CN209930084U - Ventilation structure of drive motor and transmission - Google Patents

Abstract

The utility model relates to a new energy automobile technical field discloses the structure of ventilating of driving motor and derailleur, including the connection casing of electric motor rotor axle and motor front end, its characterized in that: a sealing chamber connecting hole B is formed in the connecting shell on the front side of the bearing on the outer side of the motor rotor shaft, the sealing chamber connecting hole B is communicated with a connecting hole D formed in the connecting shell, the upper side of the connecting hole D is communicated with a motor stator outer edge communicating hole A formed in the connecting shell, and a ventilating device C is arranged on the top of the connecting hole D. The utility model discloses have and to reduce sealed room pressure effectively and reduce oil blanket oil leak risk, reduce the inside air pressure of motor simultaneously, reduce effects such as motor pivoted friction loss.

Description

Ventilation structure of drive motor and transmission

technical field

The present invention relates to the technical field of transformer accessories, in particular to the ventilation structure of a drive motor and a transmission.

Background technique

In the new energy pure electric vehicle powertrain, it is generally composed of a drive motor, a transmission and a motor controller. At present, the mainstream structure is that the motor and the transmission are connected by bolts through the front mounting surface of the motor. It specifically includes: an oil seal is installed on the transmission input shaft to prevent the leakage of lubricating oil in the transmission, a stop on the front cover of the motor is matched with the transmission, after the transmission is combined with the motor, the transmission input shaft oil seal and the motor front bearing, and the motor stopper The cylindrical surface in the mouth forms an annular space.

In order to prevent external mud and water vapor from entering the above-mentioned annular space and causing the internal shaft and splines to rust, the current practice is to add an O-ring seal to the end face of the stop or the outer circle, or apply sealant to the joint surface of the motor and the transmission. At present, the drive motor of new energy vehicles has a high-speed trend, and a few have reached 18,000 rpm. When the rotor in the motor rotates at a high speed, the air on both sides of the motor has a centrifugal effect, making the inside and outside of the motor (that is, close to the stator side) The air pressure is high, the density is high, the inner side (closer to the bearing) pressure becomes lower, and the density becomes lower.

In the above situation, the pressure difference is formed between the space on the right side and the space on the left side of the front bearing of the motor, and the outer ring of the bearing and the front end cover are in clearance fit, so that the air on both sides can communicate with each other under the action of the pressure difference, so that the annular space between the transmission and the motor is formed. The formation of negative pressure can easily cause oil leakage from the oil seal of the transmission input shaft.

The above situation is more likely to occur especially when the oil seal is worn.

In the future, with the integrated design of motor and transmission and the increase of motor speed, the above situation will become more serious.

In addition, when the motor rotates at high speed, the outer side of the rotor has a higher linear velocity, and the friction loss will also increase when the air density in contact with it is high.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problem of friction loss in the ventilation structure of the driving motor and the transmission in the prior art, and propose a ventilation structure of the driving motor and the transmission.

In order to achieve the above object, the present invention adopts the following technical solutions:

The ventilation structure of the drive motor and the transmission includes the motor rotor shaft and the connection housing at the front end of the motor. The upper side of the connection hole D communicates with the outer edge communication hole A of the motor stator provided on the connection housing, and a ventilation device C is located on the top of the connection hole D.

The ventilation device C is a two-way ventilation valve, the head of which is provided with a filter membrane, and the upper part is provided with a cap.

By measuring the problems of the prior art, it can be found that due to the centrifugal action of the rotor when the motor rotates at a high speed, a pressure difference is formed between the inner side of the rotor rotation axis and the outer side of the stator in the motor.

Outside pressure Po×(1+α), inside pressure Po×(1-α)

(Where Po is atmospheric pressure, and α is the pressure difference coefficient caused by centrifugation.)

Internal and external pressure difference Po×(1+α)-Po×(1-α)=2Poα

This value will increase as the speed of the motor and the diameter of the motor rotor increase.

The above inner negative pressure will cause negative pressure in the space between the motor front bearing and the transmission input shaft oil seal.

The negative pressure in the above space will cause the pressure difference on both sides of the oil seal of the input shaft to increase, which increases the difficulty of the oil seal lip sealing and easily causes oil leakage.

The working method of the ventilation structure of the drive motor and the transmission is characterized in that, it includes the following conditions:

Case 1: Channels A and B are connected. In this state, the inner annular space is connected to the stator side of the motor. The pressure becomes Po×(1+α) and the pressure is greater than the atmospheric pressure. The pressure outside the oil seal rises. The transmission will not leak oil. The pressure is also higher than atmospheric pressure, and air friction losses increase.

Case 2: A and C are connected. In this state, the outside of the motor is connected to the atmosphere. At this time, if the average air pressure inside the motor is P1, then P1×(1+α)=Po, and the inside is P1(1-α)=Po(1 -α)/(1+α), that is, the increase of the inner negative pressure will increase the risk of oil leakage of the oil seal, but the pressure on the rotor side will decrease, which is beneficial to reduce the air friction loss.

Case 3: B and C are connected. At this time, the pressure of the sealing chamber is the same as the atmospheric pressure, Po, the pressure inside and outside the oil seal is normal, the pressure will not change during operation, and there will be no oil leakage.

Case 4: A and B are connected to C, the inner side of the motor in the sealed chamber and the outer side of the motor are connected to the atmosphere, and the pressure is the same as Po, which will not cause the working pressure of the oil seal to change or increase the friction loss of the rotor air.

Compared with the prior art, the present invention provides a ventilation structure for a drive motor and a transmission, which has the following beneficial effects:

1. The present invention is a ventilation structure for driving the motor and the transmission, which solves the problem that the pressure difference exists in the annular space of the motor during operation, which will cause friction loss to components such as oil seals.

2. The present invention is a ventilation structure for driving the motor and the transmission, which reduces the oil leakage of the sealing device, reduces the internal pressure of the motor, and reduces the friction loss of the motor.

3. The present invention is the ventilation structure of the drive motor and the transmission, which enables the pressure difference and wear to be continuously and dynamically adjusted to achieve dynamic balance.

4. The present invention is a ventilation structure for driving motor and transmission. Its ventilation valve only allows air to flow in both directions, and can prevent water molecules from entering and leaving. A cap is installed on the upper part to prevent sediment and other adhesion, which affects the ventilation function.

5. The present invention can effectively reduce the pressure of the sealing chamber and the risk of oil leakage from the oil seal, at the same time reduce the air pressure inside the motor and reduce the friction loss of the motor rotation.

The parts not involved in the device are the same as the prior art or can be implemented by using the prior art.

Description of drawings

1 is a schematic diagram of a ventilation structure of a drive motor and a transmission;

FIG. 2 is a schematic diagram of the ventilation structure of the drive motor and the transmission;

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments.

In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inside", " The orientation or positional relationship indicated by "outside" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, so as to The specific orientation configuration and operation are therefore not to be construed as limitations of the present invention.

1-2, the ventilation structure of the drive motor and the transmission includes the motor rotor shaft 1 and the connection housing 2 at the front end of the motor. The sealing chamber connection hole B4, the sealing chamber connection hole B4 communicates with the connection hole D5 provided in the connection shell, and the upper side of the connection hole D5 communicates with the motor stator outer edge communication hole A6 set on the connection shell 2, located at the top of the connection hole D5 A ventilation device C7 is provided.

The ventilation device C7 is a two-way ventilation valve, the head of which is provided with a filter membrane, and the upper part is provided with a cap.

The working method of the ventilation structure of the drive motor and transmission, including the following cases:

Case 1: The connecting hole A on the outer edge of the motor stator is connected to the connecting hole B in the sealing chamber. In this state, the inner annular space is connected to the stator side of the motor, and the pressure becomes Po×(1+α) The pressure is greater than the atmospheric pressure, and the pressure outside the oil seal rises , the transmission will not leak oil, the pressure outside the motor is also higher than the atmospheric pressure, and the air friction loss will increase.

Case 2: The outer edge of the motor stator is connected to the ventilation device C. In this state, the outer side of the motor is connected to the atmosphere. At this time, assuming that the average air pressure inside the motor is P1, then P1×(1+α)=Po, and the inner side is P1( 1-α)=Po(1-α)/(1+α), that is, the increase of the inner negative pressure will increase the risk of oil leakage of the oil seal, but the pressure on the rotor side will decrease, which is beneficial to reduce the air friction loss.

Case 3: B and C are connected. At this time, the pressure of the sealing chamber is the same as the atmospheric pressure, Po, the pressure inside and outside the oil seal is normal, the pressure will not change during operation, and there will be no oil leakage.

Case 4: The outer edge of the stator of the motor A is connected to the connection hole of the sealing chamber. B is connected to the ventilation device C. The inner side of the motor in the sealing chamber and the outer side of the motor are connected to the atmosphere. Rotor air friction loss increases.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. The equivalent replacement or change of the inventive concept thereof shall be included within the protection scope of the present invention.

Claims (5)

1. The ventilation structure of the drive motor and the transmission, including the motor rotor shaft and the connection housing of the front end of the motor, is characterized in that: the connection housing on the front side of the bearing outside the motor rotor shaft is provided with a sealing chamber connection hole B, and the sealing chamber is connected The hole B communicates with the connection hole D provided in the connection housing. The upper side of the connection hole D communicates with the motor stator outer edge communication hole A provided on the connection housing. The top of the connection hole D is provided with a ventilation device C. 2 . The ventilation structure of the driving motor and the transmission according to claim 1 , wherein the ventilation device C is a two-way ventilation valve, the head of which is provided with a filter membrane, and the upper part is provided with a cap. 3 . 3 . The ventilation structure for a drive motor and a transmission according to claim 1 , wherein the sealed connection hole B is an annular connection hole, which is arranged around the rotor shaft of the motor. 4 . 4 . The ventilation structure of the drive motor and the transmission according to claim 1 , wherein the connecting hole D is a vertical strip-shaped connecting hole. 5 . 5 . The ventilation structure for a drive motor and a transmission according to claim 1 , wherein the connection hole A on the outer edge of the motor stator is a connection hole arranged perpendicular to the connection hole D. 6 .

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