piston result in the intake and subsequent displacement of lubricant and / or coolant into the supply line.

[0026] In a further development of the aforementioned embodiment, the housing is formed by a pump housing which is mounted on a gearbox housing of the rail vehicle transmission. This allows the feed pump to be easily positioned in the reservoir area, and also enables retrofitting by subsequently installing the feed pump.

[0027] According to one embodiment of the invention, the piston is pre-tensioned against the stroke contour by a spring element. This advantageously ensures that the piston is constantly in contact with the stroke contour. In particular, the spring element is a helical spring, which is preferably supported on one side by a head of the piston and on the other side by the housing. In combination with the variant described above, in which the housing is formed by a pump housing, the pump housing provides a corresponding bearing area for the spring end of the spring element. However, apart from a helical spring, other spring element designs could also be used.

[0028] The invention also relates to a rail vehicle drive train comprising a rail vehicle transmission according to one or more of the variants described above. In this rail vehicle drive train, the output shaft of the rail vehicle transmission is permanently coupled to drive wheels.

[0029] An advantageous embodiment of the invention, which is explained below, is illustrated in the drawings. They show: Fig. 1 and Fig. 2 sectional views of a part of a vehicle transmission according to a preferred embodiment of the invention; and Fig. 3 Another sectional view of a detail of the vehicle transmission from the Fig. 1 and Fig. 2.

[0030] From the Fig. 1 and Fig. Figure 2 shows sectional views of a part of a vehicle transmission 1, which is a railway vehicle transmission. The vehicle transmission 1 is shown in the area of ​​an output shaft 2, which is rotatably mounted in a multi-part transmission housing 4 via a bearing 3. When the vehicle transmission 1 is installed in a railway vehicle drive train, a permanent coupling to the drive wheels of the associated railway vehicle, preferably a passenger train, is established at the output shaft 2. The bearing 3 of the output shaft 2 is formed in this case by two tapered roller bearings 5 ​​arranged in an X configuration.

[0031] At a first shaft end 6, the output shaft 2 is provided radially on the outside with a drive tooth 7, which serves as the output-side interface for the coupling to the drive gears. At a second shaft end 8, located opposite this, the output shaft 2 forms a connecting flange 9, on which a radially inwardly oriented drive tooth 10 is formed. At this drive tooth 10, the output shaft 2 is non-rotatably connected to a component (not shown) located upstream of the vehicle transmission 1. In the engaged state, this component is coupled to a transmission input of the vehicle transmission 1 via a dog clutch (also not shown), thereby also coupling the output shaft 2 to the transmission input. At the transmission input of the vehicle transmission 1, a coupling to at least one upstream drive motor is established.

[0032] By disengaging the claw coupling, the output shaft 2 can be decoupled from the transmission input, thereby also decoupling the drive wheels coupled to the output shaft 2 from the at least one drive motor via the vehicle transmission 1. However, in this decoupled state, under certain operating conditions of the rail vehicle, such as towing in the event of damage or when powered by another drive system of the rail vehicle, the output shaft 2 is also set into rotation due to its permanent coupling with the drive wheels. To ensure sufficient lubrication of the bearing 3, the vehicle transmission 1 is also equipped with a feed pump 11, which is located in a reservoir 12.This reservoir 12 is designed in a vertically downward-lying area through the gearbox housing 4 in the installed position of the vehicle gearbox 1 and serves to accumulate lubricant and coolant, which is oil.

[0033] The feed pump 11, which is in Fig. Figure 3, which is shown in more detail, comprises a pump housing 13 in which a piston 14 is slidably guided. The piston 14 can perform translational stroke movements in the pump housing 13 between an upper dead center and a lower dead center, the piston 14 being pre-tensioned towards its upper dead center by a spring element 15, which is supported at one end by the pump housing 13 and at the other end by a head 16 of the piston 14.

[0034] On an end face facing away from the head 16, the piston 14, together with the pump housing 13, defines a pressure chamber 17 into which a suction channel 18 and a pressure channel 19 open. While the suction channel 18 opens into the reservoir 12 at an end facing away from the pressure chamber 17, the pressure channel 19 connects to a supply line 20. Check valves 21 and 22, designed as ball check valves, are also provided at the openings of the suction channel 18 and the pressure channel 19 in the pressure chamber 17. Check valve 21 allows oil to flow from the suction channel 18 into the pressure chamber 17, while preventing the reverse flow from the pressure chamber 17 into the suction channel 18. The check valve 22 allows oil to flow from the pressure chamber 17 into the pressure channel 19 and prevents oil from flowing back from the pressure channel 19 into the pressure chamber 17.

[0035] When the piston 14 moves towards its top dead center, it increases the size of the pressure chamber 17, drawing oil from the reservoir 12 into the pressure chamber 17 via the suction channel 18. Conversely, when the piston 14 moves towards its bottom dead center, the pressure chamber 17 decreases, causing oil to be displaced from the pressure chamber 17 through the open check valve 22 into the pressure channel 19 and thus into the supply line 20. Therefore, the pump 11 is designed as a piston pump.

[0036] In this arrangement, the feed pump 11 is mechanically driven via the output shaft 2 by means of an intermediate annular disk 23, which is rotationally fixed to the connecting flange 9 of the output shaft 2 by means of screw connections 24. This annular disk 23 bridges a radial gap that exists between the connecting flange 9 of the output shaft 2 and the feed pump 11 due to the arrangement of the feed pump 11 in the reservoir 12. To bridge this gap, the annular disk 23 extends radially outwards from the connecting flange 9 of the output shaft 2, and is equipped radially outwards with an eccentric section 25 that defines a radially variable stroke contour 26 on its outer circumference.

[0037] The piston 14 of the feed pump 11 is radially pre-tensioned against this stroke contour 26 by the spring element 15, so that the piston 14 is permanently in radial contact with the stroke contour 26. When the output shaft 2 rotates, the annular disk 23 rotates together with the output shaft 2 due to the rotationally fixed connection with the connecting flange 9. This rotation of the annular disk 23 is converted into radial stroke movements of the piston 14 between its dead centers via the radially varying path of the stroke contour 26. As a result, even when the output shaft 2 is dragged on the output side by the drive wheels of the rail vehicle, the feed pump 11 is driven, and thus oil is pumped into the supply line 20.

[0038] As particularly in Fig.As can be seen in Figure 2, the supply line 20 runs from the connection to the feed pump 11 into a vertically oriented area at the top when the vehicle transmission 1 is installed. In this area, the supply line 20 forms at least one outlet opening 27, through which the oil supplied can flow out and subsequently downwards vertically into the area of ​​the bearing 3. Accordingly, when the output shaft 2 is pulled, the bearing 3 is supplied with oil. The supply line 20 is arranged axially overlapping and radially surrounding the ring disk 23.

[0039] The inventive design provides a rail vehicle transmission in which a supply of lubricant and / or coolant via a feed pump is ensured even during output-side towing, and this is achieved with low manufacturing costs. Reference sign 1 Railway vehicle gearbox 2 Output shaft 3 Storage 4 Gearbox housings 5 tapered roller bearings 6 Wave end 7 Drive gear 8 Wave end 9 Connecting flange 10 Drive gear 11. Pump 12 Reservoir 13 Pump housings 14 pistons 15 spring element 16 heads 17 Printing room 18 Suction channel 19 Pressure channel 20 Supply line 21 Check valve 22 Check valve 23 Ring disc 24 screw connections 25 eccentric section 26 stroke contour 27 Outlet opening

Claims

[1] Railway vehicle transmission (1) comprising an output shaft (2) for coupling with drive wheels of a railway vehicle having the railway vehicle transmission, and a feed pump (11) having a piston (14), wherein the feed pump (11) draws lubricant and / or coolant from a reservoir (12) located vertically below in the installation position of the railway vehicle transmission (1) during translational stroke movements of the piston (14) and delivers it into a supply line (20), wherein the piston (14) contacts a stroke contour (26) which is rotationally fixed to the output shaft (2) and has a variable profile, whereby the stroke contour (26) converts a rotation of the output shaft (2) into the stroke movements of the piston (14) via its variable profile, characterized by, that the feed pump (11) is arranged at a radial distance from the output shaft (2) in the area of ​​the reservoir (12), that the stroke contour (26) is formed on an annular disk (23) which is rotationally fixed to the output shaft (2) and extends radially to the feed pump (11) to bridge the radial distance from the output shaft (2), that the supply line (20) extends from the feed pump (11) into an area which, in the installed position of the rail vehicle transmission (1), lies vertically above at least one supply area, that the supply line (20) has at least one outlet opening (27) in the area through which lubricant and / or coolant can be dispensed, that the at least one supply area includes a bearing (3) of the output shaft (2), and that the supply line (20) runs axially overlapping and radially surrounding the annular disk (23). [2] Railway vehicle transmission (1) according to claim 1, characterized by , that the stroke contour (26) is formed with a radially variable profile on an outer circumference of the ring disk (23) and the piston (14) runs radially against the stroke contour (26). [3] Railway vehicle transmission (1) according to claim 1 or 2, characterized by , that the stroke contour (26) is formed by an eccentric section (25) of the ring disc (23). [4] Railway vehicle transmission (1) according to at least one of claims 1 to 3, characterized by , that the pump (11) is located in the reservoir (12). [5] Railway vehicle transmission (1) according to at least one of claims 1 to 3, characterized by , that the pump is located adjacent to the reservoir, with the pump and the reservoir being connected to each other via an intermediate suction line. [6] Railway vehicle transmission (1) according to at least one of the preceding claims, characterized by, that the piston (14) is guided translationally displaceable in a housing and, together with the housing, defines a pressure chamber (17) at its end face, into which a suction channel (18) and a pressure channel (19) open, wherein the suction channel (18) is connected to the reservoir (12) and is provided at its opening into the pressure chamber (17) with a first check valve (21), which allows the flow of lubricant and / or coolant from the suction channel (18) into the pressure chamber (17) and prevents the backflow of lubricant and / or coolant from the pressure chamber (17) into the suction channel (18), and wherein the pressure channel (19) is connected to the supply line (20) and has a second check valve (22) at its opening into the pressure chamber (17),which allows the flow of lubricant and / or coolant from the pressure chamber (17) into the pressure channel (19) and prevents the backflow of lubricant and / or coolant from the pressure channel (19) into the pressure chamber (17). [7] Railway vehicle transmission (1) according to claim 6, characterized by , that the housing is formed by a pump housing (13) which is mounted on a gearbox housing (4) of the vehicle gearbox (1). [8] Railway vehicle transmission (1) according to at least one of the preceding claims, characterized by , that the piston (14) is pre-tensioned against the stroke contour (26) via a spring element (15). [9] Railway vehicle drive train comprising a railway vehicle transmission according to at least one of the preceding claims, wherein the output shaft of the railway vehicle transmission is permanently coupled to drive wheels.

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