WO2016209077A1

WO2016209077A1 - Braking device and braking system for a shaft

Info

Publication number: WO2016209077A1
Application number: PCT/NL2016/050447
Authority: WO
Inventors: Arnoldus Henricus Maria Van Aken
Original assignee: Dms Holding B.V.
Priority date: 2015-06-23
Filing date: 2016-06-23
Publication date: 2016-12-29
Also published as: NL2015014B1

Abstract

A braking device (1) for a shaft comprising a tubular body (2) that is provided with a first receiving space (3) in which the shaft is contained, in use of the braking device. The tubular body is further provided with a first cylinder (6) that is oriented in a radial direction of the tubular body and is connected with the first receiving space. In the first cylinder, a first piston (7) is provided that, in use of the braking device, can be moved into a braking and/or blocking contact with the shaft.

Description

Braking device and braking system for a shaft

The invention relates to a braking device for a shaft of, for example, an active stabilisation system for a vessel, such as a luxury yacht. Such an active stabilisation system, which is described, for example, in WO 2013/095097 Al by the inventor of the present invention, can be used to reduce the effects of the water's wave motions on the vessel, both when the vessel is moving, in particular at speeds up to and including the vessel's cruising speed, and when the vessel lies at anchor. As a consequence, the comfort of passengers on board can be improved.

When a vessel travels at a speed greater than its cruising speed, in certain situations active stabilisation is no longer necessary or even desirable. In such a situation, the stabilisation bodies of the active stabilisation system must be kept in an inactive position with respect to the vessel. When a vessel travels at a speed lower than its cruising speed, the stabilisation bodies must be kept in a certain active position with respect to the vessel, depending on the speed. The stabilisation bodies are usually connected with the vessel by means of rotary shafts. The diameter of these rotary shafts is usually in the range from 50mm to 500mm, for example 200mm.

To keep the stabilisation bodies in the above-mentioned inactive or active positions with respect to a vessel, the rotary shafts must be blocked to prevent their moving in at least one of an axial, radial or circumferential direction of the rotary shafts. For this purpose, braking devices as known from the state of the art may be used. However, if a tilt occurs between a stabilisation body's rotary shaft that is to be blocked and a braking element of a known braking device that is used in the above- mentioned application, this may at least adversely affect the performance of the braking device and lead to damage to at least one of the stabilisation system or the vessel. To avoid such a tilt, the maximum admissible clearance between the rotary shaft and the braking element is a few tenths of a millimetre. This slight maximum admissible clearance places high demands on the accuracy of the manufacturing process for known braking devices that are suitable for use in an above-mentioned active stabilisation system for a vessel. A consequence of this is that the costs of the manufacturing process for such known braking devices are higher than the costs of the manufacturing process for known braking devices that are suitable for other applications. It will be apparent that this is a drawback of the known braking devices for applications such as, for example, the above-mentioned active stabilisation system for a vessel. A further drawback of the known braking devices is that they are at least less suitable for counterbalancing a deviation in a position of the rotary shaft with respect to the known braking device in at least one of a radial or axial direction of the rotary shaft.

The invention further relates to a braking system for a shaft that comprises the braking device according to the invention.

It is an object of the invention to provide a braking device for a shaft that overcomes or at least reduces the above-described drawbacks of braking devices that are known from the state of the art.

It is a further object of the invention to provide a braking system for a shaft that comprises a braking device according to the invention.

At least one of these objects is achieved by a braking device according to the invention, in which the braking device comprises a tubular body that is provided with a first receiving space that is oriented in an axial direction of the tubular body, a first opening and a second opening that are connected with the first receiving space, in which the shaft can be positioned in the first receiving space through the first opening or the second opening. The tubular body is further provided with a first cylinder that is oriented in a radial direction of the tubular body and is connected with the first receiving space. The braking device further comprises a first piston that is provided in the first cylinder, in which the first piston comprises a side that is oriented towards the first receiving space and a side that is oriented away from the first receiving space. In use of the braking device, the first piston can be moved into at least one of a braking or blocking contact with the shaft. By using a first piston, the braking device according to the invention allows for a greater clearance between the shaft in the first receiving space and the first piston. Depending on the use, the admissible clearance between the shaft and the first piston of the braking device according to the invention can be in a range from 1mm to 50mm. Where rotary shafts of an active stabilisation system for a vessel have a diameter of, for example, 200mm, the admissible clearance is typically a few millimetres. As a result of the greater admissible clearance than in the case of known braking devices, braking devices according to the invention do not need to be manufactured by means of a manufacturing process that has the same high accuracy as the manufacturing process with which known braking devices must be manufactured for them to be usable in, for example, the above-mentioned active stabilisation device for a vessel. This means that the manufacturing costs of braking devices according to the invention can be lower than those of known braking devices that are used in the above-mentioned application.

In an embodiment of the braking device according to the present invention, the braking device further comprises a first brake shoe that is movably mounted on the side of the first piston that is oriented towards the first receiving space. An advantage of using the first brake shoe is that a maximum contact surface between the shaft and the first brake shoe can be achieved despite a possible tilt of the shaft with respect to the first receiving space of the tubular body of the braking device. As a result, the braking device according to the invention is better able to counterbalance a deviation in a position of a shaft with respect to the first receiving space in which the shaft is contained.

In an embodiment of the braking device according to the present invention, the first brake shoe is movable with respect to the first piston in at least one of a radial or axial direction of the tubular body. As a result, the first brake shoe, when, in use of the braking device, it is moved into contact with a shaft that is contained in the first receiving space, can be automatically aligned with the aforementioned shaft in at least one of a radial or axial direction of the tubular body. As a consequence of this automatic alignment of the first brake shoe with the shaft, a maximum contact surface between the first brake shoe and the shaft can be realised, as a result of which the braking or blocking of the shaft can take place as efficiently as possible. This is advantageous to the speed with which the braking device can brake a shaft, for example a rotary shaft of an active stabilisation system for a vessel, or lock it in a blocked state. The braking device according to the invention can be activated or deactivated within a few seconds. It will be clear to the person skilled in the art that the braking device according to the invention can brake and/or block a shaft in at least one of an axial, radial or circumferential direction of the tubular body.

In an embodiment of the braking device according to the present invention, the side of the first piston that is oriented towards the first receiving space comprises a concave surface and the first brake shoe has a side that is oriented away from the first receiving space and comprises a convex surface, which convex surface can be received in the aforementioned concave surface of the side of the first piston that is oriented towards the first receiving space. As a result, the first brake shoe can move with respect to the first piston in at least one of a radial or axial direction of the tubular body. As a result, the above-described automatic alignment of the first brake shoe with a shaft that, in use of the braking device, is contained in the first receiving space can be achieved.

In an embodiment of the braking device according to the present invention, the first brake shoe is provided with a first adjusting element and a second adjusting element that are arranged for adjusting a movement of the first brake shoe with respect to the first piston in an axial direction of the tubular body. The first adjusting element and the second adjusting element can be embodied as a first bolt and a second bolt, respectively, which can be sequenced between the first brake shoe and the first piston.

In an embodiment of the braking device according to the present invention, a first resilient element is provided which is arranged to position the first brake shoe in a first, neutral position with respect to the first piston. When the first brake shoe no longer makes contact or has only a non-braking or non-blocking adjoining contact with a shaft which, in use of the braking device, is contained in the first receiving space, the first brake shoe can be moved by the first resilient element, for example a draw spring, into the first, neutral position with respect to the first piston, from a second position in which the first brake shoe is moved in at least one of a radial or axial direction of the tubular body with respect to the first piston as a consequence of the automatic alignment of the first brake shoe with the shaft when these are brought into a braking or blocking adjoining contact with each other.

In an embodiment of the braking device according to the present invention, the first brake shoe has a side that is oriented towards the first receiving space, which side is provided with a first brake lining that has a concave surface that is oriented towards the first receiving space. As a result, in use of the braking device, a maximum contact surface can be formed between the first brake lining and a shaft which is contained in the first receiving space.

In an embodiment of the braking device according to the present invention, the first cylinder has a portion that is oriented away from the first receiving space and comprises a first room that can be sealed in a fluid-tight manner in a radial direction of the tubular body by the side of the first piston that is oriented away from the first receiving space and a first cover element that can be connected with the tubular body. This provides for a room in which a pressure can be built up by means of a fluid, such as oil or air, under the influence of which the first piston is movable in a radial direction of the tubular body that is oriented towards the first receiving space. The first cover element can be embodied as a lid that is connected with the tubular body.

In an embodiment of the braking device according to the present invention, an outer jacket is provided that is coaxially arranged with respect to the tubular body and comprises a first portion that is positioned across the first room of the first cylinder in a radial direction of the tubular body. The outer jacket may serve as a first cover element for sealing the first room on one side in a fluid-tight manner as described above.

Depending upon the diameter of the shaft that, in use of the braking device, is contained in the first receiving space and the braking torque that is required to brake or block the shaft, a number of separate additional cylinders may in addition to the first cylinder be applied, which are positioned equidistant along the circumference of the tubular body. In such an embodiment of the braking device, the outer jacket may serve as a joint cover element of the rooms of the separate additional cylinders. As a result, the risk of leakage of the fluid from each of the rooms of the separate additional cylinders can be reduced compared to a situation in which each room of the separate additional cylinders is sealed by a separate additional cover element.

The outer jacket can also be used to connect the braking device according to the invention with a device, such as, for example, the hull of a vessel, in which the braking device is used.

In an embodiment of the braking device according to the present invention, the first portion of the outer jacket has at least a tapered inner diameter. If the braking device can be powered hydraulically, this makes it possible to bleed the hydraulic system when filling it.

In an embodiment of the braking device according to the present invention, a second resilient element is provided that is arranged to connect the side of the first piston that is oriented away from the first receiving space with the first cover element. Once the braking device has been deactivated, this makes it possible to break an at least adjoining contact between the first brake shoe and the shaft that, in use of the braking device, is contained in the first receiving space, as a result of which the shaft is no longer braked or blocked. The second resilient element may, for example, be embodied as a leaf spring. It will be clear to the person skilled in the art that the at least adjoining contact between the first brake shoe and the shaft can also be broken in at least one of a hydraulic, pneumatic or electrical manner. In an embodiment of the braking device according to the present invention, the first brake shoe is longitudinal in an axial direction of the tubular body.

According to another aspect of the present invention, a braking device for a shaft is provided, in which the braking device comprises a tubular body that is provided with a first receiving space that is oriented in an axial direction of the tubular body, a first opening and a second opening that are connected with the first receiving space, in which the shaft can be positioned in the first receiving space through the first opening or the second opening. The tubular body is further provided with a first cylinder that is oriented in a radial direction of the tubular body. The braking device is further provided with an outer jacket that is coaxially arranged with respect to the tubular body and a first piston that is provided in the first cylinder, in which the first piston comprises a side that is oriented towards the first receiving space and a side that is oriented away from the first receiving space. In use of the braking device, the first piston can be moved into at least one of a braking or blocking contact with the outer jacket.

In this embodiment of the braking device according to the invention, the tubular body is connected with the shaft that, in use of the braking device, is contained in the first receiving space. To brake or block the shaft, the first piston is brought into a braking or blocking adjoining contact with the outer jacket. By using a first piston, the braking device according to the invention allows for a greater clearance between the outer jacket and the first piston. Depending on the use, the admissible clearance between the outer jacket and the first piston of the braking device according to the invention can be in a range from 1mm to 50mm. Where rotary shafts of an active stabilisation system for a vessel have a diameter of, for example, 200mm, the admissible clearance is typically a few millimetres. As a result of the greater admissible clearance than in the case of known braking devices, braking devices according to the invention do not need to be manufactured by means of a manufacturing process that has the same high accuracy as the manufacturing process with which known braking devices must be manufactured for them to be usable in, for example, the above- mentioned active stabilisation device for a vessel. This means that the manufacturing costs of braking devices according to the invention can be lower than those of known braking devices that are used in the above-mentioned application.

In an embodiment of the braking device according to the present invention, the braking device further comprises a first brake shoe that is movably mounted on the side of the first piston that is oriented towards the first receiving space. An advantage of the first brake shoe is that a maximum contact surface between the first brake shoe and the outer jacket can be achieved despite a possible tilt of the shaft with respect to the outer jacket.

In an embodiment of the braking device according to the present invention, the first brake shoe is movable with respect to the first piston in at least one of a radial or axial direction of the tubular body. As a result, the first brake shoe, when, in use of the braking device, it is moved into contact with the outer jacket, can be automatically aligned with the outer jacket in at least one of a radial or axial direction of the tubular body. As a consequence of this automatic alignment of the first brake shoe with the outer jacket, a maximum contact surface between the first brake shoe and the outer jacket can be realised, as a result of which the braking or blocking of the shaft can take place as efficiently as possible. This is advantageous to the speed with which the braking device can brake a shaft, for example a rotary shaft of an active stabilisation system for a vessel, or lock it in a blocked state. The braking device according to the invention can be activated or deactivated within a few seconds. It will be apparent to a person skilled in the art that the braking device according to the invention can brake and/or block a shaft in at least one of an axial, radial or circumferential direction of the tubular body.

In an embodiment of the braking device according to the present invention, the side of the first piston that is oriented away from the first receiving space comprises a concave surface and the first brake shoe has a side that is oriented towards the first receiving space and comprises a convex surface, which convex surface can be contained in the aforementioned concave surface of the side of the first piston that is oriented away from the first receiving space. As a result, the first brake shoe can move with respect to the first piston in at least one of a radial or axial direction of the tubular body. This allows for the above-described automatic alignment of the first brake shoe with the outer jacket.

In an embodiment of the braking device according to the present invention, a first resilient element is provided that is arranged to position the first brake shoe in a first, neutral position with respect to the first piston. When the first brake shoe no longer makes contact or has only a non-braking or non-blocking adjoining contact with the outer jacket, the first brake shoe can be moved by the first resilient element, for example a draw spring, into the first, neutral position with respect to the first piston, from a second position in which the first brake shoe is moved in at least one of a radial or axial direction of the tubular body with respect to the first piston as a consequence of the automatic alignment of the first brake shoe with the outer jacket when these are brought into a braking or blocking adjoining contact with each other.

In an embodiment of the braking device according to the present invention, the first brake shoe has a side that is oriented away from the first receiving space, which side is provided with a first brake lining that has a convex surface that is oriented away from the first receiving space. As a result, in use of the braking device, a maximum contact surface can be formed between the first brake lining and the outer jacket.

In an embodiment of the braking device according to the present invention, the first cylinder has a portion that is oriented towards the first receiving space and comprises a first room that can be sealed in a fluid-tight manner in a radial direction of the tubular body by the side of the first piston that is oriented towards the first receiving space and a first cover element that can be connected with the tubular body. This provides for a room in which a pressure can be built up by means of a fluid, such as oil or air, under the influence of which the first piston is movable in a radial direction of the tubular body that is oriented away from the first receiving space. The first cover element can be embodied as a lid that is connected with the tubular body.

In an embodiment of the braking device according to the present invention, an inner jacket is provided that is coaxially arranged with respect to the tubular body and comprises a first portion that is positioned across the first room of the first cylinder in a radial direction of the tubular body. The inner jacket may serve as first cover element for sealing the first room on one side in a fluid-tight manner as described above. Depending upon the diameter of the shaft and the braking torque that is required to brake or block the shaft, a number of separate additional cylinders may be applied in addition to the first cylinder, which are positioned equidistant along the circumference of the tubular body. In such an embodiment of the braking device, the inner jacket may serve as a joint cover element of the rooms of the separate additional cylinders. As a result, the risk of leakage of the fluid from each of the rooms of the separate additional cylinders can be reduced compared to a situation in which each room of the separate additional cylinders is sealed by a separate additional cover element.

In an embodiment of the braking device according to the present invention, the first portion of the inner jacket has at least a tapered inner diameter. If the braking device can be powered hydraulically, this makes it possible to bleed the hydraulic system when filling it.

In an embodiment of the braking device according to the present invention, a second resilient element is provided that is arranged to connect the side of the first piston that is oriented towards the first receiving room with the first cover element.

Once the braking device has been deactivated, this makes it possible to break an at least adjoining contact between the first brake shoe and the outer jacket, as a result of which the shaft that, in use of the braking device, is contained in the first receiving space is no longer braked or blocked. The second resilient element may, for example, be embodied as a leaf spring. It will be apparent to the person skilled in the art that the at least adjoining contact between the first brake shoe and the outer jacket can also be broken in at least one of a hydraulic, pneumatic or electrical manner.

In an embodiment of the braking device according to the present invention, the first brake shoe is longitudinal in an axial direction of the tubular body.

According to another aspect of the present invention, a braking system for a shaft is provided that comprises a first braking device according to the present invention and a first control device that is connected with the first braking device, in which the first control device is arranged to power the first braking device in at least one of a hydraulic, pneumatic, electrical or mechanical manner. The braking system according to the invention can be applied advantageously in the active stabilisation system for a vessel that has been described above by way of example.

The person skilled in the art will understand that the above-mentioned active stabilisation system for a vessel is a non-limiting example of an application in which the braking device and the braking system according to the invention can be applied advantageously and that more applications are conceivable in which a shaft can be braked or blocked advantageously by at least one of the braking device or the braking system according to the invention.

Although the invention will be described by reference to specific embodiments, the invention is not limited to these. The invention is described by reference to measures, whereby explicit advantages may be mentioned, but implicit advantages may also apply. The subject of the invention of the present application or of a divisional application can relate to any of these measures, some combinations of which are described and/or shown explicitly in this description, but may also be described implicitly. Although the figures show explicit combinations of measures, it will be clear to the person skilled in the art that a number of the measures may also be taken separately from each other.

Figure 1 shows a schematic perspective view of a first embodiment of a braking device for a shaft according to the invention.

Figure 2a shows a schematic perspective view of a first embodiment of a tubular body of a braking device according to the invention.

Figure 2b shows a schematic perspective view of the embodiment of the tubular body as shown in figure 2a, in which a first cylinder of the tubular body is sealed by means of a first cover element.

Figure 3 shows a schematic perspective view of a second embodiment of the tubular body of the braking device according to the invention.

Figure 4a shows a schematic perspective view of an embodiment of a piston of the braking device according to the invention. Figure 4a shows in particular a side of the piston which, when the piston is mounted in a cylinder of the braking device as shown in figure 2a, is oriented away from the first receiving space of the tubular body.

Figure 4b shows a schematic perspective view of the embodiment of the piston as shown in figure 4a, but from a side of the piston which, when the piston is mounted in a cylinder of the braking device as shown in figure la, is oriented towards the first receiving space of the tubular body.

Figure 5a shows a schematic perspective view of an embodiment of a brake shoe of the braking device according to the invention. Figure 5a shows in particular a side of the brake shoe which, when the brake shoe is mounted in the braking device, is oriented towards the first receiving space of the tubular body.

Figure 5b shows a schematic perspective view of the embodiment of the brake shoe as shown in figure 5a, but from a side of the brake shoe which, when the brake shoe is mounted in the braking device, is oriented away from the first receiving space of the tubular body.

Figure 6 shows a schematic perspective view of a second embodiment of a braking device for a shaft according to the invention.

Figure 7 shows a schematic perspective view of a braking system according to the invention.

The figures are not necessarily drawn to scale. In the various figures, identical or similar components may be indicated with the same reference numbers.

Figure 1 shows a schematic perspective view of an embodiment of a braking device 1 for a shaft according to the invention. According to the embodiment shown, the braking device 1 comprises a tubular body 2 that is provided with a first receiving space 3 that is oriented in the axial direction of the tubular body 2 as well as a first opening 4 and a second opening 5 that are connected with the first receiving space 3. In use of the braking device 1, a shaft 12 can be positioned in the first receiving space 3 through the first opening 4 or the second opening 5. In the embodiments of the braking device 1 that are shown by way of example in figure 1, the tubular body 2 is provided with a number of cylinders 6 that are each oriented in a radial direction of the tubular body 2 and are connected with the first receiving space 3. Each of the cylinders 6 shown is provided with a piston 7. Each piston 7 comprises a side 8 that is oriented towards the first receiving space 3 and a side 9 that is oriented away from the first receiving space 3. In the embodiment of the braking device 1 that is shown in figure 1, each of the pistons 7 is provided with a brake shoe 10 on the side 8 that is oriented towards the first receiving space 3. Each brake shoe 10 is movably mounted with respect to the piston 7 with which it is connected in at least one of a radial or axial direction of the tubular body 2. As described above, the braking device 1 according to the invention as a result allows for a greater clearance between a shaft that, in use of the braking device 1, is contained in the first receiving space 3 and each of the brake shoes 10. Depending upon the application, the admissible clearance between a shaft and the brake shoes 10 may be in a range from 1mm to 50mm. Where rotary shafts of an active stabilisation system for a vessel have a diameter of, for example, 200mm, the admissible clearance is typically a few millimetres. As a result of the greater admissible clearance, the braking device 1 according to the invention may be manufactured by means of a manufacturing process that has a lower accuracy than is required for a manufacturing process with which known braking devices must be manufactured for them to be usable in, for example, the above-mentioned active stabilisation device for a vessel. This means that the manufacturing costs of braking devices 1 according to the invention can be lower than those of known braking devices that are used in the above- mentioned application.

An advantage of brake shoes 10 that are mounted movably with respect to the pistons 7 is that a maximum contact surface between a shaft 12 and the brake shoes 10 can be realised, despite a possible tilt of the shaft 12 with respect to the first receiving space 3 of the tubular body 2 of the braking device 1. As a result, the braking device 1 according to the invention is better able than known braking devices to counterbalance a deviation in a position of a shaft 12 with respect to the first receiving space 3 in which the shaft 12 is contained in use of the braking device 1.

Owing to the fact that each of the brake shoes 10 is movable with respect to each of the pistons 7 with which they are connected in at least one of a radial or axial direction of the tubular body 2, the brake shoes 10, when these, in use of the braking device 1, are moved into contact with a shaft 12 that is contained in the first receiving space 3, can be automatically aligned with the aforementioned shaft 12 in at least one of a radial or axial direction of the tubular body 2. As a consequence of this automatic alignment of the brake shoes 10 with the shaft 12, a maximum contact surface between the brake shoes 10 and the shaft 12 can be realised, as a result of which the braking or blocking of the shaft 12 can take place as efficiently as possible. This is advantageous to the speed with which the braking device can brake a shaft 12, for example a rotary shaft of an active stabilisation system for a vessel, or lock it in a blocked state. The braking device 1 according to the invention can be activated or deactivated within a few seconds. It will be apparent to a person skilled in the art that the braking device 1 according to the invention can brake and/or block a shaft 12 in at least one of an axial, radial or circumferential direction of the tubular body 2.

In the embodiment of the braking device 1 as shown in figure 1, an outer jacket 11 is coaxially arranged with respect to the tubular body 2. The outer jacket 11 can be used to connect the braking device 1 with a device, such as, for example, the hull of a vessel, in which the braking device 1 is used.

Figure 2a shows a schematic perspective view of a first embodiment of the tubular body 2 of a braking device 1 according to the invention. In the embodiment that is shown by way of example, the tubular body 2 is provided with six cylinders 6 that are oriented in a radial direction of the tubular body 2. Each of these six cylinders 6 is connected with the first receiving space 3. By way of example, figure 2a only shows a first piston 7 that is provided in one of the six cylinders 6. It will be clear to the person skilled in the art that each of the six cylinders 6, in use of the braking device, is provided with a piston 7 such as the piston shown in figure 2a.

Figure 2b shows a schematic perspective view of the embodiment of the tubular body 2 as shown in figure 2a. Each of the six cylinders 6 has a portion that is oriented away from the first receiving space 3 and comprises a first room that can be sealed in a fluid-tight manner in a radial direction of the tubular body by the side 9 of the piston 7 that is oriented away from the first receiving space 3, which piston 7 is provided in each of the six cylinders 6, and by a cover element 13 that can be connected with the tubular body 2. This provides for a room in which a pressure can be built up by means of a fluid, such as oil or air, under the influence of which the piston 7 is movable in a radial direction of the tubular body 2 that is oriented towards the first receiving space 3. The cover element 13 can be embodied as a lid that is connected with the tubular body 2. In figure 2b only one of the six cylinders 6 of the tubular body 2, by way of example, is sealed by means of a cover element 13.

Figure 3 shows a schematic perspective view of a second embodiment of the tubular body 2 of the braking device 1 according to the invention. In the embodiment that is shown by way of example, the tubular body 2 is provided with a number of cylinders 6 that are oriented in a radial direction of the tubular body 2. Each of the cylinders 6 shown is connected with the first receiving space 3 and provided with a piston 7. Each of the pistons 7 is provided with a brake shoe 10.

Figure 3 furthers shows an outerjacket 11 that is coaxially arranged with respect to the tubular body 2 and comprises a first portion that can be positioned across each of the rooms of each of the cylinders 6 shown in a radial direction of the tubular body 2. In this way, the outerjacket 11 can serve as ajoint cover element 13 for sealing each of the rooms of each of the cylinders 6 shown on one side in a fluid-tight manner. By applying a joint cover element 13 instead of separate cover elements 13, the risk of leakage of the fluid from each of the rooms of each of the cylinders 6 shown can be reduced.

If the braking device 1 can be hydraulically powered, at least a first portion of the outer jacket 11 comprises a tapered inner diameter. It will be clear to the person skilled in the art that this makes it possible to bleed the hydraulic system when filling it with a fluid, for example oil, through a ventilation device 21.

As described above, the outer jacket 11 can also be used to connect the braking device 1 according to the invention with a device, such as, for example, the hull of a vessel, in which the braking device 1 is used.

Figure 4a shows a schematic perspective view of an embodiment of a piston 7 of the braking device 1 according to the invention. Figure 4a shows in particular a side 9 of the piston 7 which, when the piston 7 is mounted in a cylinder 6 of the braking device 1, is oriented away from the first receiving space 3 of the tubular body 2, as shown in figure 2a. The side 9 of the piston 7 that is oriented away from the first receiving space 3 is provided with a resilient element 14 that is arranged to connect the side 9 of the piston 7 that is oriented away from the first receiving space 3 with a separate cover element 13 or with the outer jacket 11, if this is used as a joint cover element. Once the braking device 1 has been deactivated, the resilient element 14 makes it possible to break an at least adjoining contact between the brake shoe 10 that is movably mounted on the side 8 of the piston 7 that is oriented towards the first receiving space 3 and the shaft 12 that, in use of the braking device 1, is contained in the first receiving space 3, as a result of which the shaft 12 is no longer braked or blocked. It will be clear to the person skilled in the art that the resilient element 14 can be embodied in various ways. An example of this is a leaf spring as is shown in figure 4a. It will also be clear to the person skilled in the art that the at least adjoining contact between the brake shoe 10 and the shaft 12 can also be broken in at least one of a hydraulic, pneumatic or electrical manner.

According to an embodiment of the piston 7 as shown in figure 3, no resilient element 14 is provided on the side 9 of the piston 7 that is oriented away from the first receiving space 3. In this case, after deactivation of the braking device 1, the brake shoe 10 remains in a non-braking or non-blocking adjoining contact with the shaft 12 that, in use of the braking device 1, is contained in the first receiving space 3. Figure 4b shows a schematic perspective view of the embodiment of the piston 7 as shown in figure 4a, but from a side 8 of the piston 7 which, when the piston 7 is mounted in a cylinder 6 of the braking device 1, is oriented towards the first receiving space 3 of the tubular body 2, as is shown in figure 1. The side 8 of the piston 7 that is oriented towards the first receiving space 3 comprises a concave surface. As shown in figure 5a, the brake shoe 10 has a side 15 that is oriented away from the first receiving space 3 and comprises a convex surface. This convex surface of the brake shoe 10 can be contained in the aforementioned concave surface of the side 8 of the piston 7 that is oriented towards the first receiving space 3. As a result, the first brake shoe 10 can move with respect to the piston 7 in at least one of a radial or axial direction of the tubular body 2. This allows for the automatic alignment of the brake shoe 10 and a shaft 12 that, in use of the braking device 1, is contained in the first receiving space 3.

The brake shoe 10 as shown in figures 4b and 5a is provided with a brake lining 17 on a side 16 that is oriented towards the first receiving space 3, which brake lining 17 has a concave surface that is oriented towards the first receiving space 3. As a result, in use of the braking device 1, a maximum contact surface can be formed between the brake lining 17 and a shaft 12 that, in use of the braking device 1 , is contained in the first receiving space 3. Although the application of the brake lining 17 shown has advantages over a brake shoe 10 that is not provided with a brake lining 17, it will be clear to the person skilled in the art that the application of the brake lining 17 shown is not absolutely necessary.

The brake shoe 10 shown in figures 4b, 5a and 5b is longitudinal in an axial direction of the tubular body 2. Instead of such a longitudinal brake shoe 10, it is also possible to provide the side 8 of the piston 7 that is oriented towards the first receiving space 3 with a number of brake shoes 10, which each, independently of each other, are movable with respect to the piston 7 in an axial or radial direction of the tubular body.

Figure 5b shows a schematic perspective view of the embodiment of the brake shoe 10 as shown in figure 5a, but from a side 15 of the brake shoe 10 which, when the brake shoe 10 is mounted in a cylinder 6 of the braking device 1, is oriented away from the first receiving space 3 of the tubular body 2. The brake shoe 10 is provided with a first adjusting element 18 and a second adjusting element 19 that are arranged for adjusting a movement of the brake shoe 10 with respect to the piston 7 in an axial direction of the tubular body 2. The first adjusting element 18 and the second adjusting element 19 can be embodied as a first bolt and a second bolt, respectively, which are sequenced between the brake shoe 10 and the piston 7.

Figure 5b further shows that a resilient element 20 is provided that is arranged to position the brake shoe 10 in a first, neutral position with respect to the piston 7. When the brake shoe 10 no longer makes contact or has only a non-braking or non-blocking adjoining contact with a shaft 12 that, in use of the braking device 1, is contained in the first receiving space 3, the brake shoe 10 can be moved by the resilient element 20, for example a draw spring, into the first, neutral position with respect to the piston 7, from a second position in which the brake shoe 10 is moved in at least one of a radial or axial direction of the tubular body 2 with respect to the piston 7 as a consequence of the automatic alignment of the brake shoe 10 with the shaft 12 when these are brought into a braking or blocking adjoining contact with each other.

Figure 6 shows a schematic perspective view of a second embodiment of a braking device 1 for a shaft 12 according to the invention. In deviation from the first embodiment of the braking device 1 as shown in figure 1, each of the brake shoes 10 is movably mounted on a side 9 of each of the pistons 7 that is oriented away from the first receiving space 3. As a result, in use of the braking device 1 , each of the brake shoes 10 can be moved into a blocking adjoining contact with the outer jacket 11 to brake or block the shaft 12. It will be clear to the person skilled in the art that, at least in use of the braking device 1 according to its embodiment shown in figure 6, the tubular body 2 and the shaft 12 cannot be moved with respect to each other. To brake or block the shaft 12, the brake shoes 10 are brought into a braking or blocking adjoining contact with the outer jacket 11. This embodiment of the braking device 1 does not need to be manufactured either by means of a manufacturing process that has the same high accuracy as the manufacturing process with which known braking devices must be manufactured for them to be usable in applications such as, for example, an active stabilisation device for a vessel. This means that the manufacturing costs of this embodiment of the braking device according to the invention can also be lower than those of known braking devices that are used in the above-mentioned application.

By applying pistons 7 and brake shoes 10 that are movably connected with them and are oriented towards the outer jacket 11 that is mounted coaxially around the tubular body 2, the braking device 1 according to the embodiment shown in figure 6 allows for a greater clearance between the brake shoes 10 and the outer jacket 11. Depending upon the application, the admissible clearance between the brake shoes 10 and the outer jacket 11 may be in a range from 1mm to 50mm. Where rotary shafts of an active stabilisation system for a vessel have a diameter of, for example, 200mm, the admissible clearance is typically a few millimetres.

As described above, an advantage of the brake shoes 10 being movable with respect to the pistons 7 is that a maximum contact surface between the brake shoes 10 and the outer jacket 11 can be achieved despite a possible tilt of the shaft 12 with respect to the outer jacket 11. The outer jacket 11 can also be used to connect the braking device 1 according to the invention with a device, such as, for example, the hull of a vessel, in which the braking device 1 is used.

Also in the embodiment of the braking device 1 shown in figure 6, each of the brake shoes 10 is movable with respect to each of the pistons 7 with which they are connected in at least one of a radial or axial direction of the tubular body 2. As a result, the first brake shoes 10, when they, in use of the braking device 1, are moved into contact with the outer jacket 11, can be automatically aligned with the outer jacket 1 1 in at least one of a radial or axial direction of the tubular body 2. As a consequence of this automatic alignment of the brake shoes 10 with the outer jacket 11, a maximum contact surface between the brake shoes 10 and the outer jacket 11 can be realised, as a result of which the braking or blocking of the shaft 12 can take place as efficiently as possible. This is advantageous to the speed with which the braking device 1 can brake a shaft 12, for example a rotary shaft of an active stabilisation system for a vessel, or lock it in a blocked state. The embodiment of the braking device 1 shown in figure 6 can be activated or deactivated within a few seconds.

In the embodiment of the braking device 1 shown in figure 6, the side of each of the pistons 7 that is oriented away from the first receiving space 3 comprises a concave surface and each brake shoe 10 has a side that is oriented towards the first receiving space 3 and comprises a convex surface. The convex surface of each brake shoe 10 can be contained in the aforementioned concave surface of the side of each of the pistons 7 that is oriented away from the first receiving space 3. As a result, each brake shoe 10 can move with respect to the piston 7 with which it is connected in at least one of a radial or axial direction of the tubular body 2. This allows for the above-described automatic alignment of the brake shoes 10 with the outer jacket 11. Each of the brake shoes 10 is further provided with a first adjusting element 18 and a second adjusting element 19 that are arranged for adjusting a movement of each of the brake shoes 10 with respect to each of the pistons 7 in an axial direction of the tubular body 2. The first adjusting element 18 and the second adjusting element 19 can be embodied as a first bolt and a second bolt, respectively, which can be sequenced between each of the brake shoes 10 and each of the pistons 7 with which they are connected.

Also in the second embodiment of the braking device 1, resilient elements 20 can be provided that are arranged to position each of the brake shoes 10 in a first, neutral position with respect to each of the pistons 7. When the brake shoes 10 no longer make contact with or have only a non-braking or non-blocking adjoining contact with the outer jacket 11, each of the brake shoes 10 can be moved by each of the resilient elements 20 into the first, neutral position with respect to each of the pistons 7, from a second position in which each of the brake shoes 10 is moved in at least one of a radial or axial direction of the tubular body 2 with respect to each of the pistons 7 as a consequence of the automatic alignment of each of the brake shoes 10 with the outer jacket 1 1 when these are brought into a braking or blocking adjoining contact with each other.

As in the first embodiment of the braking device 1, each of the brake shoes 10 according to the second embodiment of the braking device 1 as shown in figure 6 may have a side that is oriented away from the first receiving space 3, in which each of these sides is provided with a brake lining 17. Each of the brake linings 17 has a convex surface that is oriented away from the first receiving space 3. As a result, in use of the braking device 1, a maximum contact surface can be formed between the brake lining 17 of each of the brake shoes 10 and the outer jacket 11.

In the embodiment of the braking device 1 according to the invention shown in figure 6, each cylinder has a portion that is oriented towards the first receiving space 3 and comprises a room that can be sealed in a fluid-tight manner in a radial direction of the tubular body 2 by the side of the piston 7 in each cylinder that is oriented to the first receiving space 3 and a cover element 13 that can be connected with the tubular body 2. This provides for a room in which a pressure can be built up by means of a fluid, such as oil or air, under the influence of which each of the pistons 7 is movable in a radial direction of the tubular body 2 that is oriented away from the first receiving space 3. The cover element 13 can be embodied as a lid that is connected with the tubular body 2.

The embodiment of the braking device 1 according to the invention shown in figure 6 further comprises an inner jacket that is coaxially arranged with respect to the tubular body 2 and comprises a first portion that is positioned across each

aforementioned room of each of the cylinders in a radial direction of the tubular body 2. The inner jacket may serve as a cover element for sealing each of the rooms of each of the cylinders on one side in a fluid-tight manner, as described above. Depending upon the diameter of the shaft 12 and the braking torque that is required to brake or block the shaft 12, a suitable number of additional cylinders may be applied, which are positioned equidistant along the circumference of the tubular body 2. In this way, the inner jacket may serve as a joint cover element for the rooms of the cylinders. As a result, the risk of leakage of the fluid from each of the rooms of the cylinders can be reduced compared to a situation in which each room of the cylinders is sealed by a separate additional cover element.

In the embodiment of the braking device 1 shown in figure 6, the first portion of the inner jacket has at least a tapered inner diameter. If the braking device 1 can be powered hydraulically, this makes it possible to bleed the hydraulic system when filling it.

The braking device 1 in the embodiment shown in figure 6 may further be provided with a second resilient element that is arranged to connect the side 8 of each of the pistons 7 that is oriented towards the first receiving space 3 with the cover element of each of the rooms of each of the cylinders. Once the braking device 1 has been deactivated, this makes it possible to break the adjoining contact between the brake shoes 10 and the outer jacket 11, as a result of which the shaft 12 that, in use of the braking device, is contained in the first receiving space 3 is no longer braked or blocked.. The second resilient element may, for example, be embodied as a leaf spring.

Figure 7 shows a schematic perspective view of a braking system 40 for a shaft according to the invention. The braking system 40 comprises a first braking device 1 according to the present invention and a first control device 41 that is connected with the first braking device 1. The first control device 41 is arranged to power the first braking device 1 in at least one of a hydraulic, pneumatic, electrical or mechanical manner. It will be clear to the person skilled in the art that the present invention is not limited to the embodiments of the braking device and the braking system as described above by way of non-limiting examples, but that other embodiments of the braking device and the braking system are conceivable that may provide the advantages according to the invention and fall within the protective scope of the braking device and the braking system as defined in the following claims. It will further be clear to the person skilled in the art that the terms "comprising" and "comprise" should be interpreted in a non-limitative manner and that the indefinite article "a" does not exclude a multiple of the indicated technical features and in that case should be interpreted as "at least one". The mere fact that certain technical features are described in different claims, which may or may not be mutually dependent, does not exclude combinations of such technical features being applied advantageously. Finally, it is noted that the reference numbers in the claims should be interpreted as non-limiting as regards the protective scope of the present invention.

Claims

1. A braking device (1) for a shaft (12), comprising:

- a tubular body (2) that is provided with a first receiving space (3) that is oriented in an axial direction of the tubular body (2), a first opening (4) and a second opening (5) that are connected with the first receiving space (3), in which the shaft (12) can be positioned in the first receiving space (3) through the first opening (4) or the second opening (5), in which the tubular body (2) is further provided with a first cylinder (6) that is oriented in a radial direction of the tubular body (2) and connected with the first receiving space (3); and

- a first piston (7) that is provided in the first cylinder (6), in which the first piston (7) comprises a side (8) that is oriented towards the first receiving space (3) and a side

(9) that is oriented away from the first receiving space (3), in which the piston (7), in use of the braking device (1), can be brought into at least one of a braking or blocking contact with the shaft (12).

2. The braking device (1 ) according to claim 1 , further comprising a first brake shoe (10) that is movably mounted on the side (8) of the first piston (7) that is oriented towards the first receiving space (3).

3. The braking device (1) according to claim 2, in which the first brake shoe

(10) is movable with respect to the first piston (7) in at least one of a radial or axial direction of the tubular body (2).

4. The braking device (1) according to claim 2 or 3, in which the side (8) of the first piston (7) that is oriented towards the first receiving space (3) comprises a concave surface and the first brake shoe (10) has a side (15) that is oriented away from the first receiving space (3) and comprises a convex surface, which convex surface can be received in the aforementioned concave surface of the side (8) of the first piston (7) that is oriented towards the first receiving space (3).

5. The braking device (1) according to any one of the claims 2-4, in which the first brake shoe (10) is provided with a first adjusting element (18) and a second adjusting element (19) that are arranged for adjusting a movement of the first brake shoe (10) with respect to the first piston (7) in an axial direction of the tubular body (2).

6. The braking device (1) according to any one of the claims 2-5, in which a first resilient element (20) is provided that is arranged to position the first brake shoe (10) in a first, neutral position with respect to the first piston (7).

7. The braking device (1) according to any one of the claims 2-6, in which the first brake shoe (10) has a side (16) that is oriented towards the first receiving space, which side (16) is provided with a first brake lining (17) that has a concave surface that is oriented towards the first receiving space (3).

8. The braking device (1) according to any one of the claims 2-7, in which the first cylinder (6) has a portion that is oriented away from the first receiving space and comprises a first room that can be sealed in a fluid-tight manner in a radial direction of the tubular body (2) by the side (9) of the first piston (7) that is oriented away from the first receiving space and a first cover element (13) that can be connected with the tubular body (2).

9. The braking device (1) according to claim 8, in which an outer jacket (11) is provided that is coaxially arranged with respect to the tubular body (2) and comprises a first portion that is positioned across the first room of the first cylinder (6) in a radial direction of the tubular body (2).

10. The braking device (1) according to claim 9, in which the first portion of the outer jacket (11) has at least a tapered inner diameter.

11. The braking device (1) according to any one of the claims 8-10, in which a second resilient element (14) is provided that is arranged to connect the side (9) of the first piston (7) that is oriented away from the first receiving space (3) with the first cover element (13).

12. The braking device (1) according to any one of the claims 2-11, in which the first brake shoe (10) is longitudinal in an axial direction of the tubular body (2).

13. A braking device (1) for a shaft (12), comprising:

- a tubular body (2) that is provided with a first receiving space (3) that is oriented in an axial direction of the tubular body (2), a first opening (4) and a second opening (5) that are connected with the first receiving space (3), in which the shaft (12) can be positioned in the first receiving space (3) through the first opening (4) or the second opening (5), in which the tubular body (2) is further provided with a first cylinder (6) that is oriented in a radial direction of the tubular body (2);

- an outer jacket (11) that is coaxially arranged with respect to the tubular body

(2);

- a first piston (7) that is provided in the first cylinder (6), in which the first piston (7) comprises a side (8) that is oriented towards the first receiving space (3) and a side (9) that is oriented away from the first receiving space (3), in which the piston (7), in use of the braking device (1), can be brought into at least one of a braking or blocking contact with the outer jacket (1 1 ).

14. The braking device (1) according to claim 13, further comprising a first brake shoe (10) that is movably mounted on the side (9) of the first piston (7) that is oriented away from the first receiving space (3).

15. The braking device (1) according to claim 14, in which the first brake shoe (10) is movable with respect to the first piston (7) in at least one of a radial or axial direction of the tubular body (2).

16. The braking device (1) according to claim 14 or 15, in which the side (9) of the first piston (7) that is oriented away from the first receiving space (3) comprises a concave surface and the first brake shoe (10) has a side (16) that is oriented towards the first receiving space (3) and comprises a convex surface, which convex surface can be received in the aforementioned concave surface of the side (9) of the first piston (7) that is oriented away from the first receiving space (3).

17. The braking device (1) according to any one of the claims 14-16, in which the first brake shoe (10) is provided with a first adjusting element (18) and a second adjusting element (19) that are arranged for adjusting a movement of the first brake shoe (10) with respect to the first piston (7) in an axial direction of the tubular body (2).

18. The braking device (1) according to any one of claims 14-17, in which a first resilient element (20) is provided that is arranged to position the first brake shoe (10) in a first, neutral position with respect to the first piston (7).

19. The braking device (1) according to any of the claims 14-18, in which the first brake shoe (10) has a side (15) that is oriented away from the first receiving space (3), which side (15) is provided with a first brake lining (17) that has a convex surface that is oriented away from the first receiving space (3).

20. The braking device (1) according to any one of the claims 14-19, in which the first cylinder (6) has a portion that is oriented towards the first receiving space and comprises a first room that can be sealed in a fluid-tight manner in a radial direction of the tubular body (2) by the side (8) of the first piston (7) that is oriented towards the first receiving space and a first cover element (13) that can be connected with the tubular body (2).

21. The braking device (1) according to claim 20, in which an inner jacket is provided that is coaxially arranged with respect to the tubular body (2) and comprises a first portion that is positioned across the first room of the first cylinder (6) in a radial direction of the tubular body (2).

22. The braking device (1) according to claim 21, in which the first portion of the inner jacket has at least a tapered inner diameter.

23. The braking device (1) according to any one of the claims 20-22, in which second resilient element (14) is provided that is arranged to connect the side (8) of the first piston (7) that is oriented towards the first receiving space (3) with the first cover element (13).

24. The braking device (1) according to any one of the claims 14-23, in which the first brake shoe (10) is longitudinal in an axial direction of the tubular body (2).

25. A braking system (40) for a shaft (12), comprising:

- a first braking device (1) according to any one of the preceding claims;

- a first control device (41) that is connected with the first braking device (1) and is arranged to power the first braking device (1) in at least one of a hydraulic, pneumatic, electrical or mechanical manner.