JPS5825121Y2 - Air bleed device for casing in hydraulic pump - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an air venting device in a casing of a hydraulic pump used in cases where the head tank cannot be installed at a high place, such as in construction machinery or traveling vehicles.

Hydraulic pumps generally supply oil from an oil tank.

If the oil tank is installed so that the low oil level is higher than the pump casing, the air in the pump casing will be replaced with oil, so there will be no problem with pump performance.

However, if the hydraulic pump and oil tank are installed in a narrow space and the low oil level in the oil tank is lower than the top of the hydraulic pump, the inside of the pump will not be filled with oil when the hydraulic pump is operating, and air will be remains and the hydraulic pump does not perform as expected.

For this purpose, the oil tank is installed as high as possible, or a separate head tank is installed and the head tank is installed at a high place.

If the oil tank is installed at a high place or a separate head tank is provided in this way, the center of gravity of the device becomes high, and such a construction is not possible in the case of, for example, a construction machine or a traveling vehicle.

Since the oil level in a general oil tank fluctuates, in order for the pump casing to always be filled with oil, a low oil level must exist at a position higher than the top of the pump casing.

Therefore, the purpose of this invention is to replace the air in the pump casing with oil regardless of the oil level in the oil tank that supplies oil to the hydraulic pump, and to avoid raising the center of gravity of the entire device. Provide air venting device.

According to this invention, a compartment in close contact with the oil tank is formed in the side wall of the oil tank, the oil level in this compartment is made higher than the level of the top of the casing of the hydraulic pump, and the compartment and the top of the casing are connected to each other by an air vent pipe. It is connected by .

Embodiments of this invention will be described in detail below with reference to the drawings.

In the embodiment of this invention shown in FIG. 1, the hydraulic pump device A includes a pump casing 1.
An air vent pipe 2 is provided at the top 1a of the air vent.

Separately from the pump device A, an oil tank B for supplying oil to the pump device A/I is provided, and a supply pipe (not shown) is connected to the bottom of the oil tank B so that oil can be supplied to the pump device A. It has become.

On the other hand, inside the oil tank B, a compartment 3 is defined by a partition wall 7 above the side wall 6 thereof.

The oil level in this compartment 3 is determined by the hydraulic pump device A.
The top 7a of the partition wall 7 is located at a higher position than the top 1a of the casing.

Further, the other end of the air vent pipe 2 is connected to this compartment 3,
An opening 5a that communicates with a return oil pipe (not shown) opens into the compartment 3.

In the figure, 4 is a valve such as a stop valve switching valve provided in the air vent pipe 2.

During operation, when the hydraulic pump device A is operated, various actuators are driven, and all return oil from the actuators passes through a return oil pipe (not shown) and flows into the compartment 3 from the opening 5a.

When the compartment 3 is filled with oil, the oil overflows over the top 7a of the partition wall 7, accumulates in the oil tank B, and is led to the pump suction port.

Casing top 1a of hydraulic pump device A and this compartment 3
and are connected by the air vent pipe 2, and the overflow level is determined by the top 7a of the partition 7, so the oil level in the compartment 3 is higher than the casing top 1a, and therefore the oil in the oil tank B Even if the surface drops to the lowest oil level position LOL, oil is supplied from the compartment 3 to the pump casing 1 through the air vent pipe 2, and the casing 1
The air inside floats up through the air vent pipe 2 and is discharged from the compartment 3 into the atmosphere.

Therefore, there is no trouble caused by air being present in the upper part of the casing 1 during operation of the hydraulic pump.

When the operation of the pump is stopped, the oil in the compartment 3 flows back through the air vent pipe 2, and the oil level in the compartment 3 drops to the opening of the air vent pipe 2.

In this case, when the pump device A is started, the pump sucks air with a lower viscosity.

Therefore, in this invention, a valve 4 is provided, and the valve 4 is closed when the pump device A stops operating, and is also closed when the pump is started, so that air is not sucked in from the air vent pipe 2, and then the air is not sucked into the compartment 3. It is only necessary to open the valve 4 after the return oil enters and begins to overflow.

The embodiment shown in FIG. 2 is a modification of the embodiment shown in FIG. 1, in which the compartment 3 is provided outside the side wall 6 of the oil tank B.

As is obvious, the oil tank B and the compartment 3 may be formed separately and provided close to the side wall 6.

In this case, the overflow may be introduced into the oil tank using a pipe or other means.

In the embodiment shown in FIG. 2, the overflow hole 7b is provided at a high position in the side wall portion 6.

As described above, according to this invention, a relatively small compartment 3 is formed at a relatively high position in the oil tank B, and since the oil returns to the compartment 3 and flows into the compartment 3, the compartment 3 immediately begins to overflow, and therefore the pump device When the valve 4 is opened after starting and the compartment 3 overflows, the air inside the pump casing 1 is suitably discharged, and the inside of the pump casing 1 is filled with oil.

Since the compartment 3 itself is not large, the center of gravity of the entire device does not become high, and there are no restrictions on the position of the compartment 3.

Therefore, it is extremely suitable for construction machinery, etc., if this idea is implemented.

Further, fluctuations in the height of the oil level in the oil tank do not affect the air venting operation of the pump device, and even if the oil tank is installed at a relatively low position, sufficient effects can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an embodiment of the device according to this invention;
FIG. 2 is a side sectional view of another embodiment. A... Hydraulic pump, B... Oil tank, 1.
... Casing, 1a ... Casing top, 2 ... Air vent pipe, 3 ... Head tank, 4 ... Stop valve, 5 ... ... Return oil pipe, 5a ... Return oil pipe opening 0

Claims (1)

[Scope of utility model registration request] A compartment is formed in the side wall of the oil tank, and the oil level in the compartment is located at a higher position than the top of the casing of the hydraulic pump,
The low oil level of the oil tank is located at a lower level than the top of the casing of the hydraulic pump, and a return pipe is connected to the compartment so that oil that overflows the compartment flows into the oil tank. An air venting device for a casing of a hydraulic pump, characterized in that an air venting pipe extending from the top of the casing of the hydraulic pump communicates with the compartment, and the air venting pipe is provided with a valve.