CA2922789C

CA2922789C - Safety wheel assembly for a guided vehicle

Info

Publication number: CA2922789C
Application number: CA2922789A
Authority: CA
Inventors: Peter Timan
Original assignee: Bombardier Transportation GmbH
Current assignee: Alstom Transportation Germany GmbH
Priority date: 2016-03-03
Filing date: 2016-03-03
Publication date: 2017-01-03
Anticipated expiration: 2036-03-03
Also published as: BR102016030378A2; AU2016247193A1; BR102016030378B1; CN107150698B; CA2922789A1; CN107150698A; AU2016247193B2

Abstract

A guide wheel assembly, especially for use on a guided vehicle such as a monorail, comprises a hub, a guide wheel, a tire and a safety wheel. The guide wheel assembly is adapted to be mounted to a spindle mounted to a bogie of the vehicle. The guide wheel assembly is adapted to be located on a side of a guide beam guiding the vehicle. The hub has a guide wheel mounting interface and a safety wheel mounting interface spaced apart along its length. The hub is adapted to spin on the spindle. The guide wheel is mounted to the hub at the guide wheel mounting interface. The tire is mounted on the guide wheel. The safety wheel is rotatably mounted on the hub at the safety wheel mounting interface. The safety wheel has a smaller circumference than a circumference of the tire. In case the tire deflates, the safety wheel is operative to roll on the guide beam at a different radial speed than the tire.

Description

,.
= 1 SAFETY WHEEL ASSEMBLY FOR A GUIDED VEHICLE
FIELD OF THE INVENTION
[0001]
The present invention generally relates to the field of run-flat safety devices for tires used on guided vehicles such as a monorail. More specifically, the invention relates to a guide wheel assembly having a safety wheel positioned outside the guide wheel where the safety wheel may spin independently from the guide wheel.
BACKGROUND OF THE INVENTION

[0002]
Punctured, deflated and flat tires have been around for as long as tires have existed. Flat tires are still a problem today. Whereas a flat tire may sometimes simply represent an annoyance, in some other cases, a flat tire may represent a real threat. To cope with the dangers and annoyances of a flat tire, many concepts have been suggested. Some of these concepts use a solid or somewhat deformable safety wheel placed inside the tire. However, changing the tire in such an assembly is more cumbersome than when there is no safety wheel inside the tire. Exterior safety wheels, bolted to the wheel have also been suggested. However, this solution still suffers from being somewhat intricate when it comes time to change a damaged or worn tire, which first requires disassembling the safety wheel. Moreover, this solution is prone to skidding a deflated or flat tire and safety wheel on their respective rolling surfaces since the tire does not have the same circumference as the smaller safety wheel.

[0003]
There is therefore a need for an improved guide wheel and safety wheel assembly.
SUMMARY OF THE INVENTION

[0004]
It is an object of the present invention to provide a guide wheel assembly for a guided vehicle such as a monorail that overcomes or mitigates one or more disadvantages of known guide wheel assemblies, or at least provides a useful alternative.

[0005] The invention provides the advantages of making it possible to change a damaged or worn tire without having to disassemble the safety wheel.
Moreover, the invention prevents skidding a deflated tire or safety wheel on the tire's or safety wheel's respective running surfaces, thereby preventing further degrading the tire's or the safety wheel's condition as well as preventing degrading the running surface on which the tire and safety wheel roll.

[0006] In accordance with an embodiment of the present invention, there is provided a guide wheel assembly for a bogie of a guided vehicle such as a monorail vehicle where the monorail vehicle is operative to run on a guide beam.
The bogie has at least two vertical guide wheel spindles adapted to be located on a different side of the guide beam. The guide wheel assembly comprises a hub, a guide wheel, a tire and a safety wheel. The hub has a guide wheel mounting interface and a safety wheel mounting interface spaced apart along its length.

The hub is adapted to be rotatably mounted on one of the guide wheel spindles of the bogie. The guide wheel is mounted to the hub at the guide wheel mounting interface. The tire is mounted on the guide wheel. The safety wheel is rotatably mounted on the hub at the safety wheel mounting interface. The safety wheel spins on a safety wheel bearing, such as a plain bearing, placed between the safety wheel and the hub. The safety wheel has a smaller circumference than a circumference of the tire. So in case the tire deflates, the safety wheel is operative to roll on the beam at a different radial speed than the tire.

[0007] Optionally, the guide wheel may be removably mounted on the hub and the safety wheel may have a conical web to better clear the tire.

[0008] In accordance with another embodiment of the present invention, there is provided a bogie for guiding a guided vehicle such as a monorail vehicle on a guide beam. The bogie comprises a bogie frame, a load wheel, at least two guide wheel spindles and corresponding at least two guide wheel assemblies.
The load wheel is attached to the bogie frame and supports the monorail vehicle on the guide beam. Each one of the at least two guide wheel spindles extends vertically downwardly on a different side of the bogie frame. Each guide wheel assembly, being mounted to a different guide wheel spindle, is adapted to contact a different side of the guide beam when in use. Each one of the guide wheel assemblies comprises a hub, a guide wheel, a tire and a safety wheel.
The hub has a guide wheel mounting interface and a safety wheel mounting interface spaced apart along the length of the hub. The guide wheel assemblies are rotatably mounted to their respective guide wheel spindle through their respective hub. The guide wheel is attached to the hub at the guide wheel mounting interface. The tire is mounted on the guide wheel. The safety wheel is rotatably mounted on the hub at the safety wheel mounting interface. The safety wheel spins on a safety wheel bearing, such as a plain bearing, placed between the safety wheel and the hub. The safety wheel has a smaller circumference than that of the tire. Advantageously, if the tire deflates, the safety wheel is operative to roll on the side of the beam at a different rotational speed than that of the tire.

[0009] Optionally, the guide wheel may be removably mounted on the hub proximate a free extremity of the guide wheel spindle. The safety wheel may have a conical web. Advantageously the safety wheel may be mounted on the hub adjacent and in close proximity a spindle mounting interface where the spindle is connected to the bogie frame.

[0010] In yet another embodiment of the present invention, there is provided a monorail vehicle adapted to travel on a guide beam. The monorail vehicle comprises a chassis and two bogies as already described. Each one of the two bogies are connected to the chassis proximate a different extremity of the chassis.
BRIEF DESCRIPTION OF DRAWINGS

[0011] These and other features of the present invention will become more apparent from the following description in which reference is made to the appended drawings wherein:

[0012] Figure 1 is a side view of a monorail vehicle on a guide beam showing a carbody in phantom lines in accordance with an embodiment of the present invention;

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[0013] Figure 2 is an isometric view of one bogie of the monorail vehicle of Figure 1 shown on the guide beam;

[0014] Figure 3 is a top view of the bogie of Figure 2;

[0015] Figure 4 is a side view of the bogie of Figure 2;

[0016] Figure 5 is a cross-sectional front view of a guide wheel assembly of the bogie of Figure 2 mounted on a guide wheel spindle.
DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention relates to a guide wheel assembly for a guided vehicle such as a monorail vehicle, a bogie for a monorail vehicle using such guide wheel assembly and a monorail vehicle using such a bogie.

[0018] Figure 1 is now referred to. A monorail vehicle 10 sits on a guide beam 12. The monorail vehicle 10 comprises a chassis 14 and two bogies 16.
The bogies 16 are connected to the chassis 14 at its front and rear extremities to support and guide the monorail vehicle 10 on the guide beam 12.

[0019] Figures 2 and 3 are now concurrently referred to. Each bogie 16 comprises a bogie frame 18, a load wheel 20 and at least two guide wheel assemblies 24. The load wheel 20 supports the monorail vehicle 10 on the guide beam 12 through the bogie frame 18. The bogie 16 of the present embodiment uses six guide wheel assemblies 24, which are used to keep the load wheel 20 centered on and aligned with the guide beam 12. The two lower guide wheel assemblies 25 are also known as stabilizing wheel assemblies since their role is also to stabilize the roll of the monorail vehicle 10. Structurally, they are however identical to the other guide wheel assemblies 24.

[0020] Figure 4 is now concurrently referred to. To locate each guide wheel assembly 24, the bogie 16 is equipped with at least two (six in the case depicted in the present embodiment) corresponding guide wheel spindles 22.
Figure 4 shows one such guide wheel spindle 22 where the guide wheel assembly 24 has been removed for clarity. Each one of the guide wheel spindles 22 extends vertically downwardly on both sides of the bogie frame 18. Each guide wheel assembly 24, being mounted to a different spindle 22, is adapted to contact one of the sides of the guide beam 12.

[0021] Figure 5 is now concurrently referred to. Each one of the guide wheel assemblies 24 comprises a hub 26, a guide wheel 28, a tire 30 mounted on the guide wheel 28 and a safety wheel 32 co-axially rotatably mounted to the hub 26 and co-axially aligned with the guide wheel 28.

[0022] Each guide wheel assembly 24 is rotatably mounted to its respective spindle 22 through its respective hub 26, which spins on the spindle 22 through hub bearings 44. The hub 26 has a guide wheel mounting interface 34 and a safety wheel mounting interface 36 which are spaced apart along the length (along the longitudinal axis) of the hub 26. The guide wheel mounting interface 34 may be a conventional wheel mounting interface such as a flange which may use press-fitted studs 40. In conventional fashion, corresponding holes in the guide wheel 28 may be aligned with the studs 40 so that the guide wheel 28 may be solidly mounted against the flange 38 of the guide wheel mounting interface 34 using nuts 42.

[0023] Advantageously, the guide wheel 28 may be removably mounted on the hub 36 proximate a free extremity 46 of the spindle 22. The free extremity 46 is understood to be the extremity of the spindle 22 that is not held in the bogie frame 18. In case of damage to the guide wheel 28 or to the tire 30, or simply in case a worn tire 30 needs replacing, having the guide wheel 28 mounted proximate the free extremity 46 of the spindle 22 allows an easy disassembly of the guide wheel 28 without having to remove the safety wheel 32 from the hub 26. Hence, it is conveniently possible to remove the guide wheel 28 and its tire from the hub 26, change the tire 30 much like an automobile tire is changed, and reinstall the guide wheel 28 back on the hub 26. It is therefore simpler and faster to change the tire 30. The safety wheel 32 may be mounted on the hub 26 adjacent and in close proximity to a spindle mounting interface 47 where the spindle 22 is mounted to the bogie frame.

[0024] The safety wheel 32 is rotatably mounted on the hub 26 at the safety wheel mounting interface 36 through the safety wheel bearing 48. The safety wheel bearing 48 may be any type of bearing device such as a ball bearing, roller bearing, sleeve, or simply a coating such as a Teflon coating. By mounting the safety wheel 32 independently from the guide wheel 28 and by allowing the safety wheel 32 to spin independently on the hub 26, it is possible to allow some differential rotational speed between the hub 26 and the safety wheel 32, and therefore between the safety wheel 32 and the guide wheel 28 which spins with the hub 26. This differential rotational speed between the safety wheel 32 and the guide wheel 28 is required because the safety wheel 32 has a smaller radius, and therefore a smaller circumference, than a working radius, and therefore a circumference, of the tire 30. Indeed, when adequately inflated but unloaded, the tire 30 has a tire radius and a tire circumference. When adequately inflated and under load, the tire has an effective working radius which is smaller than its unloaded radius. Hence, to prevent unduly contact with the side of the guide beam 16 when the monorail vehicle 10 is in operation, the safety wheel has to have a smaller diameter than the working diameter of the tire 30.

[0025] Advantageously, should the tire 30 deflate or become flat, or if an unusual large load compresses the tire 30 sufficiently (such as in the case of higher speeds in a curve or switch or in the case of large lateral winds), the safety wheel 32 is operative to contact and roll on the side of the beam in parallel with the tire 30 and to keep on guiding and/or stabilizing the monorail vehicle 10 and/or preventing the tire from being overloaded. Because the circumference of the tire 30 remains the same, whether inflated or flat, and because the tire still rolls on the side of the guide beam 16 even when deflated, the rotational speed of the tire 30 is lower than the rotational speed of the safety wheel 32. This differential rotational speed between the safety wheel 32 and the tire 30 therefore allows a non-skidding simultaneous contact of both the safety wheel 32 and the tire 30 with the side of the guide beam 16 when the tire 30 is deflated or flat and the safety wheel 32 contacts the side of the guide beam 16. Advantageously, because the safety wheel 32 is rotatably mounted on the hub 26, which itself spins on hub bearings 44 over the spindle 22, the safety wheel bearing 48 never acquires a large rotational speed, but rather simply spins at the differential rotational speed between the tire 30 and the safety wheel 32. This low differential rotational speed allows using cheaper bearings, such as plain bearings, and advantageously may allow a longer life.

[0026] The safety wheel may have a web 50 which may be either flat, conical as depicted in Figure 4, or have a curvilinear shape. In any case, it is preferable that the web 50 clears the shape of a flat tire 30 in order to prevent rubbing against it and degrading a side wall of the tire 30. The conical or curvilinear web 50 allows having a shorter hub 26 while still clearing the tire 30.

[0027] The present invention has been described with regard to preferred embodiments. The description as much as the drawings were intended to help the understanding of the invention, rather than to limit its scope. It will be apparent to one skilled in the art that various modifications may be made to the invention without departing from the scope of the invention as described herein, and such modifications are intended to be covered by the present description.
The invention is defined by the claims that follow.

Claims

CLAIM:

1. A guide wheel assembly for a bogie of a guided vehicle operative to run on a guide beam, the bogie having two vertical guide wheel spindles adapted to be located on a different side of the guide beam, the guide wheel assembly comprising:
a hub, said hub having a guide wheel mounting interface and a safety wheel mounting interface spaced apart along a length of said hub, said hub being adapted to be rotatably mounted on one of the guide wheel spindles of the bogie;
a guide wheel, said guide wheel being attached to said hub at said guide wheel mounting interface;
a tire, said tire being mounted on said guide wheel, said tire having a circumference;
a safety wheel, said safety wheel being rotatably mounted on said hub at said safety wheel mounting interface, said safety wheel having a smaller circumference than said circumference of said tire, wherein if said tire deflates, said safety wheel is operative to freely roll on the beam at a different radial speed than said tire.

2. The guide wheel assembly of claim 1 wherein said guide wheel is removably mounted on said hub.

3. The guide wheel assembly of claim 2 wherein said safety wheel has a conical web.

4. The guide wheel assembly of claim 1 wherein the guided vehicle is a monorail vehicle.

5. The guide wheel assembly of claim 1 further comprising a safety wheel bearing between said safety wheel and said hub, said safety wheel bearing allowing said safety wheel to spin on said hub.

6. The guide wheel assembly of claim 5 wherein said safety wheel bearing is a plain bearing.

7. A bogie for guiding a guided vehicle on a guide beam, the bogie comprising:
a bogie frame;
a load wheel, said load wheel being attached to said bogie frame for supporting the guided vehicle on the guide beam;
two guide wheel spindles, each one of said two guide wheel spindles extending vertically downwardly on a different side of said bogie frame;
two guide wheel assemblies, each one of said guide wheel assemblies being mounted to a different one of said two guide wheel spindles so as to contact a different side of the guide beam when in use, each one of said guide wheel assemblies having:
a hub, said hub having a guide wheel mounting interface and a safety wheel mounting interface spaced apart along a length of said hub, said hub being rotatably mounted on one of said guide wheel spindles;
a guide wheel, said guide wheel being attached to said hub at said guide wheel mounting interface;
a tire, said tire being mounted on said guide wheel, said tire having a circumference;
a safety wheel, said safety wheel being rotatably mounted on said hub at said safety wheel mounting interface, said safety wheel having a smaller circumference than said circumference of said tire, wherein if said tire deflates, said safety wheel is operative to freely roll on the side of the beam at a different rotational speed than a rotational speed of said tire.

8. The bogie of claim 7 wherein said guide wheel is removably mounted on said hub proximate a free extremity of said guide wheel spindle.

9. The bogie of claim 7 wherein said safety wheel has a conical web.

10. The bogie of claim 7 wherein the guided vehicle is a monorail vehicle.

11. The bogie of claim 7 further comprising a safety wheel bearing between said safety wheel and said hub, said safety wheel bearing allowing said safety wheel to spin on said hub.

12.The bogie of claim 11 wherein said safety wheel bearing is a plain bearing.

13.The bogie of claim 7 wherein said safety wheel is mounted on the hub proximate a spindle mounting interface where said spindle is mounted to said bogie frame.

14.A monorail vehicle adapted to travel on a guide beam, the monorail vehicle comprising:
a chassis;
two bogies as disclosed in claim 7, each one of said two bogies being connected to said chassis proximate a different extremity of said chassis.