Lubricating device for a motor drive unit

Abstract

The utility model discloses a kind of lubricating devices, which can ensure the supply of lubricating oil, while as far as possible to inhibit oil film rupture. Rotating shaft transmits torque from the rotor shaft of motor and rotates, the lubricating device of motor drive unit is arranged in parallel with the rotating shaft and the rotor shaft, wherein, the blade that generates the axial wind towards the axis direction of rotating shaft by rotation is installed to rotating shaft in the state of extending to outside in the radial direction of rotating shaft, and the plate portion that scrapes the lubricating oil accumulated in the position lower than the rotor of motor is provided at the front end of blade. As a result, if the rotor shaft rotates, the blade rotates with the rotating shaft, so that the axial wind towards the axis direction of rotating shaft is generated, the axial wind blows away heat, so that the lubricating oil, rotating shaft and the like are cooled by so-called air cooling effect. Therefore, temperature rise of lubricating oil and oil film rupture accompanying it can be prevented or inhibited.

Description

Technical Field

[0001] This utility model relates to a device for lubricating a motor drive unit with a transmission mechanism that transmits the output torque of a motor to the outside using lubricating oil. Background Technology

[0002] As is well known, lubricating oil is supplied to the sliding parts of various mechanical devices to reduce friction or cool them, and there are known lubrication structures that scrape up the lubricating oil stored at the bottom of the housing by the rotation of rotating bodies such as gears.

[0003] For example, Patent Document 1 describes an electric drive device in which a rectifier ring is provided on the outer periphery of a stepped pinion planetary gear in a reducer, and a scraping member for scraping lubricating oil to an oil tank is further provided on the side or outer periphery of the rectifier ring.

[0004] In the device described in Patent Document 1, the turbulent flow of lubricating oil generated by the rotation of the pinion is confined within the rectifier ring so as not to affect the main flow of the lubricating oil. Furthermore, by providing a scraping component in its rectifier ring, the lubricating oil can be effectively scraped to the oil tank, and the drag resistance of the rotor in the motor (the resistance of the rotor against the rotation of the lubricating oil) can be reduced.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2005-008143 Utility Model Content

[0006] In Patent Document 1, a scraping member is provided on the rectifier ring to supply lubricating oil to the sliding parts. However, in the structure of the electric motor described in Patent Document 1, the temperature of the lubricating oil rises due to the stirring resistance or sliding resistance of the scraping member, which may cause the viscosity of the lubricating oil to decrease. If the viscosity of the lubricating oil decreases, oil film rupture is likely to occur in gears and bearings, which may lead to wear or sintering of the sliding parts.

[0007] This utility model addresses the aforementioned technical issues and aims to provide a lubrication device that ensures the supply of lubricating oil and minimizes oil film rupture.

[0008] To achieve the above objectives, this utility model provides a lubrication device for a motor drive unit in which a rotating shaft, which transmits torque from the rotor shaft of a motor, is arranged parallel to the rotor shaft. The device is characterized in that blades that generate axial wind toward the axis of the rotating shaft by rotation are mounted on the rotating shaft in a state that extends outward in the radial direction of the rotating shaft, and a plate portion is provided at the front end of the blades to scrape up lubricating oil accumulated at a position lower than the rotor of the motor.

[0009] Utility Model Effect

[0010] According to the lubrication device of this invention, when the motor outputs torque and the rotor shaft rotates, a rotating shaft arranged parallel to the rotor shaft also rotates. Since the blades rotate together with the rotating shaft, axial airflow is generated in the axial direction of the rotating shaft. This axial airflow carries heat, thus cooling the lubricating oil, rotating shaft, etc., through a so-called air-cooling effect. As a result, it is possible to prevent or suppress the temperature rise of the lubricating oil or the resulting oil film rupture. Furthermore, the plate portion provided at the leading end of the blades scrapes up the lubricating oil, so even if the rotor shaft or rotating shaft is positioned at a position higher than the oil level, sufficient lubricating oil can be supplied to these rotor shafts or rotating shafts, as well as their bearings and other supporting parts. Attached Figure Description

[0011] Figure 1 This is a skeleton diagram of a motor drive unit equipped with the lubrication device of an embodiment.

[0012] Figure 2 Here is an example of the structure of the blade: (a) is a perspective view of the blade, and (b) is a front view of the blade mounted on the driven shaft. Detailed Implementation

[0013] The lubrication device 1 of the motor drive unit in this invention is, for example, part of the power transmission mechanism 2 that transmits power from a power source such as an engine or electric motor mounted on a vehicle to the drive wheels, and is installed for the supply of lubricating oil within the power transmission mechanism 2.

[0014] The structure of the power transmission mechanism 2 and the lubrication device 1 of the motor drive unit in the embodiments of this utility model is shown below. Figure 1 The skeleton diagram. Figure 1 The upper side is the front side of the vehicle, and the lower side is the rear side. In the power transmission mechanism 2, the rotor shaft 4, which rotates integrally with the rotor of the electric motor (hereinafter referred to as motor) 3 by the output torque of the rotor (not shown), is supported by the bearing 5. An output gear 6 is mounted on the rotor shaft 4, and the output gear 6 meshes with a driven gear 7 with a larger diameter than the output gear 6. The driven gear 7 is mounted on the driven shaft 8, and rotates integrally with a driven drive gear 9 with a smaller diameter than the driven gear 7 on the right side of the vehicle in the left-right direction, on the same axis as the driven shaft 8. A differential ring gear 10 with a larger diameter than the driven drive gear 9 meshes with the driven drive gear 9. The differential ring gear 10 is a gear that constitutes part of a final reduction gear for distributing and transmitting drive torque via the integrally rotating differential shaft 11 to the left and right axles or wheels (not shown). Furthermore, the driven gear 7, which is a large-diameter gear, and the differential ring gear 10 have multiple weight-reducing holes (not shown) formed on the gear flange.

[0015] The rotor shaft 4 and differential shaft 11 are arranged side-by-side and parallel in the left-right direction of the vehicle. The driven shaft 8 is mounted further forward and parallel to the rotor shaft 4 and differential shaft 11 in the front-rear direction of the vehicle. Furthermore, the rotor shaft 4, driven shaft 8, and differential shaft 11 are arranged vertically (in...) Figure 1 The middle section (perpendicular to the paper surface) is positioned at the same height.

[0016] Oil (hereinafter referred to as lubricating oil) is sealed into the interior of a housing (not shown) along with the aforementioned rotating components such as gears. Furthermore, the housing becomes a structure that is sealed in a liquid-tight state.

[0017] The output gear 6 is used to output the power of the motor 3 to the driven gear 7. The output power is transmitted to the driven drive gear 9 located on the same axis as the driven gear 7, and then the power is transmitted to the differential ring gear 10 that meshes with the driven drive gear 9, so as to distribute and transmit the driving torque to the left and right axles or wheels.

[0018] Next, use Figure 1 and Figure 2 The scraping lubrication device of this utility model will be described. In the embodiments of this utility model, the lubrication device 1 scrapes the lubricating oil stored at the bottom of the housing and supplies the lubricating oil to the rotating component.

[0019] The lubrication device 1 is installed on the driven shaft 8, which is arranged between the driven gear 7 and the driven drive gear 9 and is parallel to the rotor shaft of the motor 3. That is, it consists of a cylindrical body 101, a plate-shaped blade portion 102, and a plate portion 103 that are integrally rotated with the driven shaft 8, which transmits torque from the rotor shaft of the motor 3.

[0020] Specifically, the cylindrical body 101 is splinedly connected to the driven shaft 8 or the driven gear 7, for example, via a spline groove (not shown). The blade portion 102 is a plate-shaped member mounted to extend radially outward from the outer circumferential surface of the cylindrical body 101 and arranged at equal intervals in the circumferential direction. Furthermore, the blade portion 102 has a twist angle from the cylindrical body 101 to the plate portion 103 at its end, with a predetermined angle relative to the central axis of the driven shaft 8. By having this twist angle, if the cylindrical body 101 rotates, the blade portion 102 generates axial wind in the axial direction of the cylindrical body 101, thereby producing a propeller-like airflow effect. Additionally, the shape of the blade portion 102 is plate-shaped in this embodiment, but it is not limited to this, such as... Figure 2 As shown in (a), the blade portion 102 can be a curved surface, or the width (circumferential width) of the blade portion 102 can be increased from the end. That is, it can be shaped like a propeller with a small aspect ratio of circumferential width to radial length, similar to a conventional fan.

[0021] Next, the plate-shaped plate portion 103 formed at the end of the blade portion 102 is a component for scraping up lubricating oil, for example, Figure 2 As shown in (a), the surface is a concave curve in the circumferential direction of the plate relative to the axis of rotation, but it is not limited to this. It can also be shaped like a scoop, such as that used in waterwheels (a type of conventional rotating machinery), to hold a predetermined amount of lubricating oil at its end. Furthermore, Figure 2 (b) is a front view of the lubrication device 1 viewed from the rear side in the front-rear direction of the vehicle, with the oil level 104 indicated by a double-dotted line. This oil level 104 is the height at which the rotor of the motor 3 is not submerged. In other words, the plate portion 103 is configured to scrape up the lubricating oil accumulated at the front end of the blade portion 102, which is located at a position lower than the rotor of the motor 3 (not shown).

[0022] If the motor 3 outputs torque and the rotor shaft 4 rotates, the driven shaft 8, which is arranged parallel to the rotor shaft 4, will also rotate. Furthermore, on the outer periphery of the cylindrical body 101, which rotates integrally with the driven shaft 8, plate-shaped blades 102 with a predetermined twist angle are arranged at equal intervals in the circumferential direction. Therefore, when the cylindrical body 101 rotates, the blades 102 also rotate, and the fluid around the blades 102 with the twist angle is discharged, generating an airflow along the rotation axis. Since this axial airflow carries heat, the lubricating oil, sliding parts, etc., are cooled through a so-called air-cooling effect. Therefore, the temperature inside the housing can be reduced, and the temperature rise of the lubricating oil and the accompanying oil film rupture can be prevented or suppressed.

[0023] Furthermore, by forming a plate-shaped portion 103 for scraping lubricating oil at the front end of the blade portion 102, even if sliding components such as the rotor shaft 4 or rotating shaft are positioned at a position higher than the oil level, the plate portion 103 can scrape up the lubricating oil, thus forcibly and adequately supplying lubricating oil to the sliding components. Moreover, the driven gear 7, which is a large-diameter gear, and the differential ring gear 10 have multiple weight-reducing holes (not shown) formed on their flange portions. Therefore, when lubricating oil splashes, it is supplied to the bearing 5 or the gear body through these weight-reducing holes in the flange portion. As a result, while ensuring the supply of lubricating oil, oil film rupture can be suppressed as much as possible.

[0024] Furthermore, the above embodiments are merely one example of implementing this utility model and do not limit the scope of this utility model. For example, the power transmission mechanism targeted by this utility model can have both scraping-type lubrication and pump-type lubrication structures. In pump-type lubrication, lubrication can be performed by an oil pump attached to the housing. Moreover, when it is desired to actively supply lubricating oil to the bearing 5, for example, an arc-shaped protrusion capable of temporarily storing lubricating oil can be provided on the inner side of the housing or on the bearing 5.

[0025] Symbol Explanation

[0026] 1-Lubrication device, 2-Power transmission mechanism, 3-Motor (electric motor), 4-Rotor shaft, 5-Bearing, 6-Output gear, 7-Driven gear, 8-Driven shaft, 9-Driven drive gear, 10-Differential ring gear, 11-Differential shaft, 101-Cylinder body, 102-Blade section, 103-Plate section, 104-Oil level.

Claims

1. A lubrication device for a motor drive unit, wherein a rotating shaft that transmits torque from the rotor shaft of the motor is arranged parallel to the rotor shaft, characterized in that, The blades that generate axial wind in the axial direction of the rotating shaft by rotation are mounted on the rotating shaft in a state that extends outward in the radial direction of the rotating shaft, and the front end of the blades is provided with a plate portion that scrapes off lubricating oil accumulated at a position lower than the rotor of the motor.

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