JPS6221961Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a gearbox cooling device for a dynamometer that can measure the power of a test machine rotating at high speed.

Conventionally, a dynamometer that measures the power of a prime mover such as an engine under test has been equipped with a dynamometer main body 3 mounted on a bed 1 using swing bearing stands 2a and 2b, as shown in FIG. It swingably supports a swinging frame 4 and a gearbox 5 integrally provided at its tip, and connects the rotating shaft 7 of the dynamometer main body 3 to the driven In order to attach the rotating shaft S of the testing machine, it was constructed by connecting a high-speed rotating shaft 8 with its tip protruding toward the front of the gearbox.

Lubricating oil is supplied to the speed increasing device 6 through a path not shown to lubricate the gears, etc. After the lubrication, the lubricating oil is released into the gearbox 5 and accumulates at the bottom of the gearbox 5. The oil is discharged to the outside from a discharge port 9 provided at the bottom of a gearbox cover 5a connected to the gearbox 5 via a drain pipe 9a. In FIG. 1, 10 is a bearing portion of the rotating shaft 7, and 11 is a high-speed bearing portion of the high-speed rotating shaft 8.

However, with the conventional dynamometer mentioned above, the test machine rotates at particularly high speeds (e.g. tens of thousands of revolutions per minute or more).
When measuring the power of the gearbox 5, the speed increasing device 6 generates heat at a high temperature, so the lubricating oil supplied to the speed increasing device 6 is heated to a high temperature and released into the gearbox 5.
The gearbox 5 is heated and undergoes thermal expansion. In particular, heated lubricating oil accumulates in the gearbox 5 before being discharged outside the gearbox 5, and since the distance from the swing bearing stand 2b to the high-speed rotating shaft 8 is long, Due to thermal expansion, the lower part of the gearbox 5 is significantly thermally deformed than the upper part, and this pushes up the high-speed bearing part 11 of the high-speed rotating shaft 8 supported at the tip of the gearbox, causing the axis of the high-speed rotating shaft 8 to shift upward. This results in misalignment that causes a large displacement. This causes vibrations in the machine under test and the dynamometer.
Increase measurement error or make measurement difficult.

On the other hand, in this type of dynamometer, there is a need to downsize the device, but if the speed increase device is downsized for this purpose, mechanical loss increases and the temperature of the lubricating oil further increases. At the same time, a large amount of lubricating oil is required, and as the device becomes smaller, the oil drain port also becomes smaller. Therefore, even higher temperature lubricating oil accumulates in the lower part of the gearbox 5, increasing the problem of misalignment.

Therefore, due to the above-mentioned circumstances, conventional dynamometers were not applicable to measuring the power of a test machine rotating at high speed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gearbox cooling device for obtaining a dynamometer that eliminates the drawbacks of the conventional dynamometers and makes it possible to measure the power of a test machine rotating at high speed.

Embodiments of the present invention will be described below based on the drawings.

FIG. 2 shows an embodiment of the present invention, in which a swing frame 24 and a gear box 25 of a dynamometer main body 23 are made swingable by two swing bearing stands 22a and 22b on a bed 21. Supported.

The swing frame 24 has a rotating shaft 2 inside it.
7 and a rotating shaft 27 to the swing frame 24, and an arm and a torque measuring device (not shown) on the outside.

A gear box 2 is installed at the tip of the dynamometer main body 23.
5 is integrally installed, and inside it,
A speed increasing device 26 is housed therein, and includes a rotating gear 28a of a high-speed rotating shaft 28, a transmission gear 26a meshing with the rotating gear 28a, and an internal gear 26b meshing with the transmission gear 26a. These speed increasers 26 allow the rotating shaft 27 and the high-speed rotating shaft 2 to
8 are connected to each other so as to change speed at a predetermined rotation ratio. The high-speed rotating shaft 28 has a bearing portion 32 formed to protrude forward along the axis of the gearbox 25.
It is supported by a high-speed bearing 31, and its tip protrudes beyond the bearing part 32, so that the rotating shaft S of the machine under test can be attached thereto. Note that 30 is a bearing that supports one end of the rotating shaft 27 of the dynamometer main body 23, and 33 is a thrust bearing.

In the figure, 26c is a boss of the internal gear 26b, and 26d is an arm that integrally connects the internal gear 26b to the boss 26c.

As shown in FIG. 3, the gear box 25 has a plurality of through holes 34 extending through its wall in the longitudinal direction.
4 is a pipe 3 provided outside the gear box 25
5 to form a passage for the cooling liquid.
The gear box 25 has four through holes 3 on each side of the wall thickness, avoiding the oil drain port 29 at the bottom.
The ends of the uppermost through hole 34a and the second through hole 34b that are disposed on the side of the swing bearing base 22a are connected to a water supply port 36.
and a discharge port 37, and both ends of each through hole 34 are connected in sequence by a pipe 35 to form one cooling liquid passage on each of the left and right sides.

Note that the temperature distribution of the gearbox 25 is such that the temperature is higher at the bottom, so when forming the coolant passage, the lower through hole 34 is located upstream of the flow of coolant, so that relatively low temperature coolant flows through the gearbox 25. It is desirable to arrange the pipe 35 so that it passes through.

In addition, in this embodiment, the dynamometer main body 23
A water supply hose 39 is distributed from a water supply pipe 38 used for the purpose of supplying water to the water supply port 36. The cooling water thus supplied from the water supply port 36 passes through the lower passage of the gearbox 25, cools the lower part of the gearbox 25, and is then drained from the drain port 37 via the drain hose 40.

As explained above, in the present invention, a through hole for passing the coolant is provided within the thickness of the lower part of the gearbox, that is, near the lubricating oil outlet provided at the lower end of the gearbox, so that the high temperature lubricating oil scattered inside the gearbox is After being cooled down in the area where the through holes are provided along the inner wall of the gearbox, it can be immediately discharged from the outlet at the lower end of the gearbox. Furthermore, since the plurality of through holes are connected by a pipe exposed outside the gearbox, the heated coolant is cooled by the outside air when passing through the pipe, thereby further increasing the cooling efficiency. In this way, by improving the cooling efficiency of the lower part of the gearbox, the temperature difference between the upper and lower parts of the gearbox can be kept as small as possible, thereby preventing misalignment of the high-speed rotation shaft, and It is possible to obtain a dynamometer that eliminates vibrations, vibrations of the dynamometer itself, and measurement errors. Furthermore, as a result, it is possible to downsize the dynamometer.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view showing an example of a conventional dynamometer, FIG. 2 is a partially cutaway side view showing an embodiment of the present invention, and FIG. 3 is a perspective view of the embodiment shown in FIG. Fourth
The diagram shows the state of the cooling device. FIG. 3 - sectional view. 21... Bed, 22a, 22b... Rocking bearing stand, 24... Rocking frame, 25... Gearbox, 26... Speed increaser, 34... Through hole, 35...
pipe.

Claims (1)

[Scope of utility model registration request] A dynamometer in which a speed increasing device is housed in a gearbox attached to a swinging frame of a dynamometer main body, and lubricating oil is supplied to the speed increasing device and discharged from an outlet at a lower end of the gearbox. A dynamometer characterized in that a plurality of through holes are provided in the thickness of the lower part, these through holes are connected by a pipe exposed outside the gearbox, and the gearbox is cooled by flowing liquid through the through holes. gearbox cooling system.