Low-cost evacuator for an engine having tuned Venturi gaps

Patent metadata

Field	Value
Publication number	US-10273978-B2
Application number	US-201514830864-A
Country	US
Kind code	B2
Filing date	Aug 20, 2015
Priority date	Aug 27, 2014
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

An evacuator for supplying vacuum to a device in a boosted engine air system is disclosed. The evacuator defines a body comprising a converging motive section, a diverging discharge section, at least one suction port, and a Venturi gap located between an outlet end of the converging motive section and an inlet end of the diverging discharge section. A lineal distance is measured between the outlet end and the inlet end. The lineal distance is decreased in length if higher suction vacuum at a specific set of operating conditions is required and the lineal distances is increased in length if higher suction flow rate at the specific set of operating conditions is required.

First claim

What is claimed is:

1. An evacuator for providing vacuum to a device in an engine system, the evacuator defining a body comprising:
a converging motive section;
a diverging discharge section;
a first Venturi gap located between an outlet end of the converging motive section which defines a first opening and an inlet end of the diverging discharge section which defines a second opening;
wherein the first Venturi gap is defined by a first lineal distance measured between the first opening and the second opening;
wherein the first Venturi gap has a first offset, the first offset being the difference in the size of the first opening and the second opening;
a second Venturi gap downstream of the first Venturi gap positioned within the diverging discharge section and separated from the first Venturi gap by a first diverging discharge body section;
wherein the first diverging body section defines the inlet end of the diverging discharge section and opposite thereof defines an inlet surface of the second Venturi gap defining a third opening;
wherein the second Venturi gap is defined by a second lineal distance measured between the third opening and a fourth opening into a second discharge body section defining an outlet surface of the second Venturi gap, the fourth opening being larger than the third opening;
wherein the second Venturi gap has a second offset, the second offset being the difference in the size of the third opening and the fourth opening; and
at least one body suction port in fluid communication with the first Venturi gap and the second Venturi gap;
wherein the first offset is smaller than the second offset.

2. The evacuator of claim 1 , further comprising at least one additional secondary Venturi gap located in the diverging discharge section downstream of the second Venturi gap.

3. The evacuator of claim 1 , further comprising a fletch insert positioned within the converging motive section of the body of the evacuator.

4. The evacuator of claim 3 , wherein the fletch insert extends along a central axis of symmetry of the evacuator.

5. The evacuator of claim 3 , wherein the fletch insert defines a tapered portion, and wherein the fletch insert gradually tapers off into a point along the tapered portion.

6. The evacuator of claim 3 , wherein the fletch insert defines a tapered portion, and wherein the fletch insert gradually tapers off into a chamfered edge along the tapered portion.

7. The evacuator of claim 6 , wherein the tapered portion of the fletch insert is shaped as an airfoil.

8. The evacuator of claim 3 , wherein the fletch insert is constructed of plastic.

9. The evacuator of claim 1 , further comprising at least one suction port that fluidly connects the at least one body suction port of the evacuator with a vacuum consuming device, wherein the at least one suction port includes a recess sized and shaped to receive a mating section of the body of the evacuator.

10. The evacuator of claim 9 , further comprising at least one check valve fluidly connected to the first Venturi gap and the at least one suction port and the second Venturi gap and the at least one suction port, the at least one check valve compressed between a recess of the at least one suction port and the mating section of the body of the evacuator such that an outer periphery of the at least one check valve creates a substantially fluid-tight seal between the body of the evacuator and the at least one suction port.

11. The evacuator of claim 10 , wherein the at least one check valve defines a first flap that corresponds to and is fluidly connected to the first Venturi gap and a second flap that corresponds to and is fluidly connected to the second Venturi gap.

12. The evacuator of claim 10 , wherein the first flap and the second flap are each bendable about a hinge.

13. The evacuator of claim 1 , further comprising:
a first suction port in fluid communication with the first Venturi gap, the first suction port sealingly connected to a top surface of the housing;
a first check valve element disposed between the top surface of the housing and the first suction port;
a second suction port in fluid communication with the second Venturi gap, the second suction port sealingly connected to a bottom surface of the housing;
a second check valve element disposed between the bottom surface of the housing and the second suction port;
wherein the first Venturi gap is shaped to generate a higher suction vacuum than the second Venturi gap, and the second Venturi gap is shaped to generate a higher suction flow rate than the first Venturi gap.

14. The evacuator of claim 13 , wherein the first check valve element and the second check valve element each include a first section and a plurality of tabs extending from the first section in a direction transverse to a longitudinal axis of the first section.

15. The evacuator of claim 14 , wherein each of the plurality of tabs of both the first check valve element and the second check valve element extend from one side of the first section or from both sides of the first section, and wherein one of the plurality of tabs is aligned with the first Venturi gap and another one of the plurality of tabs is aligned with the second Venturi gap.

16. The evacuator of claim 14 , wherein the first section of both the first check valve element and second check valve element is generally rigid, and the plurality of tabs are elastically flexible relative to the first section to move each of the plurality of tabs from a closed position to an open position.

17. The evacuator of claim 1 , further comprising:
a plurality of additional Venturi gaps bisecting the diverging discharge section downstream of the second Venturi gap;
wherein the at least one body suction port comprises:
a first suction piece defining a first suction port passageway is sealingly connected to a first portion of a top surface of the housing, wherein the first suction port passageway is in fluid communication with a first suction port which is in fluid communication with the first Venturi gap and a second suction port in fluid communication with the second Venturi gap;
a second suction piece defining a second suction port passageway is sealingly connected to a second portion of the top surface of the housing, wherein the second suction port passageway is in fluid communication with the plurality of additional Venturi gaps;

wherein the first suction piece and the second suction piece fluidly separate the first suction port and the second suction port for connection to different devices requiring vacuum; and
a check valve element disposed between the first portion of the top surface of the housing and the first suction piece and between the second portion of the top surface of the housing and the second suction piece;
wherein the first Venturi gap is shaped to generate a higher suction vacuum than one of the plurality of additional Venturi gaps and the one of the plurality of additional Venturi gaps is shaped to generate a higher suction flow rate than the first Venturi gap; wherein the first lineal distance (L 1 ) and/or the first offset are smaller than a lineal distance and/or an second offset of the one of the plurality of additional Venturi gaps.

18. The evacuator of claim 17 , wherein the first check valve element includes a first section and a plurality of tabs extending from the first section in a direction transverse to a longitudinal axis of the first portion.

19. The evacuator of claim 18 , wherein each of the plurality of tabs of the first check

Assignees

• Fletcher David E
• Graichen Brian M
• Miller James H
• Bravo Rex
• Gilmer Matthew C
• Hampton Keith
• Niedert Andrew D
• Vashuk Denis
• Dayco Ip Holdings Llc

Inventors

• Fletcher David E
• Graichen Brian M
• Miller James H
• Bravo Rex
• Gilmer Matthew C
• Hampton Keith
• Niedert Andrew D
• Vashuk Denis

Classifications

• F04F5/00

  Jet pumps, i.e. devices in which flow is induced by pressure drop caused by velocity of another fluid flow (diffusion pumps F04F9/00; combination of jet pumps with pumps of other than jet type F04B; use of jet pumps for priming or boosting non-positive-displacement pumps F04D) · CPC title

• F02M35/10157 Primary

  Supercharged engines · CPC title

• F04F5/467 Primary

  with a plurality of nozzles arranged in series · CPC title

• F04F5/20

  for evacuating · CPC title

• F04F5/46

  Arrangements of nozzles · CPC title