New energy powertrain cooling structure

Abstract

The present invention discloses a new energy powertrain cooling structure, wherein one end of a first intermediate connecting portion is connected to a first groove, and one end of a second intermediate connecting portion is connected to a second groove; a third groove having an inlet and an outlet and a labyrinth structure is arranged on the axial end surface of the inner cooling sleeve facing the common portion, and the other end of the first intermediate connecting portion is connected to the inlet of the third groove, and the other end of the second intermediate connecting portion is connected to the outlet of the third groove; after the inner cooling sleeve is matched with the outer cooling sleeve, the first groove is combined with the inner wall surface of the inner cooling sleeve to form an input cooling channel, the second groove is combined with the inner wall surface of the inner cooling sleeve to form an output cooling channel, the inner cooling sleeve is matched with the common portion to form a common portion cooling channel, and the intermediate connecting portion is combined with the inner wall surface of the inner cooling sleeve to form a cooling connecting channel connecting the common portion cooling channel with the input cooling channel and the output cooling channel. The present invention has the advantage of improving cooling efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile transmissions, and in particular to a new energy powertrain cooling structure. Background Art

[0002] New energy powertrain is the future development trend of the automotive industry. In the hybrid products of motor + controller + transmission and the three-in-one pure electric system of reducer + motor + controller, the motor and transmission (or reducer) both generate heat, and the system heat dissipation structure has a great impact on the motor performance and transmission lubrication.

[0003] In the existing common power system structure, there is a problem that the transmission end generates a lot of heat due to the clutch and the transmission oil temperature is high, and an external oil cooler is needed to cool the lubricating oil, which results in high overall cost.

[0004] To solve the above problems, the currently commonly used transmission lubricating oil cooling solution is to add an oil cooler. Summary of the invention

[0005] The invention provides a new energy powertrain cooling structure capable of improving cooling efficiency.

[0006] The technical solution to achieve the above purpose is as follows:

[0007] A new energy powertrain cooling structure includes a transmission housing and a motor housing. After one end of the transmission housing is connected to one end of the motor housing, a common portion is formed between the transmission housing and the motor housing. The motor housing includes an outer cooling sleeve and an inner cooling sleeve located in an inner cavity of the outer cooling sleeve. A first groove and a second groove are provided on the outer circumferential surface of the inner cooling sleeve. An intermediate connecting portion is also provided on the outer circumferential surface of the inner cooling sleeve. The intermediate connecting portion includes a first intermediate connecting portion and a second intermediate connecting portion, wherein one end of the first intermediate connecting portion is connected to the first groove, and one end of the second intermediate connecting portion is connected to the second groove.

[0008] A third groove having an inlet and an outlet and having a labyrinth structure is provided on the axial end surface of the inner cooling sleeve facing the common part, the other end of the first intermediate connecting part is connected to the inlet of the third groove, and the other end of the second intermediate connecting part is connected to the outlet of the third groove;

[0009] After the inner cooling sleeve and the outer cooling sleeve are matched, the first groove is combined with the inner wall surface of the inner cooling sleeve to form an input cooling channel, the second groove is combined with the inner wall surface of the inner cooling sleeve to form an output cooling channel, the inner cooling sleeve and the common part are matched to form a common part cooling channel, and the intermediate connecting part is combined with the inner wall surface of the inner cooling sleeve to form a cooling connecting channel connecting the common part cooling channel with the input cooling channel and the output cooling channel.

[0010] The present invention has the following advantages:

[0011] 1. Since the present invention forms channels for cooling medium to flow in the motor housing and the common part between the motor housing and the transmission housing, and these channels are interconnected, the present invention can simultaneously take away the heat from the motor and a part of the transmission, thereby improving the overall heat dissipation performance of the powertrain.

[0012] 2. Since the present invention sets the cooling structure as a dual-channel structure, the cooling medium area is increased while the heat dissipation contact area is increased, thereby enhancing the heat dissipation capacity of the motor. The better the heat dissipation capacity, the less power reduction will occur when the motor is running at peak value.

[0013] 3. The heat dissipation ribs enhance the heat dissipation capacity of the transmission end. When the motor cooling system and the transmission heat dissipation ribs take away enough transmission heat, the transmission oil cooler can even be eliminated to save costs.

[0014] In summary, compared with the prior art, the present invention enhances the heat dissipation capacity of the powertrain by increasing the heat dissipation contact area and the coolant area. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a cross-sectional view of the cooling structure of the new energy powertrain.

[0016] Figure 2 It is a schematic diagram of the combination of the inner cooling sleeve and the transmission housing.

[0017] Figure 3 Schematic diagram of the external structure of the inner cooling sleeve.

[0018] Figure 4 It is a cross-sectional view of the inner cooling sleeve;

[0019] Figure 5 for Figure 3 Left view of .

[0020] Figure 6 for Figure 1 Side view of.

[0021] Figure 7 Schematic diagram of the heat dissipation rib.

[0022] 1 is the transmission case, 2 is the common part, 3 is the outer cooling sleeve, 4 is the inner cooling sleeve, 5 is the first groove, 6 is the second groove, 7 is the third groove, 7a is the inlet, 7b is the outlet, 8 is the heat dissipation rib plate, 9 is the oil collecting groove, 10 is the end face of the bearing hole, 11 is the rear end cover case surface, A is the input cooling channel, B is the output cooling channel, C is the common part cooling channel, and D is the cooling connecting channel. DETAILED DESCRIPTION

[0023] Combine the following Figures 1 to 7 The present invention will be described in detail.

[0024] The new energy powertrain cooling structure of the present invention includes a transmission housing 1 and a motor housing. After one end of the transmission housing 1 is connected to one end of the motor housing, a common part 2 is formed between the transmission housing 1 and the motor housing. The motor housing includes an outer cooling sleeve 3 and an inner cooling sleeve 4 located in the inner cavity of the outer cooling sleeve 3.

[0025] The outer circumferential surface of the inner cooling sleeve 4 is provided with a first groove 5 and a second groove 6. The outer circumferential surface of the inner cooling sleeve 4 is also provided with an intermediate connecting portion, which includes a first intermediate connecting portion and a second intermediate connecting portion, wherein one end of the first intermediate connecting portion is connected to the first groove 5, and one end of the second intermediate connecting portion is connected to the second groove 6.

[0026] A third groove 7 having an inlet 7a and an outlet 7b and having a labyrinth structure is provided on the axial end surface of the inner cooling sleeve 4 facing the common part 2; the other end of the first intermediate connecting part is connected to the inlet 7a of the third groove 7; and the other end of the second intermediate connecting part is connected to the outlet 7b of the third groove 7.

[0027] After the inner cooling sleeve 4 is matched with the outer cooling sleeve 3, the first groove 5 is combined with the inner wall surface of the inner cooling sleeve 4 to form an input cooling channel A, the second groove 6 is combined with the inner wall surface of the inner cooling sleeve 4 to form an output cooling channel B, and the inner cooling sleeve 4 is matched with the common part 2 to form a common part cooling channel C, and the intermediate connecting part is combined with the inner wall surface of the inner cooling sleeve 4 to form a cooling connecting channel D connecting the common part cooling channel C with the input cooling channel A and the output cooling channel B.

[0028] The above-mentioned input cooling channel A, output cooling channel B, and cooling connecting channel D cool the internal structure of the motor (such as the stator) respectively, while the common cooling channel C cools the internal structure of the motor (such as the bearing supporting the rotor) on the one hand, and can take away the heat from the transmission housing 1 on the other hand. Therefore, the cooling structure formed by the input cooling channel A, output cooling channel B, cooling connecting channel D, and common cooling channel C can cool the motor and the transmission respectively, so that the cooling efficiency of the new energy powertrain is improved. In addition, the above-mentioned cooling structure is a dual-channel structure, that is, whether on the motor housing or at the common part 2, there are input and output channels for the cooling medium. Obviously, the dual-channel structure can further improve the cooling efficiency and improve the heat dissipation efficiency of the new energy powertrain.

[0029] The outer cooling sleeve 3 is integrally formed with the transmission housing 1, and the inner cooling sleeve 4 is welded to the transmission housing 1. The cast inner cooling sleeve 4 is installed in the outer cooling sleeve 3, and the bearing hole end face 10 and the outer cooling sleeve 3 and the rear end cover joint surface 11 are sealed by stir friction welding, or the two are sealed by a sealing ring. After the two are assembled, the inner diameter of the inner cooling sleeve 4 and the bearing hole and other positions are processed.

[0030] The first groove 5 and the second groove 6 are alternately spirally arranged on the outer circumference of the inner cooling sleeve 4, and the input cooling channel A and the output cooling channel B are both spiral channels. The first groove 5 and the second groove 6 have the same area for the cooling medium to flow, that is, the first groove 5 and the second groove 6 have the same size, that is, the spiral length, pitch P, water channel cross-section length a, and width b of the first groove 5 and the second groove 6 are the same. Since the present invention adopts a dual-channel structure to increase the number of cooling channels, the heat dissipation area is increased compared to the heat dissipation area of ​​a single water channel.

[0031] The transmission case 1 also includes a heat dissipation rib plate 8 disposed inside the transmission case 1, and an oil collecting groove 9 is disposed on the heat dissipation rib plate 8. During processing, the heat dissipation rib plate 8 is first stamped into shape by a stamping process, and the transmission case 1 is cast and then the two are welded together. Alternatively, the heat dissipation rib plate 8 is first stamped into shape, and when the transmission case 1 is cast, the stamped heat dissipation rib plate 8 is placed in the mold to cast the two into one piece.

[0032] The cooling structure of the new energy powertrain of the present invention is to increase the thermal contact area and the coolant area to enhance the heat dissipation capacity. The heat flux density calculation formula is q=Φ / X, where Φ is the heat flux and X is the cross-sectional area in the heat conduction direction.

[0033] When the cooling medium passes through the cooling structure formed by the input cooling channel A, the cooling connecting channel D, the common cooling channel C, and the output cooling channel B, the heat removal capacity calculation formula is P=h×Y×Δt, where h is the heat transfer coefficient, Y is the area of ​​the cooling medium flowing through the cooling circuit, and Δt is the temperature difference between water and the pipeline.

[0034] The heat transfer coefficient calculation formula is h=Nu×α / De, where α is the thermal conductivity of the coolant, Nu is the Nusselt number, and De is the equivalent diameter. The equivalent diameter calculation formula is De=4×Y / U=(4ab) / [2×(a+b)], where a and b are the length and width of the input cooling channel A, the cooling connecting channel D, the common cooling channel C, and the output cooling channel B, respectively. U is the wetted circumference of the water channel. The Nusselt number calculation formula is , where Re is the Reynolds number, Pr is the Prandtl number, and ɛr is the spiral pipe correction coefficient.

[0035] For the same volume of powertrain, when the flow rate of the cooling medium entering the cooling structure is 8L / min, the cooling structure of the present invention can take away 4813W of heat according to the above calculation formula, and the cooling structure with the same spiral length, pitch, etc. and a single channel that is not extended to the bottom (i.e., there is no common cooling channel C) can take away 3244W of heat. According to the calculation, the cooling structure of the new energy powertrain of the present invention has the function of increasing the cooling medium area and the heat dissipation area to enhance its heat dissipation capacity.

[0036] Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention to illustrate the technical solutions of the present invention, rather than limiting them, and certainly not limiting the patent scope of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. In addition, the direct or indirect application of the technical solutions of the present invention in other related technical fields is also included in the patent protection scope of the present invention.

Claims

1. A new energy powertrain cooling structure, comprising a transmission housing (1) and a motor housing, wherein after one end of the transmission housing (1) is connected to one end of the motor housing, a common portion (2) is formed between the transmission housing (1) and the motor housing, and the motor housing comprises an outer cooling sleeve (3) and an inner cooling sleeve (4) located in an inner cavity of the outer cooling sleeve (3), characterized in that: The outer circumferential surface of the inner cooling sleeve (4) is provided with a first groove (5) and a second groove (6), and the outer circumferential surface of the inner cooling sleeve (4) is also provided with an intermediate connecting portion, the intermediate connecting portion comprising a first intermediate connecting portion and a second intermediate connecting portion, wherein one end of the first intermediate connecting portion is connected to the first groove (5), and one end of the second intermediate connecting portion is connected to the second groove (6); A third groove (7) having an inlet (7a) and an outlet (7b) and having a labyrinth structure is provided on the axial end surface of the inner cooling sleeve (4) facing the common portion (2); the other end of the first intermediate connecting portion is connected to the inlet (7a) of the third groove (7); and the other end of the second intermediate connecting portion is connected to the outlet (7b) of the third groove (7); After the inner cooling sleeve (4) and the outer cooling sleeve (3) are matched, the first groove (5) is combined with the inner wall surface of the inner cooling sleeve (4) to form an input cooling channel (A), the second groove (6) is combined with the inner wall surface of the inner cooling sleeve (4) to form an output cooling channel (B), the inner cooling sleeve (4) is matched with the common part (2) to form a common part cooling channel (C), and the intermediate connecting part is combined with the inner wall surface of the inner cooling sleeve (4) to form a cooling connecting channel (D) connecting the common part cooling channel (C) with the input cooling channel (A) and the output cooling channel (B).

2. The cooling structure of the new energy powertrain according to claim 1 is characterized in that: The first groove (5) and the second groove (6) are arranged on the outer peripheral surface of the inner cooling sleeve (4) in an alternating spiral manner, and the input cooling channel (A) and the output cooling channel (B) are both spiral channels.

3. The cooling structure of the new energy powertrain according to claim 1, characterized in that: The outer cooling sleeve (3) is integrally formed with the transmission housing (1), and the inner cooling sleeve (4) is welded to the transmission housing (1).

4. The new energy powertrain cooling structure according to any one of claims 1 to 3, characterized in that: It also includes a heat dissipation rib plate (8) arranged inside the transmission housing (1), and an oil collecting groove (9) is provided on the heat dissipation rib plate (8).

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