# US 11,905,940 B2 · Linear compressor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,905,940 B2 - Document ID: US11905940B2 - Status: Granted - Kind: B2 - Application number: 17/523,230 - Filed: 2021-11-10 - Published: 2022-06-30 - Granted: 2024-02-20 - Earliest claimed: 2020-12-30 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Youngmun Lee; Hyeongjun Lim; Kiwon Noh - Web page: https://patentgrep.com/patent/US11905940B2 ## CPC - F04B 39/0061: {using muffler volumes} - F04B 39/121: {Casings} - F04B 39/16: Filtration; Moisture separation - F04B 11/0091: {using a special shape of fluid pass, e.g. throttles, ducts} - F04B 17/046: {the fluid flowing through the moving part of the motor} - F04B 35/045: {using solenoids} - F04B 39/0016: {with valve arranged in the piston} - F04B 39/0066: {using sidebranch resonators, e.g. Helmholtz resonators} - F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F) ## Abstract A linear compressor includes: a shell including an intake pipe configured to suction a refrigerant, a piston including a piston body, an intake muffler including a first muffler that includes a first muffler body defining a main flow passage and a first muffler flange extending in a radial direction from the first muffler body, and at least one auxiliary flow passage disposed between an outer peripheral surface of the first muffler body and an inner peripheral surface of the piston body and configured to guide the refrigerant remaining between the first muffler body and the piston body to an outside of the piston. A cross-sectional area of the at least one auxiliary flow passage is less than a cross-sectional area of an inlet hole provided at a rear end of the main flow passage and greater than or equal to 10% of the cross-sectional area of the inlet hole. ## Claims ### Claim 1 A linear compressor comprising: a shell including an intake pipe that is configured to suction a refrigerant; a cylinder provided inside the shell; a piston that is configured to reciprocate in an axial direction inside the cylinder and that includes a piston body and a piston flange; an intake muffler including a first muffler that includes (i) a first muffler body disposed inside the piston body and defining a main flow passage and (ii) a first muffler flange extending in a radial direction from the first muffler body; and at least one auxiliary flow passage that is disposed at an area between an outer peripheral surface of the first muffler body and an inner peripheral surface of the piston body and that is configured to guide refrigerant remaining in the area to an outside of the piston, wherein the intake muffler further includes a second muffler disposed at a rear side of the first muffler, wherein the at least one auxiliary flow passage is in fluid communication with the area and an expansion chamber defined between the first muffler and the second muffler, and wherein a cross-sectional area of the at least one auxiliary flow passage is (i) less than a cross-sectional area of an inlet hole provided at a rear end of the main flow passage and (ii) greater than or equal to 10% of the cross-sectional area of the inlet hole. ### Claim 2 (depends on 1) The linear compressor of claim 1, wherein the at least one auxiliary flow passage is defined at a communication pipe that is positioned at the outer peripheral surface of the first muffler body and that extends in the axial direction, and wherein the at least one auxiliary flow passage of the communication pipe is in fluid communication with a communication hole defined at the first muffler flange. ### Claim 3 (depends on 2) The linear compressor of claim 2, wherein the at least one auxiliary flow passage is positioned at an upper side of the main flow passage in the axial direction. ### Claim 4 (depends on 2) The linear compressor of claim 2, wherein the at least one auxiliary flow passage surrounds the main flow passage in the axial direction. ### Claim 5 (depends on 2) The linear compressor of claim 2, wherein a front end of the communication pipe is (i) positioned forward or rearward in the axial direction compared to a front end of the first muffler body or (i) positioned on the same line in the axial direction as the front end of the first muffler body. ### Claim 6 (depends on 2) The linear compressor of claim 2, wherein the second muffler includes (i) a second muffler body that is disposed at the rear side of the first muffler and that is in fluid communication with the first muffler and (ii) a second muffler flange that extends in the radial direction from the second muffler body, wherein the linear compressor further comprises: a third muffler configured to accommodate a part of the first muffler body and the second muffler body. ### Claim 7 (depends on 6) The linear compressor of claim 6, wherein the expansion chamber is defined between the first muffler flange and the second muffler flange, and wherein the at least one auxiliary flow passage is in fluid communication with the expansion chamber through a communication hole defined at the second muffler flange. ### Claim 8 (depends on 7) The linear compressor of claim 7, wherein the second muffler body includes a first part having a first inner diameter and a second part having a second inner diameter less than the first inner diameter, and wherein the second muffler flange is defined at an outer peripheral surface of the first part in the radial direction. ### Claim 9 (depends on 7) The linear compressor of claim 7, wherein the second muffler body includes a first part having a first inner diameter and a second part having a second inner diameter less than the first inner diameter, and wherein the second muffler flange is defined at an outer peripheral surface of the second part in the radial direction. ### Claim 10 (depends on 7) The linear compressor of claim 7, wherein a part of the first muffler and a part of the second muffler are press-fitted and coupled to an inner peripheral surface of the third muffler. ### Claim 11 (depends on 7) The linear compressor of claim 7, further comprising: a muffler filter disposed between the first muffler and the second muffler. ### Claim 12 (depends on 7) The linear compressor of claim 7, further comprising: an intake guide portion configured to guide refrigerant discharged from a discharge hole of the first muffler body to an intake port of the piston. ### Claim 13 (depends on 12) The linear compressor of claim 12, wherein the intake guide portion is provided on at least one of the outer peripheral surface of the first muffler body or an outer peripheral surface of the communication pipe. ### Claim 14 (depends on 1) The linear compressor of claim 1, further comprising: a pipe that is disposed between the outer peripheral surface of the first muffler body and the inner peripheral surface of the piston body and that surrounds the outer peripheral surface of the first muffler body, wherein the at least one auxiliary flow passage is (i) defined between an outer peripheral surface of the pipe and the inner peripheral surface of the piston body and (ii) in fluid communication with a communication hole defined at a first flange extension that extends rearward in the axial direction from the first muffler flange. ### Claim 15 (depends on 14) The linear compressor of claim 14, wherein the at least one auxiliary flow passage is configured to surround the main flow passage in the axial direction. ### Claim 16 (depends on 14) The linear compressor of claim 14, wherein a front end of the pipe is (i) positioned forward or rearward in the axial direction compared to a front end of the first muffler body or (ii) positioned on the same line in the axial direction as the front end of the first muffler body. ### Claim 17 (depends on 14) The linear compressor of claim 14, further comprising: the second muffler includes (i) a second muffler body that is disposed at the rear side of the first muffler and that is in fluid communication with the first muffler and (ii) a second muffler flange extending in the radial direction from the second muffler body; and a third muffler configured to accommodate a part of the first muffler body and the second muffler body. ### Claim 18 (depends on 14) The linear compressor of claim 14, further comprising: an intake guide portion configured to guide the refrigerant discharged from a discharge hole of the first muffler body to an intake port of the piston. ### Claim 19 (depends on 18) The linear compressor of claim 18, wherein the intake guide portion is provided at the outer peripheral surface of the first muffler body. ### Claim 20 (depends on 14) The linear compressor of claim 14, wherein the first flange extension has a cylindrical shape.