Brake or clutch device

Abstract

A brake or clutch device, comprising a housing (2) with a disk pack (4) arranged in the housing interior (3), comprising an outer disk carrier (7) with at least one outer disk (8) arranged thereon for axial movement and an inner disk carrier (9) with at least one inner disk (10) arranged thereon for axial movement, and a coolant receiving chamber (12) provided on the housing (2) for receiving a coolant (27) to be supplied to the disk pack (4), wherein the coolant receiving chamber (12), which can be filled with the coolant (27) via an external coolant supply device connectable to a connection means (15) of the coolant receiving chamber (12), is arranged above the disk pack (4) and communicates with the housing interior (3) via at least one opening (18) in such a way that the coolant (27) flows onto the disk pack (4) due to gravity when the opening (18) is open.

Description

[0001] The invention relates to a brake or clutch device comprising a housing with a disk pack arranged in the interior of the housing, comprising an outer disk carrier with at least one outer disk arranged axially movably thereon and an inner disk carrier with at least one inner disk arranged axially movably thereon, as well as a coolant receiving space provided on the housing for receiving a coolant to be supplied to the disk pack.

[0002] Such a braking or clutch device is mostly used in the automotive sector. The braking device serves to specifically brake a rotating element, usually a shaft or axle, while a clutch device serves to couple or decouple a transmission with an internal combustion engine as needed. DE 10 2016 200 009 B3 discloses such a braking or clutch device. Such a device has a disk pack comprising outer disks that are guided axially movably on an outer disk carrier, and inner disks that are guided axially movably on an inner disk carrier. The inner disk carrier is connected, for example, to a rotating element such as a shaft, whereas in the case of a braking device the outer disk carrier is fixed in position, and thus also its outer disks.In the case of a braking device, in order to brake the rotating shaft, the set of outer and inner plates is pressed together axially via a usually hydraulic actuation device, causing the plates to come into frictional contact with one another. Since the outer plates are fixed in position and therefore do not rotate, the resulting friction slows the rotation of the inner plates and consequently brakes the rotation of the shaft, at most to a standstill. In the case of a clutch device, the compression and transition to frictional engagement transmits the torque of the inner plate carriers to the turned outer plates and via these to the output shaft, or vice versa, depending on which plate carrier is connected to the input shaft. The basic structure and basic function of such a multi-disk brake device or multi-disk clutch device is well known.

[0003] As described, when the outer and inner plates are pressed together, they are brought into frictional engagement. The inner plates, for example, are designed as lined or friction plates and have a friction lining, while the outer plates are designed as unlined steel plates. The friction that occurs when they are compressed generates heat, i.e. the entire plate pack heats up when braking or engaging the clutch. The plate pack must therefore be cooled, for which purpose a coolant is supplied to it. The coolant is usually supplied from an operating unit assigned to the brake or clutch device, such as a gearbox or the like, i.e. from external sources, via a pump and supply lines. This means that the coolant is essentially pumped from the gearbox sump and supplied.From DE 10 2016 200 009 B3, it is known to arrange a separate container on the housing of the brake or clutch device, from which the coolant is extracted and fed to the disk pack, and into which the coolant draining from the disk pack is collected. The container thus forms a coolant receiving space, which is attached to the housing of the brake or clutch device as a separate component, allowing the overall housing to be small, since no larger space is required to accommodate the coolant.

[0004] As described, in known devices it is necessary to circulate the coolant or to pump it to the disc pack using a conveying means, i.e. a pumping device. Sometimes this pumping is not permanent, i.e. there is no permanent cooling, but only temporary, i.e. the coolant is only supplied when a heat-generating process is taking place. In particular with a braking device this is only the case when braking. In a motor vehicle this means only when the person driving the vehicle presses the brake pedal and the braking device is activated, i.e. the disc pack is compressed via the actuating device. In the case of normal braking, the disc pack is compressed more slowly, the deceleration is not too strong, and the heat development within the disc pack is tolerable, especially at the beginning of the braking process.The flow will begin as soon as the braking process begins, meaning that a certain, albeit very short, time passes before the coolant can first be applied to the disc pack, for example a few tenths of a second up to 1-2 seconds. During this time, no cooling takes place, which is tolerable in the case of a normal braking maneuver due to the relatively low heating of the disc pack. The situation is different, however, during heavy braking or emergency braking. In this case, the disc pack is compressed extremely quickly and extremely strongly, resulting in very high friction within the disc pack, combined with very strong heat development in a very short time.In such a case, this occurs within the period in which no or in any case insufficient amount of coolant is applied to the plate pack, so that an extremely strong heating up or even overheating of the plate pack can occur, at least for a short time, which can be detrimental in the long term.

[0005] The invention is therefore based on the problem of providing a braking or clutch device which is improved compared to the prior art.

[0006] To solve the problem, in a brake or clutch device according to the invention, it is provided that the coolant receiving space, which can be filled with the coolant via an external coolant supply device connectable to a connecting means of the coolant receiving space, is arranged above the disk pack and communicates with the housing interior via at least one opening in such a way that the coolant flows onto the disk pack due to gravity when the opening is open.

[0007] The invention provides for the arrangement of a coolant receiving chamber on the housing of the brake or clutch device, wherein, relative to the assembly position, this coolant receiving chamber is arranged above the disk pack. Thus, as seen in the assembly position, it is located on top of the housing in which the disk pack is accommodated. The coolant receiving chamber communicates with the interior of the housing via at least one opening, or possibly via several openings. During normal operation, i.e. when braking is not being applied sharply, the coolant receiving chamber is filled with coolant, for example a cooling oil. The at least one opening is closed by a suitable closing device.If a situation occurs in which heavy braking occurs, i.e., if a significant deceleration occurs, the locking device automatically opens at least one opening, allowing the coolant to flow, solely by gravity, from the coolant reservoir into the housing interior and from there directly onto the disc pack. The coolant reservoir thus forms a fluid reservoir that is always filled with coolant at the time heavy or emergency braking begins, and from which the coolant flows, due to gravity, through the open opening onto the disc pack immediately at the start of the braking process. This means that the coolant can be supplied immediately at the start of the braking process, and the disc pack can be cooled.This can at least bridge the time until the cooling liquid can be supplied to the plate pack via the usual cooling device, through which the cooling liquid is otherwise supplied to the plate pack, and thus the cooling liquid is pumped to the plate pack via the pump device to cool it.

[0008] The brake or clutch device according to the invention thus enables immediate cooling in cases where, depending on the situation, extremely strong heat development occurs in an extremely short period of time, as is particularly the case with a braking device during emergency braking. This is because the coolant falls from the coolant receiving chamber through the open aperture directly onto the disk pack, immediately at the start of the process, so that there is no or only a negligible time window in which the heavily loaded disk pack is not supplied with coolant and cooled.

[0009] The opening is preferably provided in a housing wall which delimits an at least partially cylindrical section of the housing interior, in which section the plate pack is arranged. The plate pack has a cylindrical outer shape, which is why the housing or the housing wall in the area in which the plate pack is accommodated is adapted to the shape of the plate pack, i.e. is also designed to be cylindrical at least in sections. This leads to the most compact possible design of the housing. Since, according to the invention, the opening is arranged in this cylindrical housing section, to which the plate pack is positioned closely adjacent, the coolant flows almost directly onto the plate pack, i.e. the flow path is very short. The coolant therefore falls directly onto the plate pack due to gravity.

[0010] As described, the at least one opening is to be opened when needed, i.e. when braking hard, to then allow the free flow of the cooling fluid. This is achieved by means of a suitable closing device. The closing device therefore closes the opening when driving or braking during normal operation and opens it when necessary. According to the invention, the closing device can for this purpose have a closing element which closes the opening in a closed position and which can be reversibly moved from the closed position to open the opening. A separate closing element is therefore provided which is arranged adjacent to the opening or directly on the opening and which can be reversibly moved between a closed position and an open position.

[0011] Preferably, the closing element is movable from the closed position against the restoring force of a return element. The closing element is thus preloaded into the closed position via the return element, for example, one or more coil springs connected in parallel. To move from the closed position, the closing element is moved against the return element(s), which are compressed while building up a correspondingly higher restoring force, and the opening is simultaneously opened. The restoring force serves to return the closing element to the closed position after the coolant supply or the braking process has ended.

[0012] The closing element itself is, for example, a curved closing plate, which, in the closed position, rests tightly against the walls bordering the coolant receiving chamber. This curved closing plate follows the geometry of the housing section or the housing wall, which is expediently also curved or partially cylindrical in the area of the opening. This closing plate simultaneously closes the coolant receiving chamber, for which purpose the closing plate rests tightly against the walls bordering the coolant receiving chamber in the closed position.

[0013] The locking element itself can be moved automatically from the closed position, although preferably no actuator is provided for this purpose. The arrangement of the locking element and the return element is expediently such that the locking element can be moved against the return element(s) in the direction of travel of the motor vehicle in which such a braking or clutch device is provided. In the event of sufficiently strong deceleration, the locking element, due to its mass being braked solely by the return element(s), presses or pushes against the return element(s) and compresses them, simultaneously opening the opening. The locking element is therefore accelerated against the return element during strong deceleration. This means that the automatic opening process is controlled as a function of the deceleration.In the event of a slight deceleration, i.e., when braking is only light or normal, the locking element remains in its preloaded closed position, i.e., it is held in the closed position by the return element(s). However, if the deceleration is greater, the given return force can be bridged by the locking element, the locking element moves against the spring element(s), and opens the opening. This enables a simple, delay-controlled automatic opening operation of the at least one opening.

[0014] Preferably, the housing has a one-piece, hollow portion that forms the coolant receiving space. This means that the housing, which is preferably a cast metal housing, is designed with the integrated coolant receiving space. Consequently, this space is not formed as a separate container arranged on the housing, but rather is integrated into the housing.

[0015] In this case, the section forming the coolant receiving space preferably has a further cavity into which coolant can be introduced via an external coolant supply device connectable to a further connection means, which further cavity communicates with the housing interior via at least one further opening. As already described, coolant, i.e. oil, is conveyed via a corresponding coolant supply device, for example from a lubricant sump, via a pump device or similar and fed to the plate pack, but with a time delay. This coolant supply device is expediently connected to the section that also defines the coolant receiving space, i.e. any supply lines can be routed to the same point.The section forming the coolant receiving chamber is designed to be correspondingly extended and has a separate, additional cavity separated from the coolant receiving chamber, which houses a connection means to which the coolant supply device can be connected. This additional cavity communicates with the housing interior via one or more additional openings in the housing wall, allowing the coolant to be fed into the interior through these openings.

[0016] In this embodiment, the return element(s) is / are preferably arranged in the further cavity, wherein the closing element, for example the curved closing plate, can be moved into the further cavity when moved from the closed position. The cavity therefore serves not only to hold and convey the cooling liquid, but also as a receiving space for the return element(s) and the closing element moved from the closed position. The embodiment can be such that the closing element remains in the open position or in the position pushed into the further cavity as long as there is a sufficiently strong deceleration. If this is no longer the case, the return element(s) pushes the closing element back into the closed position.However, it is also conceivable that when the flow of coolant, which has been pumped into the additional cavity with a time delay, begins and pressure builds up within it, the closing element is moved back into the closed position. At this point, the coolant receiving chamber has already drained or is at least almost empty.

[0017] It is expedient to provide several openings through which the coolant stored in the coolant receiving chamber flows into the housing interior, and / or several further openings through which the coolant supplied with a time delay flows into the housing interior, which are distributed in the circumferential direction of the cylindrical section of the housing. The coolant, whether flowing from the coolant receiving chamber or supplied with a time delay, is supplied to various circumferential positions of the plate pack via this circumferentially distributed arrangement of the openings or further openings, so that the plate pack is supplied with coolant or wetted with coolant over a relatively large area in the circumferential direction. This means that as large a surface area of the plate pack as possible comes into contact with the coolant as quickly as possible.This is particularly advantageous when the vehicle has been braked to a standstill and the coolant is supplied via the external coolant supply device and the additional cavity. In this case, the problem arises that the frictional heat from the steel plates, which become very hot during braking, can creep into the adjacent friction plates. While the coolant is circulated within the plate pack during rotation, this is no longer the case when the plate pack is stationary. In this case, the coolant supply at several points distributed around the circumference proves to be useful in order to cool the entire surface as much as possible, especially if the plate pack is released again after the brake pedal is released.

[0018] Finally, the or each opening, as well as the or each further opening, can be designed as elongated slots that extend at least across the axial width of the plate pack. This means that the coolant receiving space and, if applicable, the further cavity are designed to be correspondingly wide, as viewed in the direction of the rotational axis of the plate pack, i.e., their width corresponds at least to the width of the plate pack. The openings designed as slots or further openings are also correspondingly long, so that the coolant can be applied directly across the entire width of the plate pack, which can be several centimeters, depending on the number of outer and inner plates.

[0019] The invention is explained below using exemplary embodiments with reference to the drawings. The drawings are schematic representations and show: Fig. 1 a partial view of a braking device according to the invention with the closing element in the closed position, and Fig. 2 the partial view Fig. 1 with the locking element in an open position.

[0020] Fig. 1 shows a partial view in the form of a schematic diagram of a braking device 1 according to the invention. This comprises a housing 2, preferably made of die-cast metal, with a housing interior 3 in which a disk pack 4 is accommodated. The disk pack 4 is cylindrical in its outer shape, which is why the housing 2, at least in the area in which the disk pack 4 is accommodated, has a housing wall 5 which has a cylindrical section 6 which delimits the housing interior 3, so that, see Fig. 1, the lamella pack 4 is arranged in a form-compatible and as compact a manner as possible and with a small distance to the inner wall of the housing wall 5.

[0021] The disc pack 4 has an outer disc carrier 7, on which one or more outer discs 8, preferably steel discs, are arranged for axial movement. It also has an inner disc carrier 9, on which one or more inner discs 10, which are designed as friction or lining discs and have a corresponding friction lining 11, are arranged for axial movement. These discs 8, 10 can be pressed axially against an abutment via a suitable, usually hydraulic actuating device, so that a frictional connection can be achieved between the individual discs 8, 10. In the case of a braking device 1, the inner disc carrier 9 is connected to an axle driven, for example, by an electric motor, so that it and with it the inner discs 10 rotate when the motor vehicle 1 moves. The outer disc carrier 7 and the outer discs 8, on the other hand, are fixed in position and therefore do not rotate.If braking is desired, the actuating device is activated by depressing the brake pedal, and the disc pack with the outer and inner discs 8, 10 is compressed axially. The outer and inner discs 8, 10 then come into contact and frictional engagement, which results in the deceleration of the axle due to a deceleration of the rotation of the inner disc carrier 9. When the disc pack 4 is relieved of load, the discs 8, 10 separate again, restoring friction-free operation until the next deceleration.

[0022] During braking, heat is generated due to the frictional engagement, which is why the disk pack 4 must be cooled. For this purpose, a coolant receiving chamber 12 is provided, which is formed integrally on the housing 2 by a corresponding section 13 being integrally formed on the housing 2, as Fig. 1. This coolant receiving chamber 12 has a cavity 14 into which a connection means 15 opens, to which a line of a coolant supply device can be connected, via which a coolant, for example a cooling oil, can be conveyed into the coolant receiving chamber 12, as shown by the arrow P1. The section 13 extends further in the circumferential direction of the housing wall 5, where a further cavity 16 is formed, into which a further connection means 17 opens, to which a line of the coolant supply device or of a further coolant supply device for supplying coolant can also be connected, as shown by the arrow P2. This means that coolant can be conveyed into both cavities 14, 16.

[0023] The coolant receiving chamber 12 serves as a coolant reservoir in which a corresponding amount of coolant is stored until it is to be supplied to the disk pack 4 at a specific time. For this purpose, at least one opening 18 is provided in the housing wall 5, preferably as an elongated slot extending in the direction of the axis of rotation of the disk pack 4, which opening 18 opens directly adjacent to the disk pack 4 or the outer disk carrier 7. This opening 18 is relatively wide, since the coolant from the coolant receiving chamber 12 is to be supplied directly to the disk pack 4 via it. To enable this, but at the same time to retain the coolant in the coolant receiving chamber 12 when not needed for cooling purposes, a closing device 19 is provided, comprising a movable closing element 20, which is designed here as a curved closing plate 21.The locking device 19 further comprises at least one return element 22, here in the form of a helical spring, which is supported on the one hand on an abutment 23 in the further cavity 16, and on the other hand on an abutment section 24 of the locking element 20. The locking element 20 is consequently moved via the return element 22 into the position shown in . Fig. 1, in which it lies tightly against the walls 25 which delimit the coolant receiving space 12 and thus closes the opening 18.

[0024] Furthermore, a plurality of further openings 26 are provided in the housing wall 5, which are arranged distributed in the circumferential direction and which communicate with the further cavity 16. Thus, if coolant is conveyed into the further cavity 16 via the further connection means 17, it can flow to the plate pack 4 via the further openings 26 distributed in the circumferential direction. As a result of the distribution of the further openings 26 in the circumferential direction, the coolant is supplied at different positions relative to the entire annular surface of the plates 8, 10.

[0025] The coolant receiving chamber 12 with its cavity 14 as well as the further cavity 16 are clearly located in the Fig. 1, the brake device 1 is located above the disc pack 4, i.e., they sit on top of the housing 2. This causes the coolant to flow downwards from the opening 18 and the further openings 26 onto the disc pack 4. This inflow occurs from the coolant receiving chamber 12 solely due to gravity, as this represents a reservoir that is filled at the time braking begins, but is not actively subjected to coolant pressure at this moment. Therefore, when the closing element 20 is open, the coolant can flow directly onto the disc pack 4 solely due to gravity. The opening 18 is located at a position selected such that the incoming coolant, which directly impacts the outer disc carrier 7 and flows through it onto the discs 8, 10, is pumped counterclockwise by the rotating inner discs 10.The arrow P3 indicates the direction of travel, the arrow P4 the direction of rotation of the inner plates 10. This means that the coolant supplied from the opening 18 is automatically carried counterclockwise and distributed within the plate pack 4.

[0026] Fig. Figure 2 shows the braking device 1 during a heavy braking operation, for example an emergency braking. Starting from the situation as in Fig.1, which occurs immediately before the start of the braking process, the driver applies the brake, whereupon the actuating device immediately and with high pressure compresses the outer and inner plates 8, 10 axially. This results in an extremely rapid build-up of extremely high friction within the plate pack, combined with an extremely rapid development of heat, but also an extremely strong deceleration. Due to this deceleration, the closing element 20, i.e. the curved closing plate 21, which is ultimately only spring-loaded, moves virtually counterclockwise or in the direction of travel according to arrow P3 and works against the restoring element 22, which is thereby compressed and builds up a greater restoring force. At the same time, the opening 18 inevitably opens, which leads to the coolant 27 held in the cavity 14 flowing into the plate pack 4 due to gravity, as shown by the arrow P5.Since the closing element 20 is moved from the closed position depending on the deceleration, the opening 18 is opened when there is a sufficiently strong deceleration, associated with very high friction and high heat generation. There is no coolant in the further cavity 16 or none has yet been pumped in, since this supply occurs with a slight time delay. As soon as coolant is pumped into the further cavity 16, it can flow via the further openings 26 to the disk pack 4 and cool it additionally. Up to this point, however, cooling has already been achieved via the coolant 27 from the coolant receiving chamber 12, i.e. the extremely loaded disk pack 4 is cooled immediately when the heavy braking begins and the time period until coolant can be fed to the disk pack 4 via the further openings 26 can be bridged.

[0027] As the coolant is supplied to the additional cavity, it is conceivable that the closing element 20 is gradually pushed back into the closed position due to the coolant pressure building up in the additional cavity 16. At this point, the cavity 14 has already largely or completely emptied, so that the opening 18 can in principle be closed again. However, it is also conceivable that the opening 18 remains open even further, in particular if coolant is supplied to the cavity 14 via the coolant supply device and also via the connecting means 15, which can then additionally flow from the opening 18 to the disk pack 4. In any case, however, the closing element 20 closes when the deceleration decreases, i.e. when the vehicle has braked almost to a standstill or to a complete stop. This is because acceleration no longer acts on the closing element, and the return element 22 pushes the closing element 20 back again.In this standstill situation, cooling fluid is guided to the plate pack 4 via the additional openings 26, which are offset in the circumferential direction and are also designed as elongated slots that, like the opening 18, extend at least across the width of the plate pack 4. The plate pack 4 continues to be cooled even during standstill. This prevents overheating of the plates. List of reference symbols 1 braking device 2 housings 3 Housing interior 4 slat pack 5 Housing wall Section 6 7 outer disc carriers 8 outer slats 9 inner disc carrier 10 inner lamella 11 Friction lining 12 Coolant reservoir Section 13 14 Cavity 15 connecting elements 16 Cavity 17 Connection devices 18 Breakthrough 19 Locking device 20 locking element 21 Locking plate 22 Reset element 23 abutments 24 abutment section 25 Wall 26 Breakthrough 27 Coolant P1 - P5 arrow QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2016 200 009 B3 [0002, 0003]

Claims

[1] Brake or clutch device, comprising a housing (2) with a disk pack (4) arranged in the housing interior (3), comprising an outer disk carrier (7) with at least one outer disk (8) arranged axially movably thereon and an inner disk carrier (9) with at least one inner disk (10) arranged axially movably thereon, and a coolant receiving space (12) provided on the housing (2) for receiving a coolant (27) to be supplied to the disk pack (4), characterized by that the coolant receiving chamber (12), which can be filled with the coolant (27) via an external coolant supply device connectable to a connection means (15) of the coolant receiving chamber (12), is arranged above the plate pack (4) and communicates with the housing interior (3) via at least one opening (18) in such a way that the coolant (27) flows onto the plate pack (4) due to gravity when the opening (18) is open. [2] Brake or clutch device according to claim 1, characterized by that the opening (18) is provided in a housing wall (5) which delimits an at least partially cylindrical section of the housing interior (3), in which section the plate pack (4) is arranged. [3] Brake or clutch device according to claim 1 or 2, characterized by that a closing element (20) is provided which closes the opening (18) in a closed position and which is reversibly movable from the closed position to open the opening (18). [4] Brake or clutch device according to claim 3, characterized by that the closing element (18) can be moved out of the closed position against the restoring force of at least one restoring element (22). [5] Brake or clutch device according to claim 3 or 4, characterized bythat the closing element (20) is a curved closing plate (21) which, in the closed position, lies tightly against the walls delimiting the coolant receiving space (12). [6] Brake or clutch device according to one of the preceding claims, characterized by that the housing (2) has an integrally formed section (13) having a cavity (14) which forms the cooling liquid receiving space (12). [7] Brake or clutch device according to claim 6, characterized by that the section has a further cavity (816) into which cooling liquid can be introduced via an external cooling liquid supply device connectable to a further connection means (17), which further cavity (16) communicates with the housing interior (3) via at least one further opening (26). [8] Brake or clutch device according to claim 7 and claim 4 or 5, characterized bythat the return element (22) is arranged in the further cavity (16) and the closing element (20) is movable into the further cavity (16) when moving from the closed position. [9] Brake or clutch device according to one of the preceding claims and claim 2, characterized by that a plurality of openings (18) and / or a plurality of further openings (26) are provided, which are distributed in the circumferential direction of the cylindrical section. [10] Brake or clutch devices according to one of the preceding claims, characterized by that the or each opening (18) and the or each further opening (26) are designed as elongated slots which extend at least over the axial width of the disk pack (4).

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