JP3851510B2 - Reciprocating machine crankcase - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a crankcase provided with a piston guide into which a crosshead is slidably fitted, and more particularly to a crankcase of a reciprocating machine such as a reciprocating pump or a reciprocating compressor.
[0002]
[Prior art]
FIG. 5 is a longitudinal sectional view showing an example of a plunger pump in which a conventional crankcase is incorporated.
This plunger pump is configured by joining a manifold 12 and a crankcase lid 13 to the front end and the rear end of a crankcase 11, respectively. The crankcase 11 is filled with lubricating oil in the lower half thereof. A crankshaft 14 is rotatably supported on both side wall portions of the crankcase 11 through bearings, and a large end portion 17 of a connecting rod 16 is rotatably fitted to a crankpin 15 of the crankshaft 14, and is connected to one side. The rear end portion of the cross head 19 is connected to the small end portion 18 of the rod 16 by a cross pin 20.
[0003]
The cross head 19 is fitted into the piston guide 11 a of the crankcase 11 so as to be slidable in the front-rear direction of the crankcase 11 and is connected to the base end portion of the plunger 21. In front of the guide portion 11a ₁ of the crosshead 19 of the piston guide 11a is fitted, oil seals 20A, seal retainer 20B for pressing it is inserted. A sleeve 22 is detachably fixed to the distal end portion of the plunger 21. A pump chamber 23 in which the tip of the plunger 21 advances and retreats is formed in the manifold 12, and a suction valve 24 and a discharge valve 25 are disposed in the pump chamber 23.
[0004]
The crankcase 11 is formed in a cylindrical shape having an open front surface and a rear surface and gradually expanding from the front surface toward the rear surface. An oil cap 26 is screwed and attached to the front center portion of the upper surface of the crankcase 11. An oil gauge 27 is press-fitted and attached to the center of the crankcase lid 13, and a drain plug 28 is screwed to the center of the lower end.
[0005]
In this plunger pump, when the crankshaft 14 is rotated by a motor or the like, the rotational movement of the crankshaft 14 is converted into the reciprocating movement of the crosshead 19 by the crankpin 15 and the connecting rod 16, whereby the plunger 21 is converted into the pump chamber. As the volume of the pump chamber 23 changes, liquid flows from the suction valve 24 into the pump chamber 23 and is discharged from the discharge valve 25. At this time, the cross head 19 is guided by the guide portion 11a ₁ of the piston guide 11a, reciprocates in the longitudinal direction.
[0006]
[Problems to be solved by the invention]
By the way, the crankcase is a component that greatly affects the size and performance of the pump. That is, larger ejection amount and the pressure, the force acting such as driver and piston guide 11a of the guide portion 11a ₁ of such crankshaft 14 is increased, along with the need to increase the like diameter of the guide portion 11a ₁ The crankcase 11 needs to be enlarged.
On the other hand, since the crankcase is usually manufactured by a die casting method, the mold cost is high.
[0007]
However, since the piston guide 11a is integrally formed in the conventional crankcase 11, if the size or number of the piston guide 11a changes according to the discharge amount, pressure, or the number of plungers 21, the crankcase 11 itself needs to be produced according to this. That is, it is necessary to produce a different crankcase 11 for each type of plunger pump by the die casting method. For this reason, there is a problem that the cost of the crankcase is increased for each model, and the manufacturing cost is increased.
[0008]
In addition, since the piston guide 11a is integrally formed with the crankcase 11, the shape is complicated, the cost for manufacturing the mold is increased, and the amount of waste is increased. There is a problem that the manufacturing cost increases in these aspects as well.
Further, since the shape is complicated and there is a lot of waste, there is a problem that a cast hole is likely to occur during die casting.
[0009]
The present invention has been made in view of the above circumstances, and it is possible to manufacture reciprocating machines such as a plurality of types of reciprocating pumps and reciprocating compressors while sharing parts, and manufacture of these reciprocating machines. An object of the present invention is to provide a crankcase for a reciprocating machine capable of reducing the cost.
It is another object of the present invention to provide a crankcase for a reciprocating machine that can be simplified in shape and reduced in mold cost.
Another object of the present invention is to provide a crankcase for a reciprocating machine having a good casting yield during casting.
[0010]
[Means for Solving the Problems]
To achieve the above object, a crankcase of a reciprocating machine according to claim 1, a crankcase (40 reciprocating machine with piston guide crosshead (58) is fitted freely reciprocating sliding (42) ) comprising a crank case body (31), the crank case body (31) and separate the piston guide (42) Ri formed is attached, the piston guide (42) is parallel to a plurality each other The guide portions (42a) are provided, and these guide portions (42a) are arranged so as to be offset from the center of the crankshaft journal .
[0011]
In the invention described in claim 1, since the crankcase body and the piston guide are separate parts, a plurality of types of reciprocating pumps can be obtained by changing the type of piston guide attached to one crankcase body. Alternatively, reciprocating machines such as a plurality of types of reciprocating compressors can be manufactured. That is, a plurality of types of reciprocating pumps and the like can be manufactured by changing the piston guide while using a common crankcase body. Therefore, since the kind of crankcase main body with high mold cost can be reduced, the manufacturing cost of these reciprocating machines can be reduced.
Also, since the crankcase body and piston guide can be manufactured as separate parts, the shape of each of these parts can be simplified, so that the mold processing costs can be reduced and the mold costs can be reduced. Can be reduced.
In addition, since the shapes of the crankcase body and the piston guide can be simplified, the waste can be reduced, so that the casting yield can be improved during casting. Manufacturing cost can be reduced.
[0013]
In addition , by attaching a piston guide with the guide part shifted to the crankcase body, the pitch between the guide parts can be widened. For this reason, for example, the pitch of a cylinder or plunger of a reciprocating pump or the like. Therefore, the cylinder diameter and plunger diameter can be increased. Therefore, the discharge amount can be increased while the crankcase body is shared.
In addition, when a piston guide in which the guide portion is displaced is used, for example, a five-way reciprocating pump can be manufactured in place of a three-way reciprocating pump while using a common crankcase body.
[0014]
The crankcase of the reciprocating machine according to claim 2 is the box-like shape of the invention according to claim 1 , wherein the crankcase body (31) has a front surface opened and gradually narrowed from the front surface toward the rear surface. It is characterized by being formed.
[0015]
In the invention according to claim 2 , since the crankcase body is formed in a box shape that gradually narrows from the front surface toward the rear surface, the sound of the piston of the piston pump is prevented from diffusing backward. Therefore, the sound of the reciprocating machine can be made quieter.
Moreover, since the crankcase body is formed in a box shape, it is not necessary to create a crankcase lid and assemble it, so that the manufacturing cost can be reduced.
[0016]
In addition, the code | symbol in the bracket | parenthesis in the above expresses the corresponding element in drawing for convenience, Therefore, this invention is not limited to description on drawing. The same applies to the description in the column “Claims”.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a crankcase of a plunger pump according to a first embodiment of the present invention.
The crankcase 30 according to the present embodiment includes a crankcase body 31 and a piston guide 32.
[0018]
The crankcase main body 31 is manufactured by a die casting method, and is formed in a box shape having an open front surface and gradually narrowing from the front surface toward the rear surface. An oil cap mounting portion 31 a into which the oil cap is screwed is formed at the front center portion of the upper surface of the crankcase body 31. An oil gauge mounting portion 31b into which an oil gauge is screwed is formed at the center of the rear surface of the crankcase body 31. In addition, a circular through hole 31c for inserting and supporting a crankshaft is formed in the rear center portion of both side surfaces of the crankcase body 31.
[0019]
On the other hand, the piston guide 32 is a separate component from the crankcase body 31 and is manufactured by a die casting method. A plurality of guide portions 32a are provided in a line at equal intervals in the left-right direction at the center portion of the piston guide 32, and a crosshead is slidably fitted into the guide portions 32a in the front-rear direction. An oil seal, a seal presser, and the like are disposed in front of the guide portion 32a of the piston guide 32. Further, the piston guide 32 is formed with a flange 32b. A sealing member 33 such as an “O” ring is inserted into an annular groove 32c formed in the flange 32b. The sealing member 33 is sandwiched between the flange 32b and the front end face of the crankcase main body 32 so as to be in this state. Thus, the bolt 34 is screwed into the front end surface of the crankcase body 31, and the piston guide 32 is attached to the front end portion of the crankcase body 31.
[0020]
Further, the piston guide 32, the ribs 32d extending crank case body 31 from the guide portion 32a and the flange 32b to the rear are formed, the outer peripheral edge portion 32d ₁ of the ribs 32d is the inner surface of the crank case body 31 It is inserted. The ribs 32d reinforce the strength of both the piston guide 32 and the crankcase 31. An oil drain hole 32e for draining oil from the crankcase body 31 is provided at the center of the lower end of the flange 32b. A drain plug is screwed into the oil drain hole 32e.
[0021]
In the crankcase 30 configured in this way, the crankcase body 31 and the piston guide 32 are separate parts, so the type of the piston guide 32 attached to one crankcase body 31 is changed. Thus, a plurality of types of plunger pumps can be manufactured. That is, a plurality of types of plunger pumps can be manufactured by changing the piston guide 32 while using the crankcase body 31 in common. Therefore, since the kind of crankcase main body 31 with a high mold cost can be reduced, the manufacturing cost of the plunger pump can be reduced.
[0022]
Moreover, since the crankcase main body 31 and the piston guide 32 can be manufactured as separate parts, the shape of each of these parts can be simplified. Therefore, the mold processing cost can be reduced, and the mold cost can be reduced.
In addition, since the shapes of the crankcase body 31 and the piston guide 32 can be simplified, the waste of these parts can be reduced, so that the casting yield of these parts can be improved during casting. Therefore, the manufacturing cost of these parts can be reduced.
[0023]
FIG. 2 is a longitudinal sectional view showing a piston pump incorporating a crankcase according to the second embodiment of the present invention. In FIG. 2, the same components as those in FIG.
The crankcase 40 according to the present embodiment includes a crankcase body 31 and a piston guide 42. The piston guide 42 is different from the guide portion 32a shown in FIG. 1 in that a plurality of guide portions 42a parallel to each other are provided so as to be displaced in the vertical direction, and other configurations are the same. It is configured identically.
[0024]
The piston pump in which the crankcase 40 is incorporated is configured as follows.
In other words, the oil cap 51 is screwed into the oil cap mounting portion 31 a formed at the front center portion of the upper surface of the crankcase body 31. An oil gauge 52 is screwed into an oil gauge mounting portion 31b formed at the center of the rear surface of the crankcase body 31. In addition, the crankshaft 53 is inserted into the through holes 31c formed in the rear center part of both side surfaces of the crankcase body 31, and both ends of the crankshaft 53 are inserted through bearings mounted on a bearing case (not shown). The part is rotatably supported. A large end portion 56 of a connecting rod 55 is rotatably fitted to the crank pin 54 of the crankshaft 53, while a rear end portion of the cross head 58 is connected to a small end portion 57 of the connecting rod 55 by a cross pin 59. Has been.
[0025]
The cross head 58 is fitted into the guide portion 42 a of the piston guide 42 so as to be slidable in the front-rear direction of the crankcase 40. An oil seal 61 and a seal presser 62 for pressing the oil seal 61 are inserted in front of the guide portion 42a. The piston guide 42 sandwiches the seal member 33 so that the flange 32b and the front end surface of the crankcase main body 32 abut each other. In this state, the bolt 34 is screwed into the front end surface of the crankcase main body 31 and the crankcase main body 31 is inserted. It is attached to the front end. A drain plug 63 is screwed into the oil drain hole 32e formed at the center of the lower end of the flange 32b.
[0026]
A proximal end portion of the piston rod 71 is connected to the front end of the cross head 58. A felt packing 64 is inserted into the base end of the piston rod. Further, a suction valve 72, and a collar 73 is interposed between the suction valve 72 and the front end of the piston rod 71 with an interval corresponding to the length of the collar 73, and an outer peripheral portion. A stopper 74 having a through-hole 74 a is provided, and a suction valve valve seat 75 loosely fitted to the collar 73 is provided between the suction valve 72 and the stopper 74. A piston packing 75A made of rubber or the like is mounted on the outer peripheral side of the suction valve valve seat 75.
[0027]
A cylinder base fitting 77 is joined to the front end of the piston guide 42, and a piston rod 71 is inserted into the cylinder base fitting 77. A suction port 79 is provided between the seal 78 installed on the piston guide 42 side of the cylinder base metal 77 and the suction valve 72. The seal 78 is pressed by the front end of the seal presser 62.
[0028]
The rear end of the cylinder 81 is fitted into the front end of the cylinder base metal 77, and the front end of the cylinder 81 is fitted into the rear end of the cylinder front metal 82. The cylinder base bracket 77, the cylinder 81, and the cylinder tip bracket 82 are fixed to the front side of the piston guide 42 by tightening the cylinder tip bracket 82 toward the piston guide 42 side with bolts screwed into the piston guide 42. ing. On the inner surface of the cylinder 81, a piston packing 75A of the suction valve valve seat 75 is slid. The cylinder tip fitting 82 is provided with a discharge valve 83 and a discharge port 84.
[0029]
In the so-called forced valve type piston pump configured as described above, when the crankshaft 53 is rotated by a motor or the like, the rotational movement of the crankshaft 53 is reciprocated by the crankpin 54 and the connecting rod 55. As a result, the piston rod 71 reciprocates in the front-rear direction. At this time, the crosshead 58 is guided by the piston guide 42a of the crankcase 40 and reciprocates in the front-rear direction.
[0030]
When the piston rod 71 moves rearward (right in FIG. 2), the suction valve valve seat 75 moves away from the suction valve 72, the pressure in the cylinder 81 decreases, and the discharge valve 83 closes. Moves forward between the suction valve 72 and the suction valve valve seat 75, between the suction valve valve seat 75 and the collar 73, and further through the through hole 74a of the stopper 74. Further, the suction port 79 side has a negative pressure corresponding to the volume of movement of the piston rod 71 from the seal 78 toward the crankcase 40, and liquid is sucked from the suction port 79.
[0031]
On the other hand, when the piston rod 71 moves forward (left side in FIG. 2), the suction valve valve seat 75 comes into close contact with the suction valve 72, and the liquid in front of the suction valve 72 pushes the discharge valve 83 open and discharges to the discharge port 84. At the same time, the suction port 72 has a negative pressure on the rear side of the suction valve 72 by the volume of the movement of the suction valve 72 forward, and the liquid is sucked from the suction port 79.
[0032]
In this piston pump, a collision sound is generated when the suction valve valve seat 75 hits the suction valve 72, and this collision sound is transmitted through the piston rod 58 and the like to propagate through the crankcase body 31 and diffuse backward. . However, since the crankcase body 31 is formed in a box shape that gradually narrows from the front surface toward the rear surface, it is possible to suppress the collision sound from diffusing rearward, so that the piston pump sound can be further reduced. Can be quiet.
Further, since the crankcase body 31 is formed in a box shape, it is not necessary to create a crankcase lid and assemble it as in the conventional case, so that the manufacturing cost can be reduced.
[0033]
Next, the guide part 42a of the piston guide 42 will be described.
In the case of a triple piston pump, for example, as shown in FIGS. 2 and 3, the plurality of guide portions 42a are a center guide portion 42a and left and right guide portions 42a, 42a, respectively. It is offset from O and above and below.
In this way, as compared with the case where the three guide portions 32a as shown in FIG. 1 are arranged in a row at the same height, than the pitch L ₀ pitch L ₁ is between the guide portions 32a between the guide portions 42a Therefore, the diameter of the cylinder 81 can be increased accordingly. Therefore, the discharge amount can be increased by changing the piston guide while using the crankcase body 31 in common.
[0034]
Further, for example, in the case of a five-unit piston pump, as shown in FIG. 4, the plurality of guide portions 42a are staggered, that is, alternate from the center O of the crankshaft journal. Are formed so as to be displaced vertically.
In this way, the five guide portions 42a are formed with the same dimensions as the total pitch L of the three guide portions 32a when the three guide portions 32a of FIG. 1 are arranged in a line at the same height. Can do. Therefore, the number of cylinders can be increased by changing the piston guide while using the crankcase body 31 in common.
[0035]
Further, changing the dimension of the guide portion 42a in the guide direction can cope with a change in the crank stroke. For example, when it is desired to increase the discharge amount by extending the crank stroke, the piston guide 42 having a long guide portion 42a in the guide direction may be attached to the crankcase body 31.
[0036]
In each of the above embodiments, the case where the crankcase according to the present invention is applied to a crankcase of a plunger pump or a piston pump has been described. However, the present invention is not limited to these reciprocating pumps. It can also be applied to other crankcases.
[0037]
【The invention's effect】
As described above, according to the present invention, it is possible to manufacture reciprocating machines such as a plurality of types of reciprocating pumps and reciprocating compressors while sharing parts, and reduce the manufacturing cost of these reciprocating machines. be able to.
Further, according to the present invention, the shapes of the crankcase body and the piston guide can be simplified, so that the mold costs of these parts can be reduced.
Further, according to the present invention, the casting yield of these parts is good when casting the crankcase body and the piston guide.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a crankcase of a plunger pump according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a piston pump incorporating a crankcase according to a second embodiment of the present invention.
FIG. 3 is a view for explaining the arrangement of guide portions of the piston guide of FIG. 3;
FIG. 4 is a view for explaining the arrangement of guide portions of a piston guide in the case of a five-unit piston pump.
FIG. 5 is a longitudinal sectional view showing an example of a plunger pump incorporating a conventional crankcase.
Crankcase 30, 40
Crankcase body 30
Piston guide 32, 42
Guide part 32a, 42a
Crosshead 58

Claims (2)

A crankcase ( 40 ) of a reciprocating machine having a piston guide ( 42 ) into which a crosshead (58) is slidably fitted.
The crankcase body (31), formed Ri and separate the piston guide (42) is mounted with the crank case body (31),
The piston guide (42) includes a plurality of guide portions (42a) parallel to each other, and the guide portions (42a) are arranged so as to be offset from the center of the crankshaft journal. Crankcase. The reciprocating machine crankcase according to claim 1 , wherein the crankcase body (31) is formed in a box shape having an open front surface and gradually narrowing from the front surface toward the rear surface.

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