# US 10,767,644 B2 · Piston fuel pump for an internal combustion engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,767,644 B2 - Document ID: US10767644B2 - Status: Granted - Kind: B2 - Application number: 14/651,249 - Filed: 2013-10-17 - Published: 2015-10-29 - Granted: 2020-09-08 - Earliest claimed: 2012-12-20 - Assignees: Robert Bosch GmbH - Applicants: Robert Bosch GmbH - Inventors: Siamend Flo; Markus Hilligardt; Heiko Jahn; Franz Elischer; Cornelia Giessler; Bernd Koch - Web page: https://patentgrep.com/patent/US10767644B2 ## CPC - F04B 53/143: {Sealing provided on the piston} - F02M 59/02: of reciprocating-piston {or reciprocating-cylinder} type - F02M 59/025: {characterised by a single piston} - F02M 59/442: {means preventing fuel leakage around pump plunger, e.g. fluid barriers} - F04B 15/02: the fluids being viscous or non-homogeneous - F04B 53/14: Pistons, piston-rods or piston-rod connections - F16J 15/56: Other sealings for reciprocating rods - 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) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS ## Abstract A piston fuel pump for an internal combustion engine includes a pump cylinder and a pump piston slidably accommodated in the pump cylinder. The piston fuel pump has a supporting and sealing assembly for the pump piston. The supporting and sealing assembly includes a guiding region configured to axially guide the pump piston in the pump cylinder and a sealing region having a sealing lip. ## Claims ### Claim 1 A piston-type fuel pump for an internal combustion engine, the piston-type fuel pump comprising: a pump cylinder; a pump piston displaceably received in the pump cylinder, the pump piston including a shoulder having a circular ring-shape; and a mounting and sealing arrangement including: a guide region spaced apart from the pump cylinder by less than 0.1 mm and in direct contact with the shoulder of the pump piston, the guide region configured to axially guide the pump piston in the pump cylinder; and a sealing region axially spaced apart from the guide region, the sealing region including: a sealing lip in direct contact with the pump cylinder, a cylindrical section that is cylindrical in shape and is in direct contact with the pump piston, and a recess defined radially between the cylindrical section and the sealing lip, wherein the mounting and sealing arrangement is formed as a contiguous structure, wherein the guide region is radially interposed between the shoulder and the pump cylinder, and the sealing region is not radially interposed between the shoulder and the pump cylinder, wherein the cylindrical section and the sealing lip extend away from the shoulder in a first axial direction, and wherein the cylindrical section extends away from the shoulder by a greater axial distance than the sealing lip. ### Claim 2 (depends on 1) The piston-type fuel pump as claimed in claim 1, wherein the mounting and sealing arrangement is formed by a plastics element. ### Claim 3 (depends on 2) The piston-type fuel pump as claimed in claim 2, wherein the plastics element is made from at least one of polyamide and polyether ether ketone. ### Claim 4 (depends on 1) The piston-type fuel pump as claimed in claim 1, wherein: the mounting and sealing arrangement is fixedly connected to the shoulder. ### Claim 5 (depends on 1) The piston-type fuel pump as claimed in claim 1, wherein: the shoulder is arranged in an end section of the pump piston, and the end section faces toward a delivery chamber of the piston-type fuel pump. ### Claim 6 (depends on 1) The piston-type fuel pump as claimed in claim 1, wherein the mounting and sealing arrangement is a single, undivided part. ### Claim 7 (depends on 1) The piston-type fuel pump as claimed in claim 1, wherein the mounting and sealing arrangement is formed of multiple parts. ### Claim 8 (depends on 7) The piston-type fuel pump as claimed in claim 7, wherein the parts of the mounting and sealing arrangement are clipped and/or adhesively bonded to one another. ### Claim 9 (depends on 1) The piston-type fuel pump as claimed in claim 1, wherein: a gap is defined between the pump cylinder and guide region, and the gap has a span of between 1/100 mm and 10/100 mm. ### Claim 10 (depends on 9) The piston-type fuel pump as claimed in claim 9, wherein the gap has a span of 3/100 mm. ### Claim 11 (depends on 1) The piston-type fuel pump as claimed in claim 1, further comprising: a second mounting arrangement configured to guide the pump piston, the second mounting arrangement arranged positionally fixedly relative to the pump cylinder in a vicinity of an end section of the pump piston, the end section facing away from a delivery chamber of the piston-type fuel pump. ### Claim 12 (depends on 11) The piston-type fuel pump as claimed in claim 11, wherein the second mounting arrangement is a plastics element. ### Claim 13 (depends on 1) The piston-type fuel pump as claimed in claim 1, wherein the sealing lip is formed concentrically about the cylindrical section. ### Claim 14 (depends on 1) The piston-type fuel pump as claimed in claim 1, wherein the recess is open to a delivery chamber of the piston-type fuel pump. ### Claim 15 (depends on 1) The piston-type fuel pump as claimed in claim 1, wherein: the shoulder is shaped as a radially projecting encircling collar having a first end and a second end, the pump piston extends in a first direction from the first end and in a second direction from the second end, and the pump piston has a smaller diameter than the shoulder immediately adjacent to the shoulder in the first direction and has a smaller diameter than the shoulder immediately adjacent to the shoulder in the second direction. ### Claim 16 (depends on 1) The piston-type fuel pump as claimed in claim 1, wherein the shoulder protrudes radially outwardly from axially adjacent sections of the pump piston. ### Claim 17 (depends on 1) The piston-type fuel pump as claimed in claim 1, wherein the mounting and sealing arrangement partially defines a delivery chamber of the fuel pump, and the shoulder is sealed from the delivery chamber by the sealing region. ### Claim 18 A piston-type fuel pump for an internal combustion engine, the piston-type fuel pump comprising: a pump cylinder formed within a pump housing; a pump piston configured to be displaceably received in the pump cylinder; a guide sleeve fixedly coupled to the pump housing, the guide sleeve having a cylindrical section arranged coaxially about the pump piston, the cylindrical section including an internal wall facing toward the pump piston, and the internal wall arranged nearest to the pump piston at an inwardly projecting portion of the guide sleeve; a mounting and sealing arrangement, including: a guide region configured to axially guide the pump piston in the pump cylinder, and a sealing region axially spaced apart from the guide region, the sealing region having a sealing lip in direct contact with the pump cylinder, a cylindrical portion that is cylindrical in shape and in direct contact with the pump piston, and a recess defined radially between the cylindrical portion and the sealing lip; and a second mounting arrangement configured to guide the pump piston, the second mounting arrangement arranged positionally fixedly relative to the pump cylinder, and the second mounting arrangement arranged in the inwardly projecting portion, wherein the mounting and sealing arrangement is formed as a contiguous structure, wherein the guide region is radially interposed between the shoulder and the pump cylinder, and the sealing region is not radially interposed between the shoulder and the pump cylinder, wherein the cylindrical portion and the sealing lip extend away from the shoulder in a first axial direction, and wherein the cylindrical portion extends away from the shoulder by a greater axial distance than the sealing lip.