JPS5877187A - Gear pump or motor - Google Patents

Abstract

PURPOSE:To clash babbles before high pressure is reached to prevent errosion by forming a throttle slot in a relation positive adjacent the low pressure side of a seal portion of a tooth top. CONSTITUTION:Winding bushings 6, 7 support gear shafts 10, 11 of gears 8, 9 while the inner periphery of a side plate 12 fits the outer peripheries of these winding bushings 6, 7. The side plate 12 is provided with throttle slots 16, 17 outside point A. During high speed and high pressure running when babbles tend to be produced, pressurized oil in spaces at the high pressure side leaks into the spaces at the low pressure side to raise slightly pressure in the spaces. Thus, babbles in the spaces will be crashed before hand to prevent errosion.

Description

Detailed Description of the Invention This RQli is defined as the length t of the tooth tip seal by the seal block with respect to the adjacent pitte of the gear
(However, if t>P>, this applies to a nine-gear pump or motor.

As of this kind, the applicant #! The gear pump shown in Figure 1 is already available.

This JIII HD gear is designed so that the seal block (IJ tooth tip seal length t is almost equal to the adjacent pitch of the capacitor (2×3) O), and the loading force is well balanced. .

However, in this gear pump, when the pressure in the tooth groove changes instantaneously from the retraction pressure to the discharge pressure, the air bubbles generated in the tooth groove are instantly crushed. Therefore, there is erosion in the seal block (1) and side plate (4).
/ occurred, which had the disadvantage of significantly impairing the durability of the axillary pump.

An object of the present invention is to prevent the above-mentioned erosion 51y from occurring.

Below, we will explain the example of the gear pump failure shown in the tm2 and s diagrams.

Both gear pumps are provided with a cover and mounting 7 langes (not shown) on both sides of the body 141), and a winding bushing 6) (7) is press-fitted into these covers and mounting 7 langes. Taboshi cover gI
AOII! (only the f bush is shown). This winding bush (6) t7) is attached to the gear shaft QQ (880) of the gear (880).
b) and support this volume Bushu (6) i7.
1 Outside: The inner periphery of the side plate (6) is fitted to R.

And seal block 4 inner 1i on the outer side 41 of the side plate (6)! The l1tl-coinciding configuration supports the seal block.

The seal block supported as described above forms a loading area (b) on the outer peripheral surface that is in V-contact with the body (5), and the high pressure introduction hole (to) is connected to this loading area 04. This makes it possible to introduce high pressure.

(Then, while balancing the high pressure introduced into the loading area (b) and the internal pressure of the gear (8 tension) 1!! However, the actual seal block (to)
The length t from point A to point B in FIG. 2, which is the tip seal length, is tξP with respect to the adjacent pitch P (t>p>.

As shown in FIG. 3, when the gear (8) rotates completely in the direction of the arrow, the rotational force 1cI] d11 in the m direction
When the adjacent τ opens to the discharge side, the IilmU located 1 il behind it in the direction opens to the suction side. In other words, the pressure at dll#IjU becomes almost equal to the discharge pressure, and the pressure at dll#IjU becomes almost equal to the suction pressure. Therefore, in the distance t from point M to point B, which is the actual tooth tip seal length, the pressure inside the seal block changes from the suction pressure to the discharge pressure, and the change is unstable. No intermediate pressure occurs. The pressure in the tab or tooth groove is extremely stable, regardless of whether it is suction pressure or discharge pressure.

In this way, since the pressure change within the groove is stable, if the loading force is determined according to the pressure, a moth-proof seal can be obtained at all times.

In the above configuration, the side plate is located outward from the m reference point, that is, on the low pressure side from the tip seal portion.
The slot 4 (Ir is formed, but this throttle slot (to) σ'/) is designed to slightly increase the pressure in the tooth space just before reaching the upper half of the -tip seal. It comes out.

In other words, bubbles are likely to occur, and during ^pressure operation, the high pressure wI4v - 0 pressure oil in the groove leaks into the low pressure @O - neighbor, but
The pressure oil passes through slot 4 (b) to the low pressure chamber (to)
leaks to. Therefore, the pressure oil becomes soft and the slot)417)t
-*When the tooth is exposed, the pressure in the tooth groove corresponding to the slot will increase slightly.

Before the tooth a711S reaches high pressure, the pressure increases a little, so the air bubbles in the tooth groove collapse in advance, causing erosion etc. caused by the JIi1 force of the 4# plastic air bubbles. I won't.

Even if a pattern slot and MRk are provided, the corresponding pressure in the w1 groove should be 1/3 or less of the discharge pressure1! Since it is pressed at the same time, - tip seal length tt - 1t; P and 7
There is no benevolence that undermines the said threat.

Furthermore, the slot in this *embodiment may be provided on the skin-first contact (3) side of the seal block instead of on the side plate.

As is clear from the above description, the most distinctive feature of the present invention lies in the fact that the slot 7' is formed at a position in relation to the pressure oil rather than the tip of the seal.

By forming the pressure slot as described above, the pressure within the one groove is slightly increased just before the pressure changes to a high pressure. This pressure increase causes the air bubbles in the tooth groove to be crushed in advance.

Since the bubbles are collapsed before the membrane pressure is reached, erosion and the like will not occur.

[Brief explanation of drawings]

Figure M1 is @zono map of Kyomai Q Gabong, Figure 2.3 is Koko V
In order to show an example of the invention v1, Figure 2 is a cutaway diagram (3) of the gear pump, Figure 3 is a diagram showing the relationship between the other gears and the seal block. , Elc1)...Volume bush, 4(2)...Gear shaft, @...Side grate, Sakaki...Seal block,
40...Aperture slot. Representative Patent Attorney Sumire Shima 1 Tsukura 3 mouths

Claims (1)

[Claims] At the same time as fitting the outer part of the side plate supporting the gear shaft, the outer part of the side plate is made to match the inner circumference of the seal pull, and while the inner part of the seal block seals the tooth tip, the inner part of the seal block is In a gear pump or motor in which the target tooth tip seal length t is tξP (where t>p>) with respect to the MA shell gear OSS pitch P, a throttle slot is formed at a related position adjacent to the low pressure side of the tooth tip seal portion. Gear pump or motor made by