Poznan University of Technology. DEng. Wojciech Sawczuk

Transcription

1 FACULTY OF MECHINES AND TRANSPORT Institute of Combustion Engines and Transport D E P A R T M E N T O F R A I L V E H IC L E S Poznan University of Technology Przegląd konstrukcji tarczowych układów hamulcowych oraz wybrane zagadnienia z jego eksploatacji Overview of disc brake system design and selected issues from its operation DEng. Wojciech Sawczuk wojciech.sawczuk@put.poznan.pl Poznan, 29 November

2 Przyspieszenie [m/s2] Przyspieszenie [m/s2] Przyspieszenie [m/s2] PRESENTATION PLAN Introduction Okladzina G1=35[mm] 1. General construction of rail vehicles 0 2. Construction of bogie of rail vehicles 3. Types of brakes in rail vehicle Czas [s] Okladzina G2=25[mm] 4. Characteristics of the brakes 5. Operational problems in the brakes 0 Conclusion Czas [s] 1000 Okladzina G3=15[mm] Czas [s] 2

3 Tramp Solaris Tramino S105p Electric multiple unit EZT Pesa ELF model N76 Electric Locomotive Pafawag ET-22 Passenger car type 136AMg Subway type Siemens Inspiro High Speed Train Alsthom AGV 3

4 General construction of rail vehicles In the construction of rail vehicles, we can identify the body and chassis vehicle. Chassis of a rail vehicle is mostly bogie. Body vehicle Chassis 4

5 General construction of rail vehicles Chassis Bogies of rail vehicles Traction engine Passenger cars Boxcar 5

6 Construction of bogie of rail vehicles Beam on the second stage suspension The second stage of suspension Frame Damper The first stage of suspension Brake disc Base of bogie of rail vehicle 6

7 Types of brakes in rail vehicle With Z NAPĘDEM manual RĘCZNYM drive Vacuum PRÓŻNIOWE Direct BEZPOŚREDNIE Automatic AUTOMATYCZNE MECHANICZNE Mechanical Pneumatic PNEUMATYCZNE Direct BEZPOŚREDNIE Electro-pneumatic ELEKTROPNEUMATYCZNE Compressed air ZASILANE SPRĘŻONYM POWIETRZEM Automatic AUTOMATYCZNE The brakes URZĄDZENIA of rail HAMULCOWE vehicles Electrodynamic ELEKTRODYNAMICZNE REZYSTOROWE Resistor Recuperative REKUPERACYJNE SPRĘŻYNOWE Spring parking PARKINGOWE Eddy WIROPRĄDOWE current ELEKTROMECHANICZNE Electromechanical SZYNOWE ELEKTROMAGNETYCZNE Electromagnetic rail 7

8 Force of braking Fb [kn] Force of braking Fb [kn] Characteristic of the brakes Blending simultaneous use of several brakes Electrodynamic brake P=Fb v=constant Speed v [km/h] View of passenger car and bogie of rail vehicle Hydrodynamic brake Speed v [km/h] 8

9 Force of braking Fb [kn] Characteristic of the brakes Blending simultaneous use of several brakes Missing the braking force The desired (required) braking force Speed v [km/h] 9

10 The characteristics of constructional solutions of the rail disc brake The disc brake systems utilized in carriages and locomotives have various designs of brake discs. In regard of the brake disc design, the disc brakes can be divided into disc brakes with ventilation canals and full disc brakes non-ventilated. In regard of giving up heat, disc brakes with ventilation fans and disc bakes with ventilation rods are used. Disc with ventilation fans Characteristic of the brakes Full disc non-ventilated Disc with ventilation rods 10 10

11 Characteristic of the brakes The disc brake systems are used in three variants in carriages and locomotives: a) on axle between wheels b) on wheels c) outside the wheels. a) b) c) a) b) c) 11

12 Characteristic of the brakes Speed train v<200km/h 2 brake disc on axle of wheelset 12

13 Characteristic of the brakes Speed train v<280km/h Prędkość 3 brake pociągu disc v < on 280[km/h]- axle of wheelset 3 tarcze hamulcowe na osi zestawu kołowego 13

14 Characteristic of the brakes Speed train v>300km/h 4 brake disc on axle of wheelset 14

15 Okladzina G1=35[mm] Operational problems in the brakes Problems during operation disc brakes Czas [s] Noise and vibration generated by the brake Okladzina G2=25[mm] Hot spots Third layer Micro-crack Energy losses on ventilation Czas [s] Okladzina G3=15[mm] 15

16 A RMS [m/s 2 ] Przyspieszenie [m/s2] A RMS [m/s 2 ] Przyspieszenie [m/s2] A RMS [m/s 2 ] Przyspieszenie [m/s2] Operational problems in the brakes - noise and vibration generated by the brake a) Okladzina G1=35[mm] b) Time Czas [s] [s] Okladzina G2=25[mm] c) Time Czas [s] [s] 1000 Okladzina G3=15[mm] Time Czas [s] [s] Timing instantaneous acceleration vibration mounts with pads of varying thickness with visible resonance vibrations: a) thickness of pad G1=35mm, b) ) thickness of pad G2=25mm, c) ) thickness of pad G3=15mm 16

17 Operational problems in the brakes - noise and vibration generated by the brake The experimentally determined vibration frequencies of described brake system elements will be used to create regressive and structural diagnostic models, which enable an assessment of material consumption in brake system parts using the analysis of vibration signals recorded on the holder brake pads. To create described models, it would be the best to apply those frequencies for that are for each element, in the present case it is a band of 4,4-4,6kHz. Table 1 Estimated value of the resonant frequency of vibration elements/units of the rail disc brake. Element/unit Frequency [khz] Disc 3,0 4,0 4,2 4,5 4,7 5,8 6,2 Clamp without pads 4,0 4,5 5,9 6,2 Braking pad 4,5 4,7 5,1 5,8 Clamp with pads 3,0 3,5 4,2 4,5 4,7 6,7 An impulsive test on the brake disc: a) view of a PULSE multianalyzer on the position with a slung object of the research, b) fixing scheme of the vibration transducers on the disc, c) view of a brake disc during the impulsive test with the vibration transducers, r w - inner radius of the disc, r z - the outer radius of the disc, P 1,2,3 - vibration transducers 17

18 Operational problems in the brakes hot spots Unevenness of distribution of pressure pad brake disc, also show held in parallel with the research for the first time on the post of the drum - thermal imaging studies. Figure shows the distribution of average temperature on brake disc. There are imager shield at different times braking. View of camera IR research stationary test: a) distribution of temperature on the shield at the beginning of braking, b) temperature on the shield at 10 second, braking, c) temperature on the shield at 20 second, braking, d), temperature on the shield at the stop (v=0) 18

19 Operational problems in the brakes hot spots Figures show pad pressure distribution model from the organic material type FR20.H.2 in a function of braking time for both; the stopping brakes and for brakes with a constant power. Pressure distribution models of the pad to the brake disc based on the results of the thermal tests for braking speeds: a) v = 50km/h, b) v = 80 km/h, c) v = 120 km/h, d) v = 160 km/h 19

20 Operational problems in the brakes hot spots Pressure distribution models of the pad to the brake disc based on the results of the thermal tests for braking speeds: a) v = 200 km/h at N = 36 kn, b) v = 200 km/h at N = 25kN c) v = 80 km/h, braking with constant power P = 45 kw 20

21 Operational problems in the brakes third layer The variation of coefficient of friction also indicates Figure 5, where during the pad break-in at constant v, N, M and T disc, in a series of 40 brakes, different μ Average values were obtained. Simultaneous braking time registration causes that the fluctuation of the average coefficient of friction within the range of 0,310 to 0,380 directly influences the changes of deceleration time in the range of 37 to 47 seconds. Results from the pad break-in in the series of 40 brakes 21

22 Operational problems in the brakes third layer View of the friction pads with the out of rounds (third layer): a) the 175 pad type to the brake disc, b) the 200 pad type to the brake disc, c) The K-type brake insert to the block brake, d) Example of the out of round from the K- type block Fluctuations in the instantaneous coefficient of friction are associated with the formation of a third layer beneath the pad, resulting from the pad and disc wear products. This problem either occurs in passenger cars equipped only with a disc brake where the brake lasts from the speed of the beginning of braking until it stops and also electric multiple units, in which the disc brake is activated in the last phase of braking at a speed of about 10km/h with a low pad pressure to the disc.

23 Operational problems in the brakes third layer However, the operation of the friction of them put on the example of the French Railways SNCF TGV showed that the problem of having a third layer on the surface of pad is current. View of elements of the brake disc switch with TGV Duplex: a) the pad of sintered metal, (b) a set of wheel stroller Y237b

24 Operational problems in the brakes micro-crack Damage to the brake discs, a) schematic division, 1- single-sided crack on the whole disc brake breadth, 2- double-sided crack on the whole disc brake breadth, 3- crack on a part of disc brake breadth, 4- concavities, 5- surface cracks, 6-grooves, 7-spallings, b) crack view across the width of the brake disc c) crack view on the part of the friction ring, d) view of the surface crack

25 Operational problems in the brakes micro-crack The surface cracks (micro cracks) on the ring rail brake disc: a) a grid view of micro cracks on the segment of the BK141 disc type, b) a cross-section through a crack with a length of 64 mm, c) a cross-section through a crack with a length of 24 mm, d) the cross-section through the crack length of 40 mm.

26 Operational problems in the brakes energy losses on ventilation The discs with rotating blades and rods outside the energy losses on the fan are also losses due to rotation of the disc as a rigid body. Energy losses of the brake disc Losses on the fan losses of inertia 150 kg 26

27 Operational problems in the brakes energy losses on ventilation r k = 450 mm r t = 300 mm v=46 m/s v c 2 u 2 =32 m/s D w k 60 n m s 1 m u2 D2 2 s Forced ventilation Airflow under the vehicle Forced ventilation Wheelset with brake disc while driving at a speed v 27

28 Total losses and losses due to rotation of the disc [kw] Operational problems in the brakes energy losses on ventilation 4 3,5 3 Total losses and losses inertia brake disc Losses inertia Total losses 2,5 2 1,5 1 0, Speed [obr/min] 28 28

29 Poznań University of Technology Institute of Combustion Engines and Transport DEPARTMENT OF RAIL VEHICLES thank you for attention Adress: ul. Piotrowo 3, Poznań Phone: +48 (61) Fax: +48 (61)