JP2692044B2 - Piston pump for water - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a piston pump for water, particularly for seawater, in which a special material is combined with a member forming two sliding contact surfaces that are in sliding contact with each other. This improves the sliding characteristics of the sliding portion.

[Conventional technology]

Conventionally, as sliding materials for piston pumps that operate in seawater, as disclosed in Kawasaki Heavy Industries Technical Report No. 82, (October 1983 issue), sliding materials include alumina firing materials and alumina・ Titania ceramics spraying material was used. In some cases, a corrosion resistant metal is used.

[Problems to be solved by the invention]

5 and 6 show a piston pump conventionally used for seawater.

5 and 6 show a crankshaft type piston pump, 1 is a valve block, 2 is a cylinder, 3 is a plunger, 4 is a casing, 5 is a crosshead, 6 is a pin, and 7 is a bearing. , 8 are connecting rods, 9 is a crankshaft, and the crankshaft 9 is connected to the output shaft of the engine.

This piston pump is configured to suck and discharge seawater from the valve block 1 by vertically moving the plunger 3 via the connecting rod 8 by the rotation of the crankshaft 9.

In this piston pump, a large load is not applied between the plunger 3 and the cylinder 2, and a corrosion resistant metal can be used for the sliding portions of both members. However,
This type of pump has a drawback that the output per unit weight (output weight ratio) is small.

On the other hand, FIG. 1 shows an axial piston pump having a better output weight ratio than the above crankshaft type piston pump. In the figure, 11 is a cylinder block, 12 is a bearing plate, 13 is a valve plate, 14 is a piston, and 15 is a sleeve. , 16 is a slipper, 17 is a rocker cam, 18 is a cradle, 19 is a shaft, 20 is a spline, 21 is seawater, and the shaft 19 is adapted to be connected to an output shaft of an engine, and a spline 20 is a cylinder. Bound to block 11.

Then, when the cylinder block 11 rotates due to the rotation of the shaft 19, the piston 14 rotates integrally with the cylinder block 11 while vertically moving according to the tilt angle of the rocker cam 17. At this time, the bearing plate 12 and the valve plate 13, the piston 14 and the sleeve 15, the slipper 16 and the rocker cam 17 are in a sliding state using seawater as a lubricant.

In this axial piston pump, a very large load corresponding to seawater pressure acts between the sliding parts. If corrosion resistant metal or alumina calcined material which is a conventional material is used for these parts, these materials have high rigidity. For example, as shown in FIG. 2, in the case of corrosion resistant metal, the elastic modulus (Young's modulus) is about 20,000. kg · f / mm ² and that of alumina fired material is about 40,000 kg · f / mm ² , and the contact of the sliding surface is not uniform. Therefore, there is a problem that partial contact occurs due to partial contact, the contact surface pressure becomes higher than in the case of uniform contact, and galling and seizure occur.

The present invention has been made in view of the above, and solves the above problems by selecting and combining a special material for the sliding portion, and a hydraulic pump that is generally used at present has a high level of operation. An object of the present invention is to provide a water piston pump having an excellent output weight ratio that can be used under pressure.

[Means and actions for solving the problem]

In order to achieve the above object, a water piston pump according to the present invention uses a plastic composite material in which a plastic is combined with an organic fiber on one of two sliding contact surfaces that are in sliding contact with each other, and the other sliding contact surface on the other. In a water piston pump using a corrosion-resistant material such as metal or ceramic having a higher elastic modulus than the plastic composite material used for the surface, as the plastic composite material, polyether ether ketone is used as the base plastic, and the aromatic fiber is used as the organic fiber. The composition is such that the group-polyamide fiber is contained in an amount of 3 to 70% by volume.

In this structure, a part of the organic fibers is exposed on the surface of the plastic composite material using polyetheretherketone, and when the plastic composite material slides against a harder mating material, The soft plastic part of the product wears, and the organic fiber, which has excellent elastic modulus and wear resistance, directly supports the load. Even when used in seawater under high pressure, sliding does not occur on the sliding surface To be done.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, the bearing plate 12 located on the end surface of the cylinder block 11, the sleeve 15 fitted to the cylinder block 11, the polyether ether ketone as the base, and the aromatic polyamide fiber as the organic fiber 3
Composed of plastic composites containing up to 70% by volume,
Further, a sliding piece 16a made of the plastic composite material is fixed to the sliding contact surface side of the slipper 16. Bearing plate above 1
2 is fixed to the end surface of the cylinder block 11 with an adhesive.
If necessary, mechanically, for example, a cylinder block
A rough surface or groove may be processed on the 11 side, and the plastic composite material may be fixed to the rough surface or groove with an adhesive while being engaged with the rough surface or groove. The sleeve 15 is a cylinder block.
After applying the adhesive to 11, fit it by cold fitting. Further, the slipper 16 and the sliding piece 16a are the same as the bearing plate 12 described above.
Similarly, the adhesive is fixed by using an adhesive or a combination of the adhesive and a mechanical bond.

Corrosion-resistant materials such as ceramics and the like, which have a higher elastic modulus than the plastic composite material, are suitable for the material of the other side of the sliding member made of the plastic composite material.

The change in the elastic modulus due to the change in the content of the aromatic polyamide fiber with respect to the base polyetheretherketone of the plastic composite is shown in FIG. 2, and the elastic modulus of the plastic composite is the corrosion resistant metal and the alumina fired material. It can be seen that the value is significantly lower than

In addition, Fig. 3 shows the limits of the plastic composite material with the above configuration.
It shows the influence of the aromatic polyamide fiber content (volume%) on the PV value, and it was found that the limit PV value becomes a large value when the organic fiber is contained in an amount of 3 to 70 volume%.

When the content of the organic fiber is 3% by volume or less, the effect of the organic fiber on the sliding performance is lost, and when it exceeds 70% by volume, molding as a composite material becomes difficult.

Aromatic polyamide fibers based on conventional materials and examples of the present invention, namely polyether ether ketone
The difference in sliding characteristics when using a plastic composite material containing 30% by volume is shown in the following table for seawater and oil. In addition,
In this next table, where the wear rate is blank, it means that the wear rate could not be measured because the limit PV value was too low.

In the above table, the plastic composite materials in the examples of the present invention are compared with the sliding characteristics of the prior art,
It can be seen that the PV value, wear rate, and friction coefficient are all excellent. Further, in oil, the material according to the present invention shows almost the same results as the conventional material.

As shown in the above table, the reason why the plastic composite material according to the present invention exhibits excellent sliding characteristics as compared with the conventional example is considered as follows.

First of all, since the elastic modulus is low, there is no contact portion that causes one-sided contact, and seizure resistance is improved. Further, it is considered that the contact part is enlarged as shown in FIG. 4, and a part of the organic fiber 23 is exposed on the surface of the base plastic 22, and this plastic composite material is used as a hard mating material (ceramic or corrosion resistant material). When it slides against the metal) 24, the soft plastic part 22 in the plastic composite material is worn, and the organic fiber 23 having a high elastic modulus and excellent wear resistance supports the vertical load. Then, it will not be baked unless the water film between the plastic 22 and the mating material 24 is broken, and even if the water film is locally or momentarily broken, the organic fiber 23 and the mating material having excellent heat resistance
It will not slide easily because it slides with 24.

〔The invention's effect〕

According to the present invention, a plastic composite material in which plastic is combined with an organic fiber is used for one of the two sliding contact surfaces that are in sliding contact with each other, and has a higher elastic modulus than the plastic composite material used for the other sliding contact surface. In a water piston pump using a corrosion resistant material such as metal or ceramic, polyetherketone is used as a base plastic as the plastic composite material, and aromatic polyamide fiber is contained as an organic fiber in an amount of 3 to 70% by volume. As a result, the PV value, wear rate, and friction coefficient, which are sliding characteristics in seawater, are excellent, and as a result, under the high pressure at which a commonly used hydraulic pump is operating. Even if it is used in seawater, seizure does not occur on the sliding surface, and it is possible to obtain a water piston pump having an excellent output weight ratio.

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention.
FIG. 2 is a sectional view of an axial piston pump, FIG. 2 is a diagram showing elastic moduli of sliding materials used in conventional seawater pumps and sliding materials in the examples of the present invention, and FIG. Fig. 4 is a diagram showing the limit PV value with respect to the ratio, Fig. 4 is an enlarged sectional view showing the contact portion of the sliding surface, Fig. 5 is a partially cutaway front view of a conventional piston pump, and Fig. 6 is one of them. It is a partial fracture side view. 11 is a cylinder block, 12 is a bearing plate, 13 is a valve plate, 14 is a piston, 15 is a sleeve, 16 is a slipper, 16a is a sliding piece, 17 is a rocker cam, 22 is plastic, 23 is organic fiber, and 24 is a mating material. .

Claims (1)

(57) [Claims] 1. A metal having a higher elastic modulus than the plastic composite material used for one of the two sliding contact surfaces, which is made of a composite of plastic and organic fiber, and used for the other sliding contact surface. Alternatively, in a water piston pump using a corrosion resistant material such as ceramics, polyether ether ketone is used as a base plastic as the plastic composite material, and aromatic polyamide fiber is contained as an organic fiber in an amount of 3 to 70% by volume. Piston pump for water.