Combination replacement cartridge and electric drive system

Abstract

The invention relates to a combination exchangeable cartridge (1) for a cooling and lubricant supply device of an electric drive system. The invention is characterized in that a molecular sieve is arranged in a first cartridge area (2) and a bed of granules is arranged in a second cartridge area (3), wherein the first cartridge area (2) can be arranged upstream of the second cartridge area (3) in the direction of flow of the cooling and lubricating medium. The invention further relates to an electric drive system.

Description

[0001] The invention relates to a combination interchangeable cartridge. The invention also relates to an electric drive system with a combination interchangeable cartridge.

[0002] Electric drive systems have electric drivetrains that require gear oils. Such gear oils contain sulfur-containing additive components that are subject to aging. This aging process can be caused, for example, by temperature, oxidation, or chemical reactions. During the aging process, the individual components of the gear oil decompose, forming short-chain or low-molecular-weight sulfur-containing compounds, such as sulfides, disulfides, hydrogen sulfide, sulfites, sulfonates, SO2, and the like. These compounds are sometimes highly volatile and sometimes gaseous.

[0003] The resulting compounds have an unpleasant odor reminiscent of "rotten eggs." Furthermore, the risk of copper corrosion and the formation of copper sulfide bridges increases. This leads to an increase in the concentration of dissolved copper ions in the transmission oil, which can potentially cause short circuits in electronic circuits. The dissolved copper ions increase the electrical conductivity of the lubricating medium and have a catalytically accelerating effect on the aging processes described above. All of this is particularly undesirable in electric drivetrains.

[0004] Another disadvantage is that water can dissolve in the gear oil with increasing age. This can increase electrical conductivity and simultaneously increase the risk of corrosion for all involved metallic surfaces. Another disadvantage is that the lubricity of the fluid can be reduced, which can impair the defined friction properties.

[0005] Interactions between the sulfur-containing decomposition products and the dissolved water also affect the electrical components and circuits. With the various drive concepts, this results in a reduction in comfort and, in extreme cases, even failure of the unit. Therefore, serious consequences for functionality can be expected, especially with electric drive concepts.

[0006] The aim is therefore to remove the sulfur-containing decomposition products and the dissolved water from the gear oil so that the associated risks can be minimized.

[0007] For example, DE10 2014 016 796A1 and DE 20 2009 007 048 U1 describe mechanical filter systems for filtering particles from oil and thus extending the service life of the oils. Filtering water is hardly possible in these cases.

[0008] The object of the present invention is to provide a combination interchangeable cartridge and an electric drive system with such a combination interchangeable cartridge, which overcomes the aforementioned disadvantages.

[0009] According to the invention, this object is achieved by a combination interchangeable cartridge having the features of claim 1, and in particular in the characterizing part of claim 1. Advantageous embodiments and further developments emerge from the dependent claims. An electric drive system with such a combination interchangeable cartridge is also described.

[0010] In the core of the combination exchange cartridge according to the invention, a molecular sieve is arranged in a first cartridge area and a bed of granules is arranged in a second cartridge area, wherein the first cartridge area can be arranged upstream of the second cartridge area in the flow direction of the coolant and lubricant.

[0011] According to the invention, an exchangeable combination cartridge can therefore be provided which can be exchanged or inserted into a transmission oil circuit, for example in service.

[0012] The combination cartridge is designed for a coolant and lubricant supply system of an electric drive system. Such a combination cartridge can, in particular, remove the described pollutants from the transmission lubricant. Advantageously, the combination cartridge is first equipped with a molecular sieve for water removal, followed by a granulate arranged downstream of it. This flow direction prevents H2O from interfering with the reaction of the H2S with the granulate, especially a Ca compound.

[0013] Preferably, a partition wall can be arranged between the first cartridge region and the second cartridge region, wherein the partition wall is made of a material through which flow can occur. The partition wall can be designed, for example, as a sieve and can be either in the form of a plane or, for example, in the form of a funnel. The partition wall is therefore designed to separate the cartridge regions. The sieve can be a ceramic or a metallic sieve. The pore width is preferably smaller than the minimum particle diameter of the reactive components in the two cartridge regions. In particular, the pore width is less than 3 mm. This makes it possible to continue to provide maximum positivity in order to minimize pressure loss during flow. Alternatively, the partition wall can also be made of a flexible, in particular metallic, wire mesh. In particular, the mesh width here is a maximum of 3 mm.

[0014] According to a very advantageous development of the concept, an inlet area of ​​the combination cartridge, viewed in the flow direction of the coolant and lubricant, can be designed as a diffuser, and an outlet area of ​​the combination cartridge, viewed in the flow direction of the coolant and lubricant, can be designed as a confuser. This allows for optimized flow into and out of the cartridge. The dimensional ratio of the length to the diameter of the diffuser or confuser can be optimally designed according to the flow conditions. For example, the ratio can be 3 to 2.

[0015] According to an advantageous embodiment, the granulate can contain calcium. Another advantageous embodiment can provide for the granulate substance to contain CaO. For example, CaC2 can also be used.

[0016] The invention further relates to an electric drive system with a coolant and lubricant supply device, which has a pump by means of which coolant and lubricant are conveyed through the coolant and lubricant supply device.

[0017] It is proposed that a combination exchangeable cartridge according to the invention is included, which has a first cartridge region in which a molecular sieve is arranged and a second cartridge region in which a bed of granules is provided, wherein the first cartridge region is arranged upstream of the second cartridge region in the flow direction of the coolant and lubricant.

[0018] According to a very advantageous development of the idea, it can be provided that the granulate substance contains CaO, with at least 0.5 g of CaO per liter of lubricant being provided.

[0019] According to an advantageous embodiment, it can be provided that the combination cartridge is arranged upstream of a cooling device and downstream of the pump in the lubricant supply device.

[0020] A further advantageous embodiment may provide for a cartridge lid, a cartridge base, and a partition between the first cartridge region and the second cartridge region, each configured as a metal sieve. The cartridge lid, the cartridge base, and the partition may be configured as described above, for example, as a wire mesh or as a sieve, in particular as a metallic or ceramic sieve.

[0021] Furthermore, the same features and advantages apply to the electric drive system as already described for the combination exchange cartridge.

[0022] Further advantageous embodiments of the combination exchange cartridge according to the invention and of the electric drive system also emerge from the exemplary embodiment which is described in more detail below with reference to the figures.

[0023] Showing: Fig. 1 a possible embodiment of a combination exchange cartridge; and Fig. 2 another possible embodiment of a combination exchange cartridge.

[0024] In the presentation of the Fig. Figure 1 shows a possible embodiment of the combination cartridge 1. This comprises a first cartridge section 2 and a second cartridge section 3. A partition wall 4 is provided between the two cartridge sections. Furthermore, the combination cartridge 1 has a cartridge base 8 and a cartridge cover 7. The flow direction is indicated by the arrow.

[0025] The molecular sieve can be used to remove water dissolved in polar media as well as volatile gaseous components. A 4 Å molecular sieve is suitable for drying most non-polar liquid hydrocarbons: 4A (4 Å pore size): Adsorbs H2O, CO2, SO2, H2S,

[0026] For the quantitative design of molecular sieve requirements, the following ratios can be considered: 10-50 g of 4A molecular sieve, preferably 20-30 g, are used per liter of oil. In one possible design, the molecular sieve can be designed as a sphere or pellet bed with a sphere / pearl size of 3-5 mm.

[0027] The second cartridge section 3 can serve as a sulfur trap. This is particularly advantageous because the use of substances that can form a genuine chemical bond with the sulfur-containing pollutants (forming sulfides, disulfides, sulfites, sulfates, or sulfonates) is also important. Preferred reagents for this purpose are calcium oxides, carbides, hydroxides, and carbonates. Other alkaline earth elements such as strontium, barium, or zinc are also conceivable.

[0028] An example reaction of CaO with H2S can be described as CaO + H2S → CaS + H2O. The resulting process water can be removed from the oil cycle using the molecular sieves described above.

[0029] The following proportions can be used: For the sulfur scavenger, 0.5-2 g of CaO per liter of oil, preferably 1-1.5 g, can be used. Per liter of oil, 10-50 g of molecular sieve, preferably 20-30 g, can be used.

[0030] In one possible embodiment, the reactive substances can be embodied in small molded bodies, such as spheres, pellets, beads, and the like. In one embodiment, lumpy CaO with a grain size of 3-20 mm can be used. Alternatively, a porous ceramic molded body, particularly as a solid extrudate made from the reactive components, is also conceivable.

[0031] A further embodiment of the device 1 is shown in Fig. 2. The same components are provided with the same reference numerals, so that no further details are required. In contrast to Fig. 1, an inlet area 5 and an outlet area 6 are funnel-shaped, i.e., designed as a diffuser or confuser. Furthermore, the partition wall 4 is funnel-shaped, so that the transition area from the first cartridge area 2 to the second cartridge area 3 is designed differently.

[0032] Of course, the described versions of the combination exchange cartridge 1 can be used in the Fig. 1 and Fig. 2 can also be combined with each other, creating various possibilities. For example, the inlet area 5 and the outlet area 6 can also be combined with the design from Fig. 1 can be combined.

[0033] The illustrated combination exchange cartridge 1 can be arranged, in particular, in front of a transmission cooler. This can be a service component that is located outside the electric drive train, in particular, accessible and replaceable. For example, it can be attached with quick-release fasteners.

[0034] The housing of the combination exchange cartridge 1 can be made of metal or of a temperature-resistant plastic.

[0035] A type of replaceable cartridge can therefore be provided that can be replaced during a vehicle service. In the case of molecular sieves, variants with color indicators indicating the water fill level are also conceivable. Replacement intervals for the desulfurization components can be designed according to operation. In another embodiment, the functionality of the cleaning unit can be monitored by measuring the electrical conductivity of the transmission oil. Both water and other aging processes can increase conductivity.

[0036] According to the invention, the water that has dissolved in the oil and harmful sulfur compounds that form from the additive due to oil aging can be removed. This prevents a deterioration in tribological properties and an increased risk of corrosion, with a consequent deterioration in electrical properties. By permanently removing aging-related pollutants and dissolving the water, the metallic surfaces can be optimally protected against corrosion. In addition, an increase in electrical conductivity in the transmission oil and the formation of copper sulfide bridges can be prevented. Advantageously, this provides protection against electrical short circuits in the control elements or electrical drive components, thus preventing serious damage. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2014 016 796A1

[0007] DE 20 2009 007 048 U1

[0007]

Claims

[1] Combination exchange cartridge (1) for a coolant and lubricant supply device of an electric drive system, characterized by in that a molecular sieve is arranged in a first cartridge region (2) and a bed of granules is arranged in a second cartridge region (3), wherein the first cartridge region (2) can be arranged upstream of the second cartridge region (3) in the flow direction of the coolant and lubricant. [2] Combination exchange cartridge (1) according to claim 1, characterized by that a partition wall (4) is arranged between the first cartridge area (2) and the second cartridge area (3), wherein the partition wall (4) is formed from a material through which flow can occur. [3] Combination exchange cartridge (1) according to claim 1 or 2, characterized by that an inlet area (5) of the combination interchangeable cartridge (1) is designed as a diffuser and an outlet area (6) of the combination interchangeable cartridge (1) is designed as a confuser. [4] Combination exchange cartridge (1) according to claim 1, 2 or 3, characterized by that the granules contain calcium. [5] Combination exchange cartridge (1) according to one of claims 1 to 4, characterized by that the granulate substance contains CaO. [6] Electric drive system with a cooling and Lubricant supply device which has a pump by means of which coolant and lubricant are conveyed through the coolant and lubricant supply device, characterized by , that a combination exchangeable cartridge (1) according to one of claims 1 to 5 is included, which has a first cartridge region (2) in which a molecular sieve is arranged and a second cartridge region (3) in which a bed of granules is provided, wherein the first cartridge region (2) is arranged upstream of the second cartridge region (3) in the flow direction of the coolant and lubricant. [7] Electric drive system (1) according to claim 6, characterized by that the granular substance contains CaO, with at least 0.5 g of CaO per liter of lubricant being provided. [8] Electric drive system (1) according to claim 6 or 7, characterized by that the combination exchange cartridge (2) is arranged upstream of a cooling device and downstream of the pump in the lubricant supply device. [9] Electric drive system (1) according to one of claims 6 to 8, characterized by that a cartridge lid (7), a cartridge base (8) and a partition wall (4) between the first cartridge area (2) and the second cartridge area (3) are included, each of which is designed as a metal sieve, metal mesh and / or perforated ceramic body.

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