Annular disk brake and method of increasing a brake pad clamping force

The annular disk brake comprises a rotor disk and at least one brake pad provided on each side of the rotor disk. The brake pad or pads on one side are connected to a substantially axially-guided brake pad carrier. The brake has a force transmitting arrangement creating a force increasing amplification between an axially-actuated member and the carrier. This arrangement can increase the brake compactness and provide an even distribution of the braking force around the circumference of the rotor disk. A method of increasing a brake pad clamping force is also disclosed.

TECHNICAL FIELD

The technical field relates to annular disk brakes and methods of increasing brake pad clamping forces in annular disk brakes.

BACKGROUND

Annular disk brakes are sometimes referred to in prior references as full-contact annular disk brakes. An annular disk brake comprises at least one rotor disk that is axially movable with reference to a fixed component. The rotor disk is in a torque-transmitting engagement with a rotating element, such as the wheel of a vehicle for instance. The rotor disk is axially positioned between one or more fixed braking pads on one side, and one or more axially movable braking pads on the opposite side of the rotor disk. The set of movable brake pads is axially pushed against the corresponding side of the rotor disk by mean of an actuator, for instance a pneumatic, hydraulic or electric actuator. A braking friction and heat are generated when the fixed and the movable brake pads are in a clamping engagement with the sides of the rotor disk.

There are numerous challenges in the design of annular disk brakes. One is to be able to generate a suitable clamping force using an actuator that can fit in the space available for the brake. Annular disk brakes are often provided in vehicles and these annular disk brakes are generally mounted within or very close to a respective wheel of a vehicle. The space available for each brake is thus relatively limited, even in the case of large vehicles. Moreover, vehicle manufacturers are constantly looking for brakes that are increasingly compact to reduce this space. The various requirements can be particularly complex to meet when designing annular disk brakes to be connected to a pneumatic system used as a main source of power for the brakes. Room for improvements always exists in the design of annular disk brakes.

SUMMARY

In one aspect, there is provided an annular disk brake having a central axis, the brake being characterized in that it comprises: a main support coaxially disposed with reference to the central axis; a rotor disk coaxially disposed with reference to the central axis and being in a sliding and torque-transmitting engagement with the main support, the rotor disk having opposite outboard and inboard sides; a casing inside which the main support is mounted for rotation around the central axis; at least one first brake pad having a surface facing the outboard side of the rotor disk, the at least one first brake pad being connected inside the casing; at least one second brake pad having a surface facing the inboard side of the rotor disk; a substantially axially-guided brake pad carrier coaxially disposed with reference to the central axis, the brake pad carrier having opposite outboard and inboard sides, the at least one second brake pad being positioned on the outboard side of the brake pad carrier; an actuator assembly connected to the casing, the actuator assembly comprising an axially-actuated member; and a force transmitting arrangement comprising a first cam interface between the axially-actuated member and an intermediary member located between the axially-actuated member and the inboard side of the brake pad carrier, the intermediary member being coaxially disposed with reference to the central axis and pivoting in a radial plane, the arrangement further comprising a second cam interface between the intermediary member and the inboard side of the brake pad carrier, the brake pad carrier axially moving when the intermediary member pivots, whereby the arrangement creates a force increasing amplification between the axially-actuated member and the inboard side of the brake pad carrier.

In another aspect, there is provided a method of increasing a brake pad clamping force in an annular disk brake including an actuator and a rotor disk having a rotation axis, the method comprising the simultaneous steps of: generating a first force with the actuator of the brake, the first force being in a direction that is parallel to the rotation axis of the rotor disk and moving an axially-actuated member; generating a torque using the first force, the torque having a center of rotation that is substantially coincident with the rotation axis of the rotor disk; generating a second force using the torque, the second force being in a direction that is substantially identical to the direction of the first force and being greater in magnitude than the first force; and using the second force for clamping brake pads on opposite sides of the rotor disk.

The various aspects of the improvements presented herein will be apparent upon reading the following detailed description made in conjunction with the appended drawings.

DETAILED DESCRIPTION

FIGS. 1 to 2show an example of an assembled annular disk brake10with an example of the improved arrangement. The illustrated brake10is designed to be used with the front right wheel (not shown) of a large vehicle, such as a truck or a bus.FIG. 1is a view of the outboard side andFIG. 2is a view of the inboard side of the brake10. The words “outboard” and “inboard” in the present context refer to the relative position with reference to the longitudinal axis at the center of the vehicle. The wheel of the vehicle rotates in the clockwise rotational direction for an observer looking at the outboard side shown inFIG. 1when the vehicle moves forward. An arrow with the label “FORWARD” is shown inFIG. 1and in some of the other figures to indicate the rotational direction of the rotating components of the brake10when the vehicle moves forward. This corresponds to the main rotational direction of the brake10.

It should be noted that a brake like the brake10that is to be used at the front left side of the vehicle would be a mirror image of what is shown. The brake10as illustrated can also be modified for use on many different kinds of vehicles, including vehicles that are not intended for road traveling, such as airplanes. Furthermore, using the brake10in a machine that is not a vehicle is possible as well. Such machine can have, for instance, a pulley or another rotating element to which the brake10is connected. The uses of the word “vehicle” or its equivalents in the present text only refer to the illustrated example and do not necessarily exclude using the brake10in other environments.

The illustrated brake10comprises a main support12to which the wheel of the vehicle is attached. The support12is journaled around an internal central spindle14coaxially located with reference to the central axis R of the brake10(seeFIG. 3). The rotation axis of the wheel is coincident with the central axis R of the brake10.

The support12has a plurality of axisymmetric mounting bolts16outwardly projecting from a radial portion12aof the support12. Ten mounting bolts16are shown in the illustrated example. Such configuration is common for large trucks. It should be noted that the threads of the mounting bolts16have not been illustrated.

The illustrated support12has a bearing cavity18therein. This bearing cavity18is shown open on the outboard side. The outboard opening of the bearing cavity18can be sealed off by a cap (not shown) that is attached on a circular flange12blocated around the outboard opening. The cap can be useful for preventing dirt or other contaminants from entering the bearing cavity18at the outboard side. Other arrangements are also possible.

Many of the components of the illustrated brake10are located within a casing. This casing comprises an outboard casing part20and an inboard casing part22. In the illustrated example, the outboard casing part20is circumferentially divided in two halves20a,20b. These two halves20a,20bare secured together using two bolts24. Also in the illustrated example, the spindle14is connected to the inboard casing part22, as explained in more details later in the text, thereby forming an integral part therewith.

The outboard casing part20is connected to the inboard casing part22using a plurality of bolts26. The outboard casing part20has a plurality of circumferentially-distributed flanges28extending axially toward the inboard casing part22and which provide anchoring points for the corresponding bolts26. The flanges28of the outboard casing part20are spaced apart from each other and have a respective opening30therein. This open configuration promotes air circulation within the brake10. Variants are possible as well.

The outboard casing part20and the inboard casing part22of the casing are parts that are not rotating with the support12when the vehicle is in movement. However, in the illustrated example, they are connected to the frame or body of the vehicle through a steering knuckle32. The steering knuckle32is bolted on the rear side of the inboard casing part22.FIG. 2shows the steering knuckle32and some of the bolts34provided to connect the steering knuckle32to the inboard casing part22. The steering knuckle32is used since the brake10of the illustrated example is for a front steering wheel. The whole brake10thus pivots with the wheel of the vehicle, for instance when a driver of the vehicle steers the wheel. Other arrangements are possible as well. For instance, if the brake10is used in a non-steerable environment, for instance a non-steerable wheel such as those provided at the rear of most vehicles, the outboard casing part20and inboard casing part22can be directly connected to a component such as a cross member or to a suspension arm. The inboard casing part22can then be directed connected to an axle. Other configuration can also be devised, depending on the requirements.

In the illustrated example, an actuator assembly40has a generally annular configuration and is connected outside the casing, more particularly to the rear side of the inboard casing part22, using the bolts36. The inboard casing part22is thus positioned between the outboard casing part20and the actuator assembly40. The actuator assembly40can also be connected differently to the casing. As can be appreciated, mounting the actuator assembly40on the inboard side of the inboard casing part22can increase the compactness of the brake10compared to designs where an actuator assembly is provided inside the casing.

FIG. 2further shows a pressurized fluid inlet42for the actuator assembly40. In the case of a pneumatic actuator assembly, the inlet42can be a pneumatic connection receiving a pressurized gas, for instance pressurized air, by which the brake10is controlled. The force generated by the actuator assembly40is then controlled by the input pressure at the actuator assembly40. It is also possible to actuate the brake10using pressurized liquids, for instance pressurized oil, or using an electric actuator. Still, in the case of a vehicle using a pneumatic actuator assembly, for instance a truck, the brake10can be designed with a fail safe mode so that when the inlet receives no pressure or otherwise receives an insufficient pressure, the brake10is automatically set to a full or nearly full braking position. Likewise, it is possible to provide valves or other elements to control the pressurized fluid directly inside the actuator assembly40. The inlet would then only receive pressurized fluid at a relatively constant pressure and the actuation would be controlled within the brake10itself through a remote command. The remote command can be electric, mechanical or even using another pressurized fluid line (not shown) connected the brake10through another inlet (not shown).

FIG. 3is an enlarged view of the brake10shown inFIG. 1, the brake10being illustrated with a cutaway portion. This figure shows the support12and how the support12is mounted for rotation around the spindle14in the illustrated example. As can be seen, the support12includes a rearwardly-extending sleeve portion12cconnected to the radial portion12athereof. Two spaced-apart bearings50,52are located within the bearing cavity18of the support12. The inner races of the bearings50,52are engaged on the spindle14while the outer races are engaged inside the radial portion12aand the sleeve portion12cof the support12, respectively. The bearings50,52are coaxial with the central axis R of the brake10.

Also inFIG. 3, the spindle14is connected to a radially-disposed flange54that is itself connected or otherwise made integral with the other components of the inboard casing part22. The illustrated flange54has a plurality of holes56through which the bolts34attaching the casing to the steering knuckle32are provided.

It should be noted at this point that the specific configuration of the bearings50,52in the illustrated example is only one among a plurality of possible configurations. For instance, some configurations may require that the bearing cavity18be located on the outboard side with reference to the radial portion12aof the support12. The spindle of such configuration would be longer than the one illustrated. Many other configurations are possible as well.

FIG. 3shows that the inboard casing part22of the illustrated brake10comprises an interior circular flange22ahaving a plurality of holes that are in registry with the holes56of the flange54to which the spindle14is connected. Some of the other components that are shown inFIG. 3are explained hereafter.

FIG. 4is an isometric view similar toFIG. 1. It shows the two halves20a,20bof the outboard casing part20being separated from each other, thereby exposing the rotor disk60of the brake10. It should be noted, however, that the rotor disk60is illustrated inFIG. 4without its support. This support will be explained later. The rotor disk60is coaxially located with reference to the central axis R (FIG. 3). Hence, the rotor disk60being a rotating part of the brake10, the rotation axis of the rotor disk60is coincident with the central axis R of the brake10.

FIG. 4further shows that semicircular brake pads62are mounted at the back of the two halves20a,20bof the outboard casing part20. These brake pads62are best shown inFIG. 5, which figure is an isometric exploded view showing the rear of the halves20a,20band their respective brake pads62. Each brake pad62is attached or is otherwise made integral with the halves20a,20b. Although there are two semicircular brake pads62in the illustrated example, one for each half20a,20b, it is possible to use a single circular brake pad (not shown) providing for instance a 360-degree contact with the rotor disk60, or to use more than two semicircular brake pads. The outboard casing part20can also be made of a single block that is not separated in two halves.

The brake pads62can be connected inside the casing using screws or other removable fasteners but can also be permanently attached to the halves20a,20b. For instance, a metallic back side of the brake pads62can be welded or other permanently attached to a respective one of the halves20a,20b. This way, when the brake pads62are worn off, it would not be possible to detach the brake pads62from the halves20a,20bto replace them. Providing new sets of casing part halves20a,20bwith integrated brake pads62simplifies the maintenance and the brake pads62will always be at the right position within the halves20a,20b.

In the illustrated example, the brake pads62connected to the halves20a,20bhave a respective surface62athat engages an outboard surface60aof the rotor disk60. An inboard surface60bof the rotor disk60is engaged by another set of semicircular brake pads64, which brake pads64are shown detached form the rest of the brake10inFIG. 4. The surfaces60a,60bof the rotor disk60can be machined so as to be as radial as possible and have the desired surface shape and treatment. As will be explained later, the second set of brake pads64is mounted on an axially-guided brake pad carrier66.

When respective surfaces64aof the inboard brake pads64engage the inboard surface60bof the rotor disk60, the rotor disk60is urged to move closer to the brake pads62located on the outboard side. Because they are connected to the outboard casing part20, the brake pads62on the outboard side are fixed in position. Eventually, the rotor disk60is engaged by the brake pads62,64on both sides. Increasing the force by which the brake pads64are engaged on the inboard surface60bof the rotor disk60increases the brake pad clamping force, thus the friction with the braking pads62,64on both sides of the rotor disk60. The kinetic energy resulting from the motion of the vehicle or being supplied by the vehicle's engine is then transformed into heat in the brake10until a full stop of the vehicle or until the brake pad clamping force is released. Heat in the brake10eventually dissipates in the atmosphere.

FIG. 6is an isometric exploded view showing the rotor disk60in a cross-section view and the rotor disk support70provided in the illustrated example to mount the rotor disk60to the support12. As aforesaid, the rotor disk support70is not shown inFIG. 4.FIG. 7shows the components ofFIG. 6after being assembled. It should be noted that inFIGS. 6 and 7, only one half of the rotor disk60is illustrated.

The rotor disk60of the illustrated example is made using two parallel annular walls forming the opposite outer surfaces60a,60b. The walls are connected together through a plurality of axisymmetric and radially extending ribs60cforming air channels, as shown for instance inFIG. 6. The heated air tends to escape radially outwards while cooler air is admitted at a radially inner side of the rotor disk60. The interior is shaped to fit over the rotor disk support70. The various parts of the rotor disk60can be made integral with each other. Variants are possible as well.

As aforesaid, the rotor disk60is in a rotational engagement with the support12and the rotor disk support70allows the rotor disk60to move in the axial direction with reference to the support12. This axial movement is of a magnitude which compensates the outboard pad wear. It should be also enough to move away from the brake pads62provided on the outboard casing part20when the braking force is released. Accordingly, when the brake10is inoperative, the rotor disk60should not overly engage the brake pads62so as to minimize friction.

The rotor disk support70of the illustrated example is a generally annular member that is coaxial with the central axis R of the brake10(FIG. 3). This rotor disk support70has a cylindrical interior provided with a low friction material and is engaged around the sleeve portion12cof the support12. The periphery of the rotor disk support70is provided with a plurality of axially extending pins72that are disposed axisymmetrically thereon. The pins72have an outboard side72afitting loosely in corresponding sleeves74integrally provided at the back of the radial portion12aof the support12. Five pins72and five sleeves74are provided in the illustrated example. However, using a different number is also possible and it is also possible to invert the relative position of the pins72and the sleeves74.

As best shown inFIGS. 6 and 7, the sleeves74of the illustrated example are disposed between the heads of two mounting bolts16. Two sleeves74are separated by the heads of two mounting bolts16. An annular reinforcing wall76connects the sleeves74together. At least one among the pins72and the sleeves74is provided with a low friction material on their mating surface, either in the form of a coating or a bushing. This way, the relative axial movement between the rotor disk60and the support12can be relatively easy. Furthermore, the pins72of the illustrated example have a somewhat central portion72cthat have a larger diameter than that the sleeves74. These central portions72cact as stoppers.

As shown inFIG. 7, the rotor disk60is connected to its support70by mean of a plurality of screws or bolts78inserted into a threaded bore at the inboard end72bof the pins70. As shown, the pins72are connected to the rest of the rotor disk support70using radially-extending brackets80,82.FIG. 7also shows that large openings can be provided between the rotor disk support70and the interior of the rotor disk60to promote air circulation. Variants are possible as well.

It should be noted that the outer diameter of the pins72is not necessary the same on the outboard side72athan the inboard side72b.

In use, when the wheel that is connected to the support12rotates and the brake10is activated, the clamping force applied on each side of the rotor disk60by the brake pads62,64tends to slow down the rotation of the rotor disk60, thereby creating a braking torque in the direction opposite the rotation of the wheel. This braking torque is transmitted from the rotor disk60to the wheel by the axially extending pins72. Hence, these pins72receive substantially the entire braking torque generated by the brake10.

There are many other ways that can be devised to create the rotational engagement between the support12and the rotor disk60. Nevertheless, the illustrated rotor disk support70has good self-centering capability and can keep the rotor disk60within a radial plane at all times. The hysteresis of the brake10can also be very low.

FIG. 8is an isometric exploded view of most of the components of the brake10shown inFIGS. 1 to 3. It should be noted, however that the interior of the illustrated rotor disk60is slightly different from what is shown inFIGS. 6 and 7. InFIG. 8, the components that are rotating together with the wheel are the support12and the rotor disk60. Of course, the rotor disk support70(not shown inFIG. 8) also rotates together with the wheel. As aforesaid, the outboard casing part20and the inboard casing part22of the casing are not rotating with the support12. They can be connected, in the illustrated example, to the steering knuckle32, as shown inFIGS. 1 to 3, using the bolts34. Only some of the bolts34are illustrated inFIG. 8. The actuator assembly40is connected at the back of the inboard casing part22, as is explained later.

As aforesaid, the brake pads64are connected on one side of an axially-guided brake pad carrier66. The brake pad carrier66of the illustrated example includes two concentric ring members66a,66b(FIG. 9) that are connected together using four axisymmetric roller support units68. The brake pads64can be removably connected to the brake pad carrier66. This removable connection simplifies maintenance since the brake pads64can then be replaced when worn off without removing the brake pad carrier66from the brake10. Thus, as shown inFIG. 4, the brake10can be serviced on the inboard side by simply detaching the two brake pads64from the brake pad carrier66. This can be done, for instance, by moving a locking mechanism or bolts (not shown).

Like for the brake pads62on the outboard side, it is possible to use a single circular brake pad instead of the two semicircular brake pads64, or to use more than two semicircular brake pads64. Also, in some configurations, the brake pads64could be made integral or be otherwise permanently fastened to the brake pad carrier66.

The brake pad carrier66of the illustrated example is axially guided using a plurality of slots90provided in an inner sleeve92of the inboard casing part22.

The back of the brake pad carrier66and the inner sleeve92are illustrated inFIG. 9. It should be noted that the other components of the inboard casing part22have been omitted. The inner sleeve92can be made integral or otherwise connected to the other components of the inboard casing part22or directly journaled or permanently connected to the knuckle or spindle or axle beam.

There are two different sets of rollers on the brake pad carrier66of the illustrated example. The first set of rollers comprises rollers94. Each roller94is mounted for rotation around a corresponding axle96that is radially extending with reference to the central axis R (FIG. 3). The rollers94project on the inner side of the brake pad carrier66. They are loosely engaged in the slots90of the inner sleeve92. The width of the slots90is slightly larger than the outer diameter of the rollers94. The rollers94are then able to easily move along the slots90.

It should be noted that the rollers94can be replaced by other kinds of followers, for instance sliding buttons, or any low friction sliding device, depending on the design.

Referring back toFIG. 8, the slots90of the illustrated example are slightly oblique with reference to a direction that is parallel to the central axis R (FIG. 3). The slots90are offset in the direction of the rotation of the wheel when the vehicle moves forward. As aforesaid, when the brake10is assembled, the rollers94on the inner side of the brake pad carrier66are engaged in the corresponding slots90of the inner sleeve92. This provides the axial guidance of the brake pad carrier66when it moves closer or away from the rotor disk60. The drag torque that can be generated on the brake pad carrier66when the brake10is activated is transmitted to the inboard casing part22.

Because the slots90are inclined inFIG. 8in the direction of rotation, the drag torque transmitted to the brake pad carrier66can generate an axial reaction force increasing the braking capacity. This additional braking force is therefore somewhat proportional to the intensity of the braking. The angle of the slots90can be adjusted in accordance with the specific needs and to prevent the braking force from being out of control. For instance, the average angle can be below 20°, such as between 10 and 20°. Other values are possible. Still, the slots90can also be curved to change the additional braking force when the brake pad carrier66moves closer or away with reference to the rotor disk60. It is further possible to provide the slots90with non-parallel opposite walls. This may be useful to prevent the opposite effect if the vehicle brakes as it moves as in a reverse direction or if the vehicle is stopped in a steep hill in the upward direction.

FIG. 8also shows that an intermediary member100is located between brake pad carrier66and the inboard casing part22of the illustrated brake10. The intermediary member100is also shown inFIGS. 10 to 12. The intermediary member100has axisymmetric and axially inclined ramp surfaces102. The intermediary member100is coaxially disposed with reference to the central axis R (FIG. 3). It pivots in a radial plane within the inboard casing part22and around the inner sleeve92thereof. Bearings103or other low-friction elements are provided in the illustrated example between the rear surface of the intermediary member100and a surface105at the bottom of the inboard casing part22to facilitate the rotation of the intermediary member100. The intermediary member100does not move in the axial direction.

The ramp surfaces102of the illustrated intermediary member100face the rear side of the brake pad carrier66. These cam surfaces102are engaged by corresponding rollers104provided on the roller support units68of the brake pad carrier66. The rollers104are shown for instance inFIG. 9. They can be mounted on the same axle96as the rollers92. Other configurations are possible as well. It should be noted that the relative position of the ramp surfaces102and the rollers104can be inverted. Other variants are possible as well.

FIG. 10is an isometric view showing the inboard casing part22and some of the components connected to it.FIG. 11is a view similar toFIG. 10and shows the same back side viewed from a different angle.FIG. 12is an isometric view of all these parts.FIG. 11does not show the casing44of the actuator assembly40.FIGS. 10 and 12show the casing44of the actuator assembly40and the inboard casing part22with a partial cutaway section.

Referring back toFIG. 8, the actuator assembly40of the illustrated example has an annular configuration. It comprises a pneumatically inflatable ring actuator46that is inserted in the casing44of the actuator assembly40. The actuator assembly40also comprises an axially-actuated member48that is adjacent to the inflatable ring actuator46. The axially-actuated member48is coaxially located with reference to the central axis R (FIG. 3). The diameter of the inflatable ring actuator46can then be larger compared to an inflatable ring that would be inserted within the inboard casing22, for instance.

The axially-actuated member48comprises four axially projecting cams49with inclined cam surfaces49athat are provided in an axisymmetric manner around the axially-actuated member48. The cams49of the axially-actuated member48engage a corresponding follower, for instance a roller108, provided at the periphery of the intermediary member100. These rollers108have an axle110that is radially oriented with reference to the central axis R. As best shown inFIG. 12, arc-shaped openings112are provided at the periphery of the back wall of the illustrated inboard casing part22and the cams49of the axially-actuated member48are extending through a corresponding one of these openings112for engaging the outer rollers108.

Because the cams49are in engagement with the rollers108of the intermediary member100and that the axially-actuated member48only moves in an axial direction, the intermediary member100is forced to pivot around the central axis R when the member48moves. The pivot movement moves the rollers104of the brake pad carrier66further up the ramp surfaces102. This results in an axial movement of the brake pad carrier66towards the rotor disk60. The global aim of actuator mechanism shown inFIGS. 10 to 12is to reduce the inflatable ring axial displacement by a factor ratio to the brake pad carrier66and at the same time increase the brake pad carrier clamping force by an equivalent factor ratio from the inflatable ring actuator force. The therefore generated force amplification factor can be set around a value of 5 and be tuned by modifying the ratio of angle of the actuating ramps49and angle of the intermediate ramps102. Furthermore, because of the specific configuration of the illustrated example, the axial movement of the brake pad carrier66generates a slight pivot movement of the brake pad carrier66in the same direction as the rotation of the wheel of the vehicle traveling in a forward direction.

A return spring arrangement is provided, for instance as part of the actuator assembly40, for moving the brake pad carrier66away from the rotor disk60when the braking force decreases or is released. The return spring arrangement can include one or more springs. One spring is schematically illustrated inFIG. 8at120. The spring or springs120can be connected, for instance, between the brake pad carrier66and the inboard casing part22. The spring or springs120can also be configured and disposed otherwise and many different configurations can be devised for moving the brake pad carrier66back to its original position.

In use, inflating the inflatable ring actuator of the actuator assembly40pushes the axially-actuated member48towards the outboard side. The configuration of the illustrated brake10, however, creates a force increasing amplification between the axially-actuated member48and the brake pad carrier66. This force amplification increases the braking force in the brake10. The force transmitting arrangement of the illustrated brake10comprises the first cam interface that is provided between the axially-actuated member48and the intermediary member100, and the second cam interface that is provided between the intermediary member100and the brake pad carrier66. When the brake10is activated, such as when the driver of a vehicle depresses the brake pedal to slow down the moving vehicle, a first force is generated by the actuator46of the actuator assembly40. The first force is in a direction that is parallel to the rotation axis of the rotor disk60. A torque is simultaneously generated using the first force, the torque having a center of rotation that is substantially coincident with the rotation axis of the rotor disk60. A second force is simultaneously generated using the torque, the second force being in a direction that is substantially identical to the direction of the first force and being greater in magnitude than the first force. The second force is used as the braking force for clamping the brake pads62,64on opposite sides60a,60bof the rotor disk60.

As can be appreciated, the design of a brake like the brake10can be made more compact than ever before. The brake10can also be configured to provide a stable self-increase of the braking capacity during the braking. Overall, many aspects of the design of the disk brake can thus be improved by mounting the axially movable set of brake pads on a guided brake pad carrier that is pushed against the rotor disk by an intermediary member, as shown. This arrangement can increase, for instance, the compactness of the brake. Furthermore, evenly distributing the braking force around the circumference of the rotor disk60improves the life span of the brake pads62,64.

If desired, a mechanism (not shown) can be provided to compensate the wear of the brake pads62,64over time. Such system can moves, for instance, the lowest point on the intermediary member100to which the rollers104at the back of the brake pad carrier66can go when the braking force is released. Other configurations are also possible.

It should be noted that many modifications can be made to the brake10and the method presented herein. For instance, more than one rotor disk can be provided in an annular disk brake. In that case, the two rotor disks would be axially movable with reference to each other. Both rotor disks can be in rotational engagement with a main support of the brake. An additional brake pad carrier (not shown) can be provided between the two rotor disks. This intermediary brake pad carrier would be double-sided and freely movable in the axial direction but ideally, it can also be in rotational engagement with a fixed structure, such as the casings20,22of the illustrated brake10. If desired, the rotor disk can be a solid rotor without internal cooling channels like the ones of the illustrated example. Also, the opposite surfaces of the rotor disk, either with or without internal cooling channels, can be grooved or provided with holes to further improve cooling. If a pneumatic actuator is used, the pneumatic actuator can have a non-circular shape, for instance a square shape with rounded corners, so as to increase the surface area where needed and keep the actuator as compact as possible. As aforesaid, the actuator assembly that is shown and described can be replaced by another kind of actuator, which can involve hydraulic fluid or even an electric mechanism. Many other variants are also possible.