JP7680202B2 - Railroad car bogies - Google Patents

Description

The present invention relates to
a) two pairs of wheels, each pair of wheels being connected to each other by an axle structure;
b) an articulated chassis, each axle structure being connected through a primary suspension means;
c) a bogie for a railway vehicle comprising secondary suspension means supported by the undercarriage, the secondary suspension means comprising at least one levelling valve.

A rail vehicle typically comprises at least one passenger car (voiture) mounted on a bogie, which may be entirely located under the car or between two adjacent cars, and may also comprise at least one passenger car (voiture de transport de passagers). A passenger car typically comprises at least one passenger compartment equipped with seats for accommodating passengers, and at least one deck separated from the passenger compartment and leading to a platform with a door for passengers to board and alight from the passenger compartment.

The load on a railway vehicle, i.e., the increase in the mass carried by the vehicle and wear on the wheels, causes fluctuations in the floor height of the passenger car, which in turn causes fluctuations in the vertical distance between the floor of the passenger car and the platform.

Such variations can cause problems when accommodating people with limited mobility on board trains. Indeed, if the vertical distance between the deck floor and the platform is too large, boarding for such people becomes difficult.

U.S. Patent No. 5,947,031 describes a bogie of the above type, which has leveling valves on each longitudinal side of the bogie, connected to the secondary suspension by rods attached to the axle boxes. The rods allow the suspension to expand or contract depending on the load on the bogie. However, the bogie described in U.S. Patent No. 5,947,031 cannot compensate for variations in carriage height due to wheel wear.

U.S. Patent No. 5,947,031

One of the aims of the present invention is to remedy this deficiency by proposing a bogie truck that takes into account load variations and wheel wear to improve passenger comfort when boarding and disembarking.

The present invention therefore relates to a bogie of the aforementioned type, comprising, for at least one of the wheels, a wheel wear detection component and a link mechanism component between the leveling valve and the wheel wear detection component, the link mechanism component being suitable for transmitting the displacement of the wear detection component to the leveling valve to control the increase or decrease of the pressure in the secondary suspension means. The present invention makes it possible, by means of the wear detection component, the link mechanism component and their arrangement with the wheels and the leveling valve, to reliably reduce the height distance between the floor of the carriage and the platform, taking into account the wear of at least one wheel, while at the same time making it possible to adjust the distance according to the load of the carriage, thereby improving passenger comfort.

According to a specific embodiment of the present invention, the bogie further has one or more of the following features, either alone or in any possible combination:

- The bogie has two longitudinal sides, each of which is provided with one wheel of each pair, the secondary suspension means comprises at least one levelling valve on each longitudinal side of the bogie, the bogie comprises, for each wheel, a wheel wear detection part and a linkage part between the levelling valve and the wheel wear detection part, the linkage part being suitable for transmitting the displacement of the wear detection part to the levelling valve to control the increase or decrease of pressure in the secondary suspension means.

- Each wear detection component is connected to a corresponding wheel via a first pin connection, and the link mechanism component is connected on the one hand to the leveling valve via a second pin connection and on the other hand to the wear detection component of the wheel via a third movable pin connection and a fourth rigid pin connection.

- Each wheel is rotatably movable about an axis, and the wheel wear detection component detects wheel wear by a reduction in the diameter of the wheel resulting in a displacement of a first pin connection of the wheel wear detection component towards the axis of rotation of the wheel.

- The levelling valve is connected via a fifth pin connection to an arm extending between the two longitudinal ends, and the arm is connected at each of its two longitudinal ends to a corresponding wheel linkage component via a second pin connection.

- The distance measured in height between the fourth rigid pin connection and the wheel axis of rotation remains approximately constant regardless of wheel wear.

- The adjustment distance measured in height between the second pin connection and the wheel axis will vary with wheel wear.

- The wheel wear detection component is connected to the chassis by a sliding connection and is provided with a spring device between the first pin connection and the fourth rigid pin connection such that the wheel wear detection component is movable only in translation in the height direction and the mechanical coupling component is rotationally movable around the fourth rigid pin connection.

- The levelling valve is configured to compensate for variations in the load of the railway passenger car combined with the bogie by controlling the pressure in the secondary suspension means to increase when the load increases and to decrease when the load decreases.

The present invention also relates to a railway carriage comprising at least one bogie according to the invention.

Other aspects and advantages of the invention will become apparent from a reading of the following description, given by way of example only and with reference to the single accompanying drawing.

FIG. 2 is a schematic side view of a bogie according to the present invention.

In the following description, the terms "upper" and "lower" refer to the normal height direction Z of the railway vehicle. Therefore, on a level ground surface, the height direction Z is approximately vertical.

The bogie truck 10 of a railway vehicle will be described with reference to Figure 1.

The bogie 10 has two pairs of wheels 12.

The wheels 12 of each pair are connected to each other by an axle structure 14, which includes an axle box 16 for each wheel 12 of the corresponding pair.

The bogie has a chassis 18. The chassis is, for example, an articulated chassis 18.

Each axle structure 14 is connected to the chassis 18 through a primary suspension means 20. The primary suspension means 20 includes coil springs, air springs, etc.

The primary suspension means 20 typically comprises one or two springs per wheel 12. In the illustrated example, the primary suspension means 20 comprises one coil spring per wheel 12. The coil springs extend in the height direction Z.

The primary suspension means 20 dampens vibrations along the height direction Z of the chassis 18 of the bogie 10 relative to the wheels 12.

The bogie 10 includes a secondary suspension means 22 supported by the chassis 18. The secondary suspension means 22 includes coil springs, air springs, or the like. The secondary suspension means 22 extends between the bogie 10 and the body 23 (shown in dashed lines in FIG. 1) of the passenger carriage of the rail vehicle.

The bogie 10 has two longitudinal sides 24 extending in the longitudinal direction L.

Each longitudinal side 24 has a respective pair of wheels 12.

The secondary suspension means 22 typically comprises one or two springs per longitudinal side 24.

In the illustrated example, the secondary suspension means 22 comprises one air spring per longitudinal side 24, approximately mid-distance between the rotation axes X of the wheels 12 located on each longitudinal side 24.

The air spring extends in the height direction Z.

The secondary suspension means 22 dampens vibrations of the passenger car body 23 along the height direction Z relative to the bogie 10.

The secondary suspension means 22 includes at least one leveling valve 26 on each longitudinal side 24 of the bogie 10.

The leveling valve 26 on the longitudinal side 24 is connected on one hand to a pressurized fluid tank (not shown) and on the other hand to a secondary suspension means on the same longitudinal side 24.

The pressurized fluid is, for example, air.

The leveling valve 26 comprises a lever 28. The lever 28 is movable between a first end position and a second end position. When the lever 28 is displaced towards the first end position, the secondary suspension means 22 located on the longitudinal side 24 of the leveling valve 26 expands.

Expansion of the secondary suspension means 22 causes an upward displacement of the floor surface of the passenger car resting on the bogie 10 along the height direction Z.

When the lever 28 is displaced toward the second end position, the secondary suspension means 22 located on the longitudinal side 24 of the leveling valve 26 contracts.

Contraction of the secondary suspension means 22 causes a downward displacement of the floor surface of the passenger car resting on the bogie 10 along the height direction Z.

In the illustrated example, the leveling valves 26 are two in number and are symmetrical about the longitudinal centerline of the chassis 18, parallel to both longitudinal sides 24 and at a mid-distance from both longitudinal sides 24.

For each wheel 12, the bogie 10 is provided with a wheel 12 wear detection part 30 connected to the wheel 12 via a first pin connection 32, and a link mechanism part 34 between the leveling valve 26 and the wheel 12 wear detection part 30.

The first pin connection 32 between the wear detection component 30 and the wheel 12 is formed by a rotating wheel having a diameter between 2% and 20% of the diameter of the wheel 12 on which it rests.

In the illustrated example, the first pin connection 32 is disposed above the wheel 12 so as to be in contact with the wheel 12 along the height direction Z.

The wear detection part 30 of the wheel 12 is connected to the chassis 18 by a sliding connection 36. This sliding connection 36 allows a translational movement of the wear detection part 30, advantageously also of the first pin connection 32, along the height direction Z, but does not allow a movement of the wear detection part 30, advantageously also of the first pin connection 32, along the longitudinal direction L.

The wear detection components 30 of the wheels 12 preferably do not have electronic components.

The link mechanism component 34 is connected to the leveling valve 26 via a second pin connection 38, while being connected to the wear detection component 30 of the wheel 12 via a third movable pin connection 40 and a fourth rigid pin connection 42.

In the illustrated example, the link mechanism component 34 is generally "Z" shaped with both ends of the branch leading to a second pin connection 38 with the leveling valve 26 on one side and a third movable pin connection 40 with the wear detection component 30 on the other side.

The link mechanism component 34 is rotatable about the rigid pin connection 42 and about an axis perpendicular to the longitudinal direction L and the height direction Z.

Preferably, the wear detection component 30 of the wheel 12 includes a coil spring 44 between the first pin connection 32 or the wear detection component 30 and the fourth rigid pin connection 42. The coil spring 44 extends in the height direction Z.

Thereby, the wear detection component 30 of the wheel 12 can only move in a translational motion in the height direction Z by displacing the sliding connection 36, and the fourth rigid pin connection 42 maintains a constant distance D with respect to the rotation axis X of the wheel 12 above which the fourth rigid pin connection is located.

Preferably, the wear detection components 30 and the linkage components 34 on the same longitudinal side 24 are symmetrical about a central vertical line of the chassis 18 that is perpendicular to both longitudinal sides 24 and is at a mid-distance from the rotation axis X of the wheel 12 on the corresponding longitudinal side 24.

Each leveling valve 26 is connected via a fifth pin connection 46 to an arm 48 extending between two longitudinal ends 50, 52.

Preferably, the fifth pin connection 46 between the leveling valve 26 and the arm 48 is positioned approximately equidistant to each of the second pin connections 38 connecting the arm 48 to each of the linkage parts 34 on the same longitudinal side 24 of the bogie 10.

This arrangement of the fifth pin connection 46 can compensate for the average wear of the wheel 12 on one longitudinal side 24.

The arm 48 is connected at each of its longitudinal ends 50, 52 to the corresponding link mechanism component 34 of the wheel 12 via a second pin connection 38.

The arm 48 is preferably telescopic, which allows for smoothing out any slight relative longitudinal movements that may occur between the axle boxes 16 while traveling.

An adjustment distance a is defined, measured in the height direction Z, between the second pin connection 38 and the rotation axis X of the corresponding wheel 12. The adjustment distance a varies depending on the diameter of the wheel 12 and therefore on the wear of the wheel 12.

The operation of the bogie truck 10 according to the present invention is described below.

When any wheel 12 wears, its diameter decreases, causing the first pin connection 32 to displace toward the rotation axis X of the wheel 12.

In particular, the first pin connection 32 is displaced downward in the height direction Z.

The wear detection component 30 of the corresponding wheel 12 is driven in translation downward in the height direction Z while displacing the sliding connection 36, stretching the coil spring 44 so that the fourth rigid pin connection 42 remains at a constant distance D from the rotation axis X of the wheel 12 above which the fourth rigid pin connection 42 is located.

Displacement of the first pin connection 32 downward in the height direction Z causes the link mechanism component 34 to undergo rotational displacement about the fourth rigid pin connection 42.

When the link mechanism part 34 is rotated about the fourth rigid pin connection 42, the corresponding second pin connection 38 is displaced upward in the height direction Z.

The adjustment distance a increases. The upward displacement of the corresponding second pin connection 38 causes the arm 48 to tilt.

The tilting of the arm 48 then causes the fifth pin connection 46 to be displaced upward in the height direction Z, thereby causing the lever 28 of the leveling valve 26 to be displaced upward.

The upward displacement of the lever 28 increases the pressure in the secondary suspension means 22 on the same longitudinal side 24. Pressurized fluid in the tank is injected into the secondary suspension means 22, causing it to expand.

This raises the floor of the carriage mounted on the bogie 10, compensating for the loss of height caused by wheel wear, thereby making it easier for passengers, especially those with reduced mobility, to get on and off the carriage.

Compensation for variations in carriage load is also achieved by the levelling valve 26, preferably by displacement of the lever 28, by increasing the pressure in the secondary suspension means 22 by injecting pressurised fluid into the secondary suspension means 22 when the load increases, or by decreasing the pressure in the secondary suspension means 22 by removing pressurised fluid from the secondary suspension means 22 when the load decreases.

This will improve passenger comfort.

The bogie 10 of the present invention also reduces maintenance costs due to wear on the wheels 12 and does not require chocks (calages).

Furthermore, the wear detection components of the wheel 12, the link mechanism components 34, and the arm 48 are all completely mechanical components, and no electronic components are required for secondary suspension height adjustment, and therefore no power source is required.

10 Bogie
12 wheels
14 Axle structure
16 Axle box
18 Chassis
20 Primary Suspension Means
22 Secondary Suspension Means
23 Body
24 Longitudinal side
26 Leveling valve
28 Lever
30 Wear detection parts
32 First pin connector
34 Link mechanism parts
36 Slipping Bond
38 Second Pin Connection
40 Third movable pin connection
42 4th rigid pin connection
44 Coil springs, spring devices
46 5th pin connection
48 Arm
50, 52 Longitudinal end
D Distance
L Longitudinal
X Rotation Axis
Z height direction
a Adjustment distance

Claims (9)

a) two pairs of wheels (12), each pair of wheels (12) being connected to each other by an axle structure (14);
b ) a chassis (18) to which each axle structure (14) is connected through a primary suspension means (20);
c) a secondary suspension means (22) carried by said undercarriage (18), said secondary suspension means (22) comprising at least one levelling valve (26),
a bogie (10) comprising, for at least one of said wheels (12), a wear detection part (30) of said wheel (12) and a link mechanism part (34) between said leveling valve (26) and said wear detection part (30) of said wheel (12), said link mechanism part being suitable for transmitting a displacement of said wear detection part to said leveling valve to control an increase or decrease of pressure in said secondary suspension means (22); and each wear detection part is connected to a corresponding one of said wheels (12) via a first pin connection (32), and said link mechanism part (34) is connected on the one hand to said leveling valve (26) via a second pin connection (38) and on the other hand to said wear detection part (30) of said wheel via a third movable pin connection (40) and a fourth rigid pin connection (42). The bogie (10) according to claim 1, wherein the bogie (10) has two longitudinal sides (24), each of which is provided with one wheel (12) of each pair, the secondary suspension means (22) is provided with at least one leveling valve (26) on each longitudinal side (24) of the bogie (10), the bogie is provided with, for each wheel, a wear detection part and a linkage part (34) between the leveling valve (26) and the wear detection part (30) of the wheel (12), the linkage part being suitable for transmitting the displacement of the wear detection part to the leveling valve to control the increase or decrease of the pressure in the secondary suspension means (22). A bogie (10) according to claim 1 or 2, wherein each wheel (12) is rotatably movable about an axis (X) and the wear detection part (30) of the wheel (12) detects wear of the wheel (12) by a reduction in the diameter of the wheel (12) resulting in a displacement of the first pin connection (32) of the wear detection part of the wheel towards the rotation axis (X) of the wheel (12). 4. The bogie (10) according to any one of claims 1 to 3, wherein the levelling valve (26) is connected to an arm (48) having two longitudinal ends (50, 52) via a fifth pin connection (46), and the arm (48) is connected at each of its two longitudinal ends (50, 52) to the link mechanism part (34) of the corresponding wheel (12) via the second pin connection (38). 5. The bogie (10) according to any one of claims 1 to 4, wherein a distance (D) measured in a height direction (Z) between the fourth rigid pin connection (42) and the axis of rotation (X) of the wheel (12) is constant regardless of wear of the wheel (12). The bogie (10) according to any one of claims 1 to 5, wherein the adjustment distance (a) measured in the height direction between the second pin connection (38) and the rotation axis (X) of the wheel (12) varies depending on wear of the wheel (12). The bogie (10) according to any one of claims 1 to 6, wherein the wear detection part (30) of the wheel (12) is connected to the chassis (18) by a sliding connection (36), and a spring device (44) is provided between the first pin connection and the fourth rigid pin connection (42) so that the wear detection part (30) of the wheel (12) is movable only in a translational movement in the height direction (Z) and the link mechanism part (34) is rotatably movable around the fourth rigid pin connection (42). The bogie (10) according to any one of claims 1 to 7, wherein the leveling valve is configured to compensate for variations in the load of a passenger car of a railway vehicle combined with the bogie by controlling the pressure in the secondary suspension means to increase when the load increases and to decrease when the load decreases. A railway passenger car comprising at least one bogie (10) according to any one of claims 1 to 8.

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