This application is the U.S. National Phase of PCT Appln. No. PCT/DE2020/100770, filed Sep. 3, 2020, which claims priority from German Patent Application No. 10 2019 123 646.0, filed Sep. 4, 2019, the entire disclosures of which are incorporated by reference herein.
The disclosure relates to a coolant regulator, comprising: a housing having a coolant chamber, a rotary vane arranged in the coolant chamber, a drive shaft leading out of the coolant chamber, which rotates the rotary vane, and a shaft seal which is rotationally fixed relative to the housing and seals the coolant chamber from the surroundings of the coolant regulator, wherein the shaft seal is inserted so as to seal against a housing inner lateral surface of a housing recess and sealingly encloses the drive shaft.
A coolant regulator of this type is used in the cooling circuit of an internal combustion engine in the stepless distribution of the coolant flow over individual sub-circuits and is known, for example, from DE 10 2016 203 070 B3.
Other coolant regulators with shaft seals or a shaft seal are known from DE 10 2014 209 122 A1, DE 10 2014 209 127 A1 and DE 44 34 573 A1.
If the cooling circuit is initially filled under vacuum, the pressure difference between the ambient pressure at the coolant regulator and the negative pressure within the evacuated cooling circuit acts on the end face of the shaft seal that faces away from the coolant chamber. Depending on the surface area, pressure difference and pressing force of the shaft seal, there is a risk that the pressure force corresponding to the pressure difference will shift the shaft seal in the direction of the rotary vane, so that in the worst case the operationally required sealing effect of the shaft seal against the housing inner lateral surface will be irreversibly lost.
It is therefore the object of the disclosure to specify a coolant regulator having improved seal design.
This object is achieved in that an end portion of the shaft seal facing the rotary vane is a circular ring having a bead-shaped cross-section, which circular ring, under elastic deformation of the bead, seals against the housing inner lateral surface on the outer circumference a spreading ring on the inner circumference, which spreading ring, in order to limit an axial and directed toward the rotary vane, is opposite an axial shift of the shaft seal directed toward the rotary vane, is opposite an axial stop which limits the axial shift of the shaft seal to a dimension d<s, wherein the dimension s is the axial distance between the bead center of the undisplaced shaft seal and the opening of the housing recess facing the rotary vane.
The seal design according to the disclosure has the effect that the spreading ring on the one hand holds the bead in elastically deformed sealing contact with the housing inner lateral surface and on the other hand is a comparatively inelastic stop partner of the axial stop. The distance thereof from the spreading ring is dimensioned in such a way that when the coolant regulator is in an evacuated state, the pressure difference acting on the shaft seal cannot displace the shaft seal so far that the axial center of the bead leaves the opening of the housing recess and consequently loses the sealing contact with the housing inner lateral surface.
Advantageous embodiments are provided below and in the claims.
A preferred embodiment of the disclosure is explained in more detail below with reference to the figures. In the figures:
The rotary vane 5 shown in
As is clear when viewed together with
The shaft seal 20 is inserted so as to seal in a housing inner lateral surface 21 of the housing recess in a rotationally fixed and sealing manner, encloses the drive shaft 6 with two sealing lips 22 and 23 and, for the purpose of its sealing attachment in the housing inner lateral surface 21, has an end portion facing the rotary vane 5, which is a circular ring 24 designed with a bead-shaped cross-section. The circular ring 24 encompasses the inner circumference of the spreading ring 19 and seals with the outer circumference of the housing inner lateral surface 21 with elastic deformation of the bead 25. The shaft seal 20 is shown in
The leakage opening 15 penetrating the housing 2 causes the ambient pressure of the coolant regulator 1 to prevail on the rear side 26 of the shaft seal 20 facing away from the rotary vane 5. When it is first installed in the cooling circuit of the internal combustion engine, the cooling circuit and consequently also the coolant chamber 4 are evacuated for the purpose of complete and rapid filling with coolant. The resulting pressure difference between the back 26 of the shaft seal 20 and its front side 27 (facing the rotary vane 5) can lead to a breakaway force on the bead 25 in relation to the housing inner lateral surface 21 being exceeded, and as a result the shaft seal 20 being displaced axially towards the rotary vane 5.
Despite the displacement of the sealing ring, and so as not to impair the sealing contact between the bead 25 and the housing inner lateral surface 21, the potential axial shift is limited to a dimension d. The limitation occurs in that the front side 28 of the spreading ring 19 facing the rotary vane 5 is opposite an axial stop 29 which is part of the rotary vane 5 and is formed here by three projections 30 circumferentially distributed on the rotary vane 5; see
The axial shift is limited to the dimension d<s shown, the dimension s being the axial distance between the bead center of the undisplaced shaft seal 20 and the opening 31 of the housing recess facing the rotary vane 5. This relationship initially means that when the shaft seal 20 is displaced, the axial bead center 25 never leaves the opening 31 and consequently its sealing contact with the housing inner lateral surface 21 remains even when the shaft seal 20 is displaced to the maximum.
In addition, in the present case, the axial shift is limited to the dimension d<s−c, wherein the dimension c is the width of a section 32 of the housing inner lateral surface 21 that widens in diameter towards the rotary vane 5 between a cylindrical section 33 of the housing inner lateral surface 21 and the opening 31 of the housing recess. The dashed line in
In an alternative embodiment that is not shown, the axial shift can be limited by means of a positive (snap) connection of the shaft seal 20 or the spreading ring 19, for example with a peripheral groove in the housing inner lateral surface 21.
Number | Date | Country | Kind |
---|---|---|---|
10 2019 123 646.0 | Sep 2019 | DE | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/DE2020/100770 | 9/3/2020 | WO |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2021/043372 | 3/11/2021 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
20190085987 | Grosskopf | Mar 2019 | A1 |
Number | Date | Country |
---|---|---|
4434573 | Apr 1996 | DE |
102014209122 | Nov 2015 | DE |
102014209127 | Nov 2015 | DE |
102015216867 | Mar 2017 | DE |
102015216867 | Mar 2017 | DE |
102016203070 | Jun 2017 | DE |
202018105090 | Sep 2018 | DE |
202018105090 | Oct 2018 | DE |
202018002099 | Feb 2019 | DE |
202018002099 | Mar 2019 | DE |
Number | Date | Country | |
---|---|---|---|
20220290760 A1 | Sep 2022 | US |