# US 2018/0320701 A1 · Fan central barrel coupling structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0320701 A1 - Document ID: US20180320701A1 - Status: Published application - Kind: A1 - Application number: 15/585,113 - Filed: 2017-05-02 - Published: 2018-11-08 - Earliest claimed: 2017-05-02 - Assignees: Asia Vital Components Co., Ltd. - Applicants: Asia Vital Components Co., Ltd. - Inventors: Meng Shen; Xiang-You Zeng - Web page: https://patentgrep.com/patent/US20180320701A1 ## CPC - F04D 29/044: Arrangements for joining or assembling shafts - F04D 25/064: {Details of the rotor} - F04D 25/0646: {Details of the stator} - F04D 29/646: {Mounting or removal of fans} - F04D 25/088: {Ceiling fans} - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) ## Abstract A fan central tube coupling structure includes a base and a central tube. The base has a first section and a second section that together define an upward tapered receiving recess below the base. The central tube is externally provided on around a bottom end with a first and a second protruded section and an engagement groove defined between the first and second protruded sections. The second protruded section has an interference pressing surface defined on an outermost peripheral surface thereof. The central tube is axially extended through the base, such that the second protruded section is axially press-fitted into the tapered receiving recess and the interference pressing surface is radially outward forced against the tapered receiving recess. In the meantime, the second section of the base is fitted in the engagement groove and clamped in place by between the first protruded section and the second protruded section. ## Claims ### Claim 1 A fan central tube coupling structure, comprising a base and a central tube axially coupled to the base; the base having a bottom portion with a first section and second section formed thereon, and the first section and the second section together defining an upward tapered receiving recess below the second section; and the central tube having a first protruded section and a second protruded section located lower than the first protruded section, such that an engagement groove is defined between the first and the second protruded section; and the second protruded section being axially press-fitted into the tapered receiving recess and having an interference pressing surface defined on an outermost peripheral surface of the second protruded section adapted to radially press against the tapered receiving recess; and wherein the second section of the base is fitted in the engagement groove and clamped in place by between the first protruded section and the second protruded section. ### Claim 2 A fan central tube coupling structure, comprising: a base having a bottom portion with a first section and a second section formed thereon; the first section standing relative to the bottom portion to upward extend and taper in an axial direction of the base; the second section being connected at a radially outer edge to the first section and having a radially inner free end that radially inward and horizontally extends to define a through hole on the base; the first section and the second section together defining an upward tapered receiving recess below the second section, and the tapered receiving recess being communicable with the through hole; and one side of the first section facing the tapered receiving recess being an inward inclined wall and one side of the second section facing the tapered receiving recess being a downward-facing contact surface, on which an annular pressing groove is formed; and a central tube having a top end and a bottom end and internally defining a receiving space; the top end defining an opening communicable with the receiving space; the bottom end being formed on around an outer surface with a first protruded section and a second protruded section located lower than the first protruded section, such that an engagement groove is defined between the first protruded section and the second protruded section; the second protruded section having an upward-facing contact surface and an interference pressing surface defined on an outermost peripheral surface of the second protruded section; and wherein the top end of the central tube is extended through the through hole of the base from a lower side thereof, such that the second protruded section is press-fitted into the tapered receiving recess in the axial direction of the base, the interference pressing surface is radially outward forced against the inward inclined wall of the tapered receiving recess, and the free end of the second section of the base is fitted in the engagement groove and clamped in place by between the first protruded section and the second protruded section. ### Claim 3 (depends on 2) The fan central tube coupling structure as claimed in claim 2, wherein the upward-facing contact surface of the second protruded section is in contact with the downward-facing contact surface of the second section of the base; and wherein an annular pressing protrusion is formed on the upward-facing contact surface of the second protruded section to correspondingly engage with the annular pressing groove on the downward-facing contact surface of the second section of the base. ### Claim 4 (depends on 2) The fan central tube coupling structure as claimed in claim 2, wherein the first protruded section has a downward-facing bevel surface adapted to contact with the second section of the base. ### Claim 5 (depends on 4) The fan central tube coupling structure as claimed in claim 4, wherein the free end of the second section of the base has an upward-facing chamfered edge adapted to correspondingly engage with the downward-facing bevel surface of the first protruded section. ### Claim 6 (depends on 2) The fan central tube coupling structure as claimed in claim 2, wherein the base and the central tube are arranged in a fan frame.