Flow control device
View Patent ↗A flow restrictor for use in a cooling system of an internal engine comprises a housing enclosing an elongate body, a number of alternating first and second circumferentially extending passages formed in the elongate body. Each first passage is separated from a respective adjacent second passage by a respective land and at least one transfer passage extending across each land so as to connect the first and second passages on each side of the land and provide a significant loss in fluid momentum.
1. A flow restrictor for use in a cooling system of an internal engine comprising a restrictor housing and an elongate plastic restrictor body fitted inside the restrictor housing, the restrictor body having a number of alternating first and second circumferentially extending passages formed therein, each first passage being separated from a respective adjacent second passage by a respective land and first and second transfer passages connecting the first and second passages on each side of the land to an internal swirl chamber used to produce a momentum loss as the coolant is transferred through the swirl chamber.
2. A flow restrictor as claimed in claim 1 wherein each first transfer passage is an inlet passage through which fluid flows from one of the circumferentially extending passages into the swirl chamber.
3. A flow restrictor as claimed in claim 2 wherein each inlet passage is arranged tangentially with respect to the swirl chamber with which it cooperates so as to generate a circulatory flow within the swirl chamber.
4. A flow restrictor as claimed in claims 1 wherein the second transfer passage is an outlet passage to transfer fluid from the swirl chamber to a circumferentially extending passage.
5. A flow restrictor as claimed in claim 2 wherein the second transfer passage is an outlet passage to transfer fluid from the swirl chamber to a circumferentially extending passage and wherein each swirl chamber has a large diameter portion with which at least one inlet transfer passage cooperates and a small diameter portion with which at least one outlet transfer passage cooperates.
6. A flow restrictor as claimed in claim 1 wherein the flow restrictor body includes a number of swirl chambers spaced out along its length.
7. A flow restrictor as claimed in claim 2 wherein the second transfer passage is an outlet passage to transfer fluid from the swirl chamber to a circumferentially extending passage.
8. A flow restrictor as claimed in claim 3 wherein the second transfer passage is an outlet passage to transfer fluid from the swirl chamber to a circumferentially extending passage.
9. A flow restrictor as claimed in claim 3 wherein the second transfer passage is an outlet passage to transfer fluid from the swirl chamber to a circumferentially extending passage and wherein each swirl chamber has a large diameter portion with which at least one inlet transfer passage cooperates and a small diameter portion with which at least one outlet transfer passage cooperates.
10. A flow restrictor as claimed in claim 2 wherein the flow restrictor body is a single piece body and includes a number of swirl chambers spaced out along its length.
11. A flow restrictor as claimed in claim 1 wherein the restrictor body includes a pair of half portions joined along one edge by a flexible hinge.