WO1997007006A1

WO1997007006A1 - Vehicle compartment structure

Info

Publication number: WO1997007006A1
Application number: PCT/GB1996/001843
Authority: WO
Inventors: Stephen Richard Watson; Christopher Francis Roots
Original assignee: Normalair-Garret (Holdings) Limited
Priority date: 1995-08-19
Filing date: 1996-07-29
Publication date: 1997-02-27
Also published as: AU6625196A; GB9517055D0

Abstract

A structure (10) comprising a load or passenger carrying compartment of a vehicle having a ventilating apparatus internal for moving air between a first environment (13) and a second internal environment (14) along an air flow path (15), the air regulating means (11; 12) comprising a rotatable member (16; 17) rotatable by a drive means (35) about an axis (A; B) of rotation, and the member (16; 17) having a plurality of generally axially extending elements (18; 19) which extend generally outwardly of the axis of rotation (A; B) and the elements (18; 19) being spaced from one another by axially extending spaces (S; S') between each pair of the elements, the arrangement being such that as the member (16; 17) is rotated, each of the elements (18; 19), in turn, engages a reaction surface (21; 22) to cause a volume of air to be moved from the first (13) or second (14) environment and be driven into the second (14) or first (13) environment.

Description

Title: Vehicle Compartment Structure

Description of the Invention

This invention relates to a structure comprising a load or passenger carrying compartment of a vehicle having a ventilating apparatus for moving air. The structure may for example comprise a passenger coach of a train.

When a train travels through a tunnel for example, or when two trains e.g. travelling in opposite directions, pass one another, there is a local change in air pressure (pressure surge) externally of the train which, if allowed to be communicated to the interior of the passenger coach(es), can cause passenger discomfort.

One known way of overcoming the problems of such pressure surges, is to sense the pressure externally of a passenger coach, and to close an air flow path which otherwise provides for the introduction of air to the ventilating or air conditioning system, by means of a shutter-like device. In order to maintain some level of introduction of air into the passenger coach, a by-pass compressor may be provided which is made operative when the air flow path is closed by the shutter device. In this way the rate of air introductory to the passenger coach will not significantly be affected by pressure surges.

However, such known systems are complex, overly heavy and bulky.

Another known system uses a fan which produces a high pressure rise such that pressure surges do not affect the air flow rate. However such systems consume high power.

According to a first aspect of the invention we provide a structure comprising a load or passenger carrying compartment of a vehicle having a ventilating apparatus for moving air between an external first environment and an internal second environment along a gas flow path, the ventilating apparatus including an air regulating means, comprising a rotatable member rotatable by a drive means about an axis of rotation, and the member having a plurality of generally axially extending elements which extend generally outwardly of the axis of rotation and the elements being spaced from one another by axially extending spaces between each pair of the elements, the arrangement being such that as the member is rotated, each of the elements, in turn, engages a reaction surface to cause a volume of air to be removed from the first or second environment and be driven into the second or first environment respectively.

Thus utilising the present invention, by rotating the rotatable member at a generally constant speed, a generally constant volume of air per unit time can be moved between the first and second environments, e.g. into or out of a passenger coach, which is substantially unaffected by any external pressure surge or the like.

The ventilating apparatus can be made comparatively compact and light, whilst allowing the functions of air movement and pressure surge protection to be combined into one simple device, and such an apparatus will consume relatively low power.

Preferably, as the member is rotated, a consecutive pair of the elements engage the reaction surface simultaneously to entrap a volume of air from the first or second environment substantially equal to the volume of the space between the pair of elements, and as the member continues to rotate the volume of air is released into the second or first environment.

In a preferred arrangement a pair of rotatable members are provided which are rotatable about generally parallel axes, and are relatively positioned such that the outwardly extending elements of the members mesh, the elements of each member engaging with a respective reaction surface such that each of the pair of rotatable members is operative to move air between the first and second environments, and the meshing elements provide a seal between the pair of rotatable members.

Such an arrangement simplifies sealing of the rotatable members with respect to the gas flow path. In this case, each of the members may comprise a gear-like member and the generally outwardly and generally axially extending elements may thus comprise gear teeth.

Some means may be provided to close each axial end of the or each rotatable member so that air cannot flow between the first and second environments, other than as result of the or each of the members rotating.

The drive means may be adapted to drive the or at least one of the members at a generally constant relatively predetermined speed typically 2-3000 r.p.m., so that a generally constant volume of air per unit of time is moved from the first to the second environment.

For example, the apparatus may enable a volume of air of say, between 1000 and 2000 cubic metres per hour to be moved.

However, the rate of rotation may be controlled so that a desired amount of air is moved between the first to the second environments, per unit of time.

Preferably, where a pair of rotatable members are provided, each is adapted to be driven by an external drive means, such as timing glass, rather than one of the members driving the other. It has been found that the noise generated can be reduced to a minium by such an arrangement.

The structure may include two or more air regulating apparatus, at least one being operative to move air from the first external environment into the compartment, and at least another being operative to move air out of the compartment into the first external environment. Preferably the flow of air into the second environment is arranged to about equal to the flow of air from the second environment such that the air pressure within the compartment remains generally constant.

Thus fresh air can constantly be supplied to the compartment and stale air exhausted from the compartment, irrespective of external pressure surges. Preferably the air regulating apparatus are spaced from one another so that air is introduced into the structure at a first position and is removed from the compartment at a second, spaced, position.

According to a second aspect of the invention we provide a method of moving air between an external first environment and an internal second environment of a load or passenger carrying compartment of a vehicle along an air flow path utilising a ventilating apparatus including an air regulating means comprising a member adapted to be rotated by a drive means about an axis of rotation the member having a plurality of generally axially extending elements which extend generally outwardly of the axis of rotation and the elements being spaced from one another by axially extending spaces between each pair of the elements, and there being a reaction surface with which each of the elements engages as the rotatable member is rotated, the method comprising the steps of rotating the rotatable member such that each of the outwardly extending elements, in turn, engages the reaction surface to cause a volume of air to be removed from the first or second environment and be driven into the second or first environment respectively.

Preferably the rotatably member is rotated substantially continuously.

The invention will now be described with reference to the accompanying drawings in which:-

Figure 1 is an illustrative view of a structure comprising a passenger coach of a train, according to the invention;

Figure 2 is an enlarged end view of a ventilating apparatus, for use in the structure of Figure 1; and

Figure 3 is a side view of the apparatus of Figure 2.

Referring to the drawings there is shown a structure 10 which comprises in this example a compartment of a passenger coach of a train. The compartment 10 is generally closed although in use some air may pass into and from the structure 10 via doors to the structure as passengers enter and leave.

The structure 10 comprises an air conditioning system including a first ventilating apparatus 11 which is adapted to move air from an external environment 13 into the interior 14 of the structure 10, and a second ventilating apparatus 12 which is adapted to move air out of the structure 14 into the external environment 13.

Each ventilating apparatus 11 and 12 is substantially identical, and hence only one apparatus, apparatus 11 will be described in more detail with reference to Figures 2 and 3.

Each apparatus 11, 12 for moving air is located in a respective air flow path 15 and comprises a pair of rotatable members 16 and 17. The members 16 and 17 each comprise generally gear-like members each rotatable about a respective axis of rotation A and B. T e axes A and B are generally parallel and so axially extending elements 18 on the member 16, and elements 19 on the member 17, mesh as indicated. Thus the members 16 and 17 rotate in opposite directions to one another.

The axially extending elements 18, 19 nine on each member in this example, are spaced from each other on the respective rotatable members 16 and 17, by axially extending spaces 20. Preferably there are at least five such elements 18,19 on each member 16,19.

As the two members 16 and 17 rotate, whilst the axially extending elements 18 and 19 mesh, a tip of each axially extending element 18, 19 in turn, engages a respective reaction surface 21 and 22. The reaction surfaces 21, 22 each present an engagement part which is curved, having a radius generally equal to the radii of the respective elements 18, 19. It will be appreciated that as the axially extending elements 18 of rotatable member 16 rotate clockwise as seen in the drawing, they will each in turn come into contact with reaction surface 21. The tips of a consecutive pair of the elements 18 can simultaneously engage the reaction surface 21 to entrap a volume of air therebetween. As the member 16 continues to rotate, a volume of air will be moved from the first environment 13, which in this example is the exterior of the structure 10, into the second environment 14 which in this example is the interior space 14 of the structure 10.

Similarly the axially extending elements 19 of rotatable member 17, will, as the rotatable member 17 rotates in an anti-clockwise rotation, each in turn engage with the reaction surface 22. It can be seen in Figure 2 that a consecutive pair of the elements 19, i.e. the elements indicated at 19a and 19b_ are simultaneously engaging the reaction surface 21 to entrap a volume of air in the space S defined between the consecutive teeth 19a_. and 19b, and the reaction surface 22. As the member 17 continues to rotate in its anti-clockwise sense, the volume of air in space S will be released into the second environment 14.

By utilising the present invention, where the members 16 and 17 are rotated at a generally continuous at a constant speed, a generally constant volume of air per unit time can be moved from the first 13 to the second 14 environment i.e. from the exterior 13 to the interior 14 of the passenger coach or the like. Furthermore, any pressure surges or the like occurring locally at the exterior 13 of the structure 10 will not be communicated to the interior 14 of the structure.

In the example shown, only one of the rotatable elements 16, 17, i.e. element 17, is driven from an appropriate motive means 25 comprising in this example an electrical motor. The other rotatable member 16 may be driven by virtue of the axially extending elements 18 and 19 meshing, although any other suitable means to drive the second rotatable member 16 may be provided such as external timing gears. In any event preferably both elements 16,17 are driven by external means so as to reduce noise which may otherwise be produced and to reduce wear on the axially extending elements 18,19.

In one example the rotatable members 16, 17 were arranged to be rotated at about 2,500 r.p.m and the members 16, 17 together, moved a volume of about 1,750 cubic metres of air per hour, from the first to the second environment. If desired a clutch may be provided so that drive may be disconnected between the motor 25 and the rotatable member 17 when required, or the output shaft of the motor 25, indicated at M, may be directly coupled to a driven shaft Ml of the rotatable member 17 as indicated at 26 in Figure 2.

Means such as gaskets 27 are provided to provide a seal at each axial end of each rotatable member 16 and 17, to prevent air from flowing from the exterior 13 into the interior 14 of the structure other than as a result of the members 16, 17 rotating. It will be appreciated that the axially extending elements 18 and 19 meshing will provide a seal between the rotatable members 16 and 17.

It will be appreciated that the axially extending elements 18,19 may, when meshing, be arranged to have a minimal gap between them to avoid wear, or the meshing surfaces of the elements 18,19, or at least one of them, may have a seal provided thereon. For example an adhesive tape may be applied thus to provide a near fluid tight seal between the meshing elements 18,19.

The outline form of the elements 18,19 need not be as shown in the drawings but preferably the elements 18,19 are designed so that when meshing a minimal amount of air is returned from the environment indicated at 14 to the environment indicated at 13.

Whereas the apparatus 11 is adapted to move air from the exterior 13 to the interior 14 of the structure 10, the apparatus 12 is adapted to move air from the interior of the structure 10 the exterior 13. Preferably the two apparatus 11 and 12 operate together so that the volume of air per unit time moved into the structure 10 is generally equal to the volume of air moved out of or exhausted from the structure 10 by the apparatus 12. In this way, the pressure of air within the structure will remain generally constant.

Whereas as described, the two apparatus 11 and 12 are both part of an air conditioning system, in another arrangement, the apparatus 11 and 12 may be part of a simple air ventilating system. In each case, fresh air is drawn in by apparatus 11 and stale air is exhausted via apparatus 12. In the arrangement shown in the drawings, the apparatus 11 which is operative to move air into the structure 10 is spaced from the apparatus 12 which is operative to move air out of the structure 10. In the example shown, apparatus 11 is positioned towards an upper region of the structure 10 whilst apparatus 12 is positioned closer to a lower end of the structure 10. Preferably the apparatus 11 and 12 are also displaced along the passenger coach or other vehicle compartment to which the invention is applied. In this way, a flow of air through the structure 10 can occur, e.g. via ventilating shafts or the like.

If desired, a plurality of apparatus like apparatus 11 for moving air into the structure 10 and a plurality of apparatus like apparatus 12 for moving the air out of the structure 10 may be provided, rather than the single units described, and these may be positioned together or apart. The lengths of the rotatable members 16 and 17 may be arranged to be any desired size, and hence the volume of air per unit time which is moved by each of the apparatus 11 and 12, can be adapted to a desired level.

Of course the speed of the motors 25 may be controllable so that the volume of air moved into and out of the structure 10 can be adjusted, e.g. to suit the requirements of the air conducting and/or ventilation system.

Various further modifications may be made without departing from the scope of the invention. For example, although in the arrangement described a pair of rotatable members 16 and 17 are described, a ventilating apparatus for a structure in accordance with the invention may utilise only one or more than two such rotatable members, with there being appropriate means to prevent air being drawn back from the second environment 14 into the first environment 13 as the apparatus operates.

In the example described above, the elements 18,19 which move the air are axially extending straight along their respective rotatable members 16,17. In another example, the elements 18,19 may extend helically about their respective axles of the rotatable members 16,17. The axially extending teeth 18,19 may be made of metal, but a suitable plastic material is proffered.

Although the invention has been specifically developed for use for an air conditioning or air ventilating system of a passenger coach of a train, the invention may be applied to any other vehicle or load or passenger carrying compartment of a vehicle, or any other structure which preferably is substantially closed, where an air ventilating and/or air conditioning system is required.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A structure comprising a load or passenger carrying compartment of a vehicle having a ventilating apparatus for moving air between an external first environment and an internal second environment along a gas flow path, the ventilating apparatus including an air regulating means comprising a rotatable member rotatable by a drive means about an axis of rotation, and the member having a plurality of generally axially extending elements which extend generally outwardly of the axis of rotation and the elements being spaced from one another by axially extending spaces between each pair of the elements, the arrangement being such that as the member is rotated, each of the elements, in turn, engages a reaction surface to cause a volume of air to be removed from the first or second environment and be driven into the second or first environment respectively.

2. A structure according to claim 1 wherein as the member is rotated, a consecutive pair of the elements engage the reaction surface simultaneously to entrap a volume of air from the first or second environment substantially equal to the volume of the space between the pair of elements, and as the member continues to rotate the volume of air is released into the second or first environment.

3. A structure according to claim 1 or claim 2 wherein a pair of rotatable members are provided which are rotatable about generally parallel axes, and are relatively positioned such that the outwardly extending elements of the members mesh, the elements of each member engaging with a respective reaction surface such that each of the pair of rotatable members is operative to move air between the first and second environments, and the meshing elements provide a seal between the pair of rotatable members.

4. A structure according to claim 3 wherein each of the members comprises a gear-like member and the generally outwardly and generally axially extending elements comprise gear teeth.

5. A structure according to any one of the preceding claims wherein means are provided to close at each axial end of the or each rotatable member so that air cannot flow between the first and second environments other than as result of the or each of the members rotating.

6. A structure according to any one of claims 1 to 5 wherein the drive means is adapted to drive the or at least one of the members at a generally constant predetermined speed so that a generally constant volume of air per unit of time is moved between the first and second environments.

7. A structure according to any one of claims 3 to 6 where appendent to claim 3 wherein each of the rotatable members is driven by an external drive means.

8. A structure according to anyone of claims 1 to 7 which includes two air regulating apparatus, one being operative to move air from the external first environment into the internal second environment and the other being operative to move air out of the internal second environment into the external first environment.

9. A structure according to claim 8 wherein the flow of air into the second environment is arranged to about equal to the flow of air from the second environment such that the air pressure within the second environment remains generally constant.

10. A structure according to claim 8 or claim 9 wherein the air regulating apparatus are spaced from one another so that air is introduced into the second environment at a first position and is removed from the second environment at a second, spaced, position.

11. A method of moving air between an external first environment and an internal second environment of a load or passenger carrying compartment of a vehicle along an air flow path utilising a ventilating apparatus including an air regulating means comprising a member adapted to be rotated by a drive means about an axis of rotation the member having a plurality of generally axially extending elements which extend generally outwardly of the axis of rotation and the elements being spaced from one another by axially extending spaces between each pair of the elements, and there being a reaction surface with which each of the elements engages as the rotatable member is rotated, the method comprising the steps of rotating the rotatable member such that each of the outwardly extending elements, in turn, engages the reaction surface to cause a volume of air to be removed from the first or second environment and be driven into the second or first environment respectively.