CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2020-0073114, filed Jun. 16, 2020, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a motor apparatus having an oil circulation structure in which oil for cooling and lubrication in the motor apparatus is automatically circulated when a drive system is operated, and which allows the oil level therein to be maintained at a constant level.

Description of Related Art

In recent years, as environmental issues have become a global concern, research on vehicle technologies that consider an environment, such as reduction in the amount of exhaust gas, improvement in fuel efficiency, and the like, related to vehicles is being actively conducted. Representative examples of the vehicles are hybrid vehicles, electric vehicles, and the like as eco-friendly vehicles.

Such an eco-friendly vehicle is provided with a motor as a power source, and the motor includes a shaft mounted in a center portion of a motor housing, a rotor core having a permanent magnet, a spider integrally connecting the shaft and the rotor core, a stator core disposed on an external diameter side of the rotor core, and a coil surrounding opposite sides of the stator core. Here, an oil pump mounted, on the external surface of the motor housing, coaxially with the shaft; a cooling oil supply line extending from an outlet side of the oil pump toward an inside surface of the spider; and a cooling oil return line connecting a bottom surface of the motor housing filled with cooling oil and an inlet side of the oil pump are configured so that cooling of the motor is be performed.

Along with this, when a reduction gear is further configured in the motor, a structure for cooling the reduction gear is further added. Accordingly, the cooling structure of the motor and the reduction gear becomes complicated, and as an overall size increases, it is disadvantageous in terms of packaging.

The information included in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and may not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing a motor apparatus having an oil circulation structure in which oil for cooling and lubrication in the motor apparatus is automatically circulated when a drive system is operated, allowing desired lubrication and cooling to be performed and an oil level therein to be maintained at a constant level.

In various aspects of the present invention, there may be provided the motor apparatus having the oil circulation structure, the motor apparatus including: a motor housing through which a driveshaft is provided to pass and provided with a driving motor configured as a power source for driving the driveshaft; and a gear housing coupled to a side of the motor housing and provided with a reduction gear set disposed on a line of the driveshaft, configured to reduce rotational speed of the driveshaft, wherein the gear housing may be provided with a first reservoir unit collecting churning oil caused by the reduction gear set and with a connection flow channel guiding the oil to move to a side of the motor housing when at least a predetermined amount of the oil is stored in the first reservoir unit, and the motor housing may be provided with a second reservoir unit fluidically connected to the connection flow channel and storing the oil introduced into the second reservoir unit through the connection flow channel.

The reduction gear set may include: a differential gear unit coupled to the driveshaft; and a reduction gear unit disposed on a top side of the differential gear unit and connected to the differential gear unit.

The gear housing may be provided with a differential cover supporting the differential gear unit, and the first reservoir unit collecting the churning oil may be provided on the differential cover.

The differential cover may include: a body unit through which the driveshaft passes, and which supports the differential gear unit; and a first reservoir unit formed on a top side of the body unit and configured to be open upwards, allowing the churning oil to be collected therein.

The first reservoir unit may be provided with a first drain hole formed to penetrate through downward toward the driveshaft and with the connection flow channel connected thereto to be open to a side thereof.

The motor housing may be provided with an installation space in which a driving motor may be provided and with the second reservoir unit at an upper side of the installation space to be open to the connection flow channel.

The second reservoir unit may be provided with a second drain hole penetrating through the second reservoir unit downward toward the installation space, and a connection hole penetrating through the second reservoir unit to allow the connection flow channel to be fluidically connected to the second reservoir unit.

The motor housing and the gear housing may be provided with balance holes open to communicate with each other when being coupled to each other, whereby the oil in the motor housing and gear housing may move through the balance holes.

The gear housing may be provided with a guide unit located at a side of the gear housing above the differential gear unit, the guide unit thus being in contact with the churning oil caused by the differential gear unit and allowing the contacted oil to be moved toward the first reservoir unit.

The guide unit may be configured to have a predetermined area, with opposite end portions thereof being bent downward.

The gear housing may be provided with a third reservoir unit disposed away from the first reservoir unit and configured to collect the oil being moved by the guide unit.

The third reservoir unit may be configured to be open upward toward the guide unit and be provided with a third drain hole penetrating through downward.

The motor apparatus having the above-described oil circulation structure collects churning oil inside a housing and efficiently disperses the collected oil in each drive system, allowing cooling and lubrication of the drive system including the motor and a reduction gear to be smoothly performed. Furthermore, even under low or high load conditions of the drive system, the oil level inside the housing is maintained at a constant level to maintain desired lubrication and cooling performance.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.

