JP4435743B2 - Reciprocating compressor - Google Patents

Description

  The present invention relates to a high-pressure reciprocating compressor, and more particularly to a reciprocating compressor suitable for hydrogen or a CNG stand.

  An example of a conventional high-pressure reciprocating compressor is described in Patent Document 1. The reciprocating compressor described in this publication is a plunger-type small-volume high-pressure compressor. The high-pressure compressor is a two-stage compressor having a first-stage cylinder and a two-stage cylinder. The first-stage and second-stage plungers that move in the cylinder in the axial direction are arranged on the same axis. Each plunger is connected to a motor, which is a drive machine, via a single crank mechanism, and the rotational motion of the motor is converted into a reciprocating motion so that the plunger compresses the working gas.

  The crank mechanism that drives the plunger has a crankshaft connected to a motor and a crankcase that houses the crankshaft. One end of a connecting rod is attached to the crankshaft, and the other end of the connecting rod is connected to a cross head via a cross pin.

  The cross pin can rotate with respect to the connecting rod and the cross head. A slidable shoe portion is formed on the lower surface of the crosshead. When the crankshaft sliding with the receiving surface of the crankcase rotates, the connecting rod swings and the crosshead reciprocates while being guided by the shoe portion. The crosshead is formed in a frame shape, and rods are attached to both ends of the crosshead. A plunger is connected to the tip of the rod.

JP 2004-116329 A

In order to supply fuel supplied to fuel vehicles and CNG (Compressed Natural Gas) vehicles at the same supply station as a conventional gas station, it is essential to make the hydrogen compressor and CNG compressor that compress the fuel compact. It is. In order to make the compressor compact, it is important to reduce the size and size of the drive mechanism that occupies a considerable portion of the compressor and is the main component of the compressor.

  In the high-pressure compressor described in Patent Document 1, a reduction in size is achieved. However, in order to increase the driving distance of fuel vehicles and CNG vehicles, the pressure of the supplied fuel is increasing, and a compression stage for further increasing the pressure is required, and further downsizing is required. Yes.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to configure a high-pressure compressor in a compact manner. Another object of the present invention is to reduce the size and size of a multistage compressor in which the discharge pressure of the compressor exceeds 70 MPa.

A feature of the present invention that achieves the above object is that in a five-stage reciprocating compressor used for hydrogen supply of a fuel cell vehicle or fuel of a CNG vehicle, a first pair of plungers that can move in the horizontal direction, and a vertical direction A first piston that constitutes a first stage compression portion, a first drive portion that drives the first pair of plungers and the first piston, and a second movable in the horizontal direction. A pair of plungers, a second and a third piston that are movable in the vertical direction and constitute a second stage and a third stage compression section, and these second pair of plungers and the second and third pistons The first drive, the first crankshaft to which the first drive is connected, and the second crankshaft to which the second drive is connected. And the second drive unit are placed side by side in the horizontal direction. The first drive unit has a fork-type first horizontal connecting rod for driving the first pair of plungers and a first vertical connecting rod for driving the first piston; The second drive unit includes a fork-type second horizontal connecting rod that drives the pair of second plungers, and a second vertical connecting rod that drives the second piston. The first and second crankshafts are shafts that are eccentrically coupled to a main shaft that transmits a driving force from a driving source, and the first pair of plungers includes a fourth-stage compression section and a fifth-stage compression section. Further, the second pair of plungers also constitute a fourth stage compression part and a fifth stage compression part, and the same stage compression part is arranged on the same side with respect to the main shaft, Drive by the drive unit When the plunger of the fourth-stage compression section is compressed, the plunger of the fifth-stage compression section driven by the other drive section performs the compression operation, and the same-stage plungers move in the horizontal direction with their moving directions opposite to each other. This is because the unbalanced load is canceled .

In this feature, it is preferable to attach balance weights to both ends of each crankshaft so that these balance weights are in reverse phase for each drive unit, and between the first plunger and the first horizontal connecting rod. the frame type crosshead and compression bars, respectively is interposed a frame-type crosshead and compression bar between said second plunger and the second horizontal connecting rods, a lower rigidity than these compression bars each plunger The material is desirable.

  According to the present invention, since three cylinders are connected to one crankpin, the drive unit of the compressor becomes compact, and the entire compressor is reduced in size and size. In addition, two blocks in which these three cylinders are connected to one crank pin are connected in series so that the cylinder phase is reversed for each block, so that the compressor discharge pressure exceeds 70 Mpa. Even in this machine, the drive mechanism is reduced in size and size. Furthermore, since the balance phase is attached while changing the phase of the cylinder, the moment relating to the horizontal motion and the vertical motion of the compressor can be easily balanced, and the vibration propagating to the outside can be reduced.

  Hereinafter, an embodiment of a hydrogen compressor or a CNG compressor according to the present invention will be described with reference to the drawings. FIG. 1 is a three-side view of a drive unit of a hydrogen compressor or a CNG compressor. FIG. 1 (a) is a top sectional view, FIG. 1 (b) is a front sectional view, and FIG. 1 (c) is a side sectional view. It is. FIG. 2 is a perspective view of the main part of the hydrogen compressor or CNG compressor including the drive unit.

  First, a five-stage compressor 100 according to the present invention will be described with reference to FIG. In FIG. 2, the main part including the drive part of the five-stage compressor 100 is shown. In the compressor 100, two blocks are connected in series. In the first block located on the front side in FIG. 2, a pair of plungers 17a and 17b extending in the front-rear direction are connected to a frame-type cross head 13a formed in a frame shape via compression bars 18a and 18b. .

  An inverted T-shaped shoe portion 13c is formed at the lower portion of the frame-type cross head 13a. A cross guide 14a is slidably disposed on both the left and right sides of the shoe portion 13c and covering the upper portion. The cross head 13a has a protrusion on the rear end side, and a cross pin 12a is inserted through the protrusion. Lateral connecting rods 11a are attached to portions on both sides where the cross pin 12a extends from the frame-type cross head 13a. Elongated crank plates 21a and 21b are arranged on both the left and right sides of the horizontal connecting rod 11a. A balance weight 16a is attached to one end in the longitudinal direction of the crank plates 21a and 21b.

  The frame-type cross head 13a has an opening at the top, and the pressing plate 24a presses the opening from both sides. A vertical connecting rod 15a having one end rotatably attached to the crankshaft 10x is inserted into the opening formed between the presser plates 24a. The other end of the vertical connecting rod 15 is rotatably attached to the vertical cross head 20a. A piston shaft 19a having a piston 25a at one end is attached to the upper surface of the vertical cross head 20a.

  The distal end portions of the plungers 17a and 17c of the first block and the piston 25a are housed in cylinders (not shown). And the gas guide | induced to each cylinder is compressed by changing the volume which plunger 17a, 17b and a cylinder and piston 25a and a cylinder form. The plunger 17a forms a five-stage compression stage, and the plunger 17c forms a four-stage compression stage. The piston 25a forms the first stage compression stage.

  Similarly to the first block, the second block arranged on the right side in FIG. 2 has a pair of plungers 17b and 17d extending in the front-rear direction attached to the frame-type cross head 13b through compression bars 18b and 18d. . A vertical connecting rod 15b is inserted through an opening formed in the upper part of the frame-type cross head 13b, and one end thereof is rotatably attached to a pin of the vertical cross head 20b. One end of a piston shaft 19b is connected to the upper surface of the vertical cross head 20b. Two pistons 25b and 25c are attached to the upper end of the piston shaft 19b.

Unlike the frame-type cross head 13a, the frame-type cross head 13b has a protruding portion at the end on the near side. And the cross pin 12b has penetrated this protrusion part. Lateral connecting rods 11b are attached to portions on both sides of the cross pin 12b extending from the frame type cross head. Elongated crank plates 21c (not shown) and 21d are arranged on the left and right sides of the lateral connecting rod 11b. A balance weight 16b is attached to one end side in the longitudinal direction of the crank plates 21c and 21d. The balance weight 16a and the balance weight 16b are arranged in opposite phases, that is, at positions opposite to each other by 180 ° with respect to the center of the main shaft 10.

The distal ends of the plungers 17b and 17d of the second block and the pistons 25b and 25c are also housed in cylinders (not shown). And the plunger 17b,
The gas led to each cylinder is compressed by changing the volume formed by the cylinders 17d and the cylinders and the pistons 25b and 25c. The plunger 17b forms a five-stage compression stage, and the plunger 17d forms a four-stage compression stage. The piston 25b forms a two-stage compression stage, and the piston 25c forms a three-stage compression stage. The gas compressed in each compression stage is cooled by an intermediate cooler and an aftercooler (not shown) and supplied to a demand source.

  Here, each of the fourth-stage compression stage and the fifth-stage compression section including the plungers 17a to 17d is provided in two, but this reduces the pulsation of the gas that decreases the volume as it passes through the compression stage. It is to do. Therefore, a drive mechanism described in detail below is formed so that the movement directions of the plungers 17a and 17b and the plungers 17c and 17d are reversed.

  FIG. 1 shows the drive mechanism of the first stage block. Although a detailed description is omitted, the drive mechanism of the second stage block has substantially the same configuration as the drive mechanism of the first stage block. The end of the connecting shaft 10z of the second stage block connected to the main shaft 10 is fixed to an elongated crank plate 21a while being shifted from the center in the longitudinal direction. A balance weight 16a is attached to the end of the crank plate 21a that is shifted from the center. One end of the crankshaft 10x is fixed to the opposite end of the crank plate 21a. The other end of the crankshaft 10x is also fixed to the crank plate 21b, and the connecting shaft 10y is fixed to the crank plate 21b.

  A pair of fork portions of a horizontal connecting rod 22a formed in a fork shape is attached to the middle of the crankshaft 10x. The horizontal connecting rod 22a is rotatable with respect to the crankshaft 10x. A housing 23a is also rotatably attached to the crankshaft 10x. The housing 23a is located between a pair of forks of the horizontal connecting rod 22a. A vertical connecting rod 15a is connected to the upper portion of the housing 23a. The end of the vertical connecting rod 15a is connected to the vertical cross head 20a.

  A pair of horizontal connecting rods 11a is attached to the back side of the fork-type horizontal connecting rod 22a, and the cross pin 12a passes through the horizontal connecting rod 11a as described above. One end of a frame-type cross head 13a is attached to the cross pin 12a, and the frame-type cross head 13a is positioned between the pair of horizontal connecting rods 11a, 11a.

  The operation of the drive mechanism configured as described above will be described below. When the main shaft 10 is rotationally driven by a motor (not shown), the connecting shaft 10z also rotates around its axis. The crankshaft 10x attached eccentrically from the connecting shaft 10z by a distance Δ rotates around the center of the connecting shaft 10z with the crank plates 21a and 21b as arms. Since the fork-type horizontal connecting rod 22a is connected to the crankshaft 10x, the horizontal connecting rod 11a fixed to the horizontal connecting rod 22a moves in the front-rear direction.

At this time, the frame-type cross head 13a integrated with the horizontal connecting rod 11a and the cross pin 12a also moves in the front-rear direction using the shoe portion 13c as a guide. When the frame-type crosshead 13a moves in the front-rear direction, the plungers 17a, 17c connected to the frame-type crosshead 13a via the compression bars 18a, 18c move in the horizontal direction and in the front-rear direction. The volume between the two is changed to compress the working gas.

  Here, as a feature of the present invention, since the housing 23a having the vertical connecting rod 15a is attached to the intermediate portion of the crankshaft 10x, the piston shaft 19a connected to the vertical crosshead 20a by the eccentric rotational movement of the crankshaft 10x is provided. Move up and down. Since the piston 25a is attached to the tip of the piston shaft 19a, the piston 25a changes the volume with a cylinder (not shown) and compresses the working gas.

  Thus, in this embodiment, the vertical crosshead 20a that moves in the vertical direction and the fork-type horizontal connecting rod 22a that moves in the front-rear direction are attached to one crankshaft 10x, so a pair of horizontal plungers 17a. , 17c and the vertical piston 25a enable three-stage compression by movement of one crankshaft 10x. As a result, there is no need to provide a crank portion for each compression stage, and the axial dimension of the drive portion of the reciprocating compressor can be reduced. The drive unit can be made compact.

  By the way, the crankshaft 10x rotates eccentrically around the connecting shaft 10z. Therefore, the fork-type horizontal connecting rod 22a connected to the crankshaft 10x, the frame-type cross head 13a connected thereto, the housing 23a and the like are connected thereto. Each member such as the vertical connecting rod 15a and the crank plates 21a and 21b acts as an offset weight, and an unbalanced load is generated on the connecting shaft 10z.

  In this embodiment, since the drive units of two blocks having substantially the same mass are connected in the left-right direction, the unbalance load in the horizontal direction can be canceled by configuring the blocks in opposite phases. That is, when the main shaft 10 is rotated, when the plungers 17a and 17c of the left block move backward as shown in FIG. 1, the plungers 17b and 17d of the right block move forward. In addition, the position of the crankshaft 10x is arranged by changing the phase by 180 ° for each block. At this time, if the piston 25a of the left block moves upward, the pistons 25b and 25c of the right block move downward.

  There is a possibility that the unbalanced load in the vertical direction cannot be canceled only by making the movements of the pistons 25a to 25c out of phase. Therefore, balance weights 16a and 16b are provided on the opposite side of the crank plates 21a to 21d from the crankshaft. The balance weights 16a and 16b are 180 ° out of phase for each block. Since the balance weights 16a and 16b are employed, the moments around the connecting shaft can be balanced, and vibration due to unbalance can be reduced.

  Since the plungers 17a to 17d used for the fourth and fifth compression stages, which are high pressure stages, are made of hard and brittle tungsten carbide, bending occurred due to the undulations of the foundation on which the reciprocating compressor is installed. There is a risk of damage due to stress. Therefore, compression bars 18a to 18d using a material having lower rigidity than the plungers 17a to 17d are interposed between the frame-type cross heads 13a and 13b and the plungers 17a to 17d. Due to the spring effect of the compression bars 18a to 18d, fluctuations due to undulations can be absorbed even when the foundation on which the reciprocating compressor is installed is undulated. Therefore, damage to the reciprocating compressor can be prevented.

The 3rd page figure of the drive part of one Example of the 5-stage hydrogen compressor based on this invention. The perspective view of the principal part of one Example of the 5-stage hydrogen compressor based on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Main axis | shaft, 10x ... Crankshaft, 10y ... Connection axis | shaft, 11a, 11b ... Lateral connecting rod, 12a, 12b ... Cross pin, 13a, 13b ... Frame type cross head,
14a, 14b ... cross guide, 15a, 15b ... vertical connecting rod, 16a,
16b ... balance weight, 17a-17d ... plunger, 18a-18d ... compression bar, 19a, 19b ... piston shaft, 20a, 20b ... vertical crosshead, 21a, 21b ... crank plate, 22a ... fork type horizontal connecting rod, 23a ... housing, 24a ... presser plate, 25a-25c ... piston, 100 ... reciprocating compressor.

Claims (3)

In a five-stage reciprocating compressor used for hydrogen supply of a fuel cell vehicle or fuel supply of a CNG vehicle,
A first pair of plungers movable in a horizontal direction;
A first piston which is movable in the vertical direction and constitutes a first stage compression section;
A first drive unit that drives the first pair of plungers and the first piston;
A second pair of plungers movable in a horizontal direction;
Second and third pistons which are movable in the vertical direction and constitute the second stage and the third stage compression section;
A second drive unit that drives the second pair of plungers and the second and third pistons;
A first crankshaft to which the first drive unit is connected and a second crankshaft to which the second drive unit is connected;
The first driving unit and the second driving unit are placed side by side in the horizontal direction,
The first drive unit includes a fork-type first horizontal connecting rod that drives the first pair of plungers, and a first vertical connecting rod that drives the first piston. The drive unit has a fork-type second horizontal connecting rod that drives the pair of second plungers and a second vertical connecting rod that drives the second piston;
The first and second crankshafts are shafts eccentrically connected to a main shaft that transmits a driving force from a driving source,
The first pair of plungers constitutes a fourth stage compression part and a fifth stage compression part, and the second pair of plungers also constitutes a fourth stage compression part and a fifth stage compression part, The same stage compression unit is arranged on the same side with respect to the main shaft, and the fifth stage driven by the other drive unit during the compression operation of the plunger of the fourth stage compression unit driven by one of the drive units. A reciprocating compressor in which the plunger of the compression section performs a compression operation, and the plungers at the same stage reverse their movement directions to cancel the unbalanced load in the horizontal direction . 2. The reciprocating compressor according to claim 1 , wherein a balance weight is attached to each end of each of the first and second crankshafts, and the balance weight is reversed in phase for each drive unit. A first frame-type crosshead and a first compression bar between the first plunger and the first horizontal connecting rod; a second frame between the second plunger and the second horizontal connecting rod; 2. A reciprocating compressor according to claim 1, wherein a frame-type cross head and a second compression bar are interposed, and the first and second compression bars are made of a material having rigidity lower than that of each plunger. .

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