Control arrangement of a clutch device for a drive arrangement

Abstract

The present invention relates to a control arrangement (CA) of a clutch device (100) for a drive arrangement (D). Said clutch device (100) comprises: an annular housing (10) rotatable by means of a drive shaft (S1) about an axis (X); a piston device; a plurality of clutch discs (50) arranged about a driven shaft (S2) within said housing, and (20), such that, when pressed together by means of said piston device (20), torque is transferred to the driven shaft (S2). Said control arrangement (CA) comprises a set of housing cavities (12) distributed around and configured to radially run within said annular housing (10), and a set of fluid pressure provision devices (30) configured to be arranged within said set of housing cavities (12). The respective fluid pressure provision device (30) comprises a unit (32) radially movably arranged within the housing cavity (12) in which that fluid pressure provision device (30) is arranged such that the respective unit (32), when moving radially outwardly, provides pressure on said fluid (F) within that housing cavity (12) based on the centrifugal force so as to facilitate control of said frictional engagement of said plurality of clutch discs (50) by means of said piston device (20).

Description

[0001] CONTROL ARRANGEMENT OF A CLUTCH DEVICE FOR A DRIVE ARRANGEMENT

[0002] TECHNICAL FIELD

[0003] The present invention relates to a control arrangement of a clutch device for a drive arrangement. The present invention also relates to a clutch device having such a control arrangement. The present invention also relates to a drive arrangement having such a clutch device. The present invention also relates to a vehicle having such a drive arrangement.

[0004] BACKGROUND

[0005] Vehicles operated by means of a drive arrangement having an internal combustion engine and a transmission device, e.g. gearbox, require some kind of coupling system configured to facilitate connection to and disconnection from said transmission device. For e.g. tracked vehicles, such coupling system may be provided by a torque converter.

[0006] A disadvantage with a torque converter is that it provides a relatively high weight and takes up a relatively large volume. Further, a torque converter has a relatively high mass moment of inertia. A torque converter provides energy losses resulting in high fuel consumption.

[0007] An alternative to a torque converter may be a clutch device such as a wet clutch. US3176813A discloses a centrifugally actuated clutch wherein centrifugal force generated by a rotating housing traps fluid and moves a piston to engage clutch discs, wherein the centrifugal force exerted on the fluid within the rotating housing is used to move the piston to engage the clutch discs. There is however a need for providing a control arrangement of a clutch device for a drive arrangement which facilitates moving the piston to engage the clutch discs based on exerted centrifugal force.

[0008] OBJECTS OF THE INVENTION

[0009] An object of the present invention is to provide a control arrangement of a clutch device for a drive arrangement, which seeks to mitigate, alleviate, or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination.

[0010] A further object of the present invention is to provide a clutch device having such a control arrangement.

[0011] A further object of the present invention is to provide a drive arrangement having such a clutch device.

[0012] A further object of the present invention is to provide a vehicle comprising such drive arrangement having such a clutch device.

[0013] SUMMARY

[0014] These and other objects, apparent from the following description, are achieved by a control arrangement of a clutch device for a drive arrangement, a clutch device, a drive arrangement and a vehicle as set out in the appended independent claims. Preferred embodiments of the control arrangement are defined in appended dependent claims.

[0015] Specifically, an aspect of the present disclosure is achieved by a control arrangement of a clutch device for a drive arrangement. Said clutch device comprises an annular housing configured to be secured to and rotatable by means of a drive shaft about an axis, a plurality of clutch discs configured to be positioned within said housing and arranged about a driven shaft coaxially arranged relative to said drive shaft, and a piston device. Said plurality of clutch discs are arranged such that, when axially pressed together by means of said piston device so that they are frictionally engaged, torque is configured to be transferred to the driven shaft. Said control arrangement is configured to facilitate providing said frictional engagement of said plurality of clutch discs by means of centrifugal force exerted on fluid within said annular housing in connection to rotation of said annular housing so that said piston device acts on said plurality of clutch discs. Said control arrangement comprises a set of fluid filled housing cavities distributed around and configured to radially run within said annular housing, and a set of fluid pressure provision devices, a respective fluid pressure provision device of said set of fluid pressure provision devices being configured to be arranged within a housing cavity of said set of housing cavities. The respective fluid pressure provision device comprises a unit configured to be radially movably arranged within the housing cavity in which that fluid pressure provision device is arranged such that the respective unit, when moving radially outwardly, provides pressure on said fluid within that housing cavity based on the centrifugal force so as to facilitate control of said frictional engagement of said plurality of clutch discs by means of said piston device. According to an aspect of the present disclosure, the plurality of clutch discs comprises a set of clutch discs operably connected, i.e. engaged, to said annular housing so that they rotate together with the annular housing about said axis. According to an aspect of the present disclosure, the plurality of clutch discs comprises a set of clutch discs operably connected, i.e. engaged, to said driven shaft. According to an aspect of the present disclosure, the set of clutch discs operably connected to said annular housing and the set of clutch discs operably connected to said driven shaft are alternatingly arranged and axially movable relative to each other. The degree of frictional engagement of said plurality of clutch discs is based on the centrifugal force and hence the pressure provided by the set of fluid pressure provision devices on the fluid transferred to the piston device, wherein increased centrifugal force results in increased pressure provided by the set of fluid pressure provision devices on the fluid and hence increased degree of frictional engagement. The pressure provided by the respective unit on the fluid within the housing cavity is a positive pressure. The control arrangement utilizes centrifugal force generated by the rotation of the annular housing to induce positive fluid pressure leading to clutch engagement. Said control arrangement is configured to achieve centrifugal operation, where increasing rotational speed of said annular housing actively facilitates clutch engagement. According to an aspect of the present disclosure, the fluid within the respective cavity comprises fluid arranged radially outwardly relative to the unit. The outer radial movement of said units due to certain centrifugal results in said units applying positive pressure on the fluid in the fluid cavity, which in turn applies pressure on said piston device so that axial movement of the piston towards the clutch discs is provided, providing said engagement of the clutch discs.

[0016] By thus providing said set of housing cavities distributed around and radially running within said annular housing, each provided with fluid pressure provision devices so that pressure is provided on fluid housed within the housing cavities by means of said radially outwardly moving units based on centrifugal force generated by rotation of said annular housing, efficient control of frictional engagement of said plurality of clutch discs is facilitated. The frictional engagement increases with increased centrifugal force, i.e. higher rotational speed of said annular housing. This solution facilitates providing a simple mechanical system of a clutch device for a drive arrangement which facilitates moving the piston device to engage the clutch discs based on exerted centrifugal force in an efficient and easy way. Hereby improved performance of the drive arrangement, e.g. powertrain, may be efficiently obtained. When applied in a vehicle, this solution facilitates improved driving experience due to said efficient control, comprising improved mobility and improved safety. Further, a cost-efficient solution is provided, e.g. compared with a torque converter. Hereby is facilitated optimized drive arrangement, i.e. motor / engine, installation in that volume is made available for facilitating: arrangement of an electric motor / generator around / outside said clutch device; elimination of existing generator and starter; a possibility to regenerate the kinetic energy of the vehicle; and possibility to electric or hybrid drive of the vehicle.

[0017] According to an aspect of the present disclosure, said units are configured to be radially movably arranged within said housing cavities such that, when subjected to a centrifugal force exceeding a certain threshold value, the respective unit moves radially outwardly and applies pressure on the fluid within its cavity such that said piston device acts on said plurality of clutch discs. Hereby, efficient control of frictional engagement of said plurality of clutch discs is facilitated.

[0018] According to an aspect of the present disclosure, the respective housing cavity is configured to be operably connected to said piston device via a fluid channel so that fluid within the respective housing cavity is allowed to flow between the housing cavity and said piston device via said fluid channel. Hereby, efficient control of frictional engagement of said plurality of clutch discs is facilitated. The respective fluid channel is connected to the associated housing cavity at a position radially outwardly relative to the unit.

[0019] According to an aspect of the present disclosure, the respective unit of said set of units is configured to be spring-loadably arranged within a housing cavity of said set of housing cavities for facilitating controlled radial movement of said units based on the centrifugal force. According to an aspect of the present disclosure, the respective unit of said set of units is configured to be spring- loaded at least during a certain degree of rotation of said annular housing. According to an aspect of the present disclosure, the respective unit of said set of units is configured to be spring-loaded by means of a predetermined spring force during non-rotation of said annular housing so as to facilitate positioning of the respective unit of said set of units at essentially the same position. According to an aspect of the present disclosure, the respective unit of said set of units is configured to be radially inwardly spring-loadably arranged within a housing cavity of said set of housing cavities for facilitating controlled radial movement of said units based on the centrifugal force so that said units are maintained at a non-active inwardly spring-loaded position when there is no centrifugal force, move radially outwardly when a certain centrifugal force is exceeded to a pressure position, i.e. active position, associated with the certain exceeded centrifugal force, and moves radially inwardly and returns from the pressure position to the non-active position when said certain centrifugal force is no longer exceeded. According to an aspect of the present disclosure, the respective unit of said set of units is configured to be radially biased inwardly within a housing cavity of said set of housing cavities. Hereby, efficient control of said fluid pressure provision devices and hence efficient control of said frictional engagement of said plurality of clutch discs is facilitated.

[0020] According to an aspect of the present disclosure, the respective fluid pressure provision device comprises a spring member arranged in connection to said unit, said spring member being configured to provide a predetermined spring force so that said unit is maintained in a non-actuated position if said spring force is not exceeded, wherein said spring force is configured to be exceeded when said centrifugal force exceeds a predetermined threshold value, providing radially outward movement of said unit from said non-actuated position for providing fluid pressure of said fluid within said housing cavity for said frictional engagement of said plurality of clutch discs by means of said piston device. According to an aspect of the present disclosure, the respective fluid pressure provision device comprises a spring member arranged in connection to said unit, said unit being configured to be radially biased inwardly by the spring member and radially movably arranged within said housing cavity, such that the respective unit moves radially outwardly against the spring member when the centrifugal force exceeds a predetermined threshold value, thereby generating a positive fluid pressure on said fluid within that housing cavity, said positive fluid pressure being transferred to the piston device causing the piston device to move axially towards the plurality of clutch discs for said frictional engagement. According to an aspect of the present disclosure, said spring member and said unit are separate parts, where said unit is configured to be arranged in connection to said spring member so that said unit, when subjected to said centrifugal force, acts against said spring member, wherein said unit is allowed to move radially outwardly when the spring force provided by said spring member is exceeded by the force provided by the unit on said spring member. According to an aspect of the present disclosure, said spring member and said unit provide an integrated portion, where said spring member is configured to be arranged in connection to said unit so that said unit of the integrated portion, when subjected to said centrifugal force is allowed to move radially outwardly when the spring force provided by said spring member is exceeded by the force provided by the unit on said spring member. Such an integrated portion of said spring member and said unit is, according to an aspect of the present disclosure, provided by a spring steel member providing both the spring member and the unit as a single part. By thus providing such a spring member, where said unit is thus arranged in connection to said spring member, efficient control of said fluid pressure provision devices and hence efficient control of said frictional engagement of said plurality of clutch discs is facilitated.

[0021] According to an aspect of the present disclosure, said unit is configured to move radially inwardly and return to said non-actuated position by means of said spring force provided by said spring member when said centrifugal force no longer exceeds said predetermined threshold value. According to an aspect of the present disclosure, said unit is configured to move radially inwardly and return to said non-actuated position by means of said spring force provided by said spring member when said centrifugal force no longer exceeds said predetermined threshold value, so that disengagement of the plurality of clutch discs is provided. Hereby efficient control of said fluid pressure provision devices and hence efficient control of disengagement of said plurality of clutch discs is facilitated. According to an aspect of the present disclosure, the respective radially running cavity is configured to be open towards a radial outer end of said annual housing by means of a radial opening. Hereby an easy and efficient solution for providing said control arrangement is facilitated in that said fluid pressure provision devices may be easily and efficiently assembled. Hereby efficient control of said fluid pressure provision devices and hence efficient control of engagement of said plurality of clutch discs is facilitated. According to an aspect of the present disclosure, the respective radially running cavity is configured to be closed at the radial inner end opposite said radial opening.

[0022] According to an aspect of the present disclosure, the respective spring member comprises or is operably connected to a locking member for sealingly locking said spring member in connection to the radial opening of a housing cavity of said set of cavities, providing, for said fluid, a closed space between the radial outer end of the unit and the radial opening. According to an aspect of the present disclosure, the respective fluid pressure provision device comprises a locking member for sealingly locking the radial opening of a housing cavity of said set of cavities, providing, for said fluid, a closed space between the radial outer end of the unit and the radial opening. The spring member is comprised in or operably connected to said locking member so that the spring member is allowed to be compressed radially outwardly towards said radial opening by means of said unit when the centrifugal force exceed said threshold value, wherein the locking member provides sealed lock at the radial opening so that the spring member is locked to the housing, facilitating said compression in the radially outward direction. The locking member is configured to close the housing cavity at the radial opening and secure the entire fluid pressure provision device assembly to the housing. Thus, the locking member is configured to sealingly lock said spring member to the housing. The radial movement of the unit and the compression of the spring member occur inside this sealed boundary. Therefore, the term "locking" refers to the static fixation of the assembly to the housing, while the term "sealingly" refers to ensuring hydrodynamic integrity. According to an aspect of the present disclosure, the respective spring member comprises or is operably connected to a locking member for providing sealed locking in connection to the radial opening of a housing cavity of said set of housing cavities, providing, for said fluid, a closed space between the radial outer end of the unit and the radial opening. Hereby said fluid pressure provision devices are efficiently secured at said housing cavities. According to an aspect of the present disclosure, said spring member and said locking member are separate parts, where said locking member is configured to close the housing cavity in connection to said opening, and to provide resistance when said spring member is subjected to a force by means of said unit when subjected to said centrifugal force. According to an aspect of the present disclosure, said locking member is configured to be arranged in connection to said spring member so as to position said spring member at said locking member. According to an aspect of the present disclosure, said locking member is configured to be arranged in connection to said spring member so as to control the spring member during movement of said unit and hence movement of said spring member. According to an aspect of the present disclosure, said spring member and said locking member provide an integrated portion, where said spring member is configured to be arranged in connection to said locking member. Such an integrated portion of said spring member and said locking member is, according to an aspect of the present disclosure, provided by a spring steel member providing both the spring member and the locking member as a single part. According to an aspect of the present disclosure, said unit, spring member and locking member provide an integrated portion. Such an integrated portion of said unit, spring member and locking member is, according to an aspect of the present disclosure, provided by a spring steel member providing the unit, spring member and locking member as a single part.

[0023] According to an aspect of the present disclosure, the respective unit has an elongated configuration having a radial outer end configured to face radially outwardly in said housing cavity, an opposite radial inner end configured to face towards the bottom of the housing cavity, and an outer surface configured to face towards the inner surface of the housing cavity. Hereby housing cavities facilitating efficient control by means of said fluid pressure provision devices is provided.

[0024] According to an aspect of the present disclosure, the respective fluid pressure provision device comprises a sealing member configured to be arranged around said unit so as to provide sealing of said unit towards said inner surface of said housing cavity so as to prevent fluid within said housing cavity escaping past said unit to said bottom of said housing cavity. Hereby avoidance of fluid within said housing cavity escaping past said unit to said radial inner side of said housing cavity, thereby facilitating efficient control by means of said fluid pressure provision devices, i.e. maximising pressurisation of said fluid during rotation of said annular housing providing centrifugal force exceeding said predetermined threshold value. Thus, according to an aspect of the present disclosure, the respective fluid pressure provision device comprises a sealing member configured to be arranged around said unit so as to provide sealing of said unit towards said inner surface of said housing cavity so as to prevent fluid within said housing cavity escaping past said unit to said radial inner side of said housing cavity.

[0025] According to an aspect of the present disclosure, the respective unit is configured to be closely received within its housing cavity so that said radial movement of the unit within said housing cavity is allowed. Hereby efficient control by means of said fluid pressure provision devices is facilitated.

[0026] According to an aspect of the present disclosure, the respective unit has a cylindrical configuration, wherein the respective radially running housing cavity has an inner shape essentially corresponding to the outer shape of said cylindrically configured unit, facilitating tightly receiving said unit. According to an aspect of the present disclosure, the respective radially running housing cavity has a ring-shaped cross-section, having said opening at the radial outer side, a radially running inner wall and a closed bottom side. Hereby efficient control by means of said fluid pressure provision devices is facilitated. According to an aspect of the present disclosure, said piston device comprises a ring-shaped piston coaxially arranged around said axis, said ring-shaped piston being arranged within and operably connected to said annular housing. Hereby, efficient operation of said piston device is facilitated in that pressing together of said plurality of said clutch discs by means of said ring-shaped piston is efficient, thereby further facilitating efficient control by means of said fluid pressure provision devices. According to an aspect of the present disclosure, said piston is configured to move axially towards said plurality of clutch discs for said frictional engagement based on pressure provided by said fluid when pressurised by means of said fluid pressure provision device. According to an aspect of the present disclosure, said piston is configured to return through axial movement away from said plurality of clutch discs when said fluid pressure provision device no longer provides pressure on said fluid. According to an aspect of the present disclosure, said piston is configured to be axially movably arranged between a first position corresponding to no fluid force acting on said piston, associated with said set of units being in a nonactuated position, and different other positions associated with different fluid pressures applied on said piston based on different centrifugal forces caused by rotation of said annular housing.

[0027] According to an aspect of the present disclosure, said ring-shaped piston comprises a recess configured to run around the ring-shaped piston configured to face away from said plurality of clutch discs and face towards a portion of said annular housing so as to provide a piston cavity in connection to said recess, wherein the fluid channel connected to the respective housing cavity is connected so that fluid within the respective housing cavity is allowed to flow between said housing cavity and said piston cavity via said fluid channel. By thus providing such a piston cavity by means of said recess of said piston device and having said fluid channels thus connected, efficient control by means of said fluid pressure provision devices is facilitated. The specific configuration of the ring-shaped piston comprising a recess defining the piston cavity facilitates achieving optimal efficiency in the centrifugal engagement mode, i.e. when the centrifugal force exceeds said predetermined threshold value. The centrifugal force, acting on the plurality of radially movable units, generates fluid pressure simultaneously across multiple circumferentially distributed housing cavities, wherein these multiple fluid inputs are efficiently coupled via their respective fluid channels into the continuous, circumferential piston cavity. This unique arrangement ensures a maximized and homogeneous distribution of axial pressure across the entire annular face of the ring-shaped piston. This homogenous pressure delivery is critical for high- performance clutching, ensuring smooth, precise, and quantifiable frictional engagement proportionally to the rotational speed. This specific structural geometry facilitates enabling the necessary positive, linear relationship between rotational speed, i.e. centrifugal force, and the axial engagement pressure required to achieve controlled frictional engagement.

[0028] According to an aspect of the present disclosure, said annular housing comprises an internal ring-shaped track having a bottom side, wherein said ring-shaped piston is configured to be closely received within said ring-shaped track, and wherein said recess of the ring-shaped piston is configured to face towards said bottom side of said internal ring-shaped track. Said ring-shaped piston is axially movable within said internal track based on centrifugal force so that it moves axially towards said clutch discs with increased rotational speed.

[0029] According to an aspect of the present disclosure said bottom side of said internal ring-shaped track corresponds to said portion of said annular housing towards which said recess is configured to face. According to an aspect of the present disclosure said portion of said annular housing towards which said recess of said ring-shaped piston is facing is configured to serve as the axial abutment surface of the annular housing. The recess, configured to face away from the clutch discs and towards said axial bottom side of said internal ringshaped track, creates the precisely defined piston cavity. This specific geometry is essential because the fluid channel is connected to this cavity, ensuring efficient and maximized translation of the radial fluid pressure generated in the housing cavities into a focused axial force acting on the piston. According to an aspect of the present disclosure, said piston device comprises a sealing member for providing sealed connection of said ringshaped piston to said annular housing. According to an aspect of the present disclosure, said piston device comprises a sealing member for providing sealed connection of said ring-shaped piston to said internal ring-shaped track of said annular housing. By thus providing such a sealing member, efficient control by means of said fluid pressure provision devices is facilitated in that leakage of fluid in connection to said piston is efficiently avoided. According to an aspect of the present disclosure, said sealing member is configured so as to assist in returning said piston to said first position when no longer subjected to said fluid pressure. According to an aspect of the present disclosure, said sealing member has resilient properties so as to assist in returning said ringshaped piston device back to a non-actuated position when said piston device is no longer subjected to fluid pressure exceeding a certain threshold value.

[0030] Said resilient properties of said sealing member of said piston device facilitates efficient control of said ring-shaped piston and hence efficient control of axial movement away from said plurality of clutch discs for disengagement of said plurality of clutch discs when said piston device is no longer subjected to fluid pressure exceeding a certain threshold value.

[0031] According to an aspect of the present disclosure, the plurality of clutch discs configured to be positioned within said annular housing and arranged about said driven shaft comprise a first set of clutch discs configured to be engaged to said annular housing and a second set of clutch discs configured to be engaged to said driven shaft, clutch discs of said first set of clutch discs and clutch discs of said second set of clutch discs being alternatingly arranged relative to each other and axially movable relative to each other. Hereby efficient frictional engagement is facilitated. According to an aspect of the present disclosure, said plurality of clutch discs are configured to be operably connected to fluid for cooling said plurality of clutch discs. According to an aspect of the present disclosure, said fluid for cooling said plurality of clutch discs is separated from said fluid within said housing cavities.

[0032] Specifically, an aspect of the present disclosure is achieved by a clutch device comprising a control arrangement as set out herein and a torque transfer arrangement comprising said plurality of clutch discs for transferring torque from said drive shaft to said driven shaft.

[0033] Specifically, an aspect of the present disclosure is achieved by a drive arrangement comprising a clutch device as set out herein, said drive arrangement comprising a drive device configured to operate said drive shaft, and a transmission device operably connected to said driven shaft. Said drive device may be any suitable drive device. According to an aspect of the present disclosure, said drive device is an internal combustion engine. According to an aspect of the present disclosure, said drive device is an electric machine such as an electric motor. According to an aspect of the present disclosure, said drive device is a hybrid drive device facilitating hybrid drive. Said transmission device may be any suitable transmission device.

[0034] Specifically, an aspect of the present disclosure is achieved by a vehicle comprising a drive arrangement as set out herein. Said vehicle may be any suitable vehicle. According to an aspect of the present disclosure, said vehicle is a tracked vehicle. According to an aspect of the present disclosure, said vehicle is a wheeled vehicle. According to an aspect of the present disclosure, said vehicle is a combat vehicle.

[0035] DESCRIPTION OF THE DRAWINGS

[0036] For a better understanding of the present disclosure, reference is made to the following detailed description when read in conjunction with the accompanying drawings, wherein like reference characters refer to like parts throughout the several views, and in which:

[0037] Fig. 1 schematically illustrates a side view of a tracked vehicle according to an aspect of the present disclosure;

[0038] Fig. 2 schematically illustrates a side view of a drive arrangement according to an aspect of the present disclosure;

[0039] Fig. 3a schematically illustrates a perspective view of a clutch device operably connected to a driven shaft according to an embodiment of the present disclosure;

[0040] Fig. 3b schematically illustrates an exploded perspective view of the clutch device in fig. 3a according to an aspect of the present disclosure;

[0041] Fig. 4 schematically illustrates an axial view of a clutch device according to an aspect of the present disclosure;

[0042] Fig. 5 schematically illustrates a cross-sectional side view of the clutch device in fig. 4, according to an aspect of the present disclosure;

[0043] Fig. 6a schematically illustrates a zoomed in portion of the clutch device in fig. 5, according to an aspect of the present disclosure;

[0044] Fig. 6b schematically illustrates a zoomed in portion of the clutch device in fig. 6a comprising a piston device of the clutch device, according to an aspect of the present disclosure;

[0045] Fig. 7 schematically illustrates a partly cut-out perspective view of the clutch device in fig. 4, according to an aspect of the present disclosure;

[0046] Fig. 8a schematically illustrates an axial view of a set of fluid pressure provision devices of said clutch device, according to an aspect of the present disclosure; Fig. 8b schematically illustrates a cross sectional view of the set of fluid pressure provision devices in fig. 8a, according to an aspect of the present disclosure;

[0047] Fig. 9 schematically illustrates a perspective view of the set of fluid pressure provision devices in fig. 8a, according to an aspect of the present disclosure;

[0048] Fig. 10 schematically illustrates a cross-sectional view of a fluid pressure provision device, according to an aspect of the present disclosure;

[0049] Fig. 11 a schematically illustrates a graph of the radial force generated by means of a control arrangement of a clutch device as a function of the rounds per minute of the annular housing of said clutch device, according to an aspect of the present disclosure;

[0050] Fig. 11 b schematically illustrates a graph of the spring force generated by spring member of fluid pressure provision device of said clutch device as a function of its length compression in the radial direction, according to an aspect of the present disclosure; and,

[0051] Fig. 11c schematically illustrates a graph of the pressure generated by means of fluid pressure as a function of the rounds per minute of the annular housing of said clutch device, according to an aspect of the present disclosure.

[0052] DETAILED DESCRIPTION

[0053] Fig. 1 schematically illustrates a side view of a tracked vehicle V according to an aspect of the present disclosure.

[0054] The tracked vehicle V is according to the disclosure in fig. 1 a military vehicle.

[0055] The tracked vehicle V is according to the disclosure in fig. 1 a combat vehicle. The tracked vehicle V comprises a vehicle body B, which according to an aspect of the present disclosure comprises the chassis of the vehicle V and bodywork.

[0056] The tracked vehicle V comprises a right track assembly and a left track assembly T1 for driving the vehicle V, the left track assembly being shown in fig. 1. Each track assembly has a longitudinal extension and the right track assembly is configured to run in connection to the right side along the longitudinal extension of the vehicle body B of the vehicle V and the left track assembly is configured to run in connection to the left side along the longitudinal extension of the vehicle body B of the vehicle V. Each track assembly comprises a drive wheel member DW, a tension wheel TW, a set of road wheels RW and an endless track E arranged to run over said wheels. Here the drive wheel member DW is arranged in the front, the tension wheel TW is arranged in the back and the road wheels RW are arranged between the drive wheel member DW and the tension wheel TW. The tracked vehicle according to the present disclosure may however have track assemblies with any suitable arrangement of drive wheel member, tension wheel and road wheels. According to an aspect of the present disclosure the tension wheel may be arranged in the front, the drive wheel member arranged in the back and the road wheels arranged there between.

[0057] The endless track E of the respective track assembly is arranged to be driven and hence rotated by means of said drive wheel member DW. The tracked vehicle V comprises a drive arrangement D for driving said vehicle, here said drive wheel members DW. The drive arrangement may be any suitable drive arrangement, comprising any suitable drive device such as an internal combustion engine and / or an electric machine and any suitable transmission device, see fig. 2. The drive arrangement further comprises a clutch device according to the present disclosure operably connected to said drive device and said transmission device, said clutch device being described in detail below. Fig. 2 schematically illustrates a side view of a drive arrangement according to an aspect of the present disclosure;

[0058] The drive arrangement D may be any suitable drive arrangement. The drive arrangement comprises a drive device E. Said drive device E may be any suitable drive device such as an internal combustion engine and / or an electric machine.

[0059] Said drive arrangement D comprises a drive shaft S1 , wherein said drive device E is operably connected to said drive shaft S1 so as to, during drive operation, apply torque on said drive shaft S1 for rotating said drive shaft S1 about an axis X.

[0060] Said drive arrangement D comprises a transmission device T, comprising e.g. a gear box. Said transmission device T is configured to be operably connected to a driven shaft S2.

[0061] Said drive arrangement D comprises a clutch device 100. Said clutch device 100 is configured to facilitate transfer of torque from said drive shaft S1 to said driven shaft S2. Said clutch device 100 is described in detail below.

[0062] Fig. 3a schematically illustrates a perspective view of a clutch device 100 operably connected to a driven shaft, and fig. 3b an exploded perspective view of the clutch device in fig. 3a, according to an embodiment of the present disclosure.

[0063] Said clutch device 100 comprises an annular housing 10. Said annular housing 10 is configured to be secured to and rotatable about an axis X by means of a drive shaft, not shown in fig. 3a-b. Said drive shaft is, according to an aspect of the present disclosure, a drive shaft S1 as described with reference to fig. 2.

[0064] Said annular housing 10 has a radial inner side 10i and an opposite radial outer side 10o. Said radial inner side 10i may be denoted inner wall 10i. Said annular housing 10 has an axial first end side 10a and an opposite axial second end side 10b.

[0065] Said clutch device 100 comprises a plurality of clutch discs 50 configured to be positioned within said housing 10 and arranged about a driven shaft S2 configured to be coaxially arranged relative to said drive shaft.

[0066] Said plurality of clutch discs 50 are configured to be arranged about said driven shaft S2. According to an aspect of the present disclosure, said plurality of clutch discs 50 are configured to be concentrically arranged about said driven shaft S2. Said plurality of clutch discs 50 are configured to be axially arranged in relation to each other.

[0067] According to an aspect of the present disclosure, said plurality of clutch discs 50 have a ring-shaped configuration.

[0068] According to an aspect of the present disclosure, said plurality of clutch discs 50 are configured to extend in a plane essentially perpendicular to the axial extension of said driven shaft S2. According to an aspect of the present disclosure, said plurality of clutch discs 50 are configured to extend in a plane essentially perpendicular to said axis X.

[0069] According to an aspect of the present disclosure, said plurality of clutch discs 50 are arranged to be assembled together along and in connection to said driven shaft S2 so that clutch discs of said plurality of clutch discs are allowed to be pressed against adjacent clutch discs so as to obtain frictional engagement for transferring torque from said drive shaft to said driven shaft S2.

[0070] Said plurality of clutch discs 50 are configured to be pressed together in the axial direction, i.e. in the direction of said axis X, for providing said frictional engagement. Said plurality of clutch discs 50 are configured to be pressed together in the axial direction for increasing the friction between adjacent clutch discs of said plurality of clutch discs 50 for providing said frictional engagement.

[0071] Said ring-shaped clutch discs of said plurality of clutch discs 50 have an inner circumference and outer circumference.

[0072] According to an aspect of the present disclosure, said plurality of clutch discs 50 comprises a first set of clutch discs 52 configured to be engaged to said annular housing 10. According to an aspect of the present disclosure, said plurality of clutch discs 50 comprises a second set of clutch discs 54 configured to be engaged to said driven shaft S2. Hereby, when said plurality of clutch discs 50 are not axially pressed together, rotation of said first set of clutch discs 52 relative to said second set of clutch discs 54 is allowed.

[0073] According to an aspect of the present disclosure, said first set of clutch discs 52 and second set of clutch discs 54 are alternatingly arranged relative to each other. According to an aspect of the present disclosure, a clutch disc of said first set of clutch discs 52 being engaged to said annular housing 10 has a clutch disc 54 of said second set of clutch discs 54 being engaged to said driven shaft S2 adjacently arranged and so on.

[0074] According to an aspect of the present disclosure, said first set of clutch discs 52 configured to be engaged to said annular housing 10 are configured to be engaged so as to essentially prevent movement between said first set of clutch discs 52 and said annular housing 10 in the direction of rotation about said driven shaft S2.

[0075] According to an aspect of the present disclosure, said first set of clutch discs 52 configured to be engaged to said annular housing 10 are configured to be engaged so as to allow certain movement between said first set of clutch discs 52 and said annual housing 10 in the axial direction of said driven shaft S2.

[0076] According to an aspect of the present disclosure, said first set of clutch discs 52 configured to be engaged to said annular housing 10 are configured to be engaged to said inner wall 10i of said annular housing 10. According to an aspect of the present disclosure, said first set of clutch discs 52, configured to be engaged to said annular housing 10, comprises outer engagement members configured to engage with inner engagement members of said annular housing 10, i.e. inner engagement members at said radial inner side 10i, i.e. inner wall 10i of said housing 10.

[0077] According to an aspect of the present disclosure, said outer engagement members comprises sprocket members configured to project from the outer circumference of the respective clutch disc of said first set of clutch discs 52. According to an aspect of the present disclosure, said outer engagement members may be provided by splines.

[0078] According to an aspect of the present disclosure, said second set of clutch discs 54 configured to be engaged to said driven shaft S2 are configured to be engaged so as to essentially prevent movement between said second set of clutch discs 54 and said driven shaft S2 in the direction of rotation about said driven shaft S2, i.e. said second set of clutch discs 54 are configured to rotate with said driven shaft S2.

[0079] According to an aspect of the present disclosure, said second set of clutch discs 54 configured to be engaged to said driven shaft S2 are configured to be engaged so as to allow certain movement of said second set of clutch discs 54 relative to said driven shaft S2 in the axial direction of said driven shaft S2, i.e. in the direction of said axis X.

[0080] According to an aspect of the present disclosure, said second set of clutch discs 54 configured to be engaged to said driven shaft S2 comprises inner engagement members configured to engage with outer engagement members of said driven shaft S2.

[0081] According to an aspect of the present disclosure, said inner engagement members comprises sprocket members configured to project from the inner circumference of the respective ring-shaped clutch disc of said second set of clutch discs 54. According to an aspect of the present disclosure, said inner engagement members may be provided by splines.

[0082] Fig. 4 schematically illustrates an axial view of a clutch device 100, and fig. 5 a cross-sectional side view of the clutch device in fig. 4, according to an aspect of the present disclosure. Fig. 5 schematically illustrates a cross-sectional side view A-A of the clutch device 100 in fig. 4, according to an aspect of the present disclosure. Fig. 6a schematically illustrates a zoomed in portion of the clutch device 100 in fig. 5, and fig. 6b schematically illustrates a zoomed in portion of the clutch device 100 in fig. 6a comprising a piston device 20 of the clutch device 100, according to an aspect of the present disclosure. Fig. 7 schematically illustrates a partly cut-out perspective view of the clutch device 100 in fig. 4, according to an aspect of the present disclosure.

[0083] According to an aspect of the present disclosure, said clutch device 100 is configured to be comprised in a drive arrangement, e.g. a drive arrangement D as illustrated in fig. 1 and fig. 2.

[0084] Said clutch device 100 comprises an annular housing 10. Said annular housing is configured to be secured to and rotatable by means of a drive shaft S1 about an axis X, see e.g. fig. 5.

[0085] Said clutch device 100 comprises a control arrangement CA for controlling frictional engagement of said plurality of clutch discs 50 for transferring torque from said drive shaft S1 to said driven shaft S2.

[0086] Said clutch device 100 comprises a torque transfer arrangement TA comprising said plurality of clutch discs 50 for transferring torque from said drive shaft S1 to said driven shaft S2. According to an aspect of the present disclosure, said torque transfer arrangement TA comprises a fluid for cooling said plurality of clutch discs 50. According to an aspect of the present disclosure, said fluid is oil-based fluid. Thus, according to an aspect of the present disclosure, said clutch device 100 is a wet clutch device. According to an aspect of the present disclosure, said annular housing 10 comprises a clutch disc space DS for housing said plurality of clutch discs 50 and at least a portion of said driven shaft S2, see also fig. 3a-b. Said annular housing 10 has an inner wall 10i, as described above with reference to fig. Safa, and an opposite outer wall 10o.

[0087] Said clutch device 100 comprises a piston device 20. Said piston device is configured to be arranged in connection to an end clutch device 50 of said plurality of clutch discs 50. Said piston device 20, when subjected to a certain pressure in the direction towards said plurality of clutch discs 50, is configured to press said plurality of clutch discs 50 together so that they are fictionally engaged.

[0088] According to an aspect of the present disclosure, said piston device 20 comprises a ring-shaped piston 22 coaxially arranged around said axis X within said annular housing 10. According to an aspect of the present disclosure, said ring-shaped piston 22 is configured to be arranged within and operably connected to said annular housing 10. The ring-shaped piston 22 may also be denoted piston 22.

[0089] According to an aspect of the present disclosure, said annular housing 10 comprises an internal ring-shaped track 14T, see e.g. fig. 7, arranged around said axis X, said ring-shaped track 14T being configured to receive, i.e. house, said ring-shaped piston 22. According to an aspect of the present disclosure, said ring-shaped piston 22 is configured to be closely received within said ringshaped track 14T.

[0090] According to an aspect of the present disclosure, said annular housing comprises an inner ring-shaped portion 14. According to an aspect of the present disclosure, said inner ring-shaped portion 14 has an axial extension from said axial first end side 10a to said clutch disc space DS. According to an aspect of the present disclosure, said clutch disc space DS is configured to have an axial extension from an axial end portion of said inner ring-shaped portion 14 to said axial second end side 10b of said annual housing 10.

[0091] According to an aspect of the present disclosure, said inner ring-shaped portion 14 has a radial extension relative to the inner wall 10i. According to an aspect of the present disclosure, said inner ring-shaped portion 14 has a fist portion 14-1 running closest to said inner wall 10i and having an axial extension essentially to said clutch disc space DS, a second portion 14-2 having an axial extension essentially to said clutch disc space DS.

[0092] Said inner ring-shaped portion further comprising an intermediate portion 14- 3, running between said first portion 14-1 and second portion 14-3, said intermediate portion 14-3 having an axial extension towards said clutch disc space DS that is shorter than the axial extension of said first portion 14-1 and second portion 14-2 so that said internal ring-shaped track 14T for receiving said piston 22 is provided.

[0093] According to an aspect of the present disclosure, said piston 22 is configured to move axially towards said plurality of clutch discs 50. According to an aspect of the present disclosure, said internal ring-shaped track 14T has an innermost side 14Ta, an opposite outermost side 14Tb and a bottom side 14Tc. Said innermost side 14Ta is a radial innermost side 14Ta, and said opposite outermost side 14Tb is a radial outermost side 14Tb, and said bottom side 14Tc is an axial bottom side 14Tc facing in the direction towards said axial second end side 10b of said annual housing 10. According to an aspect of the present disclosure, said ring-shaped piston 22 comprises a recess 22R configured to run around the ring-shaped piston 22. According to an aspect of the present disclosure, said recess 22R of said ring-shaped piston 22 is configured to face away from said plurality of clutch discs 50 and face towards a portion 10P of said annular housing 10 so as to provide a piston cavity S20 in connection to said recess 22R. According to an aspect of the present disclosure, said recess 22R of said ring-shaped piston 22 is configured to face towards said intermediate portion 14-3 of said inner ring-shaped portion 14 of said annular housing 10. According to an aspect of the present disclosure, said recess 22R of said ring-shaped piston 22 is configured to face towards said axial bottom side 14Tc of said internal ring-shaped track 14T of said annular housing 10. Hereby, the axial bottom side 14Tc corresponds to the portion 10P, the portion 10P thus constituting an axial abutment surface of the annular housing 10 towards which said recess 22R of said ring-shaped piston 22 is configured to face.

[0094] According to an aspect of the present disclosure, said recess 22R has an axial bottom side 22B configured to face towards said axial bottom side 14Tc of said internal ring-shaped track 14T of said annular housing 10. According to an aspect of the present disclosure, said recess 22R of said ring-shaped piston 22 has a radial inner protrusion member 22-1 arranged radially inwardly and configured to protrude from said bottom side 22B with a main direction of extension in the axial direction, and a radial outer protrusion member 22-2 arranged radially outwardly and configured to protrude from said bottom side 22B with a main direction of extension in the axial direction. When said ringshaped piston 22 is arranged in said internal ring-shaped track 14T of said annular housing 10, said radial inner and outer protrusion members are configured to protrude towards said axial bottom side 14Tc.

[0095] According to an aspect of the present disclosure, the extension of the protrusion of said radial inner protrusion member 22-1 is longer than the extension of the protrusion of the radial outer protrusion member 22-2. When said ring-shaped piston 22 is arranged in said internal ring-shaped track 14T of said annular housing 10, the end portion said radial inner protrusion member 22-1 is closer to the axial bottom side 14Tc than the end portion of said radial outer protrusion member 22-2.

[0096] According to an aspect of the present disclosure, said ring-shaped piston 22 is configured to be closely received within said ring-shaped track 14T so that said ring-shaped track 14T and said recess 22R of said ring-shaped piston 22 provides said piston cavity S20. According to an aspect of the present disclosure, said annular housing 10 has an opening 010 at said axial first end side 10a. According to an aspect of the present disclosure, said drive shaft S1 is configured to be arranged in connection to said opening 010 so as to facilitate that said annular housing 10 can be secured to and rotatable by means of a drive shaft S1 .

[0097] According to an aspect of the present disclosure, said opening 010 of said annular housing 10 comprises a first opening portion 01 Oa configured to axially extend from the axial first end side 10a a certain distance towards said clutch disc space DS, and a second opening portion 01 Ob configured to axially extend from the end of said ring-shaped portion 14 facing said clutch disc space DS towards the first end side 10a to the first opening portion 01 Oa so that said first opening portion 01 Oa transfers into said second opening portion O10b of said opening 010 of said annular housing 10.

[0098] According to an aspect of the present disclosure, said first opening portion 01 Oa is coaxially arranged relative to said second opening portion 01 Ob. According to an aspect of the present disclosure, said second opening portion 01 Ob is wider than said first opening portion 01 Oa so that a connection portion 14C is provided within said opening 010, said connection portion 14C being configured to face towards said clutch disc space DS. According to an aspect of the present disclosure, said connection portion 14C comprises a set of connection openings C10 distributed around said first opening portion 01 Oa so as to facilitate connection of said drive shaft S1 by means of e.g. joint members.

[0099] According to an aspect of the present disclosure, said inner ring-shaped portion 14 of said annular housing 10 is arranged to receive said drive shaft S1. According to an aspect of the present disclosure, said inner ring-shaped portion 14 of said annular housing 10 is configured to provide said opening 010. According to an aspect of the present disclosure, said inner ring-shaped portion 14 of said annular housing 10 comprises said connection portion 14C. According to an aspect of the present disclosure, said annular housing 10 comprises a set of housing cavities 12 distributed around and configured to radially run within said annular housing 10. Said control arrangement CA comprises said set of housing cavities 12. Said set of housing cavities are configured to be filled with fluid F. According to an aspect of the present disclosure, the respective radially running housing cavity 12 has an open radial outer side with an opening O and a closed opposite radial inner side 12i.

[0100] Said control arrangement CA further comprises a set of fluid pressure provision devices 30 for the respective housing cavity 12 of the set of housing cavities 12. Fluid pressure provision devices 30 according to the present disclosure are illustrated in fig. 5, 6a and fig. 7. Further, fig. 8a schematically illustrates an axial view of a set of fluid pressure provision devices 30 of said clutch device 100, fig. 8b schematically illustrates a cross sectional view of the set of fluid pressure provision devices 30 in fig. 8a, fig. 9 schematically illustrates a perspective view of the set of fluid pressure provision devices 30 in fig. 8a, and fig. 10 schematically illustrates a cross-sectional view of a fluid pressure provision device 30, according to an aspect of the present disclosure.

[0101] Said control arrangement CA is configured to facilitate said frictional engagement of said plurality of clutch discs 50 by means of centrifugal force exerted on fluid F within said annular housing 10 in connection to rotation of said annular housing 10. The control arrangement CA utilizes centrifugal force generated by the rotation of the annular housing 10 to induce positive fluid pressure leading to clutch engagement. Said control arrangement CA is configured to achieve centrifugal operation, where increasing rotational speed of said annular housing 10 actively facilitates clutch engagement.

[0102] The respective fluid pressure provision device 30 comprises a unit 32 configured to be radially movably arranged within the housing cavity 12 in which that fluid pressure provision device 30 is arranged such that the unit 32 provides pressure on said fluid F within that housing cavity 12 based on the centrifugal force so as to facilitate control of said frictional engagement of said plurality of clutch discs 50 by means of said piston device 20.

[0103] According to an aspect of the present disclosure, said units 32 are configured to be radially movably arranged within said housing cavities 12 such that, when subjected to a centrifugal force exceeding a certain threshold value, the respective unit 32 apply pressure on the fluid F within its cavity such that said piston device 20 acts on said plurality of clutch discs 50.

[0104] According to an aspect of the present disclosure, the respective housing cavity 12 is configured to be operably connected to said piston device 20 via a fluid channel 40 so that fluid F within the respective housing cavity 12 is allowed to flow between the housing cavity 12 and said piston device 20 via said fluid channel 40. According to an aspect of the present disclosure, the respective housing cavity 12 has a fluid opening 012 for the fluid channel 40. Said fluid opening 012 is configured to be positioned radially outwardly relative to the unit 32 of the fluid pressure provision device 30, when the fluid pressure provision device 30 is arranged in the housing cavity 12. According to an aspect of the present disclosure, fluid is allowed to flow from the housing cavity 12 into the fluid channel 40 via the fluid opening 012 and out from the fluid channel 40 into the housing cavity 12 via the fluid opening 012. Thus, the control arrangement CA comprises said fluid channel 40.

[0105] According to an aspect of the present disclosure, the ring-shaped track 14T comprises fluid openings 014T for the respective fluid channel 40. According to an aspect of the present disclosure, the fluid openings 014T of the ringshaped track 14T for the respective fluid channel 40 are arranged at the radially outermost side 14Tb, close to the axial bottom side 14Tc the ringshaped track 14T of the ring-shape portion 14 of the annular housing 10. According to an aspect of the present disclosure, the fluid openings 014T of the ring-shaped track 14T for the respective fluid channel 40 are arranged in the corner of the radially outermost side 14Tb and the axial bottom side 14Tc. According to an aspect of the present disclosure, the fluid openings 014T of the ring-shaped track 14T for the respective fluid channel 40 are arranged at a radially inner position relative to the fluid opening 012 of the housing cavity 12. Thus, according to an aspect of the present disclosure, the respective fluid channel 40 is running from the fluid opening 012 of the housing cavity 12, radially inwardly with an angle towards the fluid opening 014T of the ringshaped track 14T.

[0106] According to an aspect of the present disclosure, when the ring-shaped piston 22 is in its first position, associated with said set of units being in a nonactuated position, the said radial inner protrusion member 22-1 is in contact with the axial bottom side 14Tc of said internal ring-shaped track 14T and the radial outer protrusion member 22-2 is arranged a certain distance from the axial bottom side 14Tc of said internal ring-shaped track 14T so that fluid from the respective fluid channel 40 is allowed to flow between the space S12 within the respective housing cavity 12 and the piston cavity S20.

[0107] According to an aspect of the present disclosure, said fluid channel 40, connected to the respective housing cavity 12, is configured to be connected so that fluid F within the respective housing cavity 12 is allowed to flow between said housing cavity 12 and said piston cavity S20 via said fluid channel 40. The respective fluid channel 40 is connected to the associated housing cavity 12 at a position radially outwardly relative to the unit 32.

[0108] According to an aspect of the present disclosure, said fluid channel 40, connected to the respective housing cavity 12, is configured to be connected to the ring-shaped track 14T so that fluid F within the respective housing cavity 12 is allowed to flow between said housing cavity 12 and said piston cavity S20 via said fluid channel 40. According to an aspect of the present disclosure, the ring-shaped track 14T has fluid opening(s) 014T for the respective fluid channel 40. According to an aspect of the present disclosure, fluid is allowed to flow from the piston cavity S20 into the fluid channel 40 via the fluid opening 014T and out from the fluid channel 40 into the piston cavity S20 via the fluid opening 014T. According to an aspect of the present disclosure, the fluid opening O14T of the ring-shaped track 14T is according to an aspect a single opening running around said ring-shaped track 14T, wherein said fluid channels 40 are connected to said single fluid opening 014T. According to an aspect of the present disclosure, the fluid opening 014T of the ring-shaped track 14T comprises is an opening for the respective fluid channel 40.

[0109] According to an aspect of the present disclosure, said fluid F arranged within and allowed to flow between said housing cavities 12 and said piston cavity S20 via said fluid channel is separated from said fluid of said torque transfer arrangement TA. According to an aspect of the present disclosure, said fluid F is oil-based fluid.

[0110] According to an aspect of the present disclosure, the respective housing cavity 12 is configured to be operably connected to said ring-shaped track 14T via said fluid channel 40 so that fluid F within the respective housing cavity 12 is allowed to flow between the housing cavity 12 and said piston device 20 via said fluid channel 40. Thus, the control arrangement CA comprises said fluid channel 40.

[0111] According to an aspect of the present disclosure, said piston 22 of said piston device 20, being arranged within and operably connected to said annular housing 10, is configured to move axially towards said plurality of clutch discs 50 for said frictional engagement based on pressure provided by said fluid F when pressurised by means of said fluid pressure provision device 30.

[0112] According to an aspect of the present disclosure, said ring-shaped piston 22, being configured to be closely received within said ring-shaped track 14T, is configured to move axially towards said plurality of clutch discs 50 for said frictional engagement based on pressure provided by said fluid F when pressurised by means of said fluid pressure provision device 30.

[0113] According to an aspect of the present disclosure, said ring-shaped piston 22 is configured to return through axial movement away from said plurality of clutch discs 50 when said fluid pressure provision device 30 no longer provides pressure on said fluid F.

[0114] According to an aspect of the present disclosure, said ring-shaped piston 22 is configured to be axially movably arranged between a first position corresponding to no fluid force acting on said piston 22, associated with said set of units 32 of said fluid pressure provision device 30 being in a nonactuated position, and different other positions associated with different fluid pressures applied on said piston 22 based on different centrifugal forces caused by rotation of said annular housing 10 causing said centrifugal force.

[0115] According to an aspect of the present disclosure, said ring-shaped piston 22 has a radial inner side 22i configured to face said innermost side 14Ta of said internal ring-shaped track 14T and an opposite radial outer side 22o configured to face said outermost side 14Tb of said ring-shaped track. According to an aspect of the present disclosure, said ring-shaped piston 22 has an engagement side 22e configured to face towards said plurality of clutch discs 50.

[0116] According to an aspect of the present disclosure, said internal ring-shaped track 14T has an innermost side 14Ta, an opposite outermost side 14Tb and a bottom side 14Tc.

[0117] According to an aspect of the present disclosure, said piston device 20 comprises a sealing member 24 for providing sealed connection of said ringshaped piston 22 to said annular housing 10. According to an aspect of the present disclosure, said sealing member 24 of said piston device 20 is configured to provide sealed connection of said ring-shaped piston 22 to said ring-shaped track 14T.

[0118] According to an aspect of the present disclosure, said sealing member 24 is configured so that said ring-shaped piston 22, when axially moved towards said plurality of clutch discs 50 based on fluid pressure by means of said fluid pressure provision devices 30, is no longer subjected to said fluid pressure, is assisted in axial movement away from said plurality of clutch discs 50 for returning to said non-actuated position.

[0119] According to an aspect of the present disclosure, said sealing member 24 has resilient properties so as to assist in returning said ring-shaped piston device 22 back to said non-actuated position when said piston device is no longer subjected to fluid pressure exceeding a certain threshold value.

[0120] According to an aspect of the present disclosure, said sealing member 24 comprises a first sealing part 24o configured to be arranged in connection to said radial outer side 22o of said piston 22 and a second sealing part 24i configured to be arranged in connection to said radial inner side 22i of said piston 22.

[0121] According to an aspect of the present disclosure, the respective unit 32 of said set of units 32 is configured to be spring-loadably arranged within a housing cavity 12 of said set of housing cavities 12 for facilitating controlled radial movement of said units 32 based on the centrifugal force. According to an aspect of the present disclosure, the respective unit 32 of said set of units 32 is configured to be spring-loaded at least during a certain degree of rotation of said annular housing 10, i.e. when subjected to a certain centrifugal force.

[0122] According to an aspect of the present disclosure, the respective unit 32 of said set of units 32 is configured to be spring-loaded by means of a predetermined spring force during non-rotation of said annular housing 10 so as to facilitate positioning of the respective unit 32 of said set of units 32 at essentially the same position.

[0123] According to an aspect of the present disclosure, the respective unit 32 of said set of units is configured to be arranged such that there is essentially no spring force applied to said unit 32 during non-rotation of said annular housing.

[0124] According to an aspect of the present disclosure, the respective fluid pressure provision device 30 comprises a spring member 34 arranged in connection to said unit 32. Said spring member 34 is configured to provide a predetermined spring force so that said unit 32 is maintained in a non-actuated position if said spring force is not exceeded.

[0125] According to an aspect of the present disclosure, the respective unit 32 of said set of units 32 is configured to be spring-loaded by means of said spring member 34 at least during a certain degree of rotation of said annular housing 10, i.e. when subjected to a certain centrifugal force.

[0126] According to an aspect of the present disclosure, the respective unit 32 of said set of units 32 is configured to be spring-loaded by means of a predetermined spring force of configured to be applied by means of said spring member 34 also during non-rotation of said annular housing 10 so as to facilitate positioning of the respective unit 32 of said set of units 32 at essentially the same position.

[0127] According to an aspect of the present disclosure, the respective fluid pressure provision device 30 comprises a spring member arranged 34 in connection to said unit 32, said unit 32 being configured to be radially biased inwardly by the spring member 34 and radially movably arranged within said housing cavity 12, such that the respective unit 32 moves radially outwardly against the spring member 34 when the centrifugal force exceeds a predetermined threshold value, thereby generating a positive fluid pressure on said fluid within that housing cavity 12, said positive fluid pressure being transferred to the piston device 20 causing the piston 22 to move axially towards the plurality of clutch discs 50 for said frictional engagement.

[0128] According to an aspect of the present disclosure, the respective unit 32 of said set of units 32 is configured to be arranged relative to said spring member 34 such that there is essentially no spring force applied to said unit 32 during nonrotation of said annular housing.

[0129] Said units 32 may be made of any suitable material. According to an aspect of the present disclosure, the respective unit 32 comprises material with high density, such as e.g. steel, bronze or tungsten. According to an aspect of the present disclosure, the respective unit 32 of said set of units 32 is a solid part. According to an aspect of the present disclosure, the respective unit 32 of said set of units 32 comprises a cavity where a spring member may be connected.

[0130] According to an aspect of the present disclosure, the respective unit 32 of said set of units 32 comprises a cavity where an inner core having a higher density than the remaining portion of the unit 32 may be mounted. According to an aspect of the present disclosure, the respective unit 32 of said set of units 32 comprises an inner core having a higher density than the remaining portion of the unit 32.

[0131] According to an aspect of the present disclosure, said spring member 34 and said unit 32 are separate parts, where said unit 32 is configured to be arranged in connection to said spring member 34 so that said unit 32, when subjected to said centrifugal force, acts against said spring member 34, wherein said unit is allowed to move radially outwardly within said housing cavity 12 when the spring force provided by said spring member 34 is exceeded by the force provided by the unit 32 on said spring member 34, pressurising said fluid F. Such a solution is schematically illustrated in e.g. fig. 5.

[0132] Said spring member 34 may be any suitable spring member. According to an aspect of the present disclosure, said spring member, as schematically illustrated in e.g. fig. 5, is a spiral spring member. Such a spring member 34 is configured to be compressed at a certain centrifugal force, allowing outward radial movement of said unit 32 and hence pressurization of said fluid F.

[0133] According to an aspect of the present disclosure, not shown, said spring member and said unit provide an integrated portion, where said spring member is configured to be arranged in connection to said unit so that said unit of the integrated portion, when subjected to said centrifugal force, is allowed to move radially outwardly when the spring force provided by said spring member is exceeded by the force provided by the unit on said spring member. In such a solution said integrated portion of said unit and spring member may be denoted spring unit. Such a spring unit is configured to be compressed at a certain centrifugal force, allowing outward radial movement of said spring unit, i.e. said unit of said integrated portion, and hence pressurization of said fluid F. Such an integrated portion of said spring member and said unit is, according to an aspect of the present disclosure, provided by a spring steel member providing both the spring member and the unit as a single part.

[0134] According to an aspect of the present disclosure, said spring force is configured to be exceeded when said centrifugal force exceeds a predetermined threshold value, providing radially outward movement of said unit 32 from said non-actuated position for providing fluid pressure of said fluid F within said housing cavity 12 for said frictional engagement of said plurality of clutch discs by means of said piston device 20.

[0135] According to an aspect of the present disclosure, when said centrifugal force exceeds a predetermined threshold value so that said spring force of said spring member 34 is exceeded so that said radially outward movement of said unit 32 from said non-actuated position, fluid pressure of said fluid F within said housing cavity 12 is provided so that pressurised fluid F from said housing cavity 12 to said piston cavity S20 is provided via said fluid channel 40 so that said piston 22 of said piston device 20 is pressed against said plurality of clutch discs 50 for said frictional engagement of said plurality of clutch discs.

[0136] According to an aspect of the present disclosure, said unit 32 is configured to return to said non-actuated position by means of said spring force provided by said spring member 34 when said centrifugal force no longer exceeds said predetermined threshold value. Hereby said piston 22 of said piston device 20 is configured to return to said non-actuated position, facilitating disengagement of said plurality of clutch discs 50. According to an aspect of the present disclosure, said unit 32 is configured to move radially inwardly and return to said non-actuated position by means of said spring force provided by said spring member 34 when said centrifugal force no longer exceeds said predetermined threshold value, so that disengagement of the plurality of clutch discs 50 is provided.

[0137] According to an aspect of the present disclosure, the respective radially running cavity 12 is configured to be open towards a radial outer end 10o of said annual housing 10 by means of a radial opening O.

[0138] According to an aspect of the present disclosure, the respective spring member 34 comprises or is operably connected to a locking member 36 for sealingly locking said spring member 34 in connection to the radial opening O of a housing cavity 12 of said set of housing cavities 12.

[0139] According to an aspect of the present disclosure, the respective fluid pressure provision device 30 comprises said locking member 36 for sealingly locking the radial opening O of a housing cavity 12 of said set of housing cavities 12, providing, for said fluid F, a closed space between the radial outer end of the unit 32 and the radial opening O. The spring member 34 is comprised in or operably connected to said locking member 36 so that the spring member 34 is allowed to be compressed radially outwardly towards said radial opening O by means of said unit 32 when the centrifugal force exceeds said threshold value, wherein the locking member 36 provides sealed lock at the radial opening O so that the spring member 34 is locked to the housing 10, facilitating said compression of the spring member 34 in the radially outward direction.

[0140] According to an aspect of the present disclosure, said spring member 34 and said locking member 36 are separate parts, where said locking member 36 is configured to close the housing cavity 12 in connection to said opening O, and to provide resistance when said spring member 34 is subjected to a force by means of said unit 32 when subjected to said centrifugal force.

[0141] According to an aspect of the present disclosure, said locking member 36 is configured to be arranged in connection to said spring member 34 so as to position said spring member 34 at said locking member 36. According to an aspect of the present disclosure, said locking member 36 is configured to be arranged in connection to said spring member so as to control the spring member 36 during movement of said unit 32 and hence movement of said spring member 34.

[0142] The locking member 36 is configured to close the housing cavity 12 at the radial opening O and secure the entire fluid pressure provision device 30 assembly to the housing 10. Thus, the locking member 36 is configured to sealingly lock said spring member 34 to the housing 10. The radial movement of the unit 32 and the compression of the spring member 34 occur inside this sealed boundary. Therefore, the term "locking" refers to the static fixation of the assembly to the housing, while the term "sealingly" refers to ensuring hydrodynamic integrity. According to an aspect of the present disclosure, the respective spring member 34 comprises or is operably connected to a locking member 36 for providing sealed locking in connection to the radial opening of a housing cavity 12 of said set of housing cavities, providing, for said fluid, a closed space between the radial outer end of the unit 32 and the radial opening O.

[0143] According to an aspect of the present disclosure, said spring member and said locking member provide an integrated portion, where said spring member is configured to be arranged in connection to said locking member. Such an integrated portion of said spring member and said locking member is, according to an aspect of the present disclosure, provided by a spring steel member providing both the spring member and the locking member as a single part.

[0144] According to an aspect of the present disclosure, said unit, spring member and locking member provide an integrated portion. Such an integrated portion of said unit, spring member and locking member is, according to an aspect of the present disclosure, provided by a spring steel member providing the unit, spring member and locking member as a single part. According to an aspect of the present disclosure, said locking member 36 for sealingly locking said spring member 34 to said annular housing 10 in connection to the radial opening O of a housing cavity 12, is configured to provide a space S12 between the unit 32 and the radial opening O, wherein said fluid F is configured to be arranged within said space S12. According to an aspect of the present disclosure, said fluid channel 40 is configured to be connected to said housing cavity 12 at said space S12.

[0145] According to an aspect of the present disclosure, the respective unit 32 has an elongated configuration. According to an aspect of the present disclosure, the respective unit 32 has a radial outer end 32o configured to face radially outwardly in said housing cavity 12, an opposite radial inner end 32i configured to face towards the bottom 12b of the housing cavity 12, and an outer surface 32a configured to face towards the inner surface 12a of the housing cavity 12. The bottom 12b of the housing cavity 12 corresponds to the radial inner side 12i of the housing cavity 12.

[0146] According to an aspect of the present disclosure, said locking member 36 is configured to provide a closed space S12 between the radial outer end 32o of the unit 32 and the radial opening O.

[0147] According to an aspect of the present disclosure, the respective unit 32 comprises a sealing member 38 arranged around its outer surface 32a so as to provide sealing of said unit 32 towards said inner surface 12a of said housing cavity 12.

[0148] According to an aspect of the present disclosure, the respective unit 32 is configured to be closely received within its housing cavity 12 so that said radial movement of the unit 32 within said housing cavity 12 is allowed.

[0149] According to an aspect of the present disclosure, the respective unit 32 has a cylindrical configuration. According to an aspect of the present disclosure, the respective radially running housing cavity 12 has an inner shape essentially corresponding to the outer shape of said cylindrically configured unit 32, facilitating tightly receiving said unit 32. According to an aspect of the present disclosure, the respective radially running housing cavity 12 has a ring-shaped cross-section, having said opening O at the radial outer side, a radially running inner wall having said inner surface 12a and said closed bottom side 12b at the radial inner side 12i.

[0150] According to an aspect of the present disclosure, the clutch device 100 according to the present may be easy assembled. According to an aspect of the present disclosure, the clutch device 100 may be assembled by applying fluid pressure provision devices 30 in said housing cavities.

[0151] According to an aspect of the present disclosure, prior to applying the fluid pressure provision devices 30, the sealing member 38 of the respective fluid pressure provision device 30 is configured to be mounted around its unit 32. According to an aspect of the present disclosure, the respective unit 32 has a track running around its outer side for facilitating applying the sealing member 38.

[0152] According to an aspect of the present disclosure, the units 32 with sealing member 38 is applied into the respective housing cavity 12, wherein the spring member 34 of the respective fluid pressure provision device 30 thereafter is introduced into the housing cavity 12 in connection to said unit 32.

[0153] Alternatively, said spring member 34 is mounted to said unit 32 prior to introducing said unit 32 into said housing cavity 12. According to an aspect of the present disclosure, the locking member 36 of the respective fluid pressure provision device 30 is applied to the housing cavity 12 in connection to said radial opening O. Said locking member 36 may be applied to the housing cavity 12 in connection to said radial opening O by means of being pressed into said opening O or screwed into said opening O or secured by means of a locking ring or the like in connection to said opening O.

[0154] According to an aspect of the present disclosure, the sealing member 24 is attached to said piston, e.g. attached to outer tracks around said piston 22. According to an aspect of the present disclosure, said annular housing 10 is arranged such that said fluid pressure provision devices 30 are horizontally arranged, wherein said fluid F is introduced into said applied to said internal ring-shaped track 14T so that said fluid F is allowed to flow into said housing cavity 12, i.e. into said space S20 of said housing cavity 12, via said fluid channel 40. According to an aspect of the present disclosure, the piston device 20 comprising said piston 22 and said sealing member 24 is applied to said internal ring-shaped track 14T of said annular housing 10 so that said piston cavity S20 is provided.

[0155] Fig. 11 a schematically illustrates a graph of the radial force generated by means of a control arrangement of a clutch device as a function of the rounds per minute of the annular housing of said clutch device, according to an aspect of the present disclosure. Thus, the Y-axis illustrates the radial force in Newton (N) generated by means of the fluid pressure provision devices 30 of the control arrangement CA of the clutch device 100 of the present disclosure as a function of the rounds per minute (rpm) of the annular housing 10 of said clutch device 100, illustrated at the X-axis. The generated radial forces (N) based on rounds per minute (rpm) of the annular housing 10 are only examples and may depend on different parameters such as dimension and configuration of the clutch device comprising parts of the control arrangement.

[0156] Fig. 11 b schematically illustrates a graph of the spring force generated by spring member 34 of fluid pressure provision device 30 of said clutch device 100 as a function of its length compression in the radial direction, according to an aspect of the present disclosure. Thus, the Y-axis illustrates the spring force in Newton (N), associated with the compression of the spring member 34 being pressed by means of centrifugal force caused by rotation of the annular housing 10 and hence radial movement of said unit 32 when predetermined spring force of said spring member 34 is exceeded, as a function of the radial length, in millimetre (mm), which said spring member 34 is compressed, the length, according to an aspect of the present disclosure, corresponding to the outer radial movement of the unit 32, applying pressure on said fluid F. The spring force (N) and the associated compression (mm) are only examples and may depend on different parameters such as dimension and configuration of the clutch device comprising parts of the control arrangement.

[0157] Fig. 11c schematically illustrates a graph of the pressure generated by means of fluid pressure in megapascal (MPa) as a function of the rounds per minute (rpm) of the annular housing 10 of said clutch devicel OO, according to an aspect of the present disclosure. The fluid pressure (MPa) and the associated rounds per minute (rpm) of the annular housing 10 are only examples and may depend on different parameters such as dimension and configuration of the clutch device comprising parts of the control arrangement.

[0158] The foregoing description of the preferred embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications suited to the particular use contemplated.

Claims

CLAIMS1. A control arrangement (CA) of a clutch device (100) for a drive arrangement (D), said clutch device (100) comprising: an annular housing (10) configured to be secured to and rotatable by means of a drive shaft (S1 ) about an axis (X); a plurality of clutch discs (50) configured to be positioned within said housing (10) and arranged about a driven shaft (S2) coaxially arranged relative to said drive shaft (S1 ), and a piston device (20), said plurality of clutch discs (50) being arranged such that, when axially pressed together by means of said piston device (20) so that they are frictionally engaged, torque is configured to be transferred to the driven shaft (S2), wherein said control arrangement (CA) is configured to facilitate providing said frictional engagement of said plurality of clutch discs (50) by means of centrifugal force exerted on fluid (F) within said annular housing (10) in connection to rotation of said annular housing (10) so that said piston device (20) acts on said plurality of clutch discs (50), wherein said control arrangement (CA) comprises a set of fluid filled housing cavities (12) distributed around and configured to radially run within said annular housing (10), and a set of fluid pressure provision devices (30), a respective fluid pressure provision device (30) of said set of fluid pressure provision devices (30) being configured to be arranged within a housing cavity (12) of said set of housing cavities (12), the respective fluid pressure provision device (30) comprising a unit (32) configured to be radially movably arranged within the housing cavity (12) in which that fluid pressure provision device (30) is arranged such that the respective unit (32), when moving radially outwardly, provides pressure on said fluid (F) within that housing cavity (12) based on the centrifugal force so as to facilitate control of said frictional engagement of said plurality of clutch discs (50) by means of said piston device (20).

2. The control arrangement according to claim 1 , wherein said units (32) are configured to be radially movably arranged within said housing cavities (12) such that, when subjected to a centrifugal force exceeding a certain thresholdvalue, the respective unit (32) moves radially outwardly and applies pressure on the fluid (F) within its cavity such that said piston device (20) acts on said plurality of clutch discs (50) providing said frictional engagement.

3. The control arrangement according to claim 1 or 2, wherein the respective housing cavity (12) is configured to be operably connected to said piston device (20) via a fluid channel (40) so that fluid (F) within the respective housing cavity (12) is allowed to flow between the housing cavity (12) and said piston device (20) via said fluid channel (40).

4. The control arrangement according to any of claims 1-3, wherein the respective unit (32) of said set of units (32) is configured to be spring-loadably arranged within a housing cavity (12) of said set of housing cavities (12) for facilitating controlled radial movement of said units (32) based on the centrifugal force.

5. The control arrangement according to any of claims 1-4, wherein the respective fluid pressure provision device (30) comprises a spring member (34) arranged in connection to said unit (32), said spring member (34) being configured to provide a predetermined spring force so that said unit (32) is maintained in a non-actuated position if said spring force is not exceeded, wherein said spring force is configured to be exceeded when said centrifugal force exceeds a predetermined threshold value, providing radially outward movement of said unit (32) from said non-actuated position for providing fluid pressure of said fluid (F) within said housing cavity (12) for said frictional engagement of said plurality of clutch discs (50) by means of said piston device (20).

6. The control arrangement according to claim 5, wherein said unit (32) is configured to move radially inwardly and return to said non-actuated position by means of said spring force provided by said spring member (34) when said centrifugal force no longer exceeds said predetermined threshold value.

7. The control arrangement according to any of claims 1-6, wherein the respective radially running cavity (12) is configured to be open towards a radial outer end (1 Oo) of said annual housing (10) by means of a radial opening (O).

8. The control arrangement according to claim 7, when claim 7 depends on claim 5 or 6, wherein the respective spring member (34) comprises or is operably connected to a locking member (36) for sealingly locking said spring member (34) to the annual housing (10) in connection to the radial opening (O) of a housing cavity (12) of said set of cavities (12), providing, for said fluid, a space (S12) between the unit (32) and the radial opening (O).

9. The control arrangement according to any of claims 1-8, wherein the respective unit (32) has an elongated configuration having a radial outer end (32o) configured to face radially outwardly in said housing cavity (12), an opposite radial inner end (32i) configured to face towards the bottom (12b) of the housing cavity (12), and an outer surface (32a) configured to face towards the inner surface (12a) of the housing cavity (12).

10. The control arrangement according to claim 9, wherein the respective fluid pressure provision device (30) comprises a sealing member (38) configured to be arranged around said unit (32) so as to provide sealing of said unit (32) towards said inner surface (12a) of said housing cavity (12) so as to prevent fluid within said housing cavity (12) escaping past said unit (32) to said bottom of said housing cavity (12).

11. The control arrangement according to any of claims 1-10, wherein the respective unit (32) is configured to be closely received within its housing cavity (12) so that said radial movement of the unit (32) within said housing cavity (12) is allowed.

12. The control arrangement according to any of claims 1-11 , wherein the respective unit (32) has a cylindrical configuration, wherein the respective radially running housing cavity (12) has an inner shape essentiallycorresponding to the outer shape of said cylindrically configured unit (32), facilitating tightly receiving said unit (32).

13. The control arrangement according to any of claims 1-12, wherein said piston device (20) comprises a ring-shaped piston (22) coaxially arranged around said axis (X), said ring-shaped piston (22) being arranged within and operably connected to said annular housing (10).

14. The control arrangement according to claim 13, wherein said ring-shaped piston (22) comprises a recess (22R) configured to run around the ring-shaped piston (22) configured to face away from said plurality of clutch discs (50) and face towards a portion (10P) of said annular housing (10) so as to provide a piston cavity (S20) in connection to said recess (22R), wherein the fluid channel (40) connected to the respective housing cavity (12) is connected so that fluid within the respective housing cavity (12) is allowed to flow between said housing cavity (12) and said piston cavity (S20) via said fluid channel (40).

15. The control arrangement according to claim 13 or 14, wherein said piston device (20) comprises a sealing member (24) for providing sealed connection of said ring-shaped piston (22) to said annular housing (10).

16. The control arrangement according to any of claims 1-15, wherein the plurality of clutch discs (50) configured to be positioned within said annular housing (10) and arranged about said driven shaft (S2) comprise a first set of clutch discs (52) configured to be engaged to said annular housing (10) and a second set of clutch discs configured to be engaged to said driven shaft (S2), clutch discs (52) of said first set of clutch discs (52) and clutch discs (54) of said second set of clutch discs (54) being alternatingly arranged relative to each other and axially movable relative to each other.

17. A clutch device (100) comprising a control arrangement (CA) according to any of claims 1-16 and a torque transfer arrangement (TA) comprising said plurality of clutch discs (50) for transferring torque from said drive shaft (S1 ) to said driven shaft (S2).

18. A drive arrangement (D) comprising a clutch device according to claim 17, said drive arrangement (D) comprising a drive device (E) configured to operate said drive shaft (S1 ), and a transmission device (T) operably connected to said driven shaft (S2).

19. A vehicle (V) comprising a drive arrangement (D) according to claim 18.

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