Cartridge, fuel cell, and method for assembling the cartridge

Abstract

The invention relates to a cartridge (1), comprising a foot (20), sliding relative to a base (10), for placing a fuel cell end plate to bear against a stack of electrochemical cells in a compression direction (X1); a spring (30), bearing on the base (10) in order to apply a pressing force (F30) to the foot (20); a holding system (40); and a stop system (80), separate from the holding system and restricting the sliding of the foot relative to the base in the compression direction, by abutting the foot against the base in the compression direction, when the foot is fitted with the base and the cartridge (1) is in a released configuration.

Description

[0001] TITLE: Cartridge, fuel cell and method for assembling the cartridge

[0002] The present invention relates to a cartridge for maintaining in compression a stack of electrochemical cells belonging to a fuel cell, relates to a fuel cell comprising such a cartridge, and relates to a method for assembling such a cartridge.

[0003] FR3143885A1 describes a cartridge for maintaining a stack of electrochemical cells in a fuel cell under compression. This cartridge comprises a base and a foot that slide relative to each other, with a spring interposed between the two. The cartridge includes a retaining system that allows the cartridge to be held in a pre-stressed configuration before it is integrated into the fuel cell. In the pre-stressed configuration, the foot is immobilized relative to the base, despite the compressive force applied by the spring on the foot relative to the base. Once the cartridge is integrated into the fuel cell, with the base held by a support wall, the retaining system is actuated to move the cartridge to a released configuration where the foot is no longer held relative to the base, so that the foot is pressed against the stack by the spring and thus applies the compressive force to the stack.

[0004] During the various operating phases of the fuel cell, the cell stack tends to expand and / or contract along the direction of compression, primarily due to thermal effects and stack aging. In the event of a significant contraction variation, for example, if the fuel cell is subjected to very low temperatures or in cases of advanced fuel cell aging, there is a risk that the base and the foot will separate and eventually disassemble, as the distance between the support wall and the stack becomes too great.

[0005] Furthermore, only the spring, applying the pressing force to the foot against the base, prevents the foot from pivoting relative to the base. Therefore, the risk of rotation of the foot relative to the base cannot be entirely ruled out, particularly when a high rotational torque is applied to the base relative to the foot, or vice versa. This can occur, for example, when the foot is attached to an end plate by screwing it in, thereby rotating the base.

[0006] It is this drawback that the invention intends to remedy in particular, by proposing new solutions to avoid disassembly of the cartridge in the event of a particularly large contraction of the stack of electrochemical cells, without prejudice to the axial size of the cartridge.

[0007] To this end, the invention relates to a cartridge for maintaining, in compression along a compression direction, a stack of electrochemical cells belonging to a fuel cell, the cartridge comprising: a base, by means of which the cartridge is configured to be retained in the opposite direction to the compression direction, by a retaining wall integral with, or belonging to, the fuel cell; a foot:

[0008] • which is arranged in the compression direction relative to the base, being fitted to the base so as to slide relative to the base along a central axis of the cartridge, parallel to the compression direction, and

[0009] • which is configured to place a fuel cell end plate against the stack in the compression direction to maintain the stack in compression in the compression direction; a spring, which bears against the base to apply a compressive force to the foot in the compression direction; and a retention system, which includes a primary retention portion, integral with the base, and a secondary retention portion, integral with the foot, the primary retention portion and the secondary retention portion being configured to:

[0010] • be coupled to each other when the cartridge is in a pre-stressed configuration, the primary retaining portion and the secondary retaining portion thus coupled preventing the foot from sliding relative to the base along the compression direction; and

[0011] • be decoupled from each other when the cartridge is in a released configuration, the primary retention portion and the secondary retention portion thus decoupled allowing the foot to slide relative to the base along the direction of compression.

[0012] According to the invention, the cartridge further comprises a stop system, separate from the retaining system, the stop system limiting the sliding of the foot relative to the base along the direction of compression, by butting the foot against the base along the direction of compression by means of the stop system, while the foot is fitted with the base and the cartridge is in the released configuration.

[0013] Thanks to the invention, excessive contraction of the stack along the compression direction leads to the stop system being brought to a stop, preventing accidental separation of the foot from the base under the action of the spring. In particular, this prevents the foot from disengaging from the base under the action of the spring. To ensure that separation does not occur, the stop system is arranged so that the foot is brought to a stop against the base along the compression direction when the foot is still in a sliding relationship with the base, i.e., still fitted into the base.

[0014] When excessive contraction occurs and the foot reaches its abutment against the baseplate, it is anticipated, for example, that if the baseplate was simply resting against the retaining wall to be held in the opposite direction to the compression, the baseplate is moved away from the retaining wall along the compression direction and is therefore no longer resting against the retaining wall. Alternatively, it is anticipated that if the foot was simply resting against the end plate along the compression direction to maintain the stack in compression, the foot is moved away from the end plate in the opposite direction to the compression direction and is therefore no longer resting against the end plate.Once the excessive contraction has ceased, i.e. once the stack expands again, the support of the cartridge is restored, i.e., depending on the embodiment chosen, the base returns to rest against the retaining wall or the foot returns to rest against the terminal plate.

[0015] It is also advantageously provided that, in the prestressed configuration, the foot is not against the base in the direction of compression, so that, when switching to the released configuration, the foot has the possibility of sliding in the direction of compression relative to the base in order to ensure the compression of the stack.

[0016] The stop system also offers additional safety by keeping the foot attached to the base, in the event that the cartridge is accidentally put into a released configuration outside the fuel cell, thus preventing ejection of the foot from the base under the action of the spring.

[0017] Depending on advantageous, but not mandatory, aspects of the invention, one or more of the following features may be incorporated, taken individually or in any technically feasible combinations:

[0018] - The stop system also prevents rotation of the foot relative to the base around the central axis. The stop system thus advantageously provides an anti-rotation function between the foot and the base, which notably facilitates the assembly of the cartridge in a pre-stressed configuration within the fuel cell, by transmitting the entire tightening torque applied to the base to the foot or to the possible assembly means defined below, without any slippage. - The stop system comprises a pin and a groove end. A first element (the pin and the groove end) is fixed to the foot, while a second element (the pin and the groove end), distinct from the first element, is fixed to the base. The foot is abutted against the base along the compression direction, such that the first element abuts against the second element along the compression direction.

[0019] - The cartridge comprises a tubular ring, coaxial with the central axis and to which the pin is fixed, and a peripheral wall, coaxial with the central axis and received inside the tubular ring, a groove, including the end of the groove, being formed in the recess of the peripheral wall, the pin protruding from the tubular ring to be received in the groove, the pin being configured to slide in the groove when the foot slides relative to the base, until it comes to rest against the end of the groove to limit the sliding of the foot relative to the base along the direction of compression.

[0020] - The foot is fitted with the base in that the peripheral wall is received in the tubular ring and the tubular ring and the peripheral wall cooperate radially to guide the sliding of the foot relative to the base, when the peripheral wall is received in the tubular ring.

[0021] - An orifice, radial with respect to the central axis, passes through the tubular ring from one side to the other, the pin being fixedly received inside the orifice to be integral with the tubular ring.

[0022] - The tubular crown belongs to the foot and the peripheral wall belongs to the base.

[0023] - The cartridge includes an assembly means for assembling the foot to the terminal plate of the fuel cell, the foot being configured to press the terminal plate against the stack in the direction of compression to maintain the stack in compression, when the foot is assembled with the terminal plate by the assembly means and the base is retained in the opposite direction of compression by the retaining wall.

[0024] - The assembly means includes an external thread coaxial with the central axis, the external thread being arranged around the foot and the secondary retaining portion and being configured to engage with an internal thread belonging to the end plate, to assemble the foot with the end plate.

[0025] - The cartridge further includes an anti-rotation device, which is configured to be mounted to prevent rotation of the foot relative to the end plate around the central axis when the external thread is engaged in the internal thread of the end plate and the retaining system is in the released configuration.

[0026] - The retention system includes a retention element, through which the primary retention portion and the secondary retention portion are coupled, when the cartridge is in prestressed configuration.

[0027] - The retaining element comprises a first threaded body.

[0028] - The secondary retaining portion is formed by a tapped hole, arranged in a through shaft parallel to the direction of compression, the primary retaining portion and the secondary retaining portion being coupled to each other when the first threaded body is engaged with the tapped hole and being decoupled from each other when the first threaded body of the retaining member is not engaged with the tapped hole.

[0029] - The spring consists of at least one spring washer, or a stack of spring washers, interposed between the base and the foot along the direction of compression.

[0030] The invention also relates to a fuel cell comprising:

[0031] - the cartridge as defined above, the cartridge being in a freed configuration;

[0032] - the retaining wall, holding the base in the opposite direction to the compression direction;

[0033] - a support wall, the support wall and the retaining wall being fixedly attached to each other, the support wall being arranged in the direction of compression relative to the retaining wall;

[0034] - the stack of electrochemical cells, which is arranged between the retaining wall and the supporting wall, bearing against the supporting wall in the direction of compression; and

[0035] - the terminal plate, being in contact with the stack along the direction of compression, the cartridge spring applying the pressing force on the stack via the foot, along the direction of compression, bearing on the base.

[0036] Preferably, the retaining wall and the support wall belong to a housing of the fuel cell, the stack being received inside the housing, the housing further comprising a longitudinal wall connecting the retaining wall to the support wall.

[0037] The invention also relates to a method for assembling the cartridge as defined above, the method comprising:

[0038] - a fitting of the foot with the base, while the spring is interposed between the foot and the base along the direction of compression; and - a setting up of the stop system, while the foot is already fitted with the base and the spring applies the pressing force on the foot, so that the stop system limits the sliding of the foot relative to the base along the direction of compression.

[0039] An embodiment independent of the above relates to a cartridge for maintaining, in compression along a compression direction, a stack of electrochemical cells belonging to a fuel cell, the cartridge comprising: a base, by means of which the cartridge is configured to be retained in the opposite direction to the compression direction, by a retaining wall integral with, or belonging to, the fuel cell; a foot:

[0040] • which is arranged in the compression direction relative to the base, being fitted to the base so as to slide relative to the base along a central axis of the cartridge, parallel to the compression direction, and

[0041] • which is configured to place a fuel cell end plate against the stack in the compression direction to maintain the stack in compression in the compression direction; a spring, which bears against the base to apply a compressive force to the foot in the compression direction; and a retention system, which includes a primary retention portion, integral with the base, and a secondary retention portion, integral with the foot, the primary retention portion and the secondary retention portion being configured to:

[0042] • be coupled to each other when the cartridge is in a pre-stressed configuration, the primary retaining portion and the secondary retaining portion thus coupled preventing the foot from sliding relative to the base along the compression direction; and

[0043] • be decoupled from each other when the cartridge is in a released configuration, the primary retention portion and the secondary retention portion thus decoupled allowing the foot to slide relative to the base along the direction of compression.

[0044] According to this independent embodiment, the cartridge further comprises a stop system, separate from the retaining system. This stop system prevents rotation of the foot relative to the base around the central axis. The stop system thus advantageously provides an anti-rotation function between the foot and the base, which notably facilitates the assembly of the cartridge in a pre-stressed configuration within the fuel cell. This is achieved by transmitting the entire tightening torque applied to the base to the foot or to the optional assembly means defined below, without any slippage.

[0045] The advantages and optional features of the invention can be applied to this independent embodiment and vice versa.

[0046] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which: [Fig. 1] Figure 1 is a perspective view of a cartridge for a fuel cell, according to a first embodiment of the invention, the cartridge being shown in longitudinal section and in a pre-stressed configuration.

[0047] [Fig. 2] Figure 2 is a perspective view of a fuel cell including several cartridges conforming to that of Figure 1, the fuel cell being shown in longitudinal section, the cartridges being in a freed configuration.

[0048] [Fig. 3] Figure 3 shows a detail of the longitudinal section of Figure 2, according to frame III shown in Figure 2.

[0049] [Fig. 4] Figure 4 is a perspective view of a cartridge for a fuel cell, according to a first embodiment of the invention, the cartridge being shown in longitudinal section and in a prestressed configuration.

[0050] Figure 1 shows a cartridge 1, which comprises a base 10, a foot 20, a spring 30, and a retaining system 40. As explained below, the cartridge 1 is configured to switch between, that is, to move between, a preloaded configuration, shown in Figure 1, and a released configuration, shown in Figures 2 and 3, by means of the retaining system 40. In other words, the retaining system 40 either holds the cartridge 1 in the preloaded configuration or is released or decoupled so that the cartridge is in the released configuration. The cartridge 1 has a direction of use, defining a compression direction X1, fixed relative to the foot 20, and directed from the base 10 to the foot 20. The cartridge 1 is geometrically traversed by a central axis X10, parallel to the compression direction X1.

[0051] The cartridge 1 is intended to be integrated into a fuel cell 50, shown in figures 2 and 3, to compress a stack 51 of electrochemical cells 52 belonging to said fuel cell 50. The outline of the stack 51 is shown schematically in dashed lines in figure 2. The electrochemical cells are not individually represented for the sake of simplification.

[0052] Preferably, the cartridge 1 belongs to a dimensional compensation system which includes, in addition to the cartridge 1, an end plate 53, shown in Figures 2 and 3. The end plate 53 is intended to bear against the stack 51 of the fuel cell 50 along the X1 direction. Preferably, the dimensional compensation system includes one or more other cartridges T to which the description of the cartridge 1 applies, and which contribute to maintaining the stack 51 in compression like the cartridge 1.

[0053] The stack 51, for example, comprises between two hundred and five hundred cells 52. Each electrochemical cell 52, for example, consists of an anode and a cathode, separated by a polymer membrane allowing the passage of protons from the anode to the cathode. During the operation of the fuel cell 50, each anode of the stack 51 is supplied with fuel, for example, dihydrogen, and each cathode of the stack 51 is supplied with an oxidant, for example, oxygen or air.

[0054] To form the stack 51, the electrochemical cells 52 are stacked, i.e. superimposed, according to a stacking direction, which here is parallel to the compression direction X1 when the cartridge 1 is integrated into the stack 50. Preferably, when the stack 50 is in operation, for example in a vehicle, the stacking direction and the compression direction X1 are approximately horizontal.

[0055] In addition to the stack 51, the fuel cell 50 includes a casing 60. The cartridges 1 serve to maintain the stack 51 in compression along the compression direction X1 during the use of the fuel cell 50, preferably throughout the life of the fuel cell 50.

[0056] The housing 60 surrounds and protects the stack 51, thus forming an advantageously sealed enclosure. The housing 60 comprises a transverse wall 61 mentioned above, referred to as the "retaining wall", a longitudinal wall 62 and a transverse wall 63 mentioned above, referred to as the "support wall".

[0057] Here, walls 61 and 63 are perpendicular to direction X1, and longitudinal wall 62 is parallel to direction X1. Longitudinal wall 62 is a peripheral wall that surrounds stack 51 and connects walls 61 and 63 to each other, being attached to their respective perimeters. Stack 51 is also arranged between walls 61 and 63, which are preferably substantially planar, with wall 63 oriented in direction X1 relative to wall 61. Overall, walls 61, 62, and 63 are arranged so that the housing 60 has a general parallelepiped shape.

[0058] In this example, the retaining wall 61 and the support wall 63 are removable relative to the longitudinal wall 62. Alternatively, the retaining wall 61 may be permanently fixed or form a single piece with the longitudinal wall.

[0059] 62, so that walls 61 and 62 form a subset which is reported on the wall

[0060] 63, which is removable relative to this subassembly. Alternatively, walls 62 and 63 may be permanently fixed or form a single piece, while wall 61 is removablely fixed to this subassembly. In any case, it is advantageous to provide that wall 61 is removable relative to wall 63, either, for example, in that wall 61 is removable relative to wall 62, or in that wall 62 is removable relative to wall 63, or both, as in the present example.

[0061] The support wall 63 serves here as a fixed end plate for the stack 51, in that the stack 51 is supported, along the X1 direction, against the support wall 63, without the interposition of an elastic element for dimensional compensation. However, it could be envisaged that the stack 51 includes a separate fixed end plate, through which the stack 51 would be supported against the support wall 63. As shown in Figure 2, preferably, the support wall 63 has openings that can be traversed by connectors, not shown, intended to be connected to fluid circulation lines, thus allowing the stack 51 to be supplied with fuel, oxidizer, a possible coolant, and the removal of reaction products if any.

[0062] The retaining wall 61, which belongs to the pier 50 once assembled, can be considered as belonging to the dimensional compensation system, in particular before its integration into the pier 50.

[0063] The base 10 of the cartridge 1 has a proximal end 11, a distal end 12, a peripheral wall 13, and preferably a central conduit 14, which are fixed relative to each other, for example, by being all one piece. The axis X10 passes successively through the ends 11 and 12, with the end 12 being in the direction X1 relative to the end 11. The wall 13 surrounds the axis X10 and connects the ends 11 and 12. The wall 13 is preferably cylindrical with a circular base, centered on the axis X10. The central conduit 14, if provided, advantageously passes through the base 10 from the end 11 to the end 12, being centered on the axis X10.

[0064] The retaining wall 61 comprises an inner face 69 and an outer face 66 opposite and perpendicular to the direction X1. The lower face 69 is oriented along the direction X1. The outer face 66 advantageously faces the outside of the housing 60 and is opposite the stack 51, while the inner face 69 faces the inside of the housing 60 and faces the stack 51.

[0065] As shown in Figure 3, each cartridge 1 is configured to be retained by the retaining wall 61 by bearing against the retaining wall 61 in the opposite direction to X1, via the base 10. In particular, the cartridge 1 is retained in that the proximal end 11 of the base 10 bears against the inner face 69, in the opposite direction to X1. If several cartridges are provided, they are then distributed over the surface of the retaining wall 61.

[0066] Preferably, the foot 20 includes a support pad 22, a tubular crown 29 and a shaft 21.

[0067] The tubular ring 29 is coaxial with the central axis X10. The tubular ring 29 is tube-shaped with a circular cross-section. The tubular ring 29 extends from the pad 22, specifically from a peripheral edge of the pad 22, in the opposite direction to X1.

[0068] The foot 20 is fitted to the base 10, such that the base 10 is preferentially received inside the tubular ring 29 of the foot 20, which surrounds the base 10. In particular, the peripheral wall 13 of the base is received inside the tubular ring 29, the foot 20 being fitted to the base 10 such that the peripheral wall 13 is coaxially received within the tubular ring 29. An internal wall of the tubular ring 29 and the peripheral wall 13 cooperate radially to guide the sliding of the foot 20 relative to the base 10 along the axis X10, when the peripheral wall 13 is received within the tubular ring 29, i.e., when the foot 20 is fitted to the base 10. There is a small positive radial clearance between the peripheral wall 13 and the internal radial wall of the ring 29 to guide the sliding.

[0069] Preferably, foot 20 and base 10 are fitted together according to the principle of a sliding pivot joint along the X10 axis.

[0070] The support pad 22 is advantageously discoidal in shape, centered on the axis X10, and advantageously has an orifice in its center through which the axis X10 passes. The support pad 22 is fixed here relative to the shaft 21 and the ring 29, preferably all three being monoblocs, and is formed in the direction X1 relative to the shaft 21 and the ring 29. Preferably, the support pad 22 has a diameter greater than that of the peripheral wall 13, so that the tubular ring 29, rising from the peripheral edge of the pad 22, extends around the base 10.

[0071] The shaft 21 is coaxial with the central axis X10. The shaft 21 is preferably in the form of a tube with a circular cross-section. The shaft 21 extends from the foot 22, in the opposite direction to X1. The shaft 21 is then coaxial with the ring 29 and is arranged inside the ring 29, being connected to the ring 29 by the foot 22. The shaft 21 forms a conduit coaxial with the axis X10, which advantageously passes completely through the foot 20.

[0072] The shaft 21 is received in a conduit 18 of the base 10, which belongs to the central conduit 14 and opens at the distal end 12 of the base 10. The shaft 21 enters the conduit 14 through its end 12. When the sliding between the base 10 and the foot 20 is guided by the crown 29, a significant radial clearance between the shaft 21 and the conduit is advantageously provided.

[0073] 18.

[0074] Alternatively, a smaller radial clearance can be provided so that the sliding guidance is achieved by radial cooperation of the shaft 21 with the conduit 18. In this case, a large radial clearance can optionally be provided between the ring 29 and the wall 13 of the base 10, so that the sliding is guided only by the shaft 21 and not by the ring 29. In this case, the fitting of the foot 20 into the base 10 is effective in that the shaft 21 is received in the conduit 18 and cooperates radially with the conduit 18 to guide the sliding.

[0075] In the present example, whatever the position of the foot 20 relative to the base 10 for its sliding, the support pad 22 is arranged in the direction X1 relative to the distal end 12 of the base 10, and thus forms a distal end of the cartridge 1. Alternatively, it could be provided that the crown 29 and / or the shaft 21 protrude from the support pad 22 in the direction X1 and thus constitute the distal end of the cartridge 1.

[0076] As shown in Figure 1, the cartridge 1 includes a stop system 80. This system is specifically configured to limit, constrain, and / or define the sliding motion of the foot 20 relative to the base 10 along the compression direction X1. In other words, the stop system allows a certain degree of freedom between the foot 20 and the base 10 along the angle X10, but within a defined and limited range by design, for example, a few millimeters or even centimeters. Preferably, the stop system 80 comprises pins 81, fixedly attached to the foot 20, and grooves 82, fixedly attached to the base 10. In this example, the pin 81 thus constitutes the first element of the system 80, which is fixed to the foot 20, while the groove 82 constitutes the second element of the system 80, which is fixed to the base 10.In any case, the stop system 80 is separate from the retaining system 40 and is specifically designed to be functional when the cartridge 1 is in the released configuration. As illustrated, the stop system 80 comprises a plurality of pins 81, advantageously two, and a plurality of grooves 82, advantageously two, said plurality of pins 81 and grooves 82 being diametrically opposed. This ensures proper delimiting and guidance of the sliding of the foot 20 relative to the base 10 along the compression direction X1, preventing any wedging phenomenon. A construction with three pins 81 and three grooves 82 distributed at 180° could also be considered without departing from the scope of the invention. Naturally, the same number of pins 81 and grooves 82 should be provided. Each groove 82 is preferably formed directly in the peripheral surface 13, thus being made of material with the peripheral surface 13.The grooves 82 are regularly distributed around the axis X1. Here, two grooves 82 are provided and are therefore arranged diametrically opposite each other. The grooves 82 are preferably at the same height along the axis X10. Each groove 82 is formed radially in the direction of the axis X1, that is to say, radially inwards.

[0077] Each groove 82 includes at least one end of a groove 83, and possibly additionally an end of a groove 84, opposite the end 83. The end 83 terminates the groove 82 along the direction X1. The end 84, if present, terminates the groove 82 in the opposite direction. In the absence of an end 84, the groove 82 is, for example, open in the opposite direction to X1, opening at the proximal end 11 of the base 10. The groove 82 is preferably parallel to the direction X1, so that the ends 83 and 84 are preferably aligned along the direction X1. Each groove 82 includes longitudinal walls 85, parallel to the axis X10 and facing each other. Each wall 85 extends from the end 83 and connects the ends 83 and 84, if the end 84 is present.

[0078] The pins 81 are regularly distributed around the axis X1. Here, two pins 81 are provided and are therefore arranged diametrically opposite each other. The pins 81 are preferably at the same height along the axis X10. Each pin 81 comprises a base end, by means of which the pin 81 is fixedly attached to the ring 29 of the foot 20, and an inner end that projects radially inward from the ring 29. Since the inner end of the pin 81 is projecting, it is received in one of the grooves 82. Preferably, each pin 81 is oriented radially, that is to say, its base and inner ends follow an axis that is perpendicular to the axis X10 and intersects the axis X10. Preferably, the pin 81 does not extend radially outward from the foot 20.

[0079] Each pin 81 is advantageously an added piece on the foot 20. For this, the foot 20 preferably includes, for each pin 81, a respective orifice 86, which passes through the ring 29 from one side to the other, that is to say from an external face of the ring 29 to the internal radial face which cooperates with the peripheral surface 13 of the base 10. The orifice 86 is radial, that is to say that the orifice 86 is crossed by an axis which is perpendicular to the axis X10 and intersects the axis X10.

[0080] Each pin 81, for example, consists of a screw, oriented radially with respect to the X10 axis, which is screwed into the orifice 86 from the outside of the ring 29 until the inner end of the pin 81 is received in the corresponding groove 82. Advantageously, the base end of the pin 81 is threaded to cooperate in screwing with an internal thread of the orifice 86 and allow this screwing. Advantageously, the base end of the pin 81 has a recess for a screwing tool, for example, a hexagonal socket as shown in Figure 1, so that the pin 81 can be screwed in from the outside of the cartridge 1 and, when the pin 81 is sufficiently driven into the orifice 86 as shown in Figure 1, through the opening of the orifice 86, which leads to the outside of the cartridge 1.Preferably, the pin 81 has a head, that is, a radial protrusion having said imprint so as to allow translational locking along the radial axis of the cartridge (that is, along the axis perpendicular to the X10 axis). Alternatively, the pin 81 has no head 81 and said imprint is then made inside the pin 81, as shown in Figure 1.

[0081] Each pin 81 is configured to slide in its corresponding groove 82 when the foot 20 slides relative to the base 10 along the X10 axis. Specifically, the inner end of the pin 81 is guided in its sliding motion by the longitudinal walls 85 of the groove 82. Preferably, the pin 81 is threaded along its entire length. Alternatively, the inner end of the pin 81 that engages with the walls 85 is not threaded. With the pin 81 thus received in the groove 82, it prevents the foot 20 from rotating relative to the base 10 around the X10 axis. For this purpose, the inner end of the pin 81 is advantageously held between the walls 85 of the groove 82.

[0082] Alternatively, without departing from the scope of the invention, the pin 81 may consist of a pin, a rivet, a stud, etc.

[0083] This anti-rotation function is particularly useful, especially from the perspective of cartridge mounting. Indeed, if the assembly means 17 is a threaded system, as described below, the stop system 80, and in particular the pin(s) 81 and the groove(s) 82, prevent any accidental unscrewing and therefore any accidental disassembly between the base 10 and the foot 20.

[0084] In addition, the anti-rotation function conferred by the stop system 80 is particularly useful when mounting the cartridge in a pre-stressed configuration in the fuel cell casing, allowing the entire rotational torque exerted on the base 10 to be transmitted to the assembly system 17 without slippage, as will be detailed below.

[0085] When the foot 20 slides along the compression direction X1 relative to the base 10, the pin 81 slides in the groove 82 until it reaches the end 83, against which the pin 81 then comes to rest along the direction X1. The foot 20 is then brought against the base 10 along the compression direction X1 in that the pin 81 comes against the end 83 of the groove 82. The sliding of the foot 20 is therefore limited by the stop system 80 along the compression direction X1 by bringing the foot 20 against the base 10, via the system 80. This stopping occurs while the foot 20 is still fitted with the base 10, that is to say here, while the peripheral wall 13 is sufficiently embedded in the ring 29 so that the guidance of the sliding of the foot 20 relative to the base 10 is ensured.This stop mechanism prevents the foot 20 from disassembling from the base 10, or from breaking the sliding guide of the foot 20 relative to the base 10. Such a stop mechanism is particularly important from a cartridge safety standpoint. Indeed, if the retaining system 40 breaks under the action of the spring 30, the base 10 could be ejected from the foot 20. The stop system 80, and more specifically the butting of the pin 81 against the end 83 of the groove 82, prevents the base 10 from moving in translation, even if the retaining system 40 is faulty or missing. However, this stopping occurs independently of whether the cartridge is in pre-stressed or free configuration, and is also useful mainly in the free configuration where no other element of the cartridge 1 holds the foot 20 against the base 10.

[0086] Optionally, when the foot 20 slides in the opposite direction to the compression direction X1 relative to the base 10, the pin 81 slides in the groove 82 until it reaches the end 84, against which the pin 81 then comes to rest in the opposite direction to the direction X1. The foot 20 is then brought against the base 10 in the opposite direction to the compression direction X1, in that the pin 81 comes against the end 84 of the groove 82. The sliding of the foot 20 is therefore advantageously limited by the stop system 80 also in this direction by bringing the foot 20 against the base 10, via the system 80. This stopping occurs while the foot 20 is still fitted to the base 10. Such a limitation makes it possible, for example, to limit the penetration of the base 10 into the foot 20 and, in particular, to avoid excessive compression of the spring 30, which could risk damaging it or generating too much stress in the cartridge.

[0087] Alternatively, according to a preferred solution, it is provided that the pin 81 does not come into contact with any part in the opposite direction of the X1 direction, but that the sliding of the foot 20 in the opposite direction of the X1 direction is only limited by the spring 30, which makes the stop in the opposite direction of the X1 direction when the spring 30 is fully compressed.

[0088] Preferably, the cartridge includes an assembly means 17. The assembly means 17 functions to allow the foot 20 to be assembled with the end plate 53, through which the cartridge 1 is intended to maintain the stack 51 in compression along the direction X1. The end plate 53, thus assembled, becomes fixed to the foot 20, or at least captures the foot 20 parallel to the direction X1. Depending on the situation, the assembly means 17 constitutes a fastener, a hook, or a connection for assembling the foot 20 with the end plate 53, which preferably includes additional features with the assembly means 17. The assembly means 17 allows the foot 20 to be assembled with the end plate 53 even though they were initially unassembled. Preferably, the assembly means 17 also allows for disassembly of the foot 20 and the terminal plate 53, while they were assembled.

[0089] Preferably, the assembly means 17 forms an external thread integral with the foot 20. Here, the assembly means 17 and the foot 20 form a single piece, the external thread being formed as part of the foot 20. The external thread is advantageously coaxial with the central axis X10. The external thread advantageously extends around the foot 20, in particular around the pad 22 and around the shaft 21, for example by being supported by the tubular ring 29. The external thread of the assembly means 17 is configured to engage with a corresponding internal thread 65, belonging to the end plate 53, to assemble the foot 20 with the end plate 53.

[0090] Alternatively, the assembly means 17 is a bayonet fitting, intended to be coupled with a complementary base, belonging to the terminal plate 53.

[0091] Alternatively, the assembly means 17 includes screws or other fasteners for fixing the foot 20 to the end plate 53.

[0092] Preferably, the base 10 includes an actuating head 16, formed at its proximal end 11. The actuating head 16 is intended to be actuated by a person, preferably using a tool, or by a machine, to rotate the cartridge 1 about the axis X10, thereby enabling the external thread of the assembly means 17 to engage with the internal thread of the end plate 53. For example, as illustrated, the actuating head 16 is formed by a hexagonal end centered on the axis X10, to be actuated by a hex key. Preferably, the stop system 80 transmits the rotational torque applied to the actuating head 16 of the base 10 to the assembly means 17 attached to the foot 20.The stop system 80 of the invention thus makes it possible to guarantee, remarkably, that the entire rotational torque applied to the actuating head 16 is transmitted completely to the assembly means 17, without slippage. The ease and reliability of the assembly operation are thereby improved, particularly compared to prior art compression systems lacking such a stop system, where only the pressure exerted by a spring allowed the torque to be transmitted.

[0093] When the foot 20 is assembled with the end plate 53 via the assembly means 17, the foot 20 is designed to bear, along the direction X1, against the end plate 53 to which the foot 20 is assembled, either directly or via the assembly means 17.

[0094] In this embodiment, the foot 20 is supported by means of the assembly means 17, which bears against the internal thread 65 along the X1 direction, as explained below. In other embodiments, when the foot 20 is directly supported, this is preferably achieved via the support pad 22, which advantageously forms the distal end of the cartridge 1. The support pad 22 then forms, for example, a discoidal axial surface, rotated in the X1 direction, to bear against the surface to be pressed along the X1 direction.

[0095] The spring 30 rests on the base 10 to apply a pressing force F30 on the foot 20 along the direction X1, by elasticity of the spring 30. Preferably, the spring 30 is a spring which acts in compression, along the direction X1.

[0096] The spring 30 consists of at least one spring washer, or preferably, a stack of spring washers, sometimes called Belleville washers. The spring washers are stacked along the X1 direction and centered on the X10 axis. A spring 30 made of spring washers has the advantage of repeating the force F30, particularly compared to a helical spring. Furthermore, the use of spring washers, depending on their characteristics, allows for a reduction in the size of the compression cartridge, thus increasing its compactness.

[0097] The spring 30, consisting of spring washers, is preferably configured so that the value of the compressive force F30 is constant, or varies very little, over a range of spring 30 elongation values. Preferably, when the cartridge 1 is in its preloaded configuration and when the cartridge 1 is in its released configuration by being installed in the stack 50, the elongation value of the spring 30 is within the range where the force F30 depends little on, or is not affected by, a variation in the elongation value. Such an operating range, known as linear, is more easily achieved with a spring washer than with a helical spring.

[0098] Preferably, spring washers with an R-ratio between 1.1 and 1.3 are used, preferably approximately equal to 1.2, the R-ratio being calculated as follows:

[0099] Ratio R = [washer height - washer thickness] / washer thickness

[0100] The "washer height" is a measurement of the spring washer along the X10 axis, when the spring washer is undeformed, from one end of the spring washer to the other. The "washer thickness" is a measurement of the thickness of the material constituting the washer along the X10 axis. Alternatively, the spring 30 could be a helical spring, centered on the X10 axis, rather than a spring with spring washers.

[0101] For example, in order to apply the force F30 to the foot 20 while bearing on the base 10, it is provided that, parallel to the direction X1, the spring 30 is interposed between the distal end 12 of the base 10 and the support pad 22. Thus, the spring bears on the support pad 22. The end 12 and the pad 22 respectively form opposing bearing walls, each receiving a respective end belonging to the spring 30. The spring 30 is, for example, arranged around the shaft 21 and inside the ring 29.

[0102] Radially with respect to the axis X10, the spring 30 advantageously has a radial footprint smaller than that of the base 10, in particular at the wall 13, and also, in the example, than that of the support pad 22. In other words, radially, the spring 30 does not protrude radially from either the foot 20 or the base 10.

[0103] Preferably, the holding system allowing the cartridge 1 to evolve between the pre-stressed configuration and the released configuration is constructed as follows.

[0104] The conduit 14 forms an axial shoulder 41, located at the proximal end 11, or between the end 11 and the conduit 18, and oriented in the opposite direction to X1. The shoulder is centered on the axis X10. The shoulder 41 is, for example, formed on an internal neck belonging to the conduit 14. The axial shoulder 41 forms a primary retention portion belonging to the retention system 40 and being integral with the base 10.

[0105] Preferably, a tapped hole 42, i.e., an internal thread, is provided in the barrel 21, at least for a portion of the barrel towards the base 10. In the present example, the tapped hole 42 even extends along the entire length of the barrel 21. The tapped hole 42 is positioned along the axis of the shoulder 41. The tapped hole 42 forms a secondary retaining portion belonging to the retaining system 40 and being integral with the foot 20. According to this example, the external thread constituting the assembly means 17 is arranged around the secondary portion, which gives the cartridge 1 good compactness.

[0106] Preferably, the retaining system 40 further comprises a screw 43, with a head 44 and a threaded body 45. The screw 43 advantageously constitutes a retaining element belonging to the retaining system 40 and which interacts with the primary retaining portion and the secondary retaining portion.

[0107] In the pre-stressed configuration, the screw 43 is received in the central channel 14 and in the threaded hole 42, as shown in Figure 1. The screw 43 ensures mutual coupling of the primary retaining portion with the secondary retaining portion, in that the screw 43 bears, along the direction X1, against the shoulder 41, via the head 44, and in that the threaded body 45 is engaged in the threaded hole 42 by means of a screw-nut connection. The screw-nut connection is preferably non-reversible, in the sense that the force imposed by the spring 30 does not allow for relative rotation between the screw 43 and the foot 20. In the pre-stressed configuration shown in Figure 1, the threaded body 45 is oriented along the compression direction X1, while the head 44 is oriented in the opposite direction, and the screw 43 is advantageously coaxial with the axis X10.This mutual coupling of the primary retaining portion with the secondary retaining portion via the retaining member means that the retaining system 40 prevents the foot 20 from sliding relative to the base 10, in the direction X1, despite the compressive force F30 applied by the spring 30 on the foot 20 while the spring bears against the base 10. In this case, the engagement of the threaded body 45 in the tapped hole 42 makes the screw 43 fixed to the foot 20, while, at the same time, the head 44 is held against the shoulder 41 of the base in the compression direction X1, due to the force F30, which is transmitted to the screw 43 via the foot 20. The pre-stressed configuration thus keeps the spring 30 pre-stressed, the spring 30 applying the force F30.

[0108] Preferably, the retaining system 40 allows adjustment of the foot 20's position relative to the base 10 along the compression direction X1, referred to as the "retaining position," for which the retaining system 40 prevents the foot 20 from sliding. For example, tightening or loosening the screw 43 in the threaded hole 42 changes the retaining position in which the foot 20 is held by the screw 43. Tightening the screw moves the foot 20 closer to the base 10, while loosening it moves the foot 20 further away from the base 10. The retaining position in which the foot 20 is held by the retaining system 40 can therefore be selected from a continuous range of foot 20 positions along the direction X1. In this example, this continuous range corresponds to the tightening stroke of the screw 43 in the threaded hole 42, parallel to the direction X1.To perform this adjustment, a press can also be used to avoid manipulating the screw 43 under the force F30 exerted by the spring 30. For example, the cartridge 1 can be positioned under the press to compress the spring 30, and then the position of the foot 20 relative to the base 10 can be adjusted and fixed without the force F30 exerted by the spring 30, as the spring is compressed by the press. This facilitates the adjustment operation and reduces the risk of breaking the screw 43.

[0109] Preferably, whether the spring 30 has spring washers or not, it is designed so that the value of the compressive force F30 of the spring 30 does not vary, or varies very little, over a range of spring 30 elongation values, a range having a certain extent around the elongation value obtained when the cartridge 1 is in its preloaded configuration. Preferably, the extent of this range covers the dimensional variation of the stack 50 during operation. This can be achieved, in particular, by a spring with spring washers as explained previously. It is then advantageously provided that, once the cartridge 1 is mounted in the stack 50 and is in its released configuration, the spring 30 is within this range of elongation values, so that the value of the compressive force F30 does not vary, or varies very little, despite the dimensional variations of the stack 51.Therefore, the pressing force F30 is not adjustable by changing the position of the foot 20, and is adjusted by changing or replacing the spring 30. For example, the number of spring washers constituting the spring 30 can be changed to vary the force F30 obtained and / or their geometric characteristics (thickness, inner / outer diameter, height).

[0110] Alternatively, whether the spring 30 has spring washers or not, the spring 30 is configured so that the value of the compressive force F30 it produces depends on an elongation value of the spring 30, measured along the axis X1, to allow adjustment of the compressive force F30 by adjusting the elongation value. "Elongation" is understood to mean a change in the length of the spring 30, measured from one end of the spring 30 to the other parallel to the direction X1. In the case of a compression spring, the force F30 increases when the length of the compression spring is reduced. Thus, the force F30 increases for a negative elongation value. Therefore, adjusting the foot support position 20 advantageously allows adjusting the value of the pressing force F30, in that each support position corresponds to a distinct extension value for the spring 30, on which the value of the pressing force F30 depends.In pre-stressed configuration, the value of the force F30 applied by the spring 30 on the foot can therefore be chosen by adjusting the retaining system 40.

[0111] To put the cartridge 1 in its released configuration, the primary retaining portion is decoupled from the secondary retaining portion, preferably by removing the retaining element. In this example, the screw 43 is removed, specifically by disengaging the threaded body 45 from the threaded hole 42 by unscrewing it. Figures 2 and 3 show the cartridge 1 in its released configuration, where the screw 43 is absent. In the released configuration, the foot 20 is therefore allowed to slide relative to the base 10, particularly under the action of the force F30, because the foot 20 is no longer retained by the retaining system 40. The foot 20 is then able to transmit the pressing force F30 to the end plate 53 to which the foot 20 is attached via the assembly means 17, along the compression direction X1, when the base 10 is otherwise retained in the opposite direction to X1.

[0112] Preferably, one end of the screw 43, located at the head 44, has a recess 46, for example a star-shaped recess, so that a person, using a tool or a machine, can rotate the screw 43 around the axis X10. In summary, the cartridge 1 has two configurations, each defined by design. In the first configuration, called the "pre-stressed configuration," the cartridge 1 is configured to be handled safely outside of a fuel cell, notably thanks to the retaining system 40 that keeps the spring 30 compressed. This pre-stressed configuration is stable. In the second configuration, called the "released configuration," the cartridge 1 is configured to apply the pressing force F30, preferably predetermined, to the end plate 53, which is to be pressed against the stack 51 of electrochemical cells 52 of the fuel cell 50.When cartridge 1 is fitted to fuel cell 50, this released configuration is stable.

[0113] As shown in Figures 2 and 3, the end plate 53 is designed to be assembled with the cartridge 1, as well as with any other cartridges T. Under the action of the compressive force F30 of each cartridge 1 and 1' in the released configuration, retained by the retaining wall 61 of the stack 50 in the opposite direction to X1 via the base 10, the end plate 53 is designed to bear against one end of the stack 51 along the X1 direction, in order to maintain the stack 51 in compression along the X1 direction, while the stack 51 is supported against the support wall 63 along the X1 direction at its opposite end. The end plate 53 can therefore be described as a movable end plate 53, in that it is movable relative to the support wall 63.

[0114] The terminal plate 53 comprises an assembly side 54 and an opposing inner face 55.

[0115] The assembly side 54 is oriented in the opposite direction to X1. The cartridges 1, T are arranged on the assembly side 54. The inner face 55 is formed on the opposite side, being rotated along the X1 direction. The inner face 55 is intended to bear directly against the stack 51, preferably directly against one of the cells 52.

[0116] On the assembly side 54, the end plate 53 preferably includes, for each cartridge 1, 1', the necessary provisions for assembly with the assembly means 17. For example, when the assembly means 17 is an external thread as illustrated, the end plate 53 includes, for each cartridge 1, T, a respective internal thread 65, preferably formed inside a base 57. For example, the base 57 protrudes from the assembly side 54 in the opposite direction to X1. Preferably, the end plate 53 forms the base 57, the internal thread 65, the assembly side 54, and the internal face 55 in a single piece. If several cartridges are provided, they are preferably distributed over the surface of the end plate 53 when assembled with the end plate.

[0117] 53.

[0118] When several cartridges 1, T are provided, they can be individually assembled with the terminal plate 53, independently of each other, via their respective assembly means 17. Thus, each cartridge 1, 1' can be assembled with the terminal plate 53, via its individual assembly means 17, while one or more other cartridges are already assembled with the plate 53.

[0119] Advantageously, by tightening or loosening the thread 17 in the thread 65, the foot 20 can be selectively butted against the end plate 53 along the X1 direction while the foot 20 is assembled by tightening the thread 17 in the thread 65, or it can be positioned at a distance from the end plate 53 while the foot 20 is still assembled by tightening the thread 17 in the thread 65. Thus, while the foot 20 remains assembled, its position relative to the plate 53 along the X1 axis can be modified. Preferably, tightening and butting the foot 20 will result in a clamping of the foot 20 and / or the thread parallel to the X1 direction, preventing the foot 20 from pivoting relative to the end plate 53 around the X10 axis. The foot 20 and the plate 53 are then immobilized relative to each other, according to all degrees of freedom.

[0120] Preferably, the cartridge 1 includes a component 49, which is advantageously designed to compensate for axial play in the assembly means 17 in the event that the thread 17 is tightened without the foot 20 being brought against the plate 53 in the direction X1. It can be provided that this same component 49 then immobilizes the rotational degree of freedom of the foot 20 relative to the plate 53 around the axis X10 and thus constitutes an anti-rotation component.

[0121] This component 49 can also be provided in the case where the screwing of the thread 17 is carried out with the foot 20 being brought against the plate 53 in the direction X1.

[0122] Preferably, the member 49 is removable with respect to the foot 20, the base 10, the retaining system 40 and the spring 30. The anti-rotation member 49 is configured to be mounted, for example, on the secondary retaining portion 42 or on the foot 20. When the external thread 17 is engaged in the internal thread 65 of the end plate 53, the member 49 thus mounted takes up the axial play and, preferably, prevents rotation of the foot 20 relative to the end plate 53 around the central axis X10. So, in the case where the member 49 serves to prevent rotation, the foot 20 and the terminal plate 53 are fixed relative to each other, since the engagement of the assembly means 17 ensures axial and radial immobility of the foot relative to the plate 53, and the engagement of the anti-rotation member 49 takes up the possible axial play and eliminates the last degree of rotational freedom of the foot 20.Preferably, the assembly of component 49 can only be carried out when the retaining system 40 is in the released configuration.

[0123] For example, the member 49 advantageously forms a screw. As such, the member 49 includes a threaded body 48, which is configured to be engaged with the tapping 42 when the threaded body 45 of the retaining member 43 is not engaged with the tapping 42, in order to take up the axial play and preferably to prevent the rotation of the foot 20 relative to the end plate 53 around the central axis X10, by bearing the member 49 against the end plate 53 along the compression direction X1. In other words, the member 49 is installed in place of the retaining member 43. More precisely, it is provided that, by screwing the member 49 into the thread 42, a distal end 47A of the member 49 comes into tight contact along the direction X1 against the assembly side 54 of the plate 53, thus immobilizing the foot 20 in rotation.For this purpose, the distal end 47A protrudes beyond the foot 20, in particular beyond the pad 22 along the direction X1, emerging from the foot 20 at a distal end of the shaft 21. Preferably, as with the retaining member 43, the member 49 can be inserted into the cartridge 1 at the proximal end 11, via the central channel 14, to be engaged in the threaded hole 42. Thus engaged, the member 49 can be actuated through the base via the central channel 14. To this end, opposite the distal end 47A, the member 49 includes a proximal end 47B forming an impression, for example a hexagonal or star-shaped impression, allowing the member 49 to be rotated around the axis X10 by means of a tool or machine. This imprint opens in the opposite direction to X1 into the inside of the shaft 21 or the central conduit 14, in order to be accessible.

[0124] This arrangement is advantageous because the secondary retaining portion 42 serves both to ensure the maintenance in pre-stressed configuration of the cartridge 1 by cooperation with the retaining member 43, and, in the absence of the retaining member 43 leading to the released configuration, to ensure the recovery of axial play and / or the anti-rotation of the foot 20 with respect to the terminal plate 53, by cooperation with the member 49.

[0125] Preferably, when the dimensional compensation system is not yet integrated into the fuel cell 50, the cartridges 1, 1' assembled with the terminal plate 53 form, with said plate 53, a solid sub-assembly.

[0126] Preferably, for each cartridge 1 to be fitted, the retaining wall 61 provides a corresponding access opening 64, which passes completely through the retaining wall 61, parallel to the compression direction X1. Each opening 64 connects the faces 66 and 69 to each other. If several cartridges are provided, the openings 64 are distributed over the surface of the retaining wall 61, at locations corresponding to those of the cartridges. When the cartridge 1 is retained by the retaining wall 61, the base 10 of said cartridge 1 is arranged so that the proximal end 11 opens into the orifice 64, or, at the very least, is accessible beyond the retaining wall 61 through the orifice 64. For example, the axis X10 passes through the orifice 64. Preferably, the cartridge 1 is aligned with the orifice 64. In other words, the base 10 can be accessed from the face 66 through the access orifice 64.

[0127] In practice, the orifice 64 provides access to the base 10 to put the cartridge 1 in the released configuration when the cartridge was in the pre-stressed configuration, in that the retaining member 43 is actuated through the orifice 64, and, preferably, can be extracted through the orifice 64. Similarly, the member 49, if provided, can be inserted into the cartridge 1 and actuated through the retaining wall 61 via the orifice 64.

[0128] More specifically, when the base 10 is retained by the retaining wall 61, the cartridge 1 is designed to be able to be moved from its outer face 66 to a free position if it was in a pre-stressed position, and / or to a pre-stressed position if it was in a free position. For this purpose, for example, when the cartridge 1 is in its pre-stressed position and received in the orifice 64, the head 44 of the screw 43, and in particular the recess 46, is accessible from the proximal end 11 of the base 10, and therefore from the outer face 66. The screw 43 can thus be operated from outside the housing 60. In particular, the screw 43 can be removed via the opening of the conduit 14 on the end side 11, to move the cartridge 1 to its free position.Conversely, when the cartridge 1 is in the released configuration, the screw 43 can be inserted into the conduit 14 through the conduit's opening at end 11, and then the screw 43 can be rotated from end 11 to engage the threaded body 45 with the threaded hole 42, thus achieving the pre-stressed configuration, for example, for opening the fuel cell casing 60. Maintenance of the fuel cell 50 is then facilitated.

[0129] Preferably, the actuation of screw 43 is intended solely to switch cartridge 1 between the preloaded and released configurations. Alternatively, screw 43 may be actuated to adjust the value of force F30 when cartridge 1 is in the preloaded configuration.

[0130] Similarly, when the base 10 is retained by the retaining wall 61, it is provided that the foot 20 can be prevented from rotating relative to the end plate 53, and / or that the axial play can be taken up by mounting the component 49, or that this play can be restored and the rotation released by removing the component 49. For this purpose, for example, the proximal end 47B of the component 49, and in particular its indentation, is provided to be accessible from the proximal end 11 of the base 10, and therefore from the outer face 66. The component 49 can thus be actuated from outside the housing 60. Specifically, the component 49 can be inserted via the orifice 64 and the opening of the conduit 14 on the end 11 side, when the cartridge 1 is in the released configuration, and then the component 49 can be rotated from the end 11. to engage the threaded body 48 with the tapped hole 42 and thus immobilize the foot 20 in rotation.

[0131] Preferably, when the cartridge 1 is retained by the retaining wall 61, it is not attached to the retaining wall 61, but merely supported in the opposite direction to X1, without any other support. In particular, the opening 64 does not include any means for attaching, or even assembling, the cartridge 1 with the wall 61, for example, no thread intended to cooperate with the cartridge 1. In particular, when the cartridge 1 is retained by the retaining wall 61, the cartridge 1 is not supported against the retaining wall 61 radially with respect to the direction X1. In particular, the orifice 64 is not used for centering the cartridge 1, which may, depending on the assembly, not be perfectly coaxial with the orifice 64. In particular, when the cartridge 1 is held by the retaining wall 61, the cartridge 1 is not in contact with the retaining wall 61 in the direction X1.In particular, the retaining wall 61 does not capture the cartridge 1, the cartridge 1 being captured only by being interposed between the retaining wall 61 and the stack 51.

[0132] Preferably, when the cartridge 1 is retained by the retaining wall 61, the cartridge is positioned beyond the wall 61 in the direction X1, except possibly for the proximal end 11 and / or part of the retaining system 40, which are received in the opening 64. Advantageously, the cartridge 1 is not provided to protrude from the wall 61 through the opening 64 in the opposite direction to X1. In any case, when the cartridge 1 is retained by the retaining wall 61, the foot 20 advantageously protrudes from the wall 61, in particular from the inner face 69, in the direction X1.

[0133] Optionally, the orifice 64 provides access to the actuating head 16 through the retaining wall 61, in order to actuate the cartridge 1 in rotation around the axis X10 while the retaining wall 61 is interposed between the cartridge 1 and the operator or the machine which must rotate the cartridge 1. This rotational actuation is preferably carried out while the cartridge 1 is not yet in contact with the retaining wall 61, in order to bring the cartridge 1 in contact with the retaining wall 61, the rotation being carried out in the direction of unscrewing the thread 17, moving the cartridge 1 away from the end plate 53 without detaching it.

[0134] Preferably, each orifice 64 is designed to be sealed by a plug, not shown, attached along the X1 direction to one end of the orifice 64 on the outer face 66, while the cartridge 1 is retained by the wall 61. Preferably, the orifice 64 has an internal thread for attaching the plug to seal the orifice 64; this thread is not designed to cooperate with the cartridge 1 itself. Thus, during the operation of the battery 50, the orifice 64 is sealed so that the housing 60 forms a sealed enclosure.

[0135] Preferably, the orifice 64 is shaped so that the cartridge 1 cannot pass through it, in particular so that the foot 20 cannot pass through it, when attempting to insert the cartridge 1 into the orifice 64 along the direction X1, from the outer face 66. Preferably, the orifice 64 is shaped so that the cartridge 1 cannot pass through it, in particular so that the base 10 cannot pass through it, except possibly through the proximal end 11, when attempting to insert the cartridge 1 into the orifice 64 in the opposite direction to X1, from the inner face 69. In practice, the orifice 64 is narrower than the cartridge 1 and is intended to be passed through only for the actuation of the cartridge through the wall 61, without being passed through by the cartridge 1 itself.

[0136] During the use of the stack 50, while the stack 51 is likely to expand and contract parallel to the direction X1, the base 10 remains held against the retaining wall 61 in the opposite direction to X1 under the action of the spring 30 of the cartridges 1, T in the released configuration. The base 10 slides, if necessary, relative to the foot 20 to accommodate this expansion or contraction. The foot 20 remains fixed relative to the end plate 53, being assembled to the plate 53 via the assembly means 17. The retaining wall 61 is fixedly attached to the opposite support wall 63, via the longitudinal wall 62. As the stack 51 comes to rest against the wall 63 along the direction X1, the stack 51 is compressed between the feet 20 of the cartridges 1 and 1' and the support wall 63, and takes in compression the pressing force F30 applied respectively by the springs 30 of each cartridge 1 and T.

[0137] In the event of significant contraction of the stack 51, the spring 30 is likely to bring the foot 20 to a stop along the X1 direction relative to the base 10, via the stop system 80. If the contraction continues, the foot 20 and the base 10 do not slide further relative to each other, and the base 10 is then separated from the retaining wall 61, being displaced in the X1 direction relative to the retaining direction 61. Thanks to the stop system 80, the foot 20 and the base 10 remain engaged despite the extreme contraction of the stack 50. With prior art systems, lacking such a stop system, there was a real risk that the compression cartridge would become dislodged, i.e., that the foot 20 and the base 10 would separate they are breaking ranks.Once the stack returns to its expanded shape, the base 10 rests against the wall 61 in the opposite direction to X1, and the foot 20 can again slide relative to the base 10 to adapt the shape of the cartridge 1 to the dimensions of the stack 51. The safety and reliability of operation of the compression cartridge are thus improved, particularly in the case of significant expansions of the stack 51 (operation under extreme stack conditions, significant stack wear, etc.).

[0138] Other elements can be interposed in the stack 51, between the plate 53 and the wall 63, for example a current collector plate and / or an insulation plate.

[0139] Below is described a method of using the compensation system described above, and in particular the cartridge 1. This use can also be seen as a manufacturing process for the fuel cell 50, or as a method of putting and maintaining the stack 51 in compression.

[0140] Preferably, while the cartridge 1 is not yet assembled to the terminal plate 53 nor received in the housing 60 or against the stack 51, it is planned on the one hand to prepare said cartridge 1 and the compensation system, and on the other hand to prepare the stack 51 and the housing 60.

[0141] To prepare the stack 51 and the housing 60, the stack 51 is placed against the support wall 63 along the compression direction X1. For this purpose, for example, the support wall 63 is positioned horizontally and the cells 52 are stacked.

[0142] Independently of the preparation of the housing 60, a process for assembling the cartridge 1 is implemented. This step can notably be carried out in parallel with the preparation of the housing 60.

[0143] The method for assembling the cartridge 1 includes the supply of the base 10, the foot 20, the spring 30, the retaining system 40 and the stop system 80.

[0144] The method first involves stacking, parallel to the axis X10, the foot 20, the spring 30, and the base 10, with the spring 30 interposed between the base 10 and the foot 20, the foot being oriented in the direction X1 relative to the base. This includes positioning the spring 30 so that it bears against the base 10 in the opposite direction to the compression direction X1 and against the foot 20 in the direction X1. At this stage, the grooves 82 are already formed in the base 10 and the holes 86 are already formed in the foot 20, but the pins 81 are not yet mounted in the holes 86, or are mounted but are not yet protruding inwards, to allow later fitting of the base 10 with the foot 20. At this stage, the retaining system 40 is in the released configuration, that is to say that the screw 43 is not yet in place in the cartridge 1.However, the sliding between the base 10 and the foot 20 is not yet guided by the base 10 and the foot 20, because they are not yet fitted together.

[0145] Next, while holding the base 10 in the opposite direction to X1, a force is applied to the foot 20 in the opposite direction to X1, for example using a press, or vice versa, to move the foot 20 towards the base 10 and thus put the spring 30 under tension, that is, in this case, under compression. In doing so, the foot 20 and the base 10 are guided relative to each other so that they fit together as they move towards each other. This fitting is carried out while the spring 30 is interposed and under tension between the base 10 and the foot 20, that is to say that the spring 30 takes support on the base 10 so as to apply a force on the foot 20 by elasticity of the spring 30, along the direction of compression X1.

[0146] The value of the force applied to foot 20 is increased up to a target value, preferably calibrated to correspond to the value of the pressing force F30 that we want cartridge 1 to apply later on stack 51, when cartridge 1 is integrated into stack 50 in the released configuration.

[0147] Once the desired force is reached, the cartridge 1 is placed in a prestressed configuration, which prevents the foot 20 from sliding relative to the base 10 and fixes the value of the compressive force F30 to the value of the force applied in the opposite direction to the foot 20. For example, the value of the compressive force F30 within the cartridge 1 in the prestressed configuration is expected to be between two and three kilonewtons if only one cartridge 1 is used. If there are several cartridges, it is advantageous to divide this value by the number of cartridges used to maintain the stack 51 in compression.

[0148] In particular, to put the cartridge 1 in the pre-stressed configuration, the screw 43 is inserted into the channel 14 until the threaded body 45 reaches the tapped hole 42. The screw 43 is then tightened, here by actuating the recess 46. This actuating causes the threaded body 45 to be screwed into the tapped hole 42 until the head 44 comes to rest, along the direction X1, against the shoulder 41. The screw 43 then prevents the foot 20 from sliding relative to the base 10 along the direction X1, so that the base 10, the foot 20, and the retaining system 40 hold the spring 30 pre-stressed with the desired value for the pressing force F30. Being able to adjust the pressing force F30 before installing the spring 30 in the stack 50 makes adjustment easier and more precise.

[0149] Once the foot 20 and the base 10 are fitted, and preferably once the cartridge 1 is in the pre-stressed configuration, the stop system 80 is put in place. In the example, the pins 81 are screwed into the holes 86 until the pins 81 protrude inwards into the cartridge 1 to be received inside the grooves 82. Then, the stop system 80 limits the sliding of the foot 20 relative to the base along the compression direction X1, as explained above, and also preferentially blocks the rotation of the foot 20 relative to the base 10 around the axis X10. If we plan to install other cartridges T for the stack, as is the case for the present example, we prepare them in the same way as cartridge 1, in order to obtain a desired value for their respective pressing force F30.

[0150] Once cartridge 1 is in its prestressed configuration, along with any other cartridges T, the compensation system is prepared. This is done prior to integrating the compensation system into the stack 50, specifically before the end plate 53 is pressed against the stack 51 and before cartridge 1 is held in place by the wall 61. The preparation of the compensation system can be carried out independently of the preparation of the casing 60 and the stack 51.

[0151] To prepare the compensation system, the foot 20 of the cartridge 1 is assembled with the end plate 53 using the assembly means 17. In practice, this assembly is performed by engaging the external thread 17 with the internal thread 65, rotating the cartridge 1 around the axis X1 relative to the plate 53. The rotation of the cartridge 1 is preferably carried out via the actuating head 16. Preferably, the cartridge 1 is rotated in this way until the foot 20 bears against the plate 53 along the direction X1. This bearing is advantageously achieved at the support pad 22. If necessary, the same procedure is followed for the other cartridges T until all the cartridges 1' are assembled with the end plate 53.

[0152] Once the cartridge 1 is assembled with the end plate 53, as well as any other cartridge T, and the stack 51 is ready, the end plate 53 carrying the cartridge(s) 1, T is placed against the stack 51 along the X1 direction. The stack 51 is then interposed between the end plate 53 and the support wall 63, parallel to the X1 direction. In practice, placing the end plate 53 in position consists of stacking the end plate 53 on top of the stack 51 already stacked on the support wall 63.

[0153] Alternatively, the assembly of the cartridge 1 in prestressed configuration with the plate 53 via the assembly means 17 is carried out while the plate 53 is already in support against the stack 51 along the direction X1, but before the application of the initial compressive force F70 mentioned below.

[0154] Alternatively, the prestressing of the cartridge 1 is performed while the cartridge 1 is already assembled with the end plate 53 via the assembly means 17, but before the end plate 53 is supported against the stack 51. Once the stack 51 is supported against the support wall 63, and the end plate 53 is supported against the stack 51 with the cartridge(s) 1, T in the prestressed configuration and assembled with the end plate 53, an initial compressive force F70 is applied to the stack 51 using a press 70, or any other pressing device separate from the compensation system and the cartridge 1 itself. The press 70 and the force F70 are schematically shown in Figure 3.Although Figure 3 shows cartridge 1 already held by wall 61, cartridge 1 in free configuration and component 49 already mounted, it should be considered that, when the force F70 is applied, cartridge 1 is not yet held by wall 61, which is not fixed to wall 62, cartridge 1 is in prestressed configuration and component 49 is not yet mounted.

[0155] In practice, to apply the force F70 to the stack 51, it is advantageous to apply the force F70 via the end plate 53. For this purpose, the end plate 53 preferably comprises one or more application surfaces 72, facing in the opposite direction to X1 and formed on the assembly side 54, against which support legs 71 belonging to the press 70 bear along the X1 direction to apply the force F70 in a distributed manner. The application surfaces 72 are preferably distributed over the surface of the plate 53, between the sockets 57 forming the threads 65, and therefore, between the cartridges 1, T.

[0156] If only one cartridge 1 is to be fitted to the pier 50, it is advantageously assumed that the value of the initial compressive force F70 is equal to or slightly greater than the value of the force F30 contained in the cartridge 1 in its prestressed configuration. If, in addition to the cartridge 1, other cartridges 1' are to be fitted to the pier 50, it is advantageously assumed that the value of the initial compressive force F70 is equal to or slightly greater than the sum of the values ​​of all the cumulative forces F30 contained in the cartridges 1 and T in their prestressed configuration.

[0157] Before the application of the force F70, it may happen that the stack 51, in an uncompressed state, presents an obstruction along the X1 direction that opposes the placement of the wall 61. In particular, the stack 51 and the compensation system protrude from the wall 62. In this case, it is advantageously provided that the application of the force F70 by the press 70 or the pressing element is carried out through the retaining wall 61, while said wall 61 is not yet fixed to the wall 63 via the wall 62. In particular, the wall 61 is positioned at a distance from the wall 62, preferably at a distance from the cartridges 1, T, in the opposite direction to X1, with the orifices 64 in alignment with the corresponding cartridges 1, 1', i.e., through which their respective axis X10 passes. For the application of the force F70, it is provided for example that the retaining wall 61 has secondary orifices 67 which pass through it parallel to the direction X1.These orifices 67 are distinct from the orifices 64. The secondary orifices 67 are aligned along the direction X1 with the surfaces 72. The support legs 71 are then passed through the orifices 67 along the direction X1, to apply together the force F70 on the stack 51, via the plate 53, through the wall 61 which is not yet attached to the wall 63, here via the wall 62.

[0158] Applying the force F70 causes a compressive deformation of the stack 51, reducing its size along the X1 direction and thus allowing the wall 61 to be attached to the wall 63, here via the wall 62. The retaining wall 61 is then fixed by attaching it to the wall 63, here by fixing it to the already installed wall 62, so that the support wall 63 and the retaining wall 61 are permanently connected to each other. The support wall 63 is then positioned in the compression direction X1 relative to the retaining wall 61. The cartridge(s) 1, T, the end plate 53, and the stack 51 are then arranged between the retaining wall 61 and the support wall 63, in that order, along the compression direction X1.

[0159] Alternatively, before the application of force F70, the stack 51, in its uncompressed state, may not impede the placement of the wall 61. In this case, the wall 61 can be fixed either before the application of force F70 or after its application, while force F70 is maintained, as explained above. In any event, the fixing of the wall 61 is carried out while the end plate 53 rests on the stack 51, and the cartridges 1 and T are in their prestressed configuration and assembled with the end plate 53 via their assembly means 17.

[0160] Regardless of the solution chosen, once the retaining wall 61 is fixed, the proximal end 11 of the cartridge 1 in its prestressed configuration is distanced from the retaining wall 61, along the X1 direction, as long as the force F70 is maintained. This is because the force F70 compresses the stack 51, thus reducing its overall size in the direction X1.

[0161] Once the retaining wall 61 is fixed, the base 10 of the cartridge 1 is placed against the retaining wall 61 in the opposite direction to the X1 direction, while the foot 20 remains assembled with the plate 53 via the assembly means 17 and the cartridge 1 remains in pre-stressed configuration.

[0162] Preferably, this step is performed before the release of force F70 and when the cartridge 1 is in its released configuration, by acting on the assembly means 17, moving the cartridge 1 relative to the plate 53 in the opposite direction to X1. This movement of the cartridge 1 is carried out until the base 10 abuts against the retaining wall 61 in the opposite direction to X1. Preferably, for this purpose, the external thread 17 is unscrewed into the thread 65, which has the effect of moving the foot 20, and therefore the cartridge 1 as a whole, relative to the plate 53, in the opposite direction to X1. The unscrewing is carried out by rotating the cartridge 1 through the access port 64, via the actuating head 16.The unscrewing is carried out until the cartridge 1 is brought against the retaining wall 61, the external thread 17 remaining engaged in the thread 65, so that the foot 20 remains assembled with the end plate 53. Then, the cartridge 1 is retained by the wall 61 in the opposite direction to the X1 direction.

[0163] Once the retaining wall 61 is fixed and the cartridge 1 is retained by the retaining wall 61, the compression force F70 is released and each cartridge 1 is put into the released configuration, which leads to the spring 30 of each cartridge 1, bearing on the base 10 of said cartridge 1 retained by the wall 61, applying the pressing force F30 on the stack 51 along the direction X1, via the foot 20 and the end plate 53, here via the assembly means 17.

[0164] Preferably, the compression force F70 is released first and cartridge 1 is put into the released configuration once the force F70 has been totally released, or partially released.

[0165] In practice, to release the force F70, the legs 71 of the press 70 are retracted in the opposite direction to the direction X1, until they are completely extracted from the pile 50.

[0166] To then put the cartridge 1 in the freed configuration, the screw 43 is advantageously unscrewed via the orifice 64 to free the translation of the foot 20 relative to the base 10. The screw 43 is preferentially extracted from the stack 50, via the orifice 64. The fact that the force F70 has been released and that the cartridge 1 is interposed between the wall 61 and the stack 51 facilitates the unscrewing of the screw 43, on which less axial force is applied. So, since the retaining system 40 no longer takes up the force F30, the spring 30 applies the force F30 to the stack 51 via the foot 20 assembled with the plate 53, bearing against the retaining wall 61 via the base 10. The cartridge 1 being put in the released configuration, the force F30 which it generates takes over from the force F70 which has already been released, preferably totally released, otherwise partially released.If several cartridges are used, their forces F30 are added together and collectively take over from the force F70. This leads to the situation shown in Figure 2. Then, for cartridge 1, or for each cartridge 1 and T, the force F30, as calibrated when the cartridge was put into the prestressed configuration, is applied to the stack 51 with the same value, or a very close value. Thanks to this method, the desired compressive force value for the stack 51 has been applied in a particularly easy, reliable, precise, and safe manner.

[0167] Alternatively, contrary to the above, one could plan to put one or more of the cartridges 1, or all of the cartridges 1, in a released configuration before releasing the compression force F70. With each cartridge 1 in a released configuration and the force F70 released, each force F30 is applied to the stack 51, as explained above.

[0168] Preferably, once the initial compression force F70 has been released and each cartridge 1, 1' has been placed in its free configuration, the component 49 is mounted in each cartridge 1, T, to take up the axial play and, preferably, to prevent the rotation of the foot 20 relative to the end plate 53 around the central axis X10. In practice, the component 49 is inserted into the relevant cartridge 1 via the orifice 64, and engaged with the threaded hole 42, by screwing until the component 49 is fully tightened in the direction X1 against the end plate 53. The component 49 is left in this position inside the stack 50 during the use of the stack 50.

[0169] Once the aforementioned steps have been completed, the orifices 64 and 67 are advantageously sealed with plugs.

[0170] Figure 4 shows a cartridge 101 according to a second embodiment. Cartridge 101 is identical to cartridge 1, is used and manufactured in the same way as cartridge 1, except for the differences described below. The same reference numerals are used for cartridges 1 and 101 for identical features or features related to the same function. Reference numerals augmented by 100 are used to designate features of cartridge 101 that correspond to features of cartridge 1 but have substantial differences.

[0171] Unlike cartridge 1, which lacks a tubular ring, the base 10 of cartridge 101 includes a tubular ring 129, extending around and at a distance from the wall 13. The tubular ring 129 is coaxial with the central axis X10. The tubular ring 129 is shaped like a tube with a circular cross-section. The tubular ring 129 extends from end 11, being attached to a peripheral edge of end 11. From this attachment, the ring 129 extends along the direction X1, so as to be radially opposite the wall 13.

[0172] For the cartridge 101, the ring 29 of the foot 20 includes a peripheral wall 113, formed externally around the ring 29, preferably over the entire height of the ring 29. The wall 113 is preferably cylindrical with a circular base, centered on the axis X10. The wall 113 of the cartridge 101 therefore replaces the assembly means 17 which is provided in the same location for the cartridge 1. The cartridge 101 is preferably devoid of the assembly means 17 which is described above for the cartridge 1.

[0173] For the cartridge 101, the ring 29 and the wall 13 do not serve to guide the sliding, and are preferably radially separated.

[0174] For the cartridge 101, the foot 20 is fitted to the base 10 such that the tubular ring 29 of the foot 20 is received inside the tubular ring 129 of the base 10, which surrounds the foot 20. The ring 29 is in fact arranged radially between the ring 129 and the wall 13. In particular, the peripheral wall 113 of the foot 20 is received inside the tubular ring 129, the foot 20 being fitted to the base 10 such that the peripheral wall 113 is coaxially received in the tubular ring 129. An internal wall of the tubular ring 129 and the peripheral wall 113 cooperate radially to guide the sliding of the foot 20 relative to the base 10 along the axis X10, when the peripheral wall 13 is received in the tubular ring 29. that is, when the foot 20 is fitted with the base 10. There is a small positive radial clearance between the peripheral wall 113 and the internal radial wall of the crown 129 to guide the sliding.

[0175] As shown in Figure 4, the cartridge 101 includes a stop system 180, which differs from the stop system 80 of the cartridge 1, but performs the same functions. The stop system 180 is specifically configured to limit, constrain, and / or define the sliding motion of the foot 20 relative to the base 10 along the compression direction X1. In other words, the stop system allows a certain degree of freedom between the foot 20 and the base 10 along the X10 axis, but within a defined and limited range by design, for example, a few millimeters or even centimeters. The stop system 180 includes pins 181, fixedly attached to the base 10, and grooves 182, fixedly attached to the foot 110. In this example, the groove 182 therefore constitutes a first element of the system 180 which is attached to the foot 20, while the pin 181 constitutes a second element of the system 180 which is attached to the base 10.In any case, the stop system 180 is separate from the retaining system 40 and is specifically designed to be functional when the cartridge 101 is in the released configuration. As illustrated, the stop system 180 comprises a plurality of pins 181, advantageously two, and a plurality of grooves 182, advantageously two, said plurality of pins 181 and grooves 182 being diametrically opposed. This ensures proper delimiting and guidance of the sliding of the foot 20 relative to the base 10 along the compression direction X1, preventing any wedging phenomenon. A construction with three pins 181 and three grooves 182 distributed at 180° could also be considered without departing from the scope of the invention. Naturally, the same number of pins should be used.

[0176] 81 and groove 82.

[0177] Each groove 182 is preferably formed directly in the peripheral wall 113, thus being formed from the material of the peripheral wall 113, that is, from the crown 26 of the foot 20. The grooves 182 are regularly distributed around the axis X1. Here, two grooves 182 are provided and are therefore arranged diametrically opposite each other. The grooves 182 are preferably at the same height along the axis X10. Each groove 182 is formed radially in the direction of the axis X10, that is, radially inwards.

[0178] Each groove 182 includes at least one end of a groove 183, and possibly also an end of a groove 184, opposite the end 183. The end 183 terminates the groove 182 in the opposite direction to X1. The end 184, if present, terminates the groove 182 in the direction X1. In the absence of an end 184, the groove 182 is, for example, open in the direction X1, opening at the level of the support pad 22. The groove 182 is preferably parallel to the direction X1, so that the ends 183 and 184 are preferably aligned in the direction X1. Each groove 182 includes longitudinal walls 185, parallel to the axis X10 and facing each other. Each wall 185 extends from end 183, and connects ends 183 and 184, if end 184 is provided.

[0179] The pins 181 are regularly distributed around the axis X1. Here, two pins 181 are provided and are therefore arranged diametrically opposite each other. The pins 181 are preferably at the same height along the axis X10. Each pin 181 comprises a base end, by means of which the pin 181 is fixedly attached to the ring 129 of the base 10, and an inner end that projects radially inward from the ring 129. Since the inner end of the pin 181 is projecting, it is received in one of the grooves 182. Preferably, each pin 181 is oriented radially, that is to say, its base and inner ends follow an axis that is perpendicular to the axis X10 and intersects the axis X10. Preferably, the pin 181 does not protrude radially outwards from the base 10.

[0180] Each pin 181 is advantageously an added piece on the base 10. For this, the base 10 preferably includes, for each pin 181, a respective orifice 186, which passes through the ring 129 from one side to the other, that is to say from an external face of the ring 129 to the internal radial face which cooperates with the peripheral surface 113 of the foot 20. The orifice 186 is radial, that is to say that the orifice 186 is crossed by an axis which is perpendicular to the axis X10 and intersects the axis X10. Each pin 181, for example, consists of a screw, oriented radially with respect to the axis X10, which is screwed into the orifice 186 from the outside of the ring 129 until the inner end of the pin 181 is received in the corresponding groove 182. Advantageously, the base end of the pin 181 is threaded to engage with an internal thread in the orifice 186 and thus enable this screwing.Advantageously, the base end of the pin 181 is provided with a recess for a screwing tool, for example, a hexagonal socket as shown in Figure 4, so that the pin 181 can be screwed in from outside the cartridge 101 and, when the pin 181 is sufficiently inserted into the hole 186 as shown in Figure 4, through the opening of the hole 186 leading to the outside of the cartridge 101. Optionally, the pin 181 has a head, that is, a radial projection having said recess so as to allow translational locking along the radial axis of the cartridge (that is, along the axis perpendicular to the X10 axis). Advantageously, the pin 181 has no head 181 and said recess is then formed inside the pin 181, as illustrated in Figure 4.

[0181] Each pin 181 is configured to slide in its corresponding groove 182 when the foot 20 slides relative to the base 10 along the X10 axis. Specifically, the inner end of the pin 181 is guided in its sliding motion by the longitudinal walls 185 of the groove 182. Preferably, the pin 181 is threaded along its entire length. Alternatively, the inner end of the pin 181 that engages with the walls 185 is not threaded. With the pin 181 thus received in the groove 182, it prevents the foot 20 from rotating relative to the base 10 around the X10 axis. For this purpose, the inner end of the pin 181 is advantageously held between the walls 185 of the groove 182.

[0182] Alternatively, without departing from the scope of the invention, the pin 181 may consist of a pin, a rivet, a stud, etc.

[0183] This anti-rotation function is, according to this embodiment, essential because the cartridge lacks an assembly system 17. Therefore, only the stop system 181 allows the foot 20 and the base 10 to be kept assembled together.

[0184] When the foot 20 slides along the compression direction X1 relative to the base 10, the pin 181 slides in the groove 182 until it reaches the end 183, against which the pin 181 then comes to rest in the opposite direction to X1. The foot 20 is then brought to rest against the base 10 along the compression direction X1 in that the end 183 comes to rest against the pin 181 along the direction X1. The sliding of the foot 20 is therefore limited by the stop system 180 along the compression direction X1 by butting the foot 20 against the base 10, via the system 180. This butting occurs while the foot 20 is still fitted with the base 10, that is to say here, while the peripheral wall 113 is sufficiently embedded in the ring 129 so that the guidance of the sliding of the foot 20 relative to the base 10 is ensured.This stop mechanism prevents the foot 20 from disassembling from the base 10, or from breaking the sliding guide of the foot 20 relative to the base 10. Such a stop is particularly important from a cartridge safety standpoint. Indeed, if the retaining system 40 breaks under the action of the spring 30, the base 10 could be ejected from the foot 20. The stop system 180, and more specifically the butting of the pin 181 against the end 183 of the groove 182, prevents the base 10 from moving in translation, even if the retaining system 40 is faulty or missing. However, this stopping occurs independently of whether the cartridge is in pre-stressed or free configuration, and is useful mainly in the free configuration where no other element of the cartridge 101 holds the foot 20 against the base 10.

[0185] Optionally, when the foot 20 slides in the opposite direction of the compression X1 relative to the base 10, the pin 181 slides in the groove 182 until it reaches the end 184, against which the pin 181 then comes to rest in the opposite direction of the X1 direction. The foot 20 is then brought against the base 10 in the opposite direction to the compression direction X1, in that the end 184 comes against the pin 181. The sliding of the foot 20 is therefore advantageously limited by the stop system 180 also in this direction, by bringing the foot 20 against the base 10, via the system 180. This stopping occurs while the foot 20 is still fitted to the base 10. Such a limitation makes it possible, for example, to limit the penetration of the base 10 into the foot 20 and in particular prevents excessive compression of the spring 30, which could risk damaging it or generating too much stress in the cartridge.

[0186] Alternatively, according to a preferred solution, it is provided that the pin 181 does not come into contact with any part along the direction X1, but that the sliding of the foot 20 in the opposite direction to the direction X1 is only limited by the spring 30, which makes the stop in the opposite direction to the direction X1 when the spring 30 is fully compressed.

[0187] For the cartridge 101, in the absence of an assembly means 17, the compression of the stack 51 is achieved by the support pad 22 of the foot bearing against the end plate 53 along the compression direction X1, without the foot 20 being assembled with the end plate 53. Preferably, for the cartridge 101, the component 49 is therefore not necessary. The manufacturing process of the fuel cell 50 thus does not include a step of assembling the foot 20 of the cartridge 101 with the end plate 53, nor of installing the component 49. Alternatively, the cartridge 101 may be provided with an assembly means for assembling the base 10 with the retaining wall 61, or for assembling the foot 20 with the end plate 53.

[0188] Any feature described above for one embodiment or variant applies to the other embodiments and variants described above, insofar as technically possible.

Claims

CLAIMS Cartridge (1; 101), for maintaining in compression, along a compression direction (X1), a stack (51) of electrochemical cells (52) belonging to a fuel cell (50), the cartridge (1; 101) comprising: a base (10), through which the cartridge (1; 101) is configured to be retained in the opposite direction to the compression direction (X1), by a retaining wall (61) integral with, or belonging to, the fuel cell (50); a foot (20): • which is arranged in the compression direction (X1) relative to the base (10), being fitted to the base (10) so as to slide relative to the base (10) along a central axis (X10) of the cartridge, parallel to the compression direction (X1), and • which is configured to place an end plate (53) of the fuel cell (50) against the stack (51) along the compression direction (X1) to maintain the stack (51) in compression along the compression direction (X1); a spring (30), which bears against the base (10) to apply a pressing force (F30) on the foot (20) along the compression direction (X1); and a retaining system (40), which includes a primary retaining portion (41), integral with the base (10), and a secondary retaining portion (42), integral with the foot (20), the primary retaining portion (41) and the secondary retaining portion (42) being configured to: • be coupled to each other when the cartridge (1; 101) is in a prestressed configuration, the primary retaining portion (41) and the secondary retaining portion (42) thus coupled preventing the foot (20) from sliding relative to the base (10) along the compression direction (X1); and • be decoupled from each other when the cartridge (1; 101) is in a released configuration, the primary retaining portion (41) and the secondary retaining portion (42) thus decoupled allowing the foot (20) to slide relative to the base (10) along the compression direction (X1), characterized in that the cartridge (1; 101) further comprises a stop system (80; 180), distinct from the retaining system (40), the stop system (80; 180) limiting the sliding of the foot (20) relative to the base (10) along the direction of compression (X1), by butting the foot (20) against the base (10) along the direction of compression (X1) via the stop system (80; 180), while the foot (20) is fitted with the base (10) and the cartridge (1; 101) is in the released configuration. 2.- Cartridge (1; 101) according to claim 1, wherein the stop system (80; 180) further prevents rotation of the foot (20) relative to the base (10) around the central axis (X10). 3.- Cartridge (1; 101) according to any one of the preceding claims, wherein the stop system (80; 180) comprises a pin (81; 181) and a groove end (83; 183), a first element among the pin (81; 181) and the groove end being integral with the foot (20), a second element among the pin (81; 181) and the groove end (83; 183), distinct from the first element, being integral with the base (10), the foot (20) being abutted against the base (10) along the compression direction (X1) in that the first element abuts against the second element along the compression direction (X1). 4.- Cartridge (1; 101) according to claim 3, in which the cartridge (1; 101) comprises: a tubular ring (29; 129), coaxial with the central axis (X10) and to which the pin (81; 181) is fixed; and a peripheral wall (13; 113), coaxial with the central axis (X10) and received inside the tubular ring (29; 129), a groove (82; 182), including the end of the groove (83; 183), being formed in the recess in the peripheral wall (13; 113), the pin (81; 181) projecting from the tubular ring (29; 129) to be received in the groove (82; 182), the pin (81; 181) being configured to slide in the groove (82; 182) when the foot (20) slides relative to the base (10), until it comes to rest against the end of the groove (83; 183) to limit the sliding of the foot (20) relative to the base (10) along the compression direction (X1). 5.- Cartridge (1; 101) according to claim 4, in which: the foot (20) is fitted with the base (10) in that the peripheral wall (13; 113) is received in the tubular ring (29; 129); and the tubular ring (29; 129) and the peripheral wall (13; 113) cooperate radially to guide the sliding of the foot (20) relative to the base (10), when the peripheral wall (13; 113) is received in the tubular ring (29; 6.- Cartridge (1; 101) according to any one of claims 4 or 5, in which an orifice (86; 186), radial with respect to the central axis (X10), passes through the tubular ring (29; 129) from one side to the other, the pin (81; 181) being fixedly received inside the orifice (86; 186) to be integral with the tubular ring (29; 129). 7.- Cartridge (1) according to any one of claims 4 to 6, wherein the tubular ring (29) belongs to the foot (20) and the peripheral wall (13) belongs to the base (10). 8.- Cartridge (1) according to any one of the preceding claims, in which: the cartridge (1) includes an assembly means (17), for assembling the foot (20) to the terminal plate (53) of the fuel cell (50), the foot (20) being configured to place the terminal plate (53) against the stack (51) along the compression direction (X1) to maintain the stack (51) in compression, when the foot (20) is assembled with the terminal plate (53) by the assembly means (17) and the base (10) is retained in the opposite direction to the compression direction (X1) by the retaining wall (61); and the assembly means (17) includes an external thread coaxial with the central axis (X10), the external thread being arranged around the foot (20) and the secondary retaining portion (42) and being configured to be engaged with an internal thread (65) belonging to the end plate (53), to assemble the foot (20) with the end plate (53). 9.- Cartridge (1) according to claim 8, wherein the cartridge (1) further comprises an anti-rotation member (49), which is configured to be mounted to prevent rotation of the foot (20) relative to the end plate (53) around the central axis (X10) when the external thread (17) is engaged in the internal thread (65) of the end plate (53) and the retaining system (40) is in the released configuration.

10. Cartridge (1; 101) according to any one of the preceding claims, wherein: the retaining system (40) comprises a retaining member (43), through which the primary retaining portion (41) and the secondary retaining portion (42) are coupled when the cartridge (1; 101) is in its prestressed configuration; the retaining member (43) comprises a first threaded body (45); and the secondary retaining portion (42) is formed by a thread arranged in a through shaft (21) parallel to the compression direction (X1), the primary retaining portion (41) and the secondary retaining portion (42) being coupled to each other. with the other when the first threaded body (45) is engaged with the tapped hole and being decoupled from each other when the first threaded body (45) of the retaining member (43) is not engaged with the tapped hole. Cartridge (1; 101) according to any one of the preceding claims, wherein the spring (30) consists of at least one spring washer, or a stack of spring washers, interposed between the base (10) and the foot (20) along the compression direction (X1). Fuel cell (50) comprising: the cartridge (1; 101) according to any one of the preceding claims, the cartridge (1; 101) being in the released configuration; the retaining wall (61), retaining the base (10) in the opposite direction to the compression direction (X1);a support wall (63), the support wall (63) and the retaining wall (61) being fixedly attached to each other, the support wall (63) being disposed in the compression direction (X1) relative to the retaining wall (61); the stack (51) of electrochemical cells (52), which is disposed between the retaining wall (61) and the support wall (63) being abutted against the support wall (63) along the compression direction (X1); and the end plate (53), being abutted against the stack (51) along the compression direction (X1), the spring (30) of the cartridge (1; 101) applying the pressing force (F30) on the stack (51) via the foot (20), along the compression direction (X1), bearing on the base (10). Fuel cell (50) according to claim 12, wherein the retaining wall; (61) and the support wall (63) belong to a housing (60) of the fuel cell (50), the stack (51) being received inside the housing (60), the housing (60) further comprising a longitudinal wall (62) connecting the retaining wall (61) to the support wall (63). Method for assembling the cartridge according to any one of claims 1 to 11, the method comprising: fitting the foot (20) with the base (10), while the spring (30) is interposed between the foot (20) and the base (10) along the compression direction (X1); and the installation of the stop system (80; 180), while the foot (20) is already fitted to the base (10) and the spring (30) applies the pressing force (F30) on the foot (20), so that the stop system (80; 180) limits the sliding of the foot (20) relative to the base (10) along the compression direction (X1).

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