Coolant regulator

Abstract

The invention relates to a coolant regulator (1) comprising: a housing (2) having a coolant chamber (3) and a coolant channel (10 to 15) that opens into the coolant chamber; a rotary slide valve (4) arranged in the coolant chamber; and a seal (18 to 23) having a primary sealing ring (18-1 to 23-1; 18-1), which is acted upon by a spring force so as to sealingly contact the rotary slide valve, and a secondary sealing ring (18-2 to 23-2), which is axially clamped between the housing and the primary sealing ring, thereby being elastically deformed, and which generates the spring force acting on the primary sealing ring and seals the coolant chamber against the coolant channel. The clamping of the secondary sealing ring against the housing is supposed to be permeable to the coolant, wherein the coolant passage leads to a radially splayed, peripheral sealing lip (26) of the secondary sealing ring, said sealing lip being in sealing contact with the housing.

Description

[0001] Coolant realiser

[0002] The invention relates to a coolant regulator comprising a housing with a coolant chamber and a coolant channel opening therein and a rotary slide valve arranged in the coolant chamber as well as a seal with a primary sealing ring which is spring-loaded in sealing contact with the rotary slide valve, and a secondary sealing ring which is axially clamped between the housing and the primary sealing ring under elastic deformation and generates the spring force acting on the primary sealing ring and seals the coolant chamber against the coolant channel.

[0003] Coolant regulators are used, for example, in the cooling circuit of an internal combustion engine or a battery-electric motor vehicle. The coolant flows through the respective subcircuits can be adjusted continuously or in stages depending on the rotary valve position. The sealing effect of the seal on the rotary valve is typically based on a metal molded spring, usually clamped as a preloaded wave spring between the seal and the housing, pressing the seal against the rotary valve.

[0004] Alternative designs are known from the patent literature in which a separate spring is omitted and the spring force is generated by the elastic deformation of the seal itself. Examples include DE 10 2016 205 750 A1 with a one-piece seal, the generic EP 3 730 823 A1 with a two-piece seal, and DE 102020207 303 A1 with a three-piece seal.

[0005] The present invention is based on the object of providing a coolant regulator of the type mentioned above with an improved sealing construction.

[0006] This object is achieved by clamping the secondary sealing ring against the housing so that it is permeable to the coolant, whereby the coolant passage leads to a radially splayed, circumferential sealing lip of the secondary sealing ring, which is in sealing contact with the housing. With this design, the coolant pressure acts directly on the sealing lip and consequently acts as a contact force amplifier in the sealing contact between the secondary sealing ring and the housing. Furthermore, the coolant pressure also acts indirectly, namely via the secondary sealing ring on the primary sealing ring and consequently also as a contact force amplifier in the sealing contact between the primary sealing ring and the rotary valve. Advantageous embodiments of the invention are the subject of the dependent patent claims.

[0007] Further features of the invention will become apparent from the following drawings illustrating exemplary embodiments of the invention. Unless otherwise stated, identical or functionally equivalent components or features are provided with the same reference numerals. They show:

[0008] Figure 1 shows a coolant regulator according to the invention in a perspective top view;

[0009] Figure 2 shows the coolant regulator in longitudinal section through its rotary valve;

[0010] Figure 3 shows an enlarged section of the longitudinal section according to Figure 2;

[0011] Figure 4 is a perspective top view of the openings of the coolant channels in the coolant chamber of the coolant regulator;

[0012] Figure 5 shows one of the inlet channels with associated seal according to Figure 4 in an enlarged longitudinal section;

[0013] Figure 6 shows one of the outlet channels with associated seal according to Figure 4 in an enlarged longitudinal section;

[0014] Figure 7 shows the seal according to Figure 5 in a perspective top view;

[0015] Figure 8 shows the seal according to Figure 7 in a perspective view from below;

[0016] Figure 9 shows the seal according to Figure 7 in longitudinal section;

[0017] Figure 10 shows the primary sealing ring of the seal according to Figure 7 in perspective top view;

[0018] Figure 11 shows the primary sealing ring of the seal according to Figure 7 in a perspective view from below;

[0019] Figure 12 shows the secondary sealing ring of the seal according to Figure 7 in a perspective top view; Figure 13 shows the secondary sealing ring of the seal according to Figure 7 in a perspective bottom view;

[0020] Figure 14 shows the seal according to Figure 6 in a perspective top view;

[0021] Figure 15 shows the seal according to Figure 14 in longitudinal section;

[0022] Figure 16 shows the seal according to Figure 14 in a perspective view from below;

[0023] Figure 17 shows a force-displacement diagram with different geometries and elastomer hardnesses of one of the secondary sealing rings as parameters;

[0024] Figure 18 shows a sealing ring according to the invention for a spherical rotary valve.

[0025] Figures 1 and 2 show a coolant regulator 1 of a cooling circuit of a battery-electric vehicle comprising several sub-circuits, in a perspective view and in a longitudinal section, respectively. The coolant regulator 1 comprises a housing 2 with a coolant chamber 3 and a rotary valve 4 arranged therein with a drive pin 5, which is rotated into discrete positions by an electric motor 7 via a transmission gear 6. The coolant regulator 1 further comprises two electric coolant pumps 8 and 9, which pump the coolant through the sub-circuits. Depending on the rotational position of the rotary valve 4, the sub-circuits are either separated from one another or connected to one another.

[0026] As can be seen from a comparison of Figures 3 to 6, coolant channels 10 to 15 run in the housing 2, opening into the coolant chamber 3, which the rotary valve 4 either connects or separates via connecting channels 16, 17 depending on its current rotational position. The coolant channels 10, 12, 13 and 15 are inlet channels through which the coolant flows to the rotary valve 4 according to the flow arrows shown in Figure 4. The coolant channels 11 and 14 are accordingly outlet channels through which the coolant flows away from the rotary valve 4. The openings of the coolant channels 10 to 15 are provided with seals 18 to 23, which on the one hand are in sealing contact with an end face 24 of the rotary valve 4, which is flat in the present embodiment, and on the other hand seal the coolant chamber 3 against the coolant channels 10 to 15.The seals 18 to 23 are each constructed in two parts and comprise a primary sealing ring 18-1 to 23-1 and a secondary sealing ring 18-2 to 23-2. Each secondary sealing ring 18-2 to 23-2 is axially clamped under elastic deformation between the housing 2 and the primary sealing ring 18-1 to 23-1 abutting the end face 24 of the rotary valve 4, thereby generating a spring force that applies spring force to the associated primary sealing ring 18-1 to 23-1 in sealing contact with the rotary valve 4. A separate spring, such as a metallic wave spring, is not provided, in favor of comparatively low component and assembly costs and a correspondingly smaller installation space requirement for the seals 18 to 23.

[0027] The primary sealing rings 18-1 to 23-1 each consist of a thermoplastic material, in this case polyoxymethylene (POM for short), or alternatively polyvinylidene fluoride (PVDF for short). Alternatively, the primary sealing rings 18-1 to 23-1 can consist of a thermoset. The secondary sealing rings 18-2 to 23-2 each consist of an elastomeric material (including thermoplastic elastomers), in this case ethylene propylene diene rubber (EPDM for short). In the present exemplary embodiment, the primary sealing rings 18-1 to 23-1 and the secondary sealing rings 18-2 to 23-2 are manufactured separately from one another and then joined together in a separable manner by simply plugging them together. Alternatively, it is also possible to produce the seals in a two-component injection molding process, whereby the components can be locally bonded to one another, taking into account the required elastic deformability of the secondary sealing rings 18-2 to 23-2.

[0028] As Figures 5 and 6 illustrate using the example of seal 18 on inlet channel 10 and seal 19 on outlet channel 11, respectively, the clamping of each secondary sealing ring 18-2 to 23-2 against the housing 2 is permeable to the coolant. The coolant passage runs between a plurality of projections 25 on a housing-side end section of the secondary sealing ring 18-2 to 23-2 and leads to a circumferential sealing lip 26 of the secondary sealing ring 18-2 to 23-2, which is in sealing contact with the housing 2. The coolant passage can optionally or alternatively be formed by a housing recess (not shown) in the region of the housing-side end section of the secondary sealing ring 18-2 to 23-2.

[0029] In the case of the inlet channels 10, 12, 13 and 15, the secondary sealing ring 18-2 to 23-2 sealingly encloses the primary sealing ring 18-1 to 23-1, wherein the sealing lip 26 is spread radially outward and is in sealing contact with an inner circumferential surface 27 of the inlet channel 10, 12, 13 or 15. In the case of the outlet channels 11 and 14, the primary sealing ring 18-1 to 23-1 sealingly encloses the secondary sealing ring 18-2 to 23-2, wherein the sealing lip 26 is spread radially inward and is in sealing contact with an outer circumferential surface 28 of the outlet channel 11 or 14. The overpressure of the coolant present in the inlet channels 10, 12, 13 and 15 and the negative pressure of the coolant present in the outlet channels 11 and 14 each cause the sealing lip 26 to be pressurized by the pressurized coolant via the coolant passage, so that the radial pressure component increases the sealing contact force between the sealing lip 26 and the housing 2.At the same time, the axial pressure component results in a sealing contact force between the primary sealing ring 18-1 to 23-1 and the rotary valve 4 that exceeds the spring force of the secondary sealing ring 18-2 to 23-2. Of the secondary sealing rings 18-2 to 23-2, only the secondary sealing rings 18-2 and 19-2 are visible in the figures and are provided with their reference numbers.

[0030] Figures 7 to 9 show the seal 18, Figures 10 and 11 its primary sealing ring 18-1, and Figures 12 and 13 its secondary sealing ring 18-2. The seal 18 is structurally identical to the seal 20 and defines a circular flow cross-section. The primary sealing ring 18-1—like all primary sealing rings 18-1 to 23-1—has a substantially L-shaped profile cross-section, and the secondary sealing ring 18-2—like all secondary sealing rings 18-2 to 23-2—has a substantially Y-shaped profile cross-section. The Y-shaped profile cross-section projects with the housing-side end section relative to the L-shaped profile cross-section and has an axially opposite primary sealing ring-side end section which is sealingly enclosed in an axial groove 29, which absorbs the spring force of the secondary sealing ring 18-2, in the L-profile leg of the primary sealing ring 18-1, which here is directed radially outwards.Thus, the secondary sealing ring 18-2 is positively connected to the primary sealing ring 18-1 both radially inside and radially outside. This double positive connection prevents circumferential local radial migration and lifting of the secondary sealing ring 18-2 from the primary sealing ring 18-1, thus preventing higher displacement forces of the seal 18 and / or uncontrolled leakage at the sealing lip 26.

[0031] The double positive connection of the secondary sealing rings 18-2 to 23-2 with the primary sealing rings 18-1 to 23-1 can alternatively be replaced by a material connection produced, for example, in a 2K injection molding process, which is limited approximately to the sealing area at the axial height of the then obsolete axial groove 29.

[0032] As explained in more detail below with reference to Figure 17, in addition to the elastomer material, the number and shape of the projections 25 forming the coolant passage have a significant influence on the spring characteristic of the secondary sealing rings 18-2 to 23-2. The secondary sealing rings 18-2 and 20-2 in this case have eight projections 25 evenly distributed around their circumference, which project essentially in a crenellated, trapezoidal shape. The (circumferential) width of the trapezoids is smaller than the gaps between them that form the coolant passage.

[0033] Figures 14 to 16 show various views of the seal 19 on the outlet channel 11, which is identical in construction to the seal 22 on the outlet channel 14 and defines a non-circular, but rather kidney-shaped flow cross-section. The above statements apply accordingly to the profile cross-sections of the primary sealing ring 19-1 and the secondary sealing ring 19-2, with the L-shaped profile leg of the primary sealing ring 19-1 directed radially inward and the sealing lip 26 spread radially inward.

[0034] The force-displacement diagram shown in Figure 17 illustrates the influence of the elastomer material and the projections 25 on the spring characteristic using the example of the secondary sealing ring 18-2. The spring force F acting on the primary sealing ring 18-1 is shown over the axial deformation path s of the seal 18. The influencing parameters listed in the legend are the Shore hardness of the secondary sealing ring material and the existence of the projections 25: For example, 'S 60 Z' designates the secondary sealing ring 18-2 shown top left in the diagram with the elastomer hardness 60 Shore A and eight projections 25. The secondary sealing rings designated 'S 50', 'S 60' and 'S70', i.e. without the suffix Z, have no projections on the housing-side end section.

[0035] The six spring characteristic curves illustrate that the spring stiffness of the secondary sealing ring 18-2 is significantly influenced not only by the Shore hardness of the elastomer material, but also by the presence of the projections 25. Quantitatively, the smallest possible spring stiffness is preferable so that installation variations in the deformation path s caused by component tolerances are accompanied by the smallest possible variations in the spring force F: If, on the one hand, the spring force is too low due to insufficient elastic deformation, undesirably high internal coolant leakage can occur due to insufficient sealing contact between the primary sealing ring and the rotary valve, especially since the sealing contact force is reduced by the frictional force of the sealing lip 26 of the secondary sealing ring 18-2 sealing with the housing 2.On the other hand, if the spring force is too high, excessive torque is required to rotate the rotary valve 4 due to frictional forces, and consequently, a more powerful and expensive electric motor 7 is required. Furthermore, increased wear in the sealing contact between the primary sealing ring 18-1 and the rotary valve 4 is to be expected. The requirement for the flattest possible spring characteristic led to a preferred secondary sealing ring design with an elastomer hardness of 50 Shore A and the eight projections 25.

[0036] The structural connection of the primary sealing ring 18-1 to 23-1 with the secondary sealing ring 18-2 to 23-2 also has a significant influence on the spring characteristic of the secondary sealing ring 18-2 to 23-2. As shown by way of example for the seal 18 in the three cross-sectional views above the spring characteristic curves, the axial clamping is intended to deform the secondary sealing ring 18-2 in a bulging manner, forming a radial gap 30 with the primary sealing ring 18-1, wherein the radial gap 30 increases with the axial clamping, i.e. the deformation path s.

[0037] Figure 18 shows an alternative embodiment of a coolant regulator according to the invention. In this embodiment, the seal 18' is in sealing contact with the spherical zone 31 of a spherical layer-shaped rotary valve 4' (indicated here by a dashed line), with the contact surface 32 on the primary sealing ring 18-1 being correspondingly spherically shaped.

Claims

Patent claims 1. Coolant regulator (1), comprising a housing (2) with a coolant chamber (3) and a coolant channel (10 to 15) opening into it and a rotary slide valve (4) arranged in the coolant chamber (3) and a seal (18 to 23) with a primary sealing ring (18-1 to 23-1; 18 -1), which is spring-loaded in sealing contact with the rotary slide valve (4), and a secondary sealing ring (18-2 to 23-2), which is axially clamped under elastic deformation between the housing (2) and the primary sealing ring (18-1 to 23-1; 18 -1) and which seals the primary sealing ring (18-1 to 23-1;18-1) and seals the coolant chamber (3) against the coolant channel (10 to 15), characterized in that the clamping of the secondary sealing ring (18-2 to 23-2) against the housing (2) is permeable to the coolant, wherein the coolant passage leads to a radially spread, circumferential sealing lip (26) of the secondary sealing ring (18-2 to 23-2) which is in sealing contact with the housing (2); 2. Coolant regulator (1) according to claim 1, characterized in that the coolant passage runs between projections (25) on a housing-side end portion of the secondary sealing ring (18-2 to 23-2).

3. Coolant regulator (1) according to claim 1 or 2, characterized in that the axial clamping deforms the secondary sealing ring (18-2 to 23-2) to form a radial gap (30) with respect to the primary sealing ring (18-1 to 23-1; 18-1), the radial gap (30) increasing with the axial clamping.

4. Coolant regulator (1) according to one of the preceding claims, characterized in that the secondary sealing ring (18-2 to 23-2) is positively connected to the primary sealing ring (18-1 to 23-1; 18-1) both radially inside and radially outside.

5. Coolant regulator (1) according to claim 4, characterized in that a primary sealing ring-side end portion of the secondary sealing ring (18-2 to 23-2) is received in an axial groove (29) of the primary sealing ring (18-1 to 23-1; 18-1).

6. Coolant regulator (1) according to one of the preceding claims, characterized in that the primary sealing ring (18-1 to 23-1; 18-1) is made of a thermoplastic material and that the secondary sealing ring (18-2 to 23-2) is made of an elastomeric material.

7. Coolant regulator (1) according to one of claims 1 to 6, characterized in that the coolant channel (10, 12, 13, 15) is an inlet channel through which the coolant flows to the rotary slide valve (4), wherein the secondary sealing ring (18-2, 20-2, 21-2, 23-2) surrounds the primary sealing ring (18-1, 20-1, 21-1, 23-1) and the sealing lip (26) is spread radially outwards and is in sealing contact with an inner circumferential surface (27) of the inlet channel.

8. Coolant regulator (1) according to one of claims 1 to 6, characterized in that the coolant channel (11, 14) is an outlet channel through which the coolant flows away from the rotary slide (4), wherein the primary sealing ring (19-1, 22-1) encloses the secondary sealing ring (19-2, 22-2) and the sealing lip (26) is spread radially inward and is in sealing contact with an outer circumferential surface (28) of the outlet channel.

9. Coolant regulator (1) according to one of the preceding claims, characterized by an L-shaped profile cross-section of the primary sealing ring (18-1 to 23-1; 18-1) and a Y-shaped profile cross-section of the secondary sealing ring (18-2 to 23-2).

10. Coolant regulator (1) according to one of the preceding claims, characterized in that the seal (19, 21, 22, 23) defines a non-circular flow cross-section.

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