# US 12,759,371 B2 · Device for reducing the noise of motor vehicle air conditioning units > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,759,371 B2 - Document ID: US12759371B2 - Status: Granted - Kind: B2 - Application number: 18/614,694 - Filed: 2024-03-24 - Published: 2024-10-10 - Granted: 2026-10-13 - Earliest claimed: 2023-04-06 - Assignees: Hanon Systems - Applicants: Hanon Systems - Inventors: Christoph Capellmann; Harald Jung; Nitin Ramesh Chincholkar - Web page: https://patentgrep.com/patent/US12759371B2 ## CPC - B60H 1/00507: {Details, e.g. mounting arrangements, desaeration devices (B60H1/32 takes precedence)} - B60H 1/00021: {Air flow details of HVAC devices} - B60H 1/00671: {Damper doors moved by rotation; Grilles} - B60H 2001/006: {Noise reduction} - B60H: ARRANGEMENTS OF HEATING, COOLING, VENTILATING OR OTHER AIR-TREATING DEVICES SPECIALLY ADAPTED FOR PASSENGER OR GOODS SPACES OF VEHICLES ## Abstract A device for reducing the noise of motor vehicle air conditioning units, having at least one air flow limiting element which projects laterally on an outer circumference of an axial air inlet opening vertically out of an air inlet opening plane and has a surface which limits or blocks a flow path next to the axial air inlet opening, at least two plate-shaped air guiding elements, which are arranged on an inside of a recirculation air flap in mutually spaced parallel planes at right angles to an axis of rotation of the recirculation air flap, and an air flow guiding element which is arranged on a fan tongue and extends radially from the fan tongue at a distance from a fan wheel into a spiral flow channel. ## Claims ### Claim 1 A device for reducing noise of motor vehicle air conditioning units, the device comprising: a radial fan, in which a driven fan wheel draws in air via an axial air inlet opening and the air drawn in is conveyed from an interior of the fan via a fan tongue to an air outlet opening, wherein a recirculation air flap is arranged pivotably at least in some areas over the axial air inlet opening in such a way that an air flow on an inside of the recirculation air flap can be deflected in a direction of the axial air inlet opening, the device further comprising: at least one air flow limiting element which projects laterally on an outer circumference of the axial air inlet opening vertically out of an air inlet opening plane and thereby has a surface which limits or blocks a flow path next to the axial air inlet opening; at least two plate-shaped air guiding elements, which are arranged on the inside of the recirculation air flap in parallel planes at right angles to an axis of rotation of the recirculation air flap; and an air flow guiding element arranged on the fan tongue, which extends radially from the fan tongue at a distance from the fan wheel into a spiral flow channel. ### Claim 2 (depends on 1) The device according to claim 1, wherein the at least one air flow limiting element is arranged in front of the recirculation air flap in a direction of flow of the air drawn in. ### Claim 3 (depends on 1) The device according to claim 1, wherein the at least one air flow limiting element is an integral component of the fan housing or of an air inlet housing. ### Claim 4 (depends on 1) The device according to claim 1, wherein a height of the at least one air flow limiting element projecting vertically out of the air inlet opening plane is less than a highest position of the recirculation air flap above the air inlet opening plane. ### Claim 5 (depends on 1) The device according to claim 1, wherein there are two air flow limiting elements arranged laterally opposite one another on the outer circumference of the axial air inlet opening, the air flow limiting elements arranged opposite one another having sloping sides leading away from one another on their facing narrow sides. ### Claim 6 (depends on 1) The device according to claim 1, wherein a plurality of the plate-shaped air guide elements are arranged on the inside of the recirculation air flap, the plurality of the plate-shaped air guide elements being evenly spaced apart. ### Claim 7 (depends on 1) The device according to claim 1, wherein the plate-shaped air guide elements are integral components of the recirculation air flap. ### Claim 8 (depends on 1) The device according to claim 1, wherein the air flow guiding element has a recess tapering in a direction of the air outlet opening. ### Claim 9 (depends on 1) The device according to claim 1, wherein the air flow guiding element is an integral component of the fan housing in a form of an extension of the fan tongue. ### Claim 10 (depends on 1) The device according to claim 1, wherein the air flow guiding element has a wrap angle related to the fan wheel in a range of 47° and 67°. ### Claim 11 (depends on 1) The device according to claim 1, wherein the air flow guiding element is formed in two parts from an upper air flow guiding element and a lower air flow guiding element, the upper air flow guiding element and the lower air flow guiding element being arranged axially opposite one another. ### Claim 12 (depends on 11) The device according to claim 11, wherein the upper air flow guiding element and/or the lower air flow guiding element has/have a tip pointing into the spiral flow channel with a radius which corresponds to 0.25 times to 0.75 times a radius of the fan tongue. ### Claim 13 (depends on 12) The device according to claim 12, wherein the upper air flow guiding element and/or the lower air flow guiding element on the fan tongue has/have an axial height which corresponds to 0.35 times to 0.75 times an axial height of the fan wheel, an axial height of the tip of the upper air flow guiding element and/or of the lower air flow guiding element corresponds to a maximum of 0.7 times the axial height at the fan tongue. ### Claim 14 (depends on 13) The device according to claim 13, wherein the axial height of the upper air flow guiding element and/or the lower air flow guiding element increases from the tip in a direction of flow. ### Claim 15 (depends on 14) The device according to claim 14, wherein a radial width of the upper air flow guiding element and/or the lower air flow guiding element increases in the direction of flow.