Brake or clutch device

Abstract

A brake or clutch assembly comprising a housing (2) with a lamellar assembly (4) arranged inside the housing (3), comprising an outer lamellar carrier (7) with at least one outer lamellar (8) axially movable thereon, and an inner lamellar carrier (9) with at least one inner lamellar (10) axially movable thereon, and a coolant receiving chamber (12) provided on the housing (2) for receiving a coolant (27) to be supplied to the lamellar assembly (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 lamellar assembly (4) and communicates with the interior of the housing (3) via at least one opening (18) such that the coolant (27) flows onto the lamellar assembly (4) by gravity when the opening (18) is open. characterized by the fact 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), wherein the closing element (20) is a curved closing plate (21) which, in the closed position, rests close to the walls bounding the coolant receiving chamber (12), and / or characterized by the fact that the housing (2) has a one-piece formed section (13) having a cavity (14) which forms the coolant receiving chamber (12), wherein the section has a further cavity (16) into which coolant can be introduced via an external coolant supply device which can be connected to a further connection means (17), which further cavity (16) communicates with the interior of the housing (3) via at least one further opening (26).

Description

[0001] The invention relates to a brake or clutch device comprising a housing with a lamellar package arranged inside the housing, comprising an outer lamellar carrier with at least one outer lamellar arranged axially movable thereon and an inner lamellar carrier with at least one inner lamellar arranged axially movable thereon, as well as a coolant receiving chamber provided on the housing for receiving a coolant to be supplied to the lamellar package.

[0002] Such a braking or clutch device is mostly used in motor vehicles. The braking device serves to selectively 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. Such a braking or clutch device is known from DE 10 2016 200 009 B3. Such a device has a lamellar assembly comprising outer lamellae, which are axially movably guided on an outer lamella carrier, and inner lamellae, which are axially movably guided on an inner lamella carrier. The inner lamella carrier is, for example, connected to a rotating element such as a shaft, while the outer lamella carrier, in the case of a braking device, is fixed in position, and thus so are its outer lamellae.In the case of a braking device, to brake the rotating shaft, the assembly of outer and inner plates is axially compressed by a mostly hydraulic actuating device, causing the plates to come into frictional contact with each other. Since the outer plates are fixed in position and therefore do not rotate, the friction slows the rotation of the inner plates and consequently brakes the rotation of the shaft, ultimately bringing it to a standstill. In the case of a clutch device, the compression and transition into frictional engagement transfers the torque of the inner plate carriers to the rotating 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 design and function of such a multi-plate brake or clutch device are well known.

[0003] As described, when the clutch plates are compressed, the outer and inner plates are brought into frictional engagement. The inner plates are designed, for example, as friction plates and have a friction lining, while the outer plates are made of unlined steel. The friction generated during compression produces heat; that is, the entire clutch pack heats up during braking or clutch engagement. Therefore, the clutch pack must be cooled, for which a coolant is supplied. This coolant is usually supplied from an external component of the brake or clutch system, such as a transmission, via a pump and supply lines. In other words, the coolant is essentially pumped from the transmission 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 assembly, from which the coolant is drawn and fed to the clutch pack, and into which the coolant flowing from the clutch pack is then collected. The container thus forms a coolant receiving chamber, which is attached to the housing of the brake or clutch assembly as a separate component, so that the housing as a whole can be made smaller, since no larger space needs to be provided within it for receiving the coolant.

[0004] DE 10 2016 010 305 A1 discloses an automatic transmission with a brake device consisting of a rotatable friction disc on the rotational side and a non-rotatable friction disc on the stationary side, and switchable between an engaged and a disengaged state. Furthermore, a transmission housing, a lubricating oil supply section that directs lubricating oil to an upper area of ​​the brake device, and a lubricating oil drain section arranged below the brake device for draining the lubricating oil are disclosed.

[0005] As described, in known systems, it is necessary to transfer the coolant to the clutch pack using a pump. Sometimes this transfer is not continuous, meaning that cooling is not constant, but only temporary, i.e., the coolant is only supplied when a heat-generating process occurs. In a braking system, this is only the case when braking. In a motor vehicle, this means only when the driver presses the brake pedal and the braking system is activated, thus compressing the clutch pack via the actuator. During normal braking, the clutch pack is compressed more slowly, the deceleration is not too strong, and the heat generation within the clutch pack is tolerable, especially at the beginning of the braking process.As soon as braking begins, the coolant flow starts, so a certain, albeit very short, time elapses—for example, a few tenths of a second up to 1-2 seconds—until coolant can first reach the clutch pack. During this time, no cooling takes place, which is tolerable in the case of normal braking maneuvers due to the relatively low temperature rise of the clutch pack. However, the situation is different during hard or emergency braking. In this case, the clutch pack is compressed extremely quickly and forcefully, resulting in very high friction within the clutch pack and a very high heat generation in a very short time.In such a case, this occurs during the period when no, or at least not a sufficient, amount of coolant has been applied to the fin pack, so that, at least briefly, extremely strong heating up to the point of overheating of the fin pack can occur, which can be detrimental in the long run.

[0006] The invention is based on the problem of providing an improved braking or clutch device. This problem is solved by a braking or clutch device with the features of claim 1.

[0007] To solve the problem, a brake or clutch device according to the invention provides that the coolant receiving chamber, which can be filled with coolant via an external coolant supply device connectable to a connection means of the coolant receiving chamber, is arranged above the lamellar pack and communicates with the interior of the housing via at least one opening in such a way that, when the opening is open, the coolant flows onto the lamellar pack due to gravity.

[0008] The invention provides for the arrangement of a coolant reservoir on the housing of the brake or clutch assembly, wherein, in the mounting position, this coolant reservoir is arranged above the clutch pack. Thus, viewed in the mounting position, it is located on top of the housing in which the clutch pack is housed. The coolant reservoir communicates with the interior of the housing via at least one opening, optionally also via several openings. In normal operation, i.e., when there is no heavy braking, the coolant reservoir is filled with coolant, for example, a cooling oil. The at least one opening is closed by a suitable closing device.In a situation requiring heavy braking, i.e., a strong deceleration, the closing mechanism automatically opens at least one opening, allowing the coolant to flow by gravity from the coolant reservoir into the housing interior and directly onto the clutch pack. The coolant reservoir thus acts as a fluid reservoir, always filled with coolant at the moment heavy or emergency braking begins. The coolant then flows by gravity through the opened opening onto the clutch pack immediately at the start of the braking process. This means that coolant is supplied and the clutch pack is cooled as soon as braking begins.This at least bridges the gap until the usual cooling system, through which the coolant is normally supplied to the finned assembly, can be used to supply the coolant, i.e., until the coolant is pumped to the finned assembly and cooled.

[0009] The brake or clutch device according to the invention thus enables immediate cooling in cases where, due to the situation, extremely high heat generation occurs in an extremely short time, as is particularly the case with a brake device during emergency braking. This is because the coolant falls directly from the coolant reservoir through the open opening onto the clutch pack immediately at the start of the process, so that there is no or only a negligible time window in which the heavily stressed clutch pack is not supplied with coolant and thus not cooled.

[0010] Preferably, an opening is provided in a housing wall that defines at least a partially cylindrical section of the housing interior, in which the fin stack is arranged. The fin stack is cylindrical in its outer shape, which is why the housing or housing wall in the area where the fin stack is accommodated is adapted in shape to the fin stack, i.e., it is also at least partially cylindrical. This results in the most compact possible housing design. Since, according to the invention, the opening is arranged in this cylindrical housing section, to which the fin stack is closely adjacent, the coolant flows almost directly onto the fin stack; that is, the flow path is very short. Consequently, the coolant falls directly onto the fin stack due to gravity.

[0011] As described, at least one opening must be opened when necessary, i.e., during heavy braking, to allow the free flow of the cooling fluid. This is achieved via a suitable closing device. The closing device closes the opening during normal operation or braking and opens it when required. According to the invention, the closing device comprises a closing element which closes the opening in a closed position and which is reversibly movable from the closed position to open the opening. Thus, a separate closing element is provided, which is arranged adjacent to or directly on the opening and is reversibly movable between a closed and an open position.

[0012] Preferably, the locking element can be moved from the closed position against the restoring force of a return element. The locking element is thus pre-tensioned into the closed position by the return element, for example, one or more parallel-connected coil springs. To move it from the closed position, the locking element is moved against the return element(s), which are thereby compressed, generating a correspondingly higher restoring force and simultaneously opening the opening. The restoring force serves to return the locking element to the closed position after the coolant supply or braking process has ceased.

[0013] The closing element itself is a curved closing plate which, in the closed position, rests tightly against the walls bordering the coolant reservoir. This curved closing plate follows the geometry of the housing section or housing wall, which is expediently also curved or partially cylindrical in the area of ​​the opening. The coolant reservoir is simultaneously closed by this closing plate, for which purpose the closing plate rests correspondingly tightly against the walls bordering the coolant reservoir in the closed position.

[0014] The locking element itself can be moved automatically from the closed position, preferably without the need for an actuator. The locking element and the return element are advantageously arranged such that the locking element can move against the return element(s) in the direction of travel of the motor vehicle in which such a brake or clutch device is provided. During sufficiently strong deceleration, the locking element, due to its mass being braked only by the return element(s), pushes against the return element(s) and compresses them, simultaneously opening the opening. Thus, during strong deceleration, the locking element is accelerated against the return element. This means that the automatic opening process is controlled depending on the deceleration.With slight deceleration, i.e., when braking is only light or normal, the locking element remains in its pre-tensioned closed position; that is, it is held in the closed position by the return element(s). However, if the deceleration is greater, the locking element can overcome the given return force, move against the spring element(s), and open the opening. In this way, a simple, delay-controlled automatic opening operation of at least one opening is achieved.

[0015] The housing has a one-piece molded, cavity-like section that forms the coolant reservoir. This means that the housing, which is preferably a cast metal housing, is designed with the coolant reservoir integrated. Consequently, this reservoir is not a separate container attached to the housing, but is integrated into the housing itself.

[0016] In this case, the section forming the coolant reservoir has a further cavity into which coolant can be introduced via an external coolant supply device, which can be connected to another connection point. This further cavity communicates with the interior of the housing via at least one additional opening. As already described, coolant, i.e., oil, is pumped from a lubricant sump, for example, via a suitable coolant supply device and fed to the fin stack, albeit with a time delay. Advantageously, this coolant supply device is connected to the section that also defines the coolant reservoir, meaning that any supply lines can be routed to the same point.The section forming the coolant reservoir is extended accordingly and features a separate, isolated cavity to which a connection point is provided for the coolant supply device. This additional cavity communicates with the interior of the housing via one or more openings in the housing wall, allowing the coolant to enter the interior.

[0017] Preferably, in this embodiment, the return element(s) are arranged in the further cavity, wherein the closing element, for example the curved closing plate, can be moved into the further cavity when moving from the closed position. The cavity thus serves not only to receive and convey the coolant, but also simultaneously 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 deceleration ceases, the return element(s) push the closing element back into the closed position.It is also conceivable that when the flow of coolant, which is conveyed into the further 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 will already be empty or at least almost empty.

[0018] It is advantageous to provide several openings through which the coolant stored in the coolant reservoir flows into the housing interior, and / or several further openings through which the coolant supplied with a time delay flows into the housing interior, distributed circumferentially around the cylindrical section of the housing. This circumferentially distributed arrangement of openings or further openings ensures that the coolant, whether flowing from the coolant reservoir or supplied with a time delay, is delivered to various circumferential positions of the fin stack, so that the fin stack is supplied or wetted with coolant over a relatively large area circumferentially. This means that as much of the fin surface as possible comes into contact with the coolant as quickly as possible.This is particularly advantageous when braking to a standstill, as coolant is supplied via the external coolant supply system and the additional cavity. In this case, the problem arises that 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. Here, supplying coolant at several points distributed circumferentially proves beneficial in order to cool as much of the surface as possible, especially when the plate pack is released and thus also vented.

[0019] Finally, each opening, as well as any further openings, can be designed as elongated slots extending at least across the axial width of the fin stack. This means that the coolant receiving chamber and, if applicable, any further cavity are designed to be sufficiently wide, viewed in the direction of the fin stack's axis of rotation; that is, their width is at least equal to the width of the fin stack. The openings designed as slots, or any further openings, are also designed to be of a corresponding length, so that the coolant can be applied directly across the entire width of the fin stack, which can be several centimeters, depending on the number of outer and inner fins.

[0020] The invention is explained below with reference to exemplary embodiments and the drawings. The drawings are schematic representations and show: Fig. 1 a partial view of a braking device according to the invention with the locking element in the closed position, and Fig. 2 the partial view from Fig. 1 with a locking element in an open position.

[0021] Fig. Figure 1 shows a partial view in the form of a schematic representation of a brake 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 lamellar pack 4 is received. The lamellar pack 4 is cylindrical in its outer shape, which is why the housing 2 also has, at least in the area in which the lamellar pack 4 is received, a housing wall 5 which has a cylindrical section 6 that delimits the housing interior 3, so that, see Figure 1. Fig. 1, the lamella package 4 is arranged in a quasi-shape-compatible and as compact a manner as possible and with a small distance to the inner wall of the housing wall 5.

[0022] The lamellar assembly 4 comprises an outer lamellar carrier 7 on which one or more outer lamellars 8, preferably steel lamellars, are arranged for axial movement. It further comprises an inner lamellar carrier 9 on which one or more inner lamellars 10, designed as friction or lining lamellars and featuring a corresponding friction lining 11, are arranged for axial displacement. These lamellars 8, 10 can be pressed axially against an abutment by means of a suitable, usually hydraulic, actuating device, so that a frictional connection between the individual lamellars 8, 10 can be achieved. In the case of a braking device 1, the inner lamellar carrier 9 is connected to an axle driven, for example, by an electric motor, so that it and with it the inner lamellars 10 rotate when the motor vehicle 1 moves. The outer lamellar carrier 7 and the outer lamellars 8, on the other hand, are fixed in position and therefore do not rotate.When braking is desired, the actuating device is activated by pressing the brake pedal, and the clutch pack with its outer and inner clutch plates 8, 10 is axially compressed. This causes the outer and inner clutch plates 8, 10 to come into contact and engage in frictional engagement, thereby decelerating the axle by slowing the rotation of the inner clutch plate carrier 9. When the clutch pack 4 is released, the clutch plates 8, 10 separate again, and frictionless operation is restored until the next braking action.

[0023] During braking, heat is generated due to friction, which is why the clutch pack 4 must be cooled. For this purpose, a coolant reservoir 12 is provided, which is integrally formed on the housing 2 by means of a corresponding section 13 being integrally molded onto the housing 2, as shown. Fig. Figure 1 shows that 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, through which a coolant, for example a cooling oil, can be conveyed into the coolant receiving chamber 12, as shown by arrow P1. Section 13 extends further in the circumferential direction of the housing wall 5, where another cavity 16 is formed, into which another connection means 17 opens, to which a line of the coolant supply device or of another coolant supply device for supplying coolant can also be connected, as shown by arrow P2. That is, coolant can be conveyed into both cavities 14 and 16.

[0024] The coolant intake chamber 12 serves as a coolant reservoir in which a corresponding quantity of coolant is stored until it is to be supplied to the fin stack 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 fin stack 4, which opens directly adjacent to the fin stack 4 or the outer fin carrier 7. This opening 18 is relatively wide, as the coolant from the coolant intake chamber 12 is to be supplied directly to the fin stack 4 through it. To enable this, but also to retain the coolant in the coolant intake chamber 12 when not needed for cooling purposes, a closing device 19 is provided, comprising a movable closing element 20, which here is designed as a curved closing plate 21.The locking device 19 further comprises at least one return element 22, here in the form of a coil spring, which is supported on one side by an abutment 23 in the further cavity 16, and on the other side by an abutment section 24 of the locking element 20. The locking element 20 is therefore inserted into the cavity via the return element 22. Fig. 1 shown closed position pre-tensioned, in which it lies close to the walls 25, which limit the coolant receiving chamber 12 and thus closes the opening 18.

[0025] Furthermore, a number of additional openings 26 are provided in the housing wall 5, distributed circumferentially and communicating with the additional cavity 16. Thus, if coolant is conveyed into the additional cavity 16 via the additional connection 17, it can flow to the fin stack 4 through the circumferentially distributed additional openings 26. As a result of the circumferential distribution of the additional openings 26, the coolant is supplied at different positions relative to the total annular area of ​​the fins 8, 10.

[0026] The coolant intake chamber 12 with its cavity 14, as well as the further cavity 16, are evidently located in the Fig. The brake assembly 1 is mounted in the position shown above the clutch pack 4, i.e., it sits on top of the housing 2. This causes the coolant to flow downwards onto the clutch pack 4 from the opening 18 and the other openings 26. This flow occurs solely by gravity from the coolant reservoir 12, as this reservoir is filled at the start of braking but is not actively pressurized by coolant at that moment. Therefore, when the closing element 20 is open, the coolant can flow directly onto the clutch pack 4 by gravity alone. The opening 18 is positioned such that the incoming coolant, which directly impacts the outer clutch carrier 7 and flows through it onto the clutch plates 8 and 10, is guided counterclockwise by the rotating inner clutch plates 10.Arrow P3 indicates the direction of travel, arrow P4 the direction of rotation of the inner fins 10. This results in the coolant supplied from the opening 18 being automatically carried along counterclockwise and distributed within the fin pack 4.

[0027] Fig. Figure 2 shows the braking device 1 during a hard braking maneuver, for example, an emergency stop. Starting from the situation as in Fig.As shown in Figure 1, which is present immediately before the start of the braking process, the driver applies the brakes, whereupon the actuating device immediately and with high pressure axially compresses the outer and inner plates 8, 10. This results in an extremely rapid build-up of extremely high friction within the plate assembly, combined with extremely rapid heat generation, but also extremely strong deceleration. Due to this deceleration, the ultimately only spring-loaded closing element 20, i.e., the curved closing plate 21, moves almost counterclockwise or in the direction of travel as shown by arrow P3 and works against the return element 22, which is thereby compressed and builds up a higher return force. At the same time, the opening 18 inevitably opens, which causes the coolant 27 contained in the cavity 14 to flow into the plate assembly 4 due to gravity, as shown by arrow P5.Since the closing element 20 is moved from the closed position depending on the deceleration, the opening 18 opens when there is a sufficiently strong deceleration, accompanied by very high friction and high heat generation. The further cavity 16 does not yet contain coolant, or it has not yet been supplied, as this supply occurs with a slight time delay. As soon as coolant is also supplied to the further cavity 16, it can flow through the further openings 26 to the fin assembly 4 and cool it additionally. Until this point, however, cooling is already achieved via the coolant 27 from the coolant intake chamber 12, meaning that the extremely stressed fin assembly 4 is cooled immediately upon the onset of heavy braking, bridging the time until coolant can be supplied to the fin assembly 4 via the further openings 26.

[0028] With the supply of coolant into the further cavity, it is conceivable that the closing element 20 will be gradually forced back into the closed position due to the coolant pressure building up in the further cavity 16. At this point, the cavity 14 will already be largely or completely empty, so that, in principle, the opening 18 can be closed again. However, it is also conceivable that the opening 18 will remain open, especially if coolant is also supplied to the cavity 14 via the coolant supply device and the connecting element 15, which can then additionally flow from the opening 18 to the lamellar assembly 4. In any case, the closing element 20 closes when the deceleration decreases, i.e., when the vehicle has braked almost to or completely come to a standstill. This is because no further acceleration acts on the closing element, and the return element 22 pushes the closing element 20 back into position.In this standstill situation, coolant is guided through the additional openings 26 to the fin stack 4 via the circumferentially offset openings 26, which are also designed as elongated slots and, like the opening 18, extend at least over the width of the fin stack 4. The fin stack 4 continues to be cooled even when stationary. This prevents the fins from overheating. Reference symbol list 1. Braking system 2 cases 3 Case interior 4 slat package 5 Housing wall Section 6 7 Outer slat carriers 8 Outer slat 9 inner slat carriers 10 inner slat 11 Friction lining 12 Coolant intake chamber Section 13 14 Cavity 15 connection devices 16 Cavity 17 connection devices 18 Breakthrough 19 Locking device 20 locking elements 21 Locking plate 22 Return element 23 abutments 24 Abutment section 25 wall 26 Breakthrough 27 Coolant P1 - P5 Arrow

Claims

[1] Brake or clutch device comprising a housing (2) with a lamellar assembly (4) arranged inside the housing (3), comprising an outer lamellar carrier (7) with at least one outer lamellar (8) axially movable thereon and an inner lamellar carrier (9) with at least one inner lamellar (10) axially movable thereon, and a coolant receiving chamber (12) provided on the housing (2) for receiving a coolant (27) to be supplied to the lamellar assembly (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 lamellar assembly (4) and communicates with the interior of the housing (3) via at least one opening (18) such that the coolant (27) flows onto the lamellar assembly (4) by gravity when the opening (18) is open. flows, 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), wherein the closing element (20) is a curved closing plate (21) which, in the closed position, rests close to the walls bounding the coolant receiving chamber (12), and / or characterized by , that the housing (2) has a one-piece formed section (13) having a cavity (14) which forms the coolant receiving chamber (12), wherein the section has a further cavity (16) into which coolant can be introduced via an external coolant supply device which can be connected to a further connection means (17), which further cavity (16) communicates with the interior of the housing (3) via at least one further opening (26). [2] Brake or clutch device according to claim 1, characterized by , that the opening (18) is provided in a housing wall (5) which limits at least a partially cylindrical section of the housing interior (3) in which section the lamellar pack (4) is arranged. [3] Brake or clutch device according to any of the preceding claims, characterized by , that the closing element (20) can be moved from the closed position against the restoring force of at least one restoring element (22). [4] Brake or clutch device according to claim 3 characterized by , that 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. [5] Brake or clutch device according to one of the preceding claims and claim 2, characterized by, that several openings (18) and / or several further openings (26) are provided, which are distributed in the circumferential direction of the cylindrical section. [6] Brake or clutch devices according to any 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 lamellar package (4).

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