Heater assembly with heater mount

Abstract

A heater assembly (10) for an aerosol-generating device (86). The heater assembly comprises a tubular heating chamber (12) for heating the aerosol-forming substrate. The tubular heating chamber includes a proximal flared end (54). The heater assembly also includes a heater housing (16) disposed around the heating chamber. The heater housing includes a proximal side wall (48). The proximal wall includes a circular groove (50) extending in a proximal direction from an inner surface of the proximal wall. The circular groove includes a chamfered inner side wall (52). The chamfered inner sidewall and the proximal flared end of the tubular heating chamber have a mating shape. The proximal flared end of the tubular heating chamber is mounted into the circular groove of the proximal wall. An aerosol-generating device including a heater assembly, and an aerosol-generating system including an aerosol-generating device and an aerosol-forming substrate.

Description

Technical Field

[0001] The present invention relates to a heater assembly for an aerosol generating device. The present invention further relates to an aerosol generating device. The present invention also relates to an aerosol generating system comprising an aerosol generating device and an aerosol-forming article. Background Art

[0002] It is known to provide an aerosol generating device for generating an inhalable vapor. Such a device can heat an aerosol-forming substrate to a temperature at which one or more components of the aerosol-forming substrate volatilize without burning the aerosol-forming substrate. The aerosol-forming substrate can be provided as part of an aerosol-generating article. The aerosol-generating article can have a strip shape for inserting the aerosol-generating article into a cavity (e.g., a heating chamber) of the aerosol-generating device. The heating element can be arranged in or around the heating chamber so as to heat the aerosol-forming substrate once the aerosol-generating article is inserted into the heating chamber of the aerosol-generating device.

[0003] The heating chamber can be arranged in the housing of the aerosol generating device and forms a part of the airflow path through the aerosol generating device. It is known to provide a seal around the airflow path and between the heating chamber and the housing in an attempt to prevent the aerosol from leaking from the airflow path and entering other parts of the aerosol generating device, which may cause damage to the electronic devices of the device. The seal can be placed in direct contact with the heating chamber and is therefore usually formed by a heat-resistant polymer (such as silicone or polysiloxane). However, exposing such polymer seals to the heating temperature of the heating chamber may generate undesirable byproducts that may contaminate the aerosol. In addition, such heating temperatures may degrade the seal over time.

[0004] Another problem encountered when sealing the airflow path within the aerosol generating device is manufacturing tolerances. Variations in the dimensions of the components caused by manufacturing tolerances may result in poor engagement between the components and potential gaps through which the aerosol may leak. Achieving a good sealed engagement between the components generally requires tight manufacturing tolerances, which may be difficult to achieve in a rapid manufacturing process such as injection molding. In addition, the device may be accidentally dropped. This may change the position of the heating chamber relative to the housing. A change in the position of the heating chamber may result in the heating chamber no longer being sealedly connected to the housing. Vibrating the heating chamber due to the aerosol generating device being dropped may further structurally damage the mounting connection of the heating chamber in the housing of the aerosol generating device. Summary of the invention

[0005] It is desirable to provide a heater assembly for an aerosol generating device that has an improved seal to its airflow path. It is desirable to provide a heater assembly for an aerosol generating device that allows for manufacturing tolerances. It is desirable to provide a heater assembly for an aerosol generating device that allows for manufacturing tolerances while providing an improved seal to its airflow path. It is desirable to provide a heater assembly for an aerosol generating device that is resistant to impacts, such as those caused by accidental dropping. It is desirable to provide a heater assembly for an aerosol generating device that has minimal or zero direct contact of the heating chamber with the seal.

[0006] According to an embodiment of the present invention, a heater assembly for an aerosol generating device is provided. The heater assembly may include a tubular heating chamber for heating an aerosol-forming substrate. The tubular heating chamber may include a proximal flared end. The heater assembly may also include a heater shell arranged around the heating chamber. The heater shell may include a proximal wall. The proximal wall may include a circular groove extending from the inner surface of the proximal wall in a proximal direction. The circular groove may include a chamfered inner side wall. The chamfered inner side wall and the proximal flared end of the tubular heating chamber may have a matching shape. The proximal flared end of the tubular heating chamber may be mounted in the circular groove of the proximal wall.

[0007] According to an embodiment of the present invention, a heater assembly for an aerosol generating device is provided. The heater assembly includes a tubular heating chamber for heating an aerosol-forming substrate. The tubular heating chamber includes a proximal flared end. The heater assembly also includes a heater shell arranged around the heating chamber. The heater shell includes a proximal wall. The proximal wall includes a circular groove extending from the inner surface of the proximal wall in a proximal direction. The circular groove includes a chamfered inner side wall. The chamfered inner side wall and the proximal flared end of the tubular heating chamber have a matching shape. The proximal flared end of the tubular heating chamber is mounted into the circular groove of the proximal wall.

[0008] By mounting the proximal flared end of a tubular heating chamber into a circular groove of a heater shell including a chamfered inner side wall having a matching shape, an improved seal may be provided. By mounting the proximal flared end of a tubular heating chamber into a circular groove of a heater shell including a chamfered inner side wall having a matching shape, a heater assembly that allows for manufacturing tolerances may be provided. By mounting the proximal flared end of a tubular heating chamber into a circular groove of a heater shell including a chamfered inner side wall having a matching shape, a heater assembly that allows for manufacturing tolerances while providing an improved seal may be provided. By mounting the proximal flared end of a tubular heating chamber into a circular groove of a heater shell including a chamfered inner side wall having a matching shape, a shock-resistant heater assembly may be provided. By mounting the proximal flared end of a tubular heating chamber into a circular groove of a heater shell including a chamfered inner side wall having a matching shape, minimal or zero contact of the heating chamber with the seal may be required. Thus, the generation of harmful or potentially harmful components (HPHCs) during heating may be reduced or prevented.

[0009] The proximal wall can be perpendicular to the longitudinal axis of the heater assembly. The proximal flared end can have an increased inner diameter in the proximal direction. The thickness of the material forming the proximal flared end can be constant. The proximal flared end can be funnel-shaped, wherein there is an increased diameter in the proximal direction. Both the inner surface and the outer surface of the proximal flared end can be inclined at the same angle relative to the longitudinal axis of the heater assembly.

[0010] The proximal flared end of the tubular heating chamber may be press-fitted into a circular groove of the heater shell. The proximal flared end of the tubular heating chamber may be fixed to a circular groove of the heater shell. The proximal flared end of the tubular heating chamber may be attached to a circular groove of the heater shell.

[0011] The tubular heating chamber may be a hollow cylinder having at least one flared end, preferably a proximal flared end. The tubular heating chamber may be a hollow tube having at least one flared end, preferably a proximal flared end. The tubular heating chamber may have at least one enlarged conical end, preferably a proximal enlarged conical end. The proximal flared end may have an inner diameter measured in a direction perpendicular to the longitudinal axis of the heater assembly. The tubular heating chamber may have a central inner diameter measured at the center of the tubular heating chamber in a direction perpendicular to the longitudinal axis of the heater assembly. The inner diameter of the proximal flared end may be larger than the central inner diameter of the tubular heating chamber.

[0012] The tubular heating chamber may include a distal flared end. The distal flared end may have an increasing diameter in the distal direction. The distal flared end may be funnel-shaped, wherein the diameter increases in the distal direction. Both the inner surface and the outer surface of the distal flared end may be inclined at the same angle.

[0013] The tubular heating chamber may include a proximal flared end and a distal flared end. The tubular heating chamber may be open at both ends. The distal flared end and the proximal flared end of the tubular heating chamber may have the same inner diameter. The distal flared end may be equivalent to the proximal flared end. The distal flared end may have the same shape as the proximal flared end. The tubular heating chamber may be a hollow cylinder with a flared end. The tubular heating chamber may be a hollow cylinder with an enlarged conical end.

[0014] The heater assembly may further include a heater mount. The heater housing may include a heater mount. The heater mount may be attached to the heater housing. The heater housing may coaxially surround the heater mount. The heater mount may be configured to receive one end of a tubular heating chamber. The flared end of the tubular heating chamber may be mounted into the heater mount. The distal flared end of the tubular heating chamber may be mounted into the heater mount. The distal flared end of the tubular heating chamber may be fixed to the heater mount. The distal flared end of the tubular heating chamber may be attached to the heater mount. The heater mount may be arranged upstream of the tubular heating chamber. The heater mount may be tubular.

[0015] The heater housing, tubular heating chamber and heater mounting may restrict an airflow path through the heater assembly. The heater housing, tubular heating chamber and heater mounting may surround an airflow path through the heater assembly. The airflow path may be restricted by an airflow channel. The airflow channel may be formed by inner walls of the heater housing, tubular heating chamber and heater mounting. The airflow channel may extend along a longitudinal axis of the heater assembly. The airflow channel may be a straight airflow channel.

[0016] The heater mount may include an additional circular groove at the proximal end extending in the distal direction from the inner proximal surface of the heater mount. The inner proximal surface of the heater mount may be perpendicular to the longitudinal axis of the heater assembly. The circular groove of the heater mount may include a chamfered inner side wall. The chamfered inner side wall of the heater mount may flare in the distal direction. The chamfered inner side wall of the heater mount and the distal flared end of the tubular heating chamber may have matching shapes. The distal flared end of the tubular heating chamber may fit into the circular groove of the heater mount.

[0017] The circular recess of both the heater housing and the heater mount may include chamfered inner sidewalls.The tubular heating chamber may include a proximal flared end and a distal flared end, both of which may have a shape matching the chamfered inner sidewalls of the heater housing and the heater mount.

[0018] According to an example of the present invention, a heater assembly for an aerosol generating device is provided. The heater assembly includes a tubular heating chamber for heating an aerosol-forming substrate. The tubular heating chamber includes a proximal flared end and a distal flared end. The heater assembly also includes a heater shell arranged around the heating chamber. The heater shell includes a proximal wall. The proximal wall includes a circular groove extending from an inner surface of the proximal wall in a proximal direction. The circular groove includes a chamfered inner side wall. The chamfered inner side wall and the proximal flared end of the tubular heating chamber have a matching shape. The proximal flared end of the tubular heating chamber is mounted into the circular groove of the proximal wall. The heater assembly also includes a heater mounting member. The heater mounting member includes an additional circular groove extending from an inner proximal surface of the heater mounting member in a distal direction at a proximal end. The circular groove of the heater mounting member includes a chamfered inner side wall. The chamfered inner side wall of the heater mounting member and the distal flared end of the tubular heating chamber have a matching shape. The distal flared end of the tubular heating chamber is mounted into the circular groove of the heater mounting member.

[0019] The chamfered inner side wall may include at least one rib, preferably three ribs. The chamfered inner side wall may include two, three, four, five or six ribs. The chamfered inner side wall of the circular recess of the heater housing may include ribs, preferably two, three, four, five or six ribs. The chamfered inner side wall of the circular recess of the heater mount may include ribs, preferably two, three, four, five or six ribs, more preferably three ribs. The chamfered inner side walls of both the heater housing and the heater mount may each include ribs, preferably three ribs.

[0020] At least one chamfered inner side wall may comprise at least one protrusion, preferably three protrusions.

[0021] The chamfered inner sidewall of the heater housing may flare in the proximal direction. The chamfered inner sidewall of the heater mount may flare in the distal direction. At least one chamfered inner sidewall may flare toward the bottom of the circular recess. The cross-section of at least one circular recess may be a right-angled trapezoid.

[0022] The chamfered inner side wall of the heater housing and the proximal flared end of the tubular heating chamber may be parallel. The chamfered inner side wall and the distal flared end of the heater mounting may be parallel. The chamfered inner side wall and the flared end may all be parallel.

[0023] The chamfered inner sidewalls of the heater housing and the heater mounting, as well as the proximal flared end and the distal flared end of the tubular heating chamber may have a chamfer angle. The chamfer angle may be measured between the longitudinal axis of the heater assembly and the chamfer of at least one chamfered inner sidewall or at least one flared end. The chamfered inner sidewall of the heater housing may have a chamfer angle that is approximately the same as the proximal flared end of the tubular heating chamber. The chamfered inner sidewall of the heater mounting may have a chamfer angle that is approximately the same as the distal flared end of the tubular heating chamber. The chamfer angles of at least one chamfered inner sidewall and at least one flared end may all be approximately the same. The chamfer angles of the chamfered inner sidewall and the flared end may have approximately the same absolute value.

[0024] The proximal flared end of the tubular heating chamber and the chamfered inner sidewall of the heater housing may have a chamfer angle of between 20° and 45°, preferably between 25° and 40°, more preferably about 30°. The distal flared end of the tubular heating chamber and the chamfered inner sidewall of the heater mount may have a chamfer angle of between 20° and 45°, preferably between 25° and 40°, more preferably about 30°. The flared end of the tubular heating chamber and the chamfered inner sidewall of the heater housing and the heater mount may have a chamfer angle of between 20° and 45°, preferably between 25° and 40°, more preferably about 30°.

[0025] The proximal flared end, the distal flared end, and the chamfered inner sidewalls of the heater housing and the heater mount may have a length measured along the chamfer. The length of the proximal flared end of the tubular heating chamber and the chamfered inner sidewall of the heater housing may be between 0.5 mm and 5 mm, preferably between 0.5 mm and 3 mm, more preferably between 0.5 mm and 2 mm, and most preferably about 1 mm. The length of the distal flared end of the tubular heating chamber and the chamfered inner sidewall of the heater mount may be between 0.5 mm and 5 mm, preferably between 0.5 mm and 3 mm, more preferably between 0.5 mm and 2 mm, and most preferably about 1 mm. Thus, a contact area between the tubular heating chamber and the heater housing and between the tubular heating chamber and the heater mount may be provided that is small enough to prevent potential generation of HPHC during heating of the heater assembly.

[0026] The proximal flared end, the distal flared end and the chamfered inner sidewalls of the heater housing and the heater mount may have an axial length measured in a direction along the longitudinal axis of the heater assembly. The axial length may be at least 0.8 mm. The axial length may be 4 mm or less.

[0027] The proximal flared end, the distal flared end and the chamfered inner sidewalls of the heater housing and the heater mount may have a transverse length measured in a direction perpendicular to the longitudinal axis of the heater assembly. The transverse length may be at least 0.5 mm. The transverse length may be 2.5 mm or less.

[0028] The dimensions of the flared end and the chamfered inner side wall can provide improved impact resistance. The heater assembly can be part of an aerosol generating device. Such a device may be accidentally dropped. By falling in this way, the device may be exposed to forces extending along the longitudinal axis of the device and therefore along the heater assembly. The chamfer angle of the flared end of the tubular heating chamber can divide the initial force of the impact extending along the longitudinal axis of the heater assembly into two perpendicular smaller forces. When the initial force magnitude is similar to the force generated when the device is dropped on a hard surface, the stress generated on the heater assembly by these two smaller forces can be borne by the heater assembly. In order to ensure this resistance, the chamfer angle can be between 20° and 45°, preferably between 25° and 40°, and more preferably about 30°.

[0029] The heater shell may be radially spaced from the tubular heating chamber and the heater mounting to define a hollow space around the tubular heating chamber and the heater mounting. Thermal insulation of the tubular heating chamber is thereby provided. The heater shell may have an outer diameter measured in a direction perpendicular to the longitudinal axis of the heater assembly. The diameter of the heater shell may be greater than the outer diameter of the tubular heating chamber measured in the same direction. The ratio of the outer diameter of the heater shell to the outer diameter of the tubular heating chamber may be between 2 and 3.5. The heater shell may be a tubular heater shell. The tubular heater shell may be coaxially arranged around the tubular heating chamber.

[0030] The inner diameter of the tubular heating chamber may substantially correspond to or be substantially equal to the outer diameter of the aerosol-generating article. In some embodiments, the inner diameter of the tubular heating chamber may be slightly smaller than the outer diameter of the aerosol-generating article, such that the aerosol-generating article is compressed in the tubular heating chamber. For example, the outer diameter of the aerosol-generating article may be about 7.4 mm, and the inner diameter of the tubular heating chamber may be about 7.3 mm. The length of the tubular heating chamber may substantially correspond to or be substantially equal to the length of the aerosol-forming substrate provided in the aerosol-generating article.

[0031] The heater housing may include a proximal heater housing and a distal heater housing. The proximal heater housing may include a proximal wall having a circular groove. The heater housing may be a two-part heater housing. The proximal heater housing may include an air outlet. The air outlet may be an opening for receiving an aerosol generating article. The aerosol may exit the opening via the aerosol generating article received in the tubular heating chamber. The distal heater housing may include an air inlet. The tubular heating chamber may be in fluid communication with the air inlet. The tubular heating chamber may be in fluid communication with the air outlet. The tubular heating chamber may be in fluid communication with both the air inlet and the air outlet to define an airflow path through the heater assembly.

[0032] The proximal heater shell may have an airflow channel. The airflow channel of the proximal heater shell may be in fluid communication with the air inlet. The distal heater shell may have an airflow channel. The airflow channel of the distal heater shell may be in fluid communication with the aerosol outlet. The tubular heating chamber may have an airflow channel. The airflow channel of the tubular heating chamber may pass through the length of the tubular heating chamber. The heater mount may have an airflow channel. The airflow channel of the heater mount may pass through the thickness or length of the heater mount. The airflow channels of each of the proximal heater shell, the distal heater shell, the tubular heating chamber, and the heater mount may be in fluid communication with each other to define an airflow path through the heater assembly.

[0033] The proximal heater shell and the distal heater shell may be attached to each other. The proximal heater shell and the distal heater shell may be attached to each other by fasteners. The proximal heater shell and the distal heater shell may be attached to each other by a plurality of fasteners. The plurality of fasteners may be symmetrically spaced around the proximal heater shell and the distal heater shell. One or more fasteners may include threaded fasteners such as screws. One or more fasteners may include snap-fit ​​fasteners.

[0034] The proximal heater shell and the distal heater shell may have a length measured in a direction along the longitudinal axis of the heater assembly. The length of the proximal heater shell may be less than the length of the distal heater shell.

[0035] The proximal heater housing may include a proximal portion and a distal portion. The proximal portion and the distal portion may have an outer diameter measured in a direction perpendicular to the longitudinal axis of the heater assembly. The outer diameter of the proximal portion may be smaller than the outer diameter of the distal portion. The distal portion may include a proximal wall, the proximal wall including a circular groove. The circular groove may have an outer diameter measured in a direction perpendicular to the longitudinal axis of the heater assembly. The outer diameter of the circular groove may be substantially the same as the outer diameter of the proximal portion of the proximal heater housing.

[0036] The distal heater housing may include a proximal portion and a distal portion. The proximal portion and the distal portion may have an outer diameter measured in a direction perpendicular to the longitudinal axis of the heater assembly. The outer diameter of the proximal portion may be greater than the outer diameter of the distal portion.

[0037] The air flow channel may be bounded by a proximal portion of the proximal heater housing, the tubular heater tube, the heater mount, and a distal portion of the distal heater housing.

[0038] The heater mount may include a proximal portion and a distal portion. The proximal portion may have a larger diameter than the distal portion measured in a direction perpendicular to the longitudinal axis of the heater assembly. The proximal portion may include a circular groove. The distal heater shell may include a heater mount. The distal heater shell may be part of the distal heater shell. Alternatively, the heater mount may be mounted into the distal heater shell. The heater mount may be connected to the distal heater shell via a snap fit or a threaded engagement. The heater mount may be mounted into a distal opening of the distal heater shell. The proximal portion of the distal heater shell may include a distal wall. The distal wall may include a distal opening. The distal portion of the heater mount may be at least partially inserted into the distal opening of the distal heater shell.

[0039] The tubular heating chamber may be arranged between the proximal heater shell and the heater mounting member. The tubular heating chamber may be sandwiched between the proximal heater shell and the heater mounting member. The tubular heating chamber may be press-fitted into the proximal heater shell and the heater mounting member. The proximal flared end of the tubular heating chamber may be mounted into the proximal wall of the proximal heater shell, and the distal flared end of the tubular heating chamber may be mounted into the proximal portion of the heater mounting member. When the tubular heating chamber is sandwiched between the proximal heater shell and the heater mounting member or press-fitted into the proximal heater shell and the heater mounting member, the matching shapes of the chamfered inner side wall and the flared end may provide a sealed connection.

[0040] When the heater mount is mounted in the distal opening of the distal heater housing, the seal may be disposed between the heater mount and the inner surface of the distal heater housing. When the heater mount is mounted in the distal opening of the distal heater housing, the seal may be disposed between the heater mount and the inner surface of the distal heater housing. The seal may be disposed between a distal end of the proximal portion of the heater mount and a distal wall of the proximal portion of the distal heater housing.

[0041] The seal may be elastic. The seal may be formed of any suitable material. The seal may include an elastomeric material. The seal may include a polymer. The seal may include an elastomeric polymer. The seal may include or be formed of any suitable polymer, including but not limited to ethylene propylene diene monomer (EPDM) rubber or silicone. The seal may be an O-ring. The O-ring may have a diameter measured in a direction perpendicular to the longitudinal axis of the heater assembly. The diameter of the O-ring may be approximately equal to or less than the outer diameter of the proximal portion of the heater mount measured in the same direction.

[0042] When the heater assembly is assembled, the seal may be compressed.When the heater assembly is assembled, the seal may be compressed between the heater mount and the distal heater housing.

[0043] The seal may have a Shore hardness between 30A and 90A, preferably between 50A and 80A, and more preferably about 70A. These Shore hardness values ​​have been found to be soft enough to absorb manufacturing tolerances, but still hard enough to provide sufficient force to the heater assembly to achieve airflow path sealing and heater assembly integrity. The Shore hardness may be determined by technical standard ISO868 Type A.

[0044] The seal may include any suitable shape. The seal may include a shape that conforms to the shape of the heater mount. The seal may include a shape that conforms to the shape of one of the proximal heater housing and the distal heater housing. The seal may include an O-ring. The seal may have any suitable cross-sectional shape in the longitudinal plane of the heater assembly, including but not limited to a circular cross-sectional shape or a cross-sectional shape having two opposing flat surfaces, such as a square or rectangular cross-sectional shape.

[0045] The seal may have an uncompressed thickness or diameter between 0.5 mm and 2 mm. The seal may have an uncompressed thickness or diameter of about 1 mm. These uncompressed thicknesses have been found to be particularly effective for absorbing manufacturing tolerances and providing airflow path sealing and heater assembly integrity.

[0046] An advantage of mounting the seal between the heater housing and the heater mounting, rather than between the heater housing and the tubular heating chamber, is that it avoids contact between the seal and the tubular heating chamber. Furthermore, the seal is advantageously arranged so that it is spaced or distanced from the tubular heating chamber. This distance between the tubular heating chamber and the seal means that the seal is maintained at a lower temperature than the tubular heating chamber and does not overheat. Since the seal is not subject to high thermal stresses, improved sealing of the airflow path through the heater assembly can be achieved.

[0047] The heater assembly of the present disclosure is also less susceptible to manufacturing tolerances because the seal can absorb at least a portion of the manufacturing tolerances to achieve improved sealing. In addition, the matching shapes of the chamfered inner sidewall and the flared end can provide correct alignment and retention of the heater shell, the tubular heating chamber, and the heater mounting.

[0048] The proximal heater housing, the distal heater housing, the tubular heating chamber, the heater mounting member, and the seal may enclose an air space. The proximal heater housing, the distal heater housing, the tubular heating chamber, the heater mounting member, and the seal may enclose an airtight space. The airtight space may be hollow. Alternatively or additionally, the airtight space may include an insulating material.

[0049] When the chamfered inner sidewall includes at least one rib, preferably three ribs, the proximal heater housing, the distal heater housing, the tubular heating chamber, the heater mount, and the seal may enclose an air space. When at least one chamfered inner sidewall of the heater housing and the heater mount each includes at least one rib, preferably three ribs, the proximal heater housing, the distal heater housing, the tubular heating chamber, the heater mount, and the seal may enclose an air space. The air space may improve the overall heating efficiency of the heater assembly.

[0050] The ribs and O-ring combination can provide an airtight seal. The ribs and O-ring combination can limit the possibility of air leaking out of the air space. Alternatively or additionally, the ribs and O-ring combination can limit the possibility of leakage from the airflow path into the heater housing. The ribs and O-rings can absorb manufacturing tolerances. Thus, the effect of manufacturing tolerances on the seal may be small or even zero.

[0051] A heater assembly comprising a two-part heater housing, a tubular heating chamber having a flared end that mounts into the proximal heater housing, and a heater mount disposed on a seal, the heater assembly providing a less complex assembly while allowing for manufacturing tolerances and providing a good seal.

[0052] The tubular heating chamber may comprise metal. The tubular heating chamber may be made of metal. The tubular heating chamber may be made of stainless steel.

[0053] One or more of the walls of the heater housing and the heater mount may comprise a plastic material. One or more of the walls of the heater housing and the heater mount may be made of a plastic material. The plastic material may be polyaryletherketone (PAEK), polyetheretherketone (PEEK) or polyphenylsulfone (PPSU), more preferably polyphenylsulfone (PPSU).

[0054] In one example of the present invention, a heater assembly includes a tubular heating chamber made of metal, a heater shell and a heater mount made of a plastic material, and a seal between the heater mount and the heater shell. In addition, the tubular heating chamber includes a proximal flared end and a distal flared end mounted into the chamfered inner sidewalls of the heater shell and the heater mount. This heater assembly can reduce the contact between the metal tubular heating chamber and the plastic heater shell and the plastic heater mount while providing a sealed connection. Direct contact between the seal and the metal tubular heating chamber is prevented. Therefore, a heater assembly is provided that can reduce or prevent the generation of HPHC.

[0055] The tubular heating chamber may have an elongated shape. The length measured in a direction along the longitudinal axis of the heater assembly may be greater than the diameter of the tubular heating chamber measured in the same direction. The heating chamber may be an elongated hollow tube.

[0056] The heater assembly may further comprise a heating element. The heating element may be arranged at least partially around the tubular heating chamber. The heating element may comprise one or more conductive tracks on an electrically insulating substrate. The heating element may be flexible. The heating element may be wrapped at least partially around the tubular heating chamber. The heating element may be arranged between the heater housing and the tubular heating chamber.

[0057] Alternatively, the distal heater housing may include a circular recess having a chamfered inner sidewall, and the distal flared end of the tubular heating chamber may fit into the circular recess, and the proximal flared end may fit into a heater mount that is mounted into the proximal heater housing.

[0058] The present invention further relates to an aerosol generating device comprising a heater assembly as described herein. Preferably, the aerosol generating device comprises a power supply configured to supply power to the heating element. The power supply preferably comprises a power source. Preferably, the power source is a battery, such as a lithium-ion battery. Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may need to be recharged. For example, the power source may have sufficient capacity to allow continuous generation of aerosol for a period of about six minutes, or for a multiple of six minutes. In another example, the power source may have sufficient capacity to allow a predetermined number of puffs or discontinuous activation of the heater assembly.

[0059] The power supply may include control electronics. The control electronics may include a microcontroller. The microcontroller is preferably a programmable microcontroller. The circuit may include further electronic components. The circuit may be configured to regulate the supply of power to the heater assembly. Power may be supplied to the heater assembly continuously after system activation, or may be supplied intermittently, such as on a puff-by-puff basis. Power may be supplied to the heater assembly in the form of current pulses.

[0060] The invention also relates to an aerosol generating system comprising an aerosol generating device and an aerosol generating article. The aerosol generating article may comprise a substrate portion comprising an aerosol-forming substrate. The aerosol generating article may be configured to be at least partially inserted into a tubular heating chamber.

[0061] The aerosol generating article may include a substrate portion comprising an aerosol-forming substrate. The length of the substrate portion may be shorter than or equal to the length of the heating element. The length of the substrate portion may be greater than the length of the heating element. The length of the substrate portion may be greater than the length of the heating element but shorter than the length of the heating chamber. The length of the substrate portion may be equal to or greater than the length of the heating chamber. The aerosol generating article may include a substrate portion and another mouthpiece portion. The mouthpiece portion may be positioned at the proximal end of the aerosol generating article. The mouthpiece portion may include a filter.

[0062] As used herein, the terms "upstream" and "downstream" are used to describe the relative position of components or parts of components of an aerosol generating device relative to the direction of airflow through the aerosol generating device during use of the aerosol generating device. The aerosol generating device according to the present invention includes a proximal end, through which the aerosol leaves the device in use. The proximal end of the aerosol generating device may also be referred to as the mouth end or downstream end. The mouth end is downstream of the distal end. The distal end of the aerosol generating article may also be referred to as the upstream end. Components or parts of components of the aerosol generating device may be described as being upstream or downstream of each other based on their relative position relative to the airflow path of the aerosol generating device.

[0063] The proximal end of the heater assembly according to the invention is configured to be arranged within the aerosol generating device in a direction towards the mouth end or downstream end of the device. The distal end of the heater assembly according to the invention is configured to be arranged within the aerosol generating device in a direction towards the distal end or upstream end of the device. The longitudinal axis of the tubular heating chamber may extend between the proximal end of the heating chamber and the distal end of the heating chamber. The longitudinal axis of the tubular heating chamber may extend between the proximal end of the heater assembly and the distal end of the heater assembly.

[0064] In all aspects of the present disclosure, the heating element may include a resistive material. Suitable resistive materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials made of ceramic and metallic materials. Such composite materials may include doped or undoped ceramics.

[0065] As described, in any of the aspects of the present disclosure, the heating element may be part of a heating chamber for a heater assembly of an aerosol generating device. The heater assembly may include an internal heating element or an external heating element or both internal and external heating elements, where "inside" and "outside" are for an aerosol-forming substrate. The internal heating element may take any suitable form. For example, the internal heating element may take the form of a heating blade. Alternatively, the internal heater may take the form of a sleeve or substrate with different conductive portions, or a resistive metal tube. Alternatively, the internal heating element may be one or more heating needles or rods extending through the center of the aerosol-forming substrate. Other alternatives include heating wires or filaments, for example, Ni-Cr (nickel-chromium), platinum, tungsten or alloy wires or heating plates. Optionally, the internal heating element may be deposited in or on a rigid carrier material. In one such embodiment, the resistive heating element may be formed using a metal having a defined relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track on a suitable insulating material (such as a ceramic material) and then sandwiched in another insulating material (such as glass). A heater formed in this manner may be used to both heat and monitor the temperature of the heating element during operation.

[0066] The external heating element can take any suitable form. For example, the external heating element can take the form of one or more flexible heating foils on a dielectric substrate (e.g., polyimide). The flexible heating foil can be shaped to conform to the periphery of the substrate receiving cavity. Alternatively, the external heating element can take the form of a metal grid, a flexible printed circuit board, a molded interconnect device (MID), a ceramic heater, a flexible carbon fiber heater, or can be formed on a suitable shaped substrate using a coating technique (e.g., plasma vapor deposition). The external heating element can also be formed using a metal having a defined relationship between temperature and resistivity. In such an exemplary device, metal can be formed as a track between two layers of suitable insulating materials. The external heating element formed in this way can be used for both heating and monitoring the temperature of the external heating element during operation.

[0067] Advantageously, the heating element heats the aerosol-forming substrate by means of heat conduction. The heating element may at least partially contact the substrate or a carrier on which the substrate is placed. Alternatively, heat from an internal heating element or an external heating element may be conducted to the substrate by means of a heat conducting element.

[0068] During operation, the aerosol-forming substrate may be completely contained within the aerosol-generating device. In this case, the user may draw on the mouthpiece of the aerosol-generating device. Alternatively, during operation, the smoking article containing the aerosol-forming substrate may be partially contained within the aerosol-generating device. In this case, the user may draw directly on the smoking article.

[0069] The heating element may be configured as an induction heating element. The induction heating element may include an induction coil and a susceptor. In general, a susceptor is a material that is capable of generating heat when penetrated by an alternating magnetic field. According to the present invention, the susceptor may be conductive or magnetic, or both conductive and magnetic. The alternating magnetic field generated by one or several induction coils heats the susceptor, which then transfers heat to the aerosol-forming substrate, so that an aerosol is formed. The heat transfer may be mainly by thermal conduction. This heat transfer is optimal if the susceptor is in close thermal contact with the aerosol-forming substrate. When an induction heating element is employed, the induction heating element may be configured as an internal heating element as described herein or as an external heater as described herein. If the induction heating element is configured as an internal heating element, the susceptor element is preferably configured as a pin or blade for penetrating the aerosol-generating article. If the induction heating element is configured as an external heating element, the susceptor element is preferably configured as a cylindrical susceptor that at least partially surrounds the cavity or forms the side wall of the cavity.

[0070] As used herein, the term "aerosol-forming substrate" refers to a substrate capable of releasing volatile compounds that can form an aerosol. The volatile compounds can be released by heating or burning the aerosol-forming substrate. As an alternative to heating or burning, in some cases, the volatile compounds can be released by chemical reaction or by mechanical stimulation (such as ultrasound). The aerosol-forming substrate can be solid or liquid, or can include both solid and liquid components. The aerosol-forming substrate can be part of an aerosol-generating article.

[0071] The aerosol-forming substrate may comprise nicotine. The nicotine-containing aerosol-forming substrate may be a nicotine salt substrate.

[0072] The aerosol-forming substrate may include plant-based materials.The aerosol-forming substrate may include tobacco.The aerosol-forming substrate may include tobacco-containing materials, and the tobacco-containing materials include volatile tobacco flavor compounds released from the aerosol-forming substrate when heated.Alternatively, the aerosol-forming substrate may include non-tobacco materials.The aerosol-forming substrate may include homogenized plant-based materials.The aerosol-forming substrate may include homogenized tobacco materials.The homogenized tobacco materials may be formed by agglomerating particle tobacco.

[0073] The aerosol-forming substrate may include at least one aerosol-forming agent. The aerosol-forming agent is any suitable known compound or a mixture of compounds, which is conducive to forming a dense and stable aerosol in use and is substantially resistant to thermal degradation at the operating temperature of the device. Suitable aerosol-forming agents are well known in the art and include, but are not limited to: polyols, such as triethylene glycol, 1,3-butylene glycol and glycerol; esters of polyols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol formers are polyols or mixtures thereof, such as triethylene glycol, 1,3-butylene glycol. Preferably, the aerosol-forming agent is glycerol. If present, the aerosol-forming agent content of the homogenized tobacco material may be equal to or greater than 5 weight percent by dry weight, and preferably 5 weight percent to 30 weight percent by dry weight. The aerosol-forming substrate may include other additives and ingredients, such as flavors.

[0074] As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate capable of releasing volatile compounds that can form an aerosol. The aerosol-generating article may be disposable.

[0075] As used herein, the term "aerosol generating device" refers to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol generating device may interact with one or both of an aerosol generating article comprising an aerosol-forming substrate or a cartridge comprising an aerosol-forming substrate. In some examples, the aerosol generating device may heat the aerosol-forming substrate to promote release of volatile compounds from the substrate. An electrically operated aerosol generating device may include an atomizer, such as an electric heater, to heat the aerosol-forming substrate to form an aerosol.

[0076] As used herein, the term "aerosol generating system" refers to the combination of an aerosol generating device and an aerosol-forming substrate. When the aerosol-forming substrate forms part of an aerosol-generating article, the aerosol generating system refers to the combination of an aerosol generating device and an aerosol-generating article. In an aerosol generating system, the aerosol-forming substrate and the aerosol generating device cooperate to generate an aerosol.

[0077] A non-exhaustive list of non-limiting examples is provided below.Any one or more features of these examples may be combined with any one or more features of another example, embodiment or aspect described herein.

[0078] Example ex1. A heater assembly for an aerosol generating device, comprising:

[0079] a tubular heating chamber for heating the aerosol-forming substrate, wherein the tubular heating chamber comprises a proximal flared end; and

[0080] A heater shell is arranged around the heating chamber, wherein the heater shell includes a proximal wall, wherein the proximal wall includes a circular groove extending from an inner surface of the proximal wall in a proximal direction, wherein the circular groove includes a chamfered inner wall, wherein the chamfered inner wall and the proximal flared end of the tubular heating chamber have matching shapes, and wherein the proximal flared end of the tubular heating chamber is mounted in the circular groove of the proximal wall.

[0081] Example ex2. The heater assembly according to example ex1, wherein the chamfered inner side wall of the heater housing flares in the proximal direction.

[0082] Example ex3. A heater assembly according to any of the preceding examples, wherein the tubular heating chamber comprises a distal flared end.

[0083] Example ex4. The heater assembly according to example ex3, further comprising a heater mount, wherein the distal flared end of the tubular heating chamber is mounted into the heater mount.

[0084] Example ex5. The heater assembly of example ex4, wherein the heater housing, the tubular heating chamber, and the heater mount restrict an airflow path through the heater assembly.

[0085] Example ex6. A heater assembly according to any one of examples ex4 or ex5, wherein the heater mount includes an additional circular groove at the proximal end extending in the distal direction from the inner proximal surface of the heater mount, wherein the circular groove includes a chamfered inner side wall, wherein the chamfered inner side wall flares in the distal direction, wherein the chamfered inner side wall and the distal flared end of the tubular heating chamber have matching shapes, and wherein the distal flared end of the tubular heating chamber is mounted into the circular groove of the heater mount.

[0086] Example ex7. The heater assembly according to any of the preceding examples, wherein one or both of the chamfered inner sidewall of the proximal wall and the chamfered inner sidewall of the heater mount comprises at least one rib, preferably three ribs.

[0087] Example ex8. The heater assembly according to any of the preceding examples, wherein the chamfered inner sidewall of the heater housing has the same chamfer angle as the proximal flared end of the tubular heating chamber.

[0088] Example ex9. A heater assembly according to example ex8, wherein the proximal flared end of the tubular heating chamber and the chamfered inner wall of the heater shell have a chamfer angle between 20° and 45°, preferably between 25° and 40°, and more preferably about 30°.

[0089] Example ex10. A heater assembly according to any of the preceding examples, wherein the length of the proximal flared end of the tubular heating chamber and the chamfered inner wall of the heater shell is between 0.5 mm and 5 mm, preferably between 0.5 mm and 3 mm, more preferably between 0.5 mm and 2 mm, and most preferably about 1 mm.

[0090] Example ex11. The heater assembly according to any of the preceding examples, wherein the heater shell is a tubular heater shell, preferably wherein the tubular heater shell is coaxially arranged around the tubular heating chamber.

[0091] Example ex12. The heater assembly according to any of the preceding examples, wherein the heater housing comprises a proximal heater housing and a distal heater housing, and wherein the proximal heater housing comprises the proximal wall having the circular groove.

[0092] Example ex13. The heater assembly of example ex12, wherein the proximal heater housing includes an air outlet and the distal heater housing includes an air inlet.

[0093] Example ex14. The heater assembly according to any one of examples ex12 or ex13, further comprising the heater mount of example ex4, wherein the distal heater housing comprises the heater mount, or wherein the heater mount is mounted to a distal opening of the distal heater housing.

[0094] Example ex15. The heater assembly according to example ex14, wherein the tubular heating chamber is sandwiched between or press-fitted into the proximal heater shell and the heater mount.

[0095] Example ex16. The heater assembly according to any one of examples ex14 or ex15, wherein the heater mount is mounted into the distal opening of the distal heater housing, and wherein a seal is arranged between the heater mount and the inner surface of the distal heater housing.

[0096] Example ex17. A heater assembly according to example ex16, wherein one or both of the chamfered inner wall of the proximal wall and the chamfered inner wall of the heater mount include the at least one rib, preferably three ribs, and wherein the proximal heater shell, the distal heater shell, the tubular heating chamber, the heater mount and the seal enclose an air space, preferably the air space is an airtight space, more preferably the airtight space is hollow.

[0097] Example ex18. The heater assembly according to any of the preceding examples, wherein the tubular heating chamber is made of metal, preferably stainless steel.

[0098] Example ex19. A heater assembly according to any one of Examples ex4 to ex18, wherein one or more of the walls in the heater housing and the heater mount are made of a plastic material, preferably polyaryletherketone (PAEK), polyetheretherketone (PEEK) or polyphenylsulfone (PPSU), more preferably polyphenylsulfone (PPSU).

[0099] Example ex20. The heater assembly according to any of the preceding examples, wherein the tubular heating chamber has an elongated shape, preferably wherein the tubular heating chamber is an elongated hollow tube.

[0100] Example ex21. The heater assembly according to any of the preceding examples, further comprising a heating element, preferably wherein the heating element is arranged at least partially around the tubular heating chamber.

[0101] Example ex22. The heater assembly of example ex21, wherein the heating element comprises one or more conductive tracks on an electrically insulating substrate.

[0102] Example ex23. A heater assembly according to any one of examples ex21 or ex22, wherein the heating element is flexible and is at least partially wrapped around the tubular heating chamber.

[0103] Example ex24. An aerosol generating device comprising a heater assembly according to any one of the preceding examples.

[0104] Example ex25. An aerosol generating system, comprising the aerosol generating device of example ex24 and an aerosol generating article, the aerosol generating article comprising a substrate portion, the substrate portion comprising an aerosol-forming substrate, wherein the aerosol generating article is configured to be at least partially inserted into the tubular heating chamber.

[0105] Features described with respect to one embodiment may be equally applicable to other embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0106] The present invention will be further described, by way of example only, with reference to the accompanying drawings, in which:

[0107] Figure 1 An embodiment of a heater assembly for an aerosol generating device is shown;

[0108] Figure 2A , 2B , 2C and 2D respectively show the flared end of a tubular heating chamber having a chamfered inner side wall;

[0109] Figure 3 An embodiment of an aerosol generating device comprising a heater assembly is shown. DETAILED DESCRIPTION

[0110] Figure 1 A cross section of a heater assembly 10 is shown. The heater assembly 10 includes a tubular heating chamber 12 and a heater housing 14 arranged around the tubular heating chamber 12. The heater housing 14 includes a proximal heater housing 16 and a distal heater housing 18. The proximal heater housing 16 includes a proximal portion 20 and a distal portion 22. The proximal portion 20 has a smaller diameter than the distal portion 22. Both the proximal portion 20 and the distal portion 22 are tubular. The proximal portion 20 limits the proximal air flow channel. The proximal portion also includes an air outlet 24. The distal heater housing 18 includes a proximal portion 26 and a distal portion 28. The proximal portion 26 has a larger diameter than the distal portion 28. Both the proximal portion 26 and the distal portion 28 are tubular. The distal portion 28 limits the distal air flow channel. The distal portion 28 includes a distal air inlet 30.

[0111] The heater assembly 10 also includes a heater mount 32. The heater mount 32 includes a proximal portion 34 and a distal portion 36. The proximal portion 34 has a larger diameter than the distal portion 36. Both the proximal portion 34 and the distal portion 36 are tubular.

[0112] The proximal and distal heater housings 16, 18 and the heater mount 32 are made of a plastic material, preferably they are made of polyetheretherketone (PEEK) due to its advantageous mechanical and thermal insulation properties.

[0113] The proximal portion 20, the tubular heating chamber 12, the heater mount 32, and the distal portion 28 define an air flow passage including an air flow path 38. The proximal heater housing 16, the tubular heating chamber 12, the heater mount 32, and the distal heater housing 18 are coaxially arranged about a longitudinal axis 40 of the heater assembly 10. The proximal heater housing 16, the tubular heating chamber 12, the heater mount 32, and the distal heater housing 18 enclose a hollow air space. The hollow air space provides thermal insulation for the tubular heating chamber 12. Thus, heat loss from the tubular heating chamber 12 and heat transfer to the exterior of the heater assembly are reduced.

[0114] The wall of the tubular heating chamber 12 is a metal tube, preferably, the tubular heating chamber is made of stainless steel. A flexible heating element 42 is wrapped around the outer surface of the metal tube to heat the tubular heating chamber 12, which in turn heats the aerosol-forming substrate (not shown) received in the interior space of the tubular heating chamber 12. The heating element 42 includes a conductive heating track 44 on an electrically insulating flexible substrate 46. The electrically insulating flexible substrate 46 includes a heat-resistant flexible polyimide film having a conductive heating track 44 thereon, which is generally formed in a serpentine pattern on the film. The conductive heating track 44 is connected to a power source (not shown) and generates heat when current passes through them. In the illustrated embodiment, the proximal edge portion and the distal edge portion of the flexible substrate 46 are not covered by the heating track 44. In other embodiments, different regions or even the entire surface of the flexible substrate 46 may be covered by the heating track 44. Alternatively, the heating element 42 may be configured as an induction heating element including a susceptor and an induction coil (not shown).

[0115] The distal portion 22 of the proximal heater housing 16 includes a proximal wall 48. The proximal wall 48 includes a circular groove 50. The circular groove 50 includes a chamfered inner side wall 52. Thus, the circular groove 50 has a right-angled trapezoidal cross-section. The proximal flared end 54 of the tubular heating chamber 12 is mounted in the circular groove 50. The chamfered inner side wall 52 and the proximal flared end 54 have the same chamfer.

[0116] The proximal portion 26 of the distal heater housing 18 includes a distal wall 56, which includes a distal opening 58. The distal portion 36 of the heater mount 32 is mounted in the distal opening 58. A seal 60 is arranged between the proximal portion 34 of the heater mount 32 and the inner surface of the proximal portion 26 of the distal heater housing 18. Thus, the proximal portion 34 of the heater mount 32 is spaced apart from the inner wall of the distal heater housing 18. In addition, the seal 60 is spaced apart from the tubular heating chamber 12. The seal 60 is an O-ring made of ethylene propylene diene monomer (EPDM) rubber. The seal 60 has a Shore hardness of 70A determined by technical standard ISO868 Type A. It has been found that this hardness is soft enough for manufacturing tolerances, but also hard enough for applying force to the heater assembly 10 to provide sealing of the airflow path 38 and the integrity of the heater assembly 10. The seal 60 has an uncompressed thickness or diameter of 1 mm. This thickness has also been found to be suitable for absorbing manufacturing tolerances and applying a force to the heater assembly 10 to provide sealing of the airflow channel 38 and integrity of the heater assembly 10 .

[0117] The heater mounting member 32 comprises a circular groove 62, which comprises a chamfered inner side wall 64. Thus, the circular groove 62 has a right-angled trapezoidal cross section. The distal flared end 66 of the tubular heating chamber 12 is mounted into the circular groove 62.

[0118] The flared ends 54 and 66 of the tubular heating chamber 12 are press fit into the circular recesses 50 and 62, respectively. The flared ends 54 and 66 are not defined by the heating element 42.

[0119] Figure 2A and 2B A cross section of a chamfered sidewall 68 having a flared end 70 is shown. The chamfered sidewall 68 may be one or both of the chamfered inner sidewalls 52 and 64. The flared end 70 may be one or both of the flared ends 54 and 66. The chamfered sidewall 68 and the flared end 70 have a length 72 measured along the chamfer, a transverse length 74 measured in a direction perpendicular to the longitudinal axis 40, and an axial length 76 measured along the longitudinal axis 40. The chamfered inner sidewalls 52 and 64 have an axial length between 0.8 mm and 4 mm, and a transverse length between 0.5 mm and 2.5 mm. The flared ends 54 and 66 have an axial length between 0.8 mm and 4 mm, and a transverse length between 0.5 mm and 2.5 mm.

[0120] The chamfered sidewall 68 is chamfered at a chamfer angle 78. The flared end 70 is chamfered at a chamfer angle 80. The chamfer angles 78 and 80 are measured relative to the longitudinal axis 40 of the heater assembly 10. The chamfered sidewall 68 and the flared end 70 are parallel. Therefore, the chamfer angles 78 and 80 have the same absolute value. The chamfer angle 78 is between 20° and 45°, preferably between 25° and 40°, and more preferably about 30°. The chamfer angle 80 is between 20° and 45°, preferably between 25° and 40°, and more preferably about 30°. Both the chamfer angles 78 and 80 are between 20° and 45°, preferably between 25° and 40°, and more preferably about 30°. By these chamfer angle ranges, particularly the chamfer angle of 30°, improved impact resistance is provided when the initial force of an impact extending along the longitudinal axis of the heater assembly 10 is divided into two perpendicular smaller forces.

[0121] Figure 2C It is shown how the initial force extending along the longitudinal axis F is divided into a force F1 (extending along the chamfer) and a force F2 (extending perpendicular to the chamfer). For example, for a chamfer angle of 30°, F1 is about 87% (cos30°) of the initial force F. However, this force F1 is limited because the tubular heating chamber 12 cannot move along this force without expanding its flared end. The second force F2 is about 50% (sin30°) of the initial force F. F2 pushes the chamfered inner sidewalls 52 and 64 toward the tubular hollow core. However, when the F magnitude is within the range of the drop test force, the conical structure has reduced F2 to a sustainable force that the elastic properties of the plastic part can withstand.

[0122] Figure 2DA cross section of a chamfered side wall 82 is shown. The chamfered side wall 82 may be one or both of the chamfered inner side walls 52 and 64. The chamfered side wall 82 includes three ribs 84. The ribs 84 press against the surface of the flared end.

[0123] Figure 3 8 shows a cross section of an aerosol generating device 86. The aerosol generating device 86 comprises Figure 1 The heater assembly 10 of the embodiment of the present invention. The aerosol generating device 86 also includes a power supply 88 and control electronics 90. The power supply 88 may be a rechargeable battery. At the opening 92, an aerosol-forming substrate (not shown) may be at least partially inserted into the tubular heating chamber 12 of the heater assembly 10.

Claims

1. A heater assembly for an aerosol generating device, comprising: a tubular heating chamber for heating the aerosol-forming substrate, wherein the tubular heating chamber comprises a proximal flared end; as well as A heater shell is arranged around the heating chamber, wherein the heater shell includes a proximal wall, wherein the proximal wall includes a circular groove extending from an inner surface of the proximal wall in a proximal direction, wherein the circular groove includes a chamfered inner wall, wherein the chamfered inner wall and the proximal flared end of the tubular heating chamber have matching shapes, and wherein the proximal flared end of the tubular heating chamber is mounted in the circular groove of the proximal wall. 2 . The heater assembly of claim 1 , wherein the chamfered inner sidewall of the heater housing flares in a proximal direction.

3. A heater assembly according to any one of the preceding claims, wherein the tubular heating chamber comprises a distal flared end, preferably wherein the heater assembly further comprises a heater mount, and wherein the distal flared end of the tubular heating chamber is mounted into the heater mount.

4. The heater assembly according to claim 3, wherein the heater assembly further comprises the heater mount, and wherein the distal flared end of the tubular heating chamber is mounted into the heater mount, wherein the heater mount comprises an additional circular groove at the proximal end extending in the distal direction from the inner proximal surface of the heater mount, wherein the circular groove comprises a chamfered inner side wall, wherein the chamfered inner side wall flares in the distal direction, wherein the chamfered inner side wall and the distal flared end of the tubular heating chamber have matching shapes, and wherein the distal flared end of the tubular heating chamber is mounted into the circular groove of the heater mount.

5. A heater assembly according to any one of the preceding claims, wherein one or both of the chamfered inner sidewall of the proximal wall and the chamfered inner sidewall of the heater mount comprises at least one rib, preferably three ribs.

6. A heater assembly according to any one of the preceding claims, wherein the chamfered inner side wall of the heater housing has the same chamfer angle as the proximal flared end of the tubular heating chamber.

7. The heater assembly according to claim 6, wherein the proximal flared end of the tubular heating chamber and the chamfered inner wall of the heater shell have a chamfer angle between 20° and 45°, preferably between 25° and 40°, and more preferably about 30°.

8. A heater assembly according to any of the preceding claims, wherein the length of the proximal flared end of the tubular heating chamber and the chamfered inner wall of the heater shell is between 0.5 mm and 5 mm, preferably between 0.5 mm and 3 mm, more preferably between 0.5 mm and 2 mm, and most preferably about 1 mm.

9. The heater assembly of any one of the preceding claims, wherein the heater housing comprises a proximal heater housing and a distal heater housing, and wherein the proximal heater housing comprises the proximal wall having the circular recess.

10. The heater assembly of claim 9, wherein the tubular heating chamber comprises a distal flared end, wherein the heater assembly further comprises a heater mount, and wherein the distal flared end of the tubular heating chamber is mounted to the heater mount, wherein the distal heater shell comprises the heater mount, or wherein the heater mount is mounted to a distal opening of the distal heater shell.

11. The heater assembly of claim 10, wherein the tubular heating chamber is sandwiched between or press-fitted into the proximal heater housing and the heater mount.

12. The heater assembly of any one of claims 10 or 11, wherein the heater mount is mounted into a distal opening of the distal heater housing, and wherein a seal is disposed between the heater mount and an inner surface of the distal heater housing.

13. A heater assembly according to claim 12, wherein one or both of the chamfered inner wall of the proximal wall and the chamfered inner wall of the heater mount include the at least one rib, preferably three ribs, and wherein the proximal heater shell, the distal heater shell, the tubular heating chamber, the heater mount and the seal enclose an air space, preferably the air space is an airtight space, and more preferably the airtight space is hollow.

14. An aerosol generating device comprising a heater assembly according to any preceding claim.

15. An aerosol generating system comprising an aerosol generating device according to claim 14 and an aerosol generating article, the aerosol generating article comprising a substrate portion, the substrate portion comprising an aerosol-forming substrate, wherein the aerosol generating article is configured to be at least partially inserted into the tubular heating chamber.

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