JP2001153064A - Reciprocating pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reciprocating pump capable of easily assembling and disassembling a gland and being manufactured at low cost without being limited by the material of the gland. SOLUTION: This reciprocating pump comprises a plunger 14 having one end connected to a drive part and reciprocating in a cylinder 12, a seal member 16 installed on the inner peripheral surface of the cylinder 12 and coming in contact slidably with the plunger 14 for prevention of leakage, a bracket 10 for storing the cylinder 12, a delivery flange 44 covering the closed side of the bracket 10, and a gland 22 continuously installed, coaxially with the cylinder 12, on the opening side of the bracket 10 and having a coolant flow path 28C allowing the coolant to flow therein. A flange part 30 engaged with a stepped surface 10a formed in the bracket 10 is formed in the gland 22, and the delivery flange and bracket 10 are tightened so as to engage the stepped part with the flange part 30 in order to fix the gland 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crank type reciprocating pump used for washing machine parts using, for example, high-pressure water, or for removing concrete.

[0002]

2. Description of the Related Art A crank type reciprocating pump is a pump in which a rotary motion of a driving machine such as a motor or an engine is converted into a reciprocating motion by a crankshaft and a fluid is pushed out by a plunger or a piston. It has a high discharge pressure while discharging amount.

FIG. 2 shows a main part of a conventional general reciprocating pump (plunger pump), which comprises a cylinder 12 housed in a bracket 10 and a cylinder 1.
The plunger 14 reciprocates a predetermined stroke S between the top dead center (suction end) and the bottom dead center (discharge end) inside the inside of the cylinder 2, and pressurized high-pressure water does not leak outside from the upper part of the cylinder 12. A sealing member 16 is provided. Then, the fluid sucked into the cylinder 12 from the suction port 18 in the suction stroke due to the rise of the plunger 14 is
Discharge port 20 in the discharge stroke due to lowering of plunger 14
, A high discharge pressure is obtained.

Here, the discharge pressure is, for example, 49 MPa.
In a high-pressure pump, the temperature of the surface of the plunger and the sliding surface of the seal member 16 rises due to heat generated by sliding between the plunger 14 and the seal member 16, and ceramic is mainly used for the plunger. Although there is no heat problem, the life of the seal member 16 is reduced. Therefore, in such a high-pressure pump, a gland 22 is provided for cooling the plunger 14 and the seal member 16 disposed around the plunger 14. Then, the surface of the plunger 14 is cooled by injecting the cooling liquid from the injection tube 72a of the ground collar 68 and discharging it from the discharge tube 72b. By cooling the plunger surface in this way, the temperature rise on the sliding surface of the seal member 16 is limited.

The gland 22 firstly prevents the sealing member from jumping upward due to the internal pressure of the cylinder, and secondly forms a liquid pool of a cooling liquid for cooling the plunger surface, so that the cooling liquid does not leak upward. For sealing the ground seal. The ground 22
A screw having a cylindrical shaft portion 28 and a flange portion 30 and screwing a male screw portion 28a carved on the outer peripheral surface of the shaft portion 28 to a female screw portion 12a carved on the inner peripheral surface of the cylinder 12. It is fastened to the cylinder 12 by coupling.

Although not shown, there is also a structure in which the end surface of the flange portion of the gland is brought into contact with the end surface of the cylinder or the bracket, and the gland is fastened to the cylinder or the bracket via a plurality of bolts penetrating the flange portion in the axial direction. It is well known.

[0007]

However, the former of the prior art in which the gland is fastened to the cylinder by so-called screw connection has the following problems. In order to screw the gland into the cylinder, it is necessary to fix the cylinder, and therefore, the cylinder needs to be chamfered for vise. Since the cylinder is generally a component having a large outer diameter, a large vise is required to fix the cylinder. In order to firmly fix the cylinder to the vise, a chamfer having a wide surface is necessary, and there is a possibility that the thickness of the cylinder is reduced at this portion, resulting in insufficient strength.

[0008] A repetitive reaction force of the discharge pressure acts on the screw through the seal, and the screw may be minutely deformed by the reaction force, or wear debris of the seal may cut into the ground portion. In such a case, a large force is required to disassemble. Since the deformation of the screw may cause galling, the cylinder and the gland must be made of different materials. For this reason, a cylinder requiring high strength is mainly made of precipitation hardening stainless steel, and the gland is often made of a copper alloy in consideration of galling resistance. However, when dealing with liquids that dislike copper alloys, it is difficult to select materials. Although the gland seal 25 is attached to the gland, the gland seal is hard to come out of the plunger due to the play of the screw, so that leakage is likely to occur.

[0009] The latter, in which the gland is fastened to the cylinder or the bracket using bolts, has the following problems. The bolts for fastening the gland must be tightened from the side of the opening (window W in FIG. 2) of the bracket, but there is not enough space on the side of the opening, and the tightening operation is considerably troublesome. In addition, if there is a bolt on the opposite side of the window W, the workability is further deteriorated, and a tool may be applied to the plunger during the work, possibly damaging the plunger. Repetitive reaction force of the discharge pressure acts on the bolt via the seal, and thus a repeated load acts. We want to control the torque so that the bolts do not become loose or fatigue-damaged by this repeated load, but the work space is too narrow to perform the work we think. The cylinder is made thick because pressure resistance is required, but the internal thread must be set up for the bolt, so the strength of the cylinder is sacrificed.

In order to solve such a problem, it is conceivable to increase the size of the bracket. However, the cost and weight increase, and the demand for compactness cannot be met.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a reciprocating pump which is easy to assemble and disassemble a gland and can be manufactured at a low cost without being restricted by the material of the gland. The purpose is to provide.

[0012]

According to the first aspect of the present invention, a plunger having one end connected to a drive unit and reciprocating in a cylinder is mounted on an inner peripheral surface of the cylinder and slidably contacts the plunger. A seal member for preventing liquid leakage, a bracket for accommodating the cylinder, a discharge flange for covering a sealed side of the bracket, and a coaxially connected cylinder with an open side of the bracket for circulating a coolant therein. A gland having a coolant flow path to be formed, the gland is formed with a flange portion that engages with a step surface formed on the bracket, and the discharge flange and the bracket are fastened to form the flange. The reciprocating pump is characterized in that the step surface and the flange are engaged to fix the gland.

Accordingly, the gland can be formed without embossing a male screw or using a bolt for fastening the gland.
As the discharge flange and the bracket are fastened, the flange portion is clamped and fixed between the bracket and the end face of the cylinder.

According to a second aspect of the present invention, there is provided a tightening nut for connecting the plunger to the plunger rod, and an outer diameter of the tightening nut is set smaller than a minimum inner diameter of the bracket. A reciprocating pump according to claim 1. Thereby, the fastening nut can be passed through the inside of the bracket with the fastening nut attached to the plunger, and the structure of the fastening nut portion and the assembling work can be simplified.

According to a third aspect of the present invention, a seal member for surface sealing is interposed between an end surface of the cylinder and an end surface of a flange portion of the gland. Reciprocating pump. The sealing member for surface sealing is formed by a rubber O-ring such as NBR. Thus, even if the bracket is made of a rust-prone material such as a casting, it is possible to prevent the liquid from entering the inner periphery of the bracket and to prevent the cylinder from sticking to the bracket.

According to a fourth aspect of the present invention, a portion of the gland protruding from the bracket is provided with a circumferential groove for a cylindrical seal and a through hole radially penetrating therethrough, and the inside of the circumferential groove is watertight. 2. The reciprocating pump according to claim 1, further comprising a ground collar for supplying a coolant while surrounding the pump. This greatly simplifies the work of attaching the ground collar to the ground. It should be noted that bolts are provided for circumferential alignment of the ground collar and axial fixing.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. This embodiment shows an example in which the present invention is applied to a plunger pump, and the same members as those in the conventional example shown in FIG.

The plunger pump has a bracket 10
And a plunger 14 reciprocating within the cylinder 12 by a predetermined stroke S
And a seal member 16 for preventing pressurized high-pressure water from leaking from the upper portion of the cylinder 12 to the outside. In this example, the sealing member 16 is made of a string-like packing having a fiber structure impregnated with resin and having a rectangular cross section, and a bearing 34 fitted to the upper part and a lower sealing part on the inner peripheral surface of the cylinder 12. It is clamped between the presser 36 and fixed. Further, a compression coil spring 40 that urges the seal member 16 upward to provide a seal effect to the seal member 16 is interposed between the seal retainer 36 and the cylinder sleeve 38 mounted on the lower part of the cylinder 12. .

A suction case 42 having a suction port 18 is connected to the lower end of the bracket 10.
A discharge flange 44 having a discharge port 20 is connected to a lower end of the discharge flange 44. At the lower end of the cylinder 12, a check valve sheet 46 is discharged inside the suction case 42 so that the flange 4
4 and is fixed.

Inside the check valve seat 46, there are provided a suction side flow path 46a communicating with the suction port 18 and a discharge side flow path 46b communicating with the discharge port 20 respectively. Further, on the upper surface of the check valve seat 46, the suction side valve spring 4
The suction-side poppet 50 urged downward at 8 is arranged to form the suction check valve 52, and the check valve seat 46 is provided.
A discharge side poppet 56 urged upward by a discharge side valve spring 54 is disposed on a lower surface of the discharge check valve 58.
Is configured.

Accordingly, when the suction side poppet 50 is separated from the upper surface of the check valve seat 46 against the elastic force of the suction side valve spring 48, the fluid is sucked from the suction port 18 into the cylinder 12. When the discharge side poppet 56 separates from the lower surface of the check valve seat 46 against the elastic force of the discharge side valve spring 54, the cylinder 12
The discharge of the fluid inside is performed. A discharge tube 60 is connected to the discharge port 20.

On the upper part of the cylinder 12, a cylindrical shaft part 2 is provided.
A gland 22 having a flange 8 and a flange portion 30 formed at the end of the shaft portion 28 on the cylinder 12 side is arranged so that the plunger 14 is inserted therein. The bracket 10 is provided with an opening 10 b having an inner diameter substantially the same as the outer diameter d ₁ of the shaft 28 of the gland 22 concentrically with the plunger 14, and the gland 22 engages the shaft 28 in the opening 10 b. Are housed in the bracket 10 with their ends protruding from the bracket 10 to the outside. Between the end surface of the flange portion 30 and the end surface of the cylinder 12, a sealing member 62 for sealing the surface, which is constituted by a rubber O-ring such as NBR, is interposed.

At the other end of the bracket 10, a plurality of studs 64 are protruded and studded, and the discharge flange 44 is inserted through the studs 64, and a nut 66 is screwed into the stud. The other end of the bracket 10 is fixed. Then, the discharge flange 44 and the bracket 10
The check valve seat 46, the cylinder 12, and the gland 22 are housed therein while receiving a compressive stress in the axial direction.

To assemble the plunger pump of this embodiment, the gland 22 and the cylinder 12 containing the plunger 14 are sequentially arranged inside the bracket 10, and the suction case 42, the check valve seat 46 and the discharge flange 4
After sequentially disposing the nuts 4, the nut 66 is screwed into the studs 64 and tightened. Suction case 4
2 has a bolt (not shown) for attaching only this to the bracket, and once attached, usually does not disassemble. The gland 22 is firmly fixed by the flange portion 30 being sandwiched between the step surface 10 a inside the bracket 10 and the end surface of the cylinder 12. Here, even in the case of a multiple plunger pump having a plurality of cylinders, the discharge flange is configured to be paired with the cylinder, so that a subtle error in the length direction of the cylinder 12 or the gland 22 can be absorbed. Can be.

The disassembly of the plunger pump is performed by the nut 6
After removing 6, the pressing can be easily performed by pressing the end face of the shaft portion 28 of the ground 22 on the open portion (the window W provided in the frame 84) side downward. In this example, an example is shown in which the stud bolt 64 and the nut 66 are used. However, an ordinary bolt may be screwed into a screw hole provided in the bracket 10 and tightened.

The bracket 10 of the shaft 28 of the ground 22
A more protruding end is provided with a circumferential groove for a cylindrical seal and a through hole 28c extending radially. A ground collar 68 having a circumferential groove 28b therein for supplying a coolant to the inside of the ground 22 is provided with one bolt 7
The bracket 10 is fixed to the bracket 10 via the “0”. Of course, the circumferential groove 28b may be formed on the ground side.

A cooling liquid injection tube 72a and a discharge tube 72b are connected to the ground collar 68, and the cooling liquid injected into the ground collar 68 from the injection tube 72a is supplied and held inside the gland 22,
It is configured to be discharged from the discharge tube 72b.
If these tubes 72a and 72b are fixed outside the bracket 10, the fixing bolt 70 is unnecessary. If a resin tube is used, a bolt 70 is required. Since the shaft portion 28 of the gland 22 can be attached at an arbitrary position in the circumferential direction, when the gland 22 is fitted into the bracket, the work is simplified because it is not trapped in the circumferential direction.

The plunger 14 is connected to the lower end of a plunger rod 76 via a connecting portion 74 having a universal joint structure. The plunger rod 76 is configured to move up and down with rotation of a crankshaft (not shown). The connecting portion 74 is a thrust ring 80 that sandwiches the tightening nut 78 and the ball portion 14 a provided at the end of the plunger 14 from above and below so as not to escape.
And a thrust plate 82, and a tightening nut 78
And the plunger 14 and the plunger rod 76 are connected so as to be relatively movable. That is, since the dimensions are controlled so that a gap of about 0.05 mm is formed in the axial direction, the plunger 14 can absorb the misalignment between the cylinder 12 and the plunger rod 76.

The outer diameter d ₂ of the tightening nut 78 is set to be smaller than the inner diameter of the bracket 10 on the open side, that is, the outer diameter d ₁ of the shaft portion 28 of the gland 22 (d ₂ <d ₁ ).
The fastening nut 78 is configured to be able to pass through the opening 10 b of the bracket 10. Thereby, the assembling can be performed with the tightening nut 78 and the thrust ring 80 set at the upper end of the plunger 14. By adopting such a structure, it is not necessary to use, for example, a horseshoe-shaped connecting piece or the like for preventing the plunger from coming off. Therefore, the present invention can be applied to a thicker plunger, and the assembling work can be simplified. it can.

In this example, the bracket 10 and the frame 84 including the crank mechanism extending upward from the bracket 10 are shown as separate bodies. However, it is needless to say that they may be integrally formed. It is. In this case, since it is difficult to machine the female screw for the bolt 70, the injection tube 72a and the discharge tube 72b must be made of a stainless steel pipe or the like and fixed outside the bracket.

As described above, in the plunger pump according to this embodiment, the gland 22 and the cylinder 12 containing the plunger 14 are sequentially arranged inside the bracket 10, and the suction case 42 and the check valve seat 46 are further arranged.
After the discharge flanges 44 are sequentially arranged, the nut 66 is screwed into the stud bolt 64 and tightened.
The ground 22 can be fixed by a simple process. Then, a ground collar 68 is mounted on the shaft portion 28 of the ground 22, and the tubes 72a, 7
By connecting 2b, a cooling liquid is introduced and held in the gland 22, and the plunger 14 is cooled with the cooling liquid, thereby suppressing a rise in the temperature of the seal member 16 and maintaining stable operation.

[0032]

As described above, according to the present invention,
The plunger can be cooled by fixing the gland in a predetermined position without performing a screwing operation or a bolt tightening operation for the gland. This facilitates assembly and disassembly of the gland, eliminates restrictions on the material of the gland, and reduces the manufacturing cost by using only spigot parts.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a plunger pump according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of a conventional plunger pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Bracket 10a Step surface 10b Opening 12 Cylinder 14 Plunger 14a Ball part 16 Sealing member 22 Gland 28 Shaft part 28b Circular groove 28c Through hole 30 Flange part 44 Discharge flange 46 Check valve seat 48 Suction side valve spring 50 Suction side poppet 52 Suction check valve 54 Suction side valve spring 56 Discharge side poppet 58 Discharge check valve 62 Face seal 64 Stud bolt 66 Nut 68 Ground collar 72a Coolant injection tube 72b Coolant discharge tube 74 Connecting portion 76 Plunger rod 78 Plunger tightening Nut 80 Thrust ring 82 Thrust plate

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Shoji Saito 11-1 Haneda Asahimachi, Ota-ku, Tokyo F-term in Ebara Corporation (reference) 3H071 AA01 CC01 CC28 CC31 CC32 DD01 DD06 DD31 DD51 DD82 DD89

Claims (4)

[Claims] 1. A plunger having one end connected to a drive unit and reciprocating in a cylinder, a seal member mounted on an inner peripheral surface of the cylinder and slidingly contacting the plunger to prevent liquid leakage, and accommodating the cylinder. A bracket, a discharge flange that covers the closed side of the bracket, and a gland that is provided coaxially with the cylinder on the open side of the bracket and that has a coolant flow path through which coolant flows, A flange portion is formed on the gland to engage with a step surface formed on the bracket. By fastening the discharge flange and the bracket, the step surface and the flange portion engage to form the gland. The reciprocating pump is characterized in that the pump is fixed. 2. The reciprocating device according to claim 1, further comprising a tightening nut for connecting the plunger to a plunger rod, wherein an outer diameter of the tightening nut is set smaller than a minimum inner diameter of the bracket. Dynamic pump. 3. The reciprocating pump according to claim 1, wherein a seal member for surface sealing is interposed between an end surface of the cylinder and an end surface of the flange portion of the gland. 4. A portion of the gland protruding from the bracket to the open side is provided with a circumferential groove for a cylindrical seal and a through hole radially penetrating therethrough, and watertightly surrounds the inside of the circumferential groove. 2. The reciprocating pump according to claim 1, further comprising a ground collar for supplying a cooling liquid through the pump.