CA-3022474-C - RAIL VEHICLE AND METHOD FOR OPERATING A RAIL VEHICLE

Abstract

The invention relates to a rail vehicle (1) having a vehicle frame (4) supported on ontrack undercarriages (2, 3) and a hydraulic drive system (6) powered by a motor (5). The drive system comprises a hydrodynamic drive (7) associated with a first on-track undercarriage (2) as well as a hydrostatic drive (8) associated with a second on-track undercarriage (3). With the latter is associated a drive pump (10) connected to a drive motor (9). The motor (5) is designed for a higher power output than is necessary for the operation of the hydrodynamic drive (7). A pump distribution gear (11) is switched between the motor (5) and the hydrodynamic drive (7), via which the drive pump (10) of the hydrostatic drive (8) can be connected. This takes place in dependence on a friction value μ between the rail (18) and wheel (19).

Inventors

• Christian WEITERSBERGER
• Christoph Kaiser

Assignees

• PLASSER & THEURER EXPORT VON BAHNBAUMASCHINEN GESELLSCHAFT M.B.H.

Dates

Publication Date

20260505

Application Date

20170526

Priority Date

20160621

Claims (4)

1. We Claim: 1. A rail vehicle (1) having a vehicle frame (4) supported on on-track undercarriages (2, 3) and a hydraulic drive system (6) powered by a motor (5), the drive system (6) comprising a hydrodynamic drive (7) arranged on a first said on-track undercarriage (2), a hydrostatic drive (8) arranged on a second said on-track undercarriage (3) and comprising a drive pump (10) connected to a drive motor (9), wherein the motor (5) is designed for higher power output than necessary for the operation of the hydrodynamic drive (7), and wherein a pump distribution gear (11) is interposed between the motor (5) and the hydrodynamic drive (7), via which the drive pump (10) of the hydrostatic drive (8) is connectable.
2. 2. The rail vehicle (1) according to claim 1, characterized in that at least one additional hydraulic pump (12) for operation of at least one additional hydraulic drive (13) for a work unit (14) is associated with the pump distribution gear (11 ).
3. 3. A method for operation of the rail vehicle (1) with the hydraulic drive system (6) according to claim 1 or 2, characterized in that the hydrostatic drive (8) is added or removed in dependence an a friction value between a rail (18) and a wheel (19). 6
4. 4. The method according to claim 3, characterized by the following steps: a) detecting a sinking friction value during operation with the hydrodynamic drive (7), b) switching the hydrostatic drive (7) on by engaging the drive pump (10) and the drive motor (9), c) increasing the output of the motor (5), d) operating the rail vehicle (1) with the hydrodynamic drive and the hydrostatic drive, e) reducing the output of the motor (5) upon exceeding a critical speed, f) switching the hydrostatic drive (8) off by disengaging the drive pump (10) and the drive motor (9), and g) operating the rail vehicle (1) with the hydrodynamic drive (7).

Description

1 Description Rail vehicle and method for operating a rail vehicle Field of technology [01] The invention relates to a rail vehicle having a vehicle frame supported on on-track undercarriages and a hydraulic drive system powered by a motor, the drive system comprising a hydrodynamic drive associated with a first ontrack undercarriage as well as a hydrostatic drive, associated with a second on-track undercarriage, with which is associated a drive pump connected to a drive motor. The invention also relates to a method for operation of said rail vehicle. Prior art [02] Rail vehicles and track maintenance machines with hydrodynamic and/or hydrostatic drive are already well known. The power required for the operation of such vehicles is the product of traction and speed. The traction, in turn, is dependent on the mass of the rail vehicle, the number of axles (total or driven) as well as on the friction value between rail and wheel. [03] Thus, WO 2015/128770 A1 describes a method for operation of a rail vehicle and a rail vehicle in which both a hydrodynamic as well as a hydrostatic transmission powered by the same motor are used either selectively or together. The use of the transmissions occurs in dependence on the travel speed and the friction rail/wheel. [04] According to DE 24 09 333 A1, a shunting locomotive is known which can be operated selectively via a hydrodynamic or a hydrostatic transmission. Summary of the invention [05] It is the object of the invention to provide a rail vehicle and a method for the operation thereof, by means of which it is possible to achieve an optimal 4 [16] the hydrodynamic drive 7 is a pump distribution gear 11. By means of the latter, the drive pump 10 of the hydrostatic drive 8 can be added. Associated with the pump distribution gear 11 is at least one additional hydraulic pump 12 for operation of at least one additional hydraulic drive 13 for a work unit 14. Examples of such work units 14 would be a crane 15, lifting platform 16 or snow blower 17. In this, the number of the additional hydraulic pumps 12 may vary inasmuch as either a separate hydraulic pump 12 is associated with each work unit 14, or one hydraulic pump 12 alternatingly drives one of the work units 14. [17] The operation of the rail vehicle 1 will now be described briefly. The operation takes place in dependence on a friction value μ between a rail 18 and a wheel 19, wherein the hydrostatic drive 8 is added or removed. [18] Generally, the rail vehicle 1 is moved mainly by means of the hydrodynamic drive 7. With the aid of a measuring device 20, the sinking friction value u is determined. Then, manual or automatic switching-on of the hydrostatic drive 8 takes place by engaging the clutch of the drive pump 10 and the drive motor 9. With increasing the output of the motor 5, the rail vehicle 1 is now operated with hydrodynamic and hydrostatic drive 7, 8. Upon exceeding a critical speed vk, the output of the motor 5 is reduced again and the hydrostatic drive 8 is switched off. This takes place by disengaging the drive pump 10 and the drive motor 9. Thereafter, the rail vehicle 1 is again powered only by the hydrodynamic drive 7. [19] As can be perceived from the diagram in Fig. 3, the critical speed vk İs approximately 50 km/h. Up to this value, a combined drive (hydrodynamic and hydrostatic) with sufficient traction Fz is possible. At higher speeds v, a friction value μ = 0,107 is already sufficient to employ the reduced motor output via the hydrodynamic drive 7.