JPS62221918A - Electric wheel drive device - Google Patents

Abstract

PURPOSE:To facilitate an easy maintenance as well as to attempt an improvement of a cooling efficiency in the titled device such as a dump trucks for mines and the like by forming a cooling circuit including a disc brake, an electric motor, an oil cooler and the like whereby circulating oil by means of a hydraulic pump which can be rotated in either way of the normal and reverse directions. CONSTITUTION:Oil in the bottom of each speed reducer 12 and 20 is sucked out by a pump M through a gear case 18, a ring gear 17, and an oil path (d) in a plate 41 whereby a part of the oil is pressure fed to the plate 41, the ring gear 17, the gear case 18, an inner case 32, and a disc brake 30 through an oil path (e) so as to be lubricated while being cooled. And a pump shaft 15, a sun gear 13, and an output shaft 9 are lubricated while being cooled through an oil path (f) by the rest of the pressure oil, which is forwarded to a passageway (g) by centrifugal force of a rotor 8 for lubricating and cooling the rotor 8 and a stater 4. Oil accumulated at the bottom of an electric motor 3 is sent back to an oil cooler 43 through an oil path (j) by a pump 10 so as to be cooled by wind. This constitution can improve a cooling efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric wheel drive device applied to mining dump trucks, wheel loaders, scrapers, dozers, towing tractors, and the like.

(Prior Art) A conventional electric wheel drive device of this type has two parts depending on the position of the reducer as shown in Section 5 and Fig. 6.
They are broadly divided into types, but all use air-cooled electric motors and dry brakes.

- In the one shown in FIG. 5, a primary reduction gear 61. The secondary reduction gear 62 is arranged inside the vehicle body, and the brake device 54 is arranged outside the vehicle body. To cool the electric T153, air introduced through an air cleaner (not shown) is guided into the electric VJ machine 53 through the gap 56 between the gear case 55 and the axle case 52, and is then discharged to the outside from the exhaust port 57 through the brake device 54. This is done by

The one in FIG. 6 has an electric tF173 placed on the innermost side of an axle case 72 attached to a vehicle body 71, and an electric vJ machine 7.
From 3 to the outside of the vehicle body, the primary reduction gear 81° and the secondary reduction gear 8
2 are arranged.

Electric! Cooling of the l1 aircraft 73 is done by directing air introduced through an air cleaner (not shown) through the intake 076 of the electric motor 73 and discharging it to the outside of the electric motor through the exhaust lower 7. Since there is a reduction annex outside the axle case 72, the cooling air discharged from the axle case 72 is
Axle case 72 and electric VJ machine 73 are not discharged to the outside.
and is discharged to the inside of the vehicle body 71 through a gap 78.

[Problem that the invention seeks to solve]

In all of the conventional devices mentioned above, the motor is cooled by air, so if the cleaner does not completely remove harmful substances, it may adhere to the inside of the motor or rust due to moisture in the air, resulting in performance deterioration. This could sometimes occur. However, the structure makes it difficult to remove the axle case from the main body, making maintenance difficult.

Further, in the case shown in FIG. 5, the flow of the cooling air is obstructed by the gear case 55, and the cooling air is forced to take a large detour. Also,
The cooling air may be warmed by the gear case 55,
This was not desirable in terms of cooling efficiency.

Furthermore, in the case of FIG. 6, the air heated and discharged by the electric motor 73 passes through the surface of the electric motor 73 again, which is not desirable in terms of cooling efficiency.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electric wheel drive device that allows easy maintenance of a reduction gear, a brake device, an electric motor, etc., has high cooling efficiency, and is suitable for use, for example, in a large vehicle.

[Means for solving problems]

In order to solve the above-mentioned problems and achieve the object, the present invention takes the following measures.

■The brake and reducer are placed outside the motor body.

■The brake system is a wet multi-plate type, the electric motor is oil cooled, a reversible pump is directly connected to the electric motor, and a hydraulic circuit is built into the axle case.

■An oil cooler is installed inside the axle case, and the cooling air taken in is passed straight through the outer circumference of the electric motor and through the reduction gear passage.

[Effect]

By taking the measure (2), maintenance can be performed without removing the axle case from the main body.

By taking the measure (2), durability and maintenance intervals can be extended.

By taking the measure (2), the cooling efficiency can be improved.

(Example) FIGS. 1 to 4 are diagrams showing an example of the present invention. There is an electric F! inside the axle case 2 attached to the vehicle body 1! M3
is installed. The stator 4 of the electric motor 3 is fixed by a flange 5 and an end cover 6, and the outer periphery is covered with a plate 7.
is sealed by.

The rotor 8 is fixed on a hollow output shaft 9, and an oil pump 10 and a driving boss 11 are attached to the output shaft 9 on the vehicle body side, and a primary reduction gear 12 is attached on the reduction gear side.
The sun gear 13 is in spline engagement. sun gear 1
3 has a through hole, and a spline for driving an oil pump 14 is provided at the outer end of the through hole, and a pump shaft 15 is engaged with the spline. The power transmitted to the sun gear 13 is transmitted to the planetary gear 16, but since the ring gear 17 meshing with the planetary gear 16 is fixed to the gear case 18, the carrier 19 rotates and transmits the power to the secondary reduction gear 20. It is transmitted to the sun gear 21 of. The sun gear 21 is hollow, and the hollow part is the primary reducer 1.
The shaft of the second sun gear 13 passes through it. The power from the sun gear 21 is transmitted to the ring gear 2 via the counter gear 22.
3. The ring gear 23 is spline engaged with the hub wheel case 24 and transmits power.

The hub wheel case 24 is connected to the axle case 2 by hub bearings 25 and 26 engaged with the axle case 2.
and drives a tire 28 via a rim 27. The outer case 29 is fixed to the hub wheel case 24 with bolts.

A spline is provided inside the outer case 29 and engages with the brake disc 30. Fixing plates 31 are engaged with splines provided on the outside of the inner case 32 so as to be arranged alternately with the brake discs 30 in the circumferential direction. A piston 33, a release piston 34, and a spring 35 are arranged between the outer case 29 and the inner case 32, and are fixed by a housing 36 and a cover 37.

When pressurized oil is sent to the chamber m section, the piston 33 presses the brake disc 30 and the fixed plate 31, and the rIJflI generates a braking action. When pressurized oil is sent to the n section of the chamber, the release piston 34 resists the spring 35, and the pin engaged with the piston 33 separates the piston 33 from the brake disc 30 and the fixed plate 31, making it free. Furthermore, when the pressure oil is not sent to both chambers m and n, the piston 33 presses the brake disc 30 and the fixed plate 31 by the spring 35 to generate a braking action.

The oil pump 14 includes an inner rotor 38, an outer rotor 39, and a housing 40 fixed to the pump shaft 15.
It is fixed to the main body by a plate 41 provided with an oil passage.

The oil pump 10 has the same configuration as the oil pump 14 and is fixed to the end cover 6, but there is a reduction gear 1171 on the suction side! A piping 42 from the motor section f and the electric motor section is provided, and a piping 44 to an oil cooler 43 is provided on the delivery side.

The oil cooler 43 is fixed to the intake lobe plate 45 and is provided with a pipe 46 returning to the reducer case. A duct 47 for guiding cooling air from a blower (not shown) is attached to the intake lobe plate 45. Seals 48 are provided at both ends of the reducer section.

Part a indicates a gap around the outer periphery of the electric motor 3, part b indicates a through passage provided in the gear case 18, and part 0 indicates a cooling air outlet.

2 is a right side view of FIG. 1, and FIG. 3 is a FF cross-sectional view of FIG. 1, showing that three discharge ports C are provided in each of the through passages of the gear case 18.

FIG. 4 is a diagram showing the flow of cooling oil and cooling air.

First, the flow of cooling oil will be explained. oil pump 14
Then, the oil at the bottom of the reducer is sucked from the oil passage d provided in the gear case 18 → ring gear 17 → plate 41. A portion of the sucked oil is force-fed through an oil path e provided in the plate 41 → ring gear 17 → gear case 18 → inner case 32 to the disc brake section, where it is lubricated and cooled. Also, in some cases, the pump shaft 15 → sun gear 13
It passes through the oil passage f inside and is fed under pressure to the hollow part inside the output shaft 9 inside the electric motor 3. The pumped oil is discharged to the outside of the rotor by centrifugal force caused by the rotation of the rotor 8 through a through passage Q provided in the output shaft 9 and the rotor 8 in the circumferential direction. The discharged oil passes between the stator 4 and the rotor 8 and falls from both sides to the bottom, or some of the oil passes through the through holes provided in the stator 4 from the outer periphery of the stator to both sides and falls to the bottom. During this process, the electric motor R3 is cooled down.

The oil pump 10 sucks oil from the bottom of the reducer through a pipe 42 from an oil path j provided at the bottom of the axle case 2 . At this time, the oil accumulated at the bottom of the electric motor 3 is also sucked up. The sucked oil passes through the pipe 44 to the oil cooler 5.
43.

The pressure-fed oil is cooled by cooling air in the cooler 43 and returned to the reduction gear section through the pipe 46.

Next, the flow of cooling air will be explained. Cold fJl wind is duct 47. It is introduced from the intake Roblate 45 and passes through the oil cooler section 43. It passes through the outer circumferential gap a of the IJ 13, passes through the through passage of the gear case 18, and is discharged to the outside through the discharge port C. The blower is an engine (both diagrams omitted)
Since the pump is driven by the pump, the pump stops when the electric motor 3 stops (when the vehicle body stops), but the cooling air flows, so that residual heat immediately after the motor 3 stops can be cooled by the cooling air.

Note that the present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

〔Effect of the invention〕

According to the present invention, the following effects are achieved.

(1) Since the brake device and speed reducer are located outside the axle case, maintenance work can be performed without removing the axle case from the main body.

(2) Directly connect the cold water oil pump to the electric motor,
Since the brake system is oil-cooled, it is no longer affected by the external environment (air containing harmful substances such as iron and salt). Additionally, the pump does not require any other power source and stops when the vehicle is stopped, reducing energy loss.

(3) By installing an oil cooler inside the axle case and passing the cooling air through the outer circumference of the electric motor 1 and the through-hole inside the reducer, the cooling function can be compacted, and
Even when the vehicle is stopped, residual heat can be cooled down by cooling air.

In this way, it is possible to provide an electric wheel drive device that allows easy maintenance of the reducer, brake device, electric motor, etc., has high cooling efficiency, and is suitable for use, for example, in large vehicles.

[BRIEF DESCRIPTION OF THE DRAWINGS] Figs. 1 to 4 are views showing an embodiment of the present invention, in which Fig. 1 is a sectional view of an electric wheel device, and Fig. 2 is a sectional view of an electric wheel device.
3 is a partial sectional view of FIG. 1, FIG. 4 is a diagram showing the flow of cooling oil and cooling air, and FIGS. 5 and 6 are sectional views showing a conventional example. DESCRIPTION OF SYMBOLS 1... Vehicle body, 2... Axle case, 3... Electric motor, 9... Output shaft, 10... Oil pump, 12...
...Primary reducer, 14...Oil pump, 15...
・Pump shaft, 18... Gear A7 case, 20... 2nd
Secondary reducer, 43...Oil cooler, 45...Cooling air intake lobe plate, 47...Duct, a...Gap around electric motor, b...Cooling air n passage, C...Cooling Wind outlet, d, e, f... oil passage, q... penetration passage. Applicant's sub-agent Patent attorney Takehiko Suzue Drawing i'7'l mat (no change in content) Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) An electric vehicle characterized in that an oil path is provided that reaches an oil cooler section after passing through a disc brake, an electric motor, etc., and a hydraulic pump that can be rotated in forward and reverse directions is driven by the electric motor to cool the oil. Wheel drive device. (2) An oil path is provided that reaches the oil cooler after passing through a disc brake, an electric motor, etc., and a hydraulic pump that can be rotated in forward and reverse directions is driven by the electric motor to cool the oil.
The oil cooler is installed after the cooling air intake of the axle case, and a passage for the cooling air that has passed through the oil cooler is provided linearly between the outer periphery of the reducer section, the outer periphery of the motor, and the inner wall of the axle case. An electric wheel drive device characterized by discharging wind to the outside.