JP4569039B2 - Hermetic pump device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hermetic pump device excellent in shut-off from the outside, and is a technique suitable for use in, for example, a hydrogen circulation pump for fuel cells, a flammable fluid, or a toxic fluid pump.
[0002]
[Prior art]
As a hermetic pump device, a diaphragm pump disclosed in Japanese Patent Laid-Open No. 9-259912 is known. This hermetic pump device changes the volume of the working chamber partitioned by the diaphragm by displacing the diaphragm, and uses the volume change of the working chamber due to the displacement of the diaphragm to suck and discharge the working fluid. Is what you do.
[0003]
[Problems to be solved by the invention]
However, in a hermetic pump device using a diaphragm, the expansion / contraction amount of the diaphragm cannot be increased. For this reason, in order to increase capacity, such as a circulation pump of the large flow volume required for circulating the unreacted gas for fuel cells, it is necessary to enlarge the size of the pump device. In particular, in the case of in-vehicle use, when the size of the pump device is increased, it becomes difficult to mount the pump device on the vehicle.
In addition, since the drive mechanism for driving the diaphragm is provided in a portion different from the working chamber by the diaphragm, this also increases the size of the pump device.
[0004]
OBJECT OF THE INVENTION
A first object of the present invention is to provide a hermetic pump device that can be reduced in size, and a second object is to provide a hermetic pump device in which sliding powder does not enter the fluid. The third object is to provide a low-vibration hermetic pump apparatus, and the fourth object is to provide a hermetic pump apparatus that does not cause malfunction due to freezing.
[0005]
[Means for Solving the Problems]
[Claims 1, 2, 11, 16Means]
  PiBy arranging a drive mechanism for reciprocating the piston in the internal space of the stone, the size of the hermetic pump device can be reduced. In addition, since the drive mechanism is arranged inside the isolation space formed inside the expansion and contraction member, there is no problem that sliding powder or lubricant generated by the operation of the drive mechanism is mixed in the working chamber, and the hermetic pump There is no problem of contaminating the fluid discharged from the device.
[0007]
[Claims 1, 2Means]
  Claims 1, 2The dead space formed between the pistons can be used effectively by arranging the drive mechanism in the isolated space between the opposed pistons, and the physique of the hermetic pump device can be reduced in size. Can be
  Moreover, the vibration accompanying the reciprocating motion of the piston is canceled by the opposing operation of the piston, and the hermetic pump device can be reduced in vibration.
[0008]
[Claim 3Means]
  Claim 3The first sliding guide connected and fixed to the piston and the second sliding guide connected and fixed to the casing are provided so as to reciprocate only in the axial direction. The piston is reciprocated only in the axial direction.
  Note that the sliding contact resistance of the first sliding guide and the second sliding guide is reduced by covering the sliding contact surfaces of the first sliding guide and the second sliding guide with a solid lubricant (fluorine resin or the like), and the piston Smooth reciprocation.
[0009]
[Claim 4Means]
  Claim 4Is generated around the drive shaft by arranging the second telescopic member in the space formed between the piston and the casing and arranging the periphery of the drive shaft in the second isolation space. There is no problem that the sliding powder is mixed into the fluid. Thus, there is no problem of contaminating the fluid discharged from the hermetic pump device.
[0010]
[Claim 5Means]
  Claim 5This means that the piston is supported by the drive shaft so that the piston does not slide on the cylinder, so that no sliding powder is generated between the piston and the cylinder, and the fluid discharged from the hermetic pump device. There are no defects that contaminate the.
[0011]
[Claim 6Means]
  Claim 6By adopting the above means, the piston is reciprocated only in the axial direction with respect to the cylinder, whereby the rotation of the piston is prevented and the piston reciprocates only in the axial direction.
  In addition, by covering the sliding contact surfaces of the cylinder and the piston with a solid lubricant (fluorine resin or the like), the sliding resistance of the piston with respect to the cylinder is reduced, and the piston can be smoothly reciprocated.
[0012]
[Claim 7Means]
  Claim 7By adopting the above means, the volume change of the space sandwiched between the pistons that are opposed to each other is also used as the second working chamber, so that two intake strokes and two times are performed while one piston makes one reciprocation. And a discharge stroke. For this reason, the suction amount and the discharge amount increase, and as a result, the size of the hermetic pump device can be reduced.
[0013]
[Claim 8Means]
  If the piston is provided so that it does not slide in contact with the cylinder, fluid leakage may occur due to the clearance between the cylinder and the piston, leading to a decrease in pump efficiency.
  Therefore,Claim 8By adopting the above means and providing a labyrinth groove on the outer peripheral surface of the piston, fluid leakage in the clearance can be suppressed, and as a result, a decrease in pump efficiency can be prevented.
[0014]
  on the other hand,Claim 8By adopting the above means and providing a labyrinth groove on the outer peripheral surface of the piston, even when condensed water is generated between the cylinder and the piston, the water is accumulated in the labyrinth groove. For this reason, even if it is a case where water freezes by temperature fall during operation stop, the malfunction which a cylinder and a piston lock when starting can be avoided.
  Further, even when the cylinder and the piston are coupled by freezing water, the coupled area by freezing is reduced by the labyrinth groove. For this reason, the starting torque at the time of freezing can be reduced, and damage to the hermetic pump device due to freezing can be prevented.
[0015]
[Claims 9 and 10Means]
  Claims 9 and 10By adopting the above means, the drive shaft rotates 180 °, and the piston arranged oppositely reciprocates one time, so the intake amount and the discharge amount increase, and as a result, the size of the sealed pump device is reduced. it can.
[0016]
[Claim 11Means]
  Claim 11By adopting this means, it is possible to convert the rotation of the drive shaft into the reciprocating motion in the orthogonal direction without having a crank mechanism having a crank and a connecting rod. As a result, the hermetic pump device that reciprocates in the direction orthogonal to the drive shaft can be miniaturized.
  Moreover, since the vibration accompanying the reciprocating motion of the piston is canceled by the opposing operation of the piston, the hermetic pump device can be reduced in vibration.
[0017]
[Claim 12Means]
  Claim 12By adopting the above structure, the piston is not slidably contacted with the cylinder by adopting a structure in which the restraining member holder fixed to the piston is supported by the cylindrical fixing member via the sliding bearing in the isolation space in the expansion and contraction member. You can For this reason, the sliding powder of a piston and a cylinder does not generate | occur | produce, and there is no malfunction which contaminates the fluid discharged from a hermetic type pump device.
[0018]
[Claim 13Means]
  Claim 13When the suction port is provided on the outer peripheral side of the cylinder, the open end of the plate-like suction reed valve is provided toward the drive shaft, so that the suction fluid from the outer periphery toward the inner periphery is provided. It can be smoothly guided into the cylinder. Thereby, the suction efficiency of the fluid sucked by the piston is increased, and the hermetic pump device can be downsized and the flow rate can be increased.
  Further, since the fluid is sucked toward the inside of the cylinder, the central portion of the piston can be efficiently cooled. Accordingly, it is possible to prevent the temperature of the drive mechanism disposed inside the piston from being increased, and as a result, it is possible to improve the durability of the drive mechanism.
  Furthermore, since the suction reed valve having a plate shape is used, the valve mechanism can be simplified, and the hermetic pump device can be downsized.
[0019]
[Claim 14Means]
  Claim 14When the discharge port is provided on the outer peripheral side of the cylinder, the open end of the plate-like discharge reed valve is directed toward the side different from the drive shaft, so that the outer periphery from the inner periphery It is possible to smoothly guide the discharged fluid toward the discharge port to the discharge port. As a result, the fluid discharge efficiency increases, and the hermetic pump device can be reduced in size and flow rate.
[0020]
Furthermore, since the discharge reed valve having a plate shape is used, the valve mechanism can be simplified, and the hermetic pump device can be downsized.
[0021]
[Claim 15Means]
  The elastic member can be regarded as a spring because it elastically expands and contracts. For this reason, since an elongating member becomes long, a natural frequency will become low, and at the time of high-speed operation | movement, it may raise | generate surging and may be damaged.
  Therefore,Claim 15The elastic member that elastically expands and contracts is divided between the opposed pistons, and the connecting member is fixed to the fixed member, so that the natural frequency of the expandable member is doubled. Can do. Accordingly, surging can be prevented even during high-speed operation, and damage to the connecting member can be prevented.
[0022]
[Claim 16Means]
  If the piston is provided so that it does not slide in contact with the cylinder, fluid leakage may occur due to the clearance between the cylinder and the piston, leading to a decrease in pump efficiency.
  Therefore,Claim 16By adopting the above-mentioned means, a part of the fluid compressed by the piston is guided into the piston, and by providing a reverse injection means for blowing out from the outer peripheral surface of the piston toward the top of the piston, The fluid blown out from the reverse injection means collides, and a large merge loss occurs. As a result, fluid leakage in the clearance can be suppressed, and as a result, a decrease in pump efficiency can be prevented.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described using a plurality of examples and modifications.
[First embodiment]
FIG. 1 is a cross-sectional view of a hermetic pump device. This hermetic pump device is used, for example, as a hydrogen circulation pump for a fuel cell mounted on a vehicle, and is roughly divided into a pump unit 1 and an electric motor 2 for driving the pump unit 1. Composed.
The pump unit 1 shown in this embodiment is made of a metal material (for example, stainless steel such as SUS316L) that does not permeate hydrogen and has excellent toxicity and durability.
[0026]
The pump unit 1 is housed in a casing 3, and the casing 3 has a cylindrical case 4 having a substantially cylindrical shape, and a disk-like shape fastened to both ends of the cylindrical case 4 by bolts or the like. It consists of a side wall 5.
A cylindrical cylinder 6 is formed inside the cylindrical case 4.
Inside the cylinder 6, a piston 8 is disposed oppositely to reciprocate the inside of the cylinder 6 to change the volume of the first working chamber 7 formed in the cylinder 6 and perform fluid suction and compression operations. ing. The piston 8 is operated oppositely by a drive mechanism 10 to be described later, and a second working chamber 11 that performs suction and compression of fluid is also formed in a space sandwiched between the pistons 8 that operate oppositely.
[0027]
A first bellows 12 (corresponding to an expansion / contraction member) that elastically expands and contracts along the reciprocating direction of the piston 8 is disposed inside the facing piston 8, and is isolated by the first bellows 12 inside the piston 8. A space 13 is formed. The first bellows 12 has a bellows-like cylindrical shape that elastically expands and contracts along the reciprocating direction of the piston 8.
[0028]
The first bellows 12 is divided between the opposed pistons 8, and a central connecting member 14 that connects the divided first bellows 12 is fixed to the casing 3. As shown in FIG. 2, a plurality of bolt holes 15 are provided on the side surface of the cylindrical case 4. By fastening bolts (not shown) to the bolt holes 15, the connecting member 14 is attached to the casing 3. Fixed.
As in this embodiment, by dividing the first bellows 12 that elastically expands and contracts and the connecting member 14 is fixed to the casing 3, the natural frequency of the first bellows 12 can be doubled. Accordingly, surging can be prevented even during high-speed operation, and damage to the first bellows 12 can be prevented.
[0029]
A drive mechanism 10 for reciprocally driving the piston 8 in the cylinder 6 is disposed inside the isolation space 13 isolated by the first bellows 12.
The drive mechanism 10 is disposed in an isolated space 13 formed between the opposed pistons 8, and is rotated integrally with the drive shaft 16 that is driven to rotate by the electric motor 2. The roller 18 has a face cam 17 projecting in the form of a rib around the drive shaft 16 and a roller 18 along the axial cam surface of the face cam 17, and the axial displacement of the roller 18 is transmitted to the piston 8. A holder 19 is provided, and the opposed pistons 8 are operated to face each other.
[0030]
The drive shaft 16 is inserted into the output shaft 20 of the electric motor 2 and rotates integrally with the output shaft 20. The drive shaft 16 is rotatably supported by a shaft bearing 21 disposed in the center hole of the disk-shaped side wall 5. ing.
As shown in FIG. 3, the face cam 17 is provided so as to wave twice in the axial direction when the drive shaft 16 rotates once.
[0031]
The roller holder 19 transmits the axial displacement of the face cam 17 to the piston 8, and the outline of the roller holder 19 will be described with reference to FIGS. 2 to 4. 2 to 4, a roller pin 18 ′ (corresponding to the roller 18) sandwiching the face cam 17 from both sides in the axial direction is provided, and the roller pin 18 ′ is rotatably supported via a bearing 22 ′. Is. When the face cam 17 rotates by 90 °, the opposed piston 8 is driven away as shown in FIGS. 4A to 4B, and when the face cam 17 further rotates by 90 °, FIG. As shown in FIG. 4A from FIG. 4B, the opposed pistons 8 are driven so as to approach each other. That is, when the drive shaft 16 is rotated by 180 °, the piston 8 disposed oppositely reciprocates once.
[0032]
As shown in FIG. 1, the specific roller holder 19 is a combination of an upper holder 19a and a lower holder 19b. 4 is provided with a roller 18 that rotates along the face cam 17, and this roller 18 is rotated by a roller support pin 22 supported by an upper holder 19a and a lower holder 19b. It is supported freely. The axial displacement of the roller holder 19 is transmitted to the piston 8 via the ring plate 23 fixed to both the piston 8 and the roller holder 19.
[0033]
When the face cam 17 rotates, rotational torque is applied to the piston 8 via the roller holder 19. For this reason, means for preventing the rotation of the piston 8 and reciprocating the piston 8 is provided.
This means is provided around both sides of the drive shaft 16 and is connected and fixed to the casing 3 and the first sliding guide 24 having a substantially cylindrical shape connected and fixed to the piston 8 via the ring plate 23. And a second sliding guide 25 fitted to the outer periphery of the first sliding guide 24. As shown in FIG. 5, the inner peripheral surface of the second sliding guide 25 is provided with a spline groove 25 a along the axial direction, and the outer peripheral surface of the first sliding guide 24 is axially fitted into the spline groove 25 a. The spline convex part 24a along is provided. By being provided in this way, the rotation of the piston 8 can be prevented and the piston 8 can be reciprocated.
[0034]
Note that the sliding contact surfaces of the first sliding guide 24 and the second sliding guide 25 are covered with a solid lubricant such as a fluorine-based resin. Thereby, the sliding contact resistance between the first sliding guide 24 and the second sliding guide 25 is reduced, and the piston 8 can be smoothly reciprocated.
A sliding bearing 26 capable of sliding in the rotational direction and the axial direction is disposed between the first sliding guide 24 supporting the piston 8 and the drive shaft 16, regardless of the rotation of the drive shaft 16. One sliding guide 24 is supported around the drive shaft 16.
[0035]
Around the first sliding guide 24 and the second sliding guide 25, a second bellows 27 (corresponding to a second expansion / contraction member) that extends and contracts along the reciprocating direction of the piston 8 is disposed. The second bellows 27 has an accordion-like cylindrical shape that elastically expands and contracts, similar to the first bellows 12 described above. In the space formed between the piston 8 and the casing 3, A second isolation space 28 for accommodating the drive shaft 16, the first sliding guide 24, and the second sliding guide 25 is formed.
[0036]
Thus, by covering the periphery of the drive shaft 16, the first sliding guide 24, and the second sliding guide 25 with the second bellows 27, the first sliding guide 24 and the second sliding guide 25 that are support members of the piston 8 are covered. There is no problem that the sliding powder, the sliding powder of the first sliding guide 24 and the sliding bearing 26, the sliding powder of the sliding bearing 26 and the drive shaft 16 and the like are mixed into the fluid. Thus, there is no problem of contaminating the fluid discharged from the hermetic pump device with the sliding powder.
[0037]
As described above, the piston 8 is supported around the drive shaft 16 via the first sliding guide 24, the sliding bearing 26, and the like, and is provided so that the piston 8 does not slide on the cylinder 6. . With this configuration, the sliding powder between the piston 8 and the cylinder 6 is not generated, and there is no problem that the fluid discharged from the hermetic pump device is contaminated with the sliding powder.
[0038]
If the piston 8 is provided so as not to be in sliding contact with the cylinder 6, the first working chamber 7 facing the cylinder 6 and the piston 8 is connected to each other, and fluid leakage due to the clearance may occur, resulting in a decrease in pump efficiency. There is sex.
Therefore, as shown in FIG. 6, a plurality of labyrinth grooves 31 are provided on the outer peripheral surface of the piston 8 along the circumferential direction. By providing a plurality of labyrinth grooves 31 in this way, fluid leakage in the clearance can be suppressed, and reduction in pump efficiency can be prevented.
[0039]
The fluid (circulation gas of the fuel cell) driven by the hermetic pump device includes nitrogen and condensed water in addition to hydrogen. For this reason, condensed water may be generated in the clearance between the cylinder 6 and the piston 8. However, by providing a plurality of labyrinth grooves 31 on the outer peripheral surface of the piston 8, even when condensed water is generated between the cylinder 6 and the piston 8, the water accumulates in the labyrinth groove 31. For this reason, even if it is a case where water freezes by the temperature fall during operation stop, the malfunction that the cylinder 6 and piston 8 lock by freezing when it starts can be avoided.
Even if the cylinder 6 and the piston 8 are coupled by freezing water, the coupled area by freezing is reduced by the labyrinth groove 31. For this reason, the starting torque at the time of freezing can be reduced, and damage to the hermetic pump device due to freezing can be prevented.
[0040]
A suction port 32 that guides fluid into the pump unit 1 is provided on a side surface (lower surface in FIG. 1) of the cylindrical case 4. The suction port 32 of this embodiment is a suction passage formed in the casing 3. In order to guide the suction fluid to 33 and the second working chamber 11 formed between the two pistons 8, a three-way suction passage 33a is provided.
A discharge port 34 for guiding the fluid compressed in the pump unit 1 to the outside is provided on the side surface (upper surface in FIG. 1) of the cylindrical case 4 on the side different from the suction port 32. Similarly to the suction port 32 described above, the outlet 34 leads the fluid pumped from the discharge passage 35 formed in the casing 3 and the second working chamber 11 formed between the two pistons 8 to the outside. In addition, a three-way discharge path 35b is provided.
[0041]
The fluid sucked from the suction port 32 on the outer peripheral side is guided to the first working chamber 7 through a suction valve 36 of a valve mechanism fixed to both ends of the cylinder 6. Therefore, the fluid sucked from the outer peripheral side passes through the suction valve 36 and then is sucked toward the center side of the piston 8.
On the contrary, the fluid compressed in the first working chamber 7 is guided to the discharge port 34 provided on the outer peripheral side through the discharge valve 37 of the valve mechanism fixed to both ends of the cylinder 6. For this reason, the fluid compressed in the first working chamber 7 passes through the discharge valve 37 and is discharged toward the outer peripheral direction.
[0042]
Here, the valve mechanisms provided at both ends of the cylinder 6 will be described with reference to FIG. The valve mechanism includes a thin plate-like valve element ring 41 that forms the suction reed valve 38 and the discharge reed valve 39, and a suction valve restraint 42a and a discharge hole 42b that restrict the amount of displacement on the suction side of the suction reed valve 38 to a predetermined amount. The formed suction valve restraining ring 42 is laminated with the delivery valve restraining ring 43 in which the amount of displacement on the delivery side of the delivery reed valve 39 is restricted to a predetermined amount and the delivery valve restraining ring 43 in which the suction hole 43b is formed. .
[0043]
Here, the open end of the suction reed valve 38 is provided toward the drive shaft 16. Thereby, the suction fluid from the outer periphery toward the inner periphery can be smoothly guided into the first working chamber 7. As a result, the efficiency of sucking fluid into the first working chamber 7 is increased.
Further, since the fluid is sucked toward the inside of the first working chamber 7, the central portion of the piston 8 can be efficiently cooled. As a result, the temperature of the drive mechanism 10 disposed inside the piston 8 can be prevented from increasing, and as a result, the durability of the drive mechanism 10 can be improved.
[0044]
Further, by providing the open end of the discharge reed valve 39 toward the side different from the drive shaft 16, the discharge fluid from the inner periphery to the outer periphery can be smoothly guided to the discharge port 34. This increases the fluid ejection efficiency.
[0045]
The second suction valve 44 that guides the fluid to the second working chamber 11 and the second discharge valve 45 that guides the fluid compressed in the second working chamber 11 to the discharge port 34 also have a plate shape, similar to the valve mechanism described above. Reed valve is used.
Thus, by using a reed valve that is simple in structure and can be thinned in each valve mechanism, the valve mechanism can be simplified, and the hermetic pump device can be downsized.
[0046]
[Operation of the first embodiment]
When the electric motor 2 is operated and the face cam 17 rotates as the drive shaft 16 rotates, the two roller holders 19 reciprocate in the axial direction as the face cam 17 is displaced in the axial direction. When the two roller holders 19 reciprocate, the two pistons 8 connected to the roller holders 19 face each other inside the cylinder 6.
Each time the drive shaft 16 rotates 180 °, the pistons 8 face each other and reciprocate so that the first working chambers 7 on both sides of the two pistons 8 suck and compress the fluid, respectively. The second working chamber 11 in between performs compression and suction of fluid.
The fluid is sucked from the suction port 32 by the suction stroke of the fluid in the first working chamber 7 and the second working chamber 11, and the fluid compressed in the first working chamber 7 and the second working chamber 11 is discharged from the discharge port. 34 is discharged.
[0047]
[Effects of the first embodiment]
As shown in the above embodiment, the hermetic pump device can reduce the size of the hermetic pump device by disposing the drive mechanism 10 in the internal space of the piston 8. In addition, since the drive mechanism 10 is arranged inside the isolation space 13 formed inside the first bellows 12, there is no problem that sliding powder or lubricant generated by the operation of the drive mechanism 10 is mixed into the fluid. There is no problem of contaminating the fluid discharged from the hermetic pump device.
Further, since a fine clearance is maintained between the cylinder 6 and the piston 8, there is no sliding portion outside the isolation space 13 of the first bellows 12, and sliding powder accompanying the sliding does not enter the fluid. There is no problem of contaminating the fluid discharged from the hermetic pump device.
[0048]
A dead space generated between the opposed pistons 8 can be used effectively, and the size of the hermetic pump device including the opposed pistons 8 can be reduced in size.
Since the piston 8 opposes the vibration caused by the reciprocating motion of the piston 8, the hermetic pump device can be reduced in vibration and noise can be reduced.
[0049]
By the expansion and contraction of the piston 8 once, the first working chamber 7 and the second working chamber 11 suck the fluid twice in a state where the phase is shifted by 90 ° with respect to the rotation of the drive shaft 16 once. At the same time, the first working chamber 7 and the second working chamber 11 discharge the fluid twice continuously in a state where the phase is shifted by 90 ° once. Thereby, pump capability becomes high and the physique of a sealed pump apparatus can be reduced in size compared with the past.
Since the phases of the suction stroke and the discharge stroke of the first working chamber 7 and the second working chamber 11 are shifted by 90 °, the pulsation of fluid suction and discharge is averaged.
[0050]
[Second Embodiment]
A second embodiment will be described with reference to FIG. In the following embodiments, only portions different from the above-described embodiment will be described, and the same functional components as those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted.
[0051]
In the second embodiment, the drive mechanism 10 is different from the first embodiment, and the drive mechanism 10 of this embodiment rotates integrally with the drive shaft 16 and has a cam rotor 51 with a cam groove 51 formed on the outer periphery. 52 and a guide pin holder 54 that has a guide pin 53 inserted into the cam groove 51 and transmits the axial displacement of the guide pin 53 to the piston 8. The reciprocating motion of the piston 8 causes the opposed pistons 8 to face each other.
[0052]
As shown in FIG. 8, the cam groove 51 is provided so as to wave twice in the axial direction when the drive shaft 16 rotates once.
The guide pin 53 is rotatably supported by the guide pin holder 54 via a bearing 55.
By being provided in this way, as with the drive mechanism 10 of the first embodiment, when the cam rotor 52 rotates 90 °, the opposing piston 8 is driven away from it, and when the cam rotor 52 further rotates 90 °, they face each other. The piston 8 is driven to approach.
[0053]
[Third embodiment]
A third embodiment will be described with reference to FIG.
The third embodiment is different from the first embodiment in that the piston 8 is prevented from rotating and the piston 8 is reciprocated. In this embodiment, as shown in FIG. A groove 8a along the axial direction is provided on the outer peripheral wall, and a convex portion 6a (for example, a rib along the axial direction) that fits into the groove 8a of the piston 8 is provided on the inner peripheral wall of the cylinder 6 as shown in FIG. 9B. It is a thing. By providing in this way, the rotation of the piston 8 can be prevented and the piston 8 can be reciprocated as in the first embodiment.
[0054]
In addition, at least one of the sliding contact surfaces of the cylinder 6 and the piston 8 is coated with a solid lubricant such as a fluorine-based resin to reduce the sliding contact resistance of the piston 8 with respect to the cylinder 6 so that the piston 8 can reciprocate smoothly. Is provided.
In the third embodiment, since the first sliding guide 24 and the second sliding guide 25 shown in the first embodiment are not necessary, slip in the rotational direction and the axial direction is caused between the piston 8 and the drive shaft 16. A possible sliding bearing (not shown) is arranged, and the piston 8 is supported on the drive shaft 16 via this sliding bearing.
[0055]
[Fourth embodiment]
A fourth embodiment will be described with reference to FIG.
The piston 8 shown in the fourth embodiment has a plurality of reverse injection holes for guiding a part of the fluid compressed by the piston 8 into the piston 8 and blowing out from the outer peripheral surface of the piston 8 toward the top side of the piston 8. 56 (corresponding to the reverse injection means) is provided.
Thus, by providing the plurality of reverse injection holes 56 in the piston 8, the fluid that flows in from the clearance between the cylinder 6 and the piston 8 collides with the fluid that blows out from the reverse injection holes 56, resulting in a merge loss. Arise. As a result, fluid leakage in the clearance can be suppressed, and as a result, a decrease in pump efficiency can be prevented.
[0056]
[Fifth embodiment]
In the first embodiment, the labyrinth groove 31 is provided on the outer peripheral surface of the piston 8 to prevent the piston 8 from being locked due to water freezing generated in the clearance between the cylinder 6 and the piston 8. In the fifth embodiment, the outer peripheral surface of the piston 8 is coated with a water repellent material (for example, fluorine resin) that repels water.
Thereby, the amount of water adhering between the cylinder 6 and the piston 8 can be reduced. For this reason, since the joint area by freezing becomes small, the starting torque at the time of freezing can be reduced, and the failure | damage of the sealed pump apparatus by freezing can be prevented.
The labyrinth groove 31 shown in the first embodiment may be used in combination.
[0057]
[Sixth embodiment]
In the fifth embodiment, the example in which the outer peripheral surface of the piston 8 is coated with a water repellent material has been shown. However, in the sixth embodiment, the inner peripheral surface of the cylinder 6 is repelled with water (for example, fluorine Resin). By providing in this way, the same effect as the fifth embodiment can be obtained.
[0058]
[Seventh embodiment]
In the seventh embodiment, the valve body (the valve body ring 41 forming the suction reed valve 38 and the discharge reed valve 39) or the valve seat (the suction valve restraining ring 42 and the discharge valve restraining ring 43) constituting the valve mechanism. At least one is coated with a water repellent material (for example, fluorine resin) that repels water.
By providing in this way, the amount of water adhering between the valve body and the valve seat can be reduced. For this reason, malfunction of the valve mechanism due to freezing can be suppressed, and malfunction of the hermetic pump device due to freezing can be suppressed.
[0059]
[Eighth embodiment]
The eighth embodiment will be described with reference to FIGS.
The eighth embodiment shows a hermetic pump device in which the piston 8 reciprocates in a direction orthogonal to the axial direction of the drive shaft 16.
The drive mechanism 10 that causes the piston 8 to reciprocate in the orthogonal direction with respect to the drive shaft 16 is disposed in an isolation space 13 between the pistons 8 that is disposed opposite to the piston 8, and is integrated with the drive shaft 16. A constraining member 62 that has an elliptical cam 61 that exhibits a rotating elliptical shape, and a chain shape that includes four connecting chains that surround the elliptical cam 61, and that converts the rotation of the elliptical cam 61 into a reciprocating stroke, The restraint member holder 63 is configured to transmit the stroke of the reciprocating motion by the restraint member 62 to the piston 8, and the restraint member holder 63 is formed by connecting opposing connecting portions of four connecting chains. The drive mechanism 10 adopting such a configuration causes the opposed pistons 8 to face each other.
[0060]
In this embodiment, since the piston 8 reciprocates in the direction orthogonal to the axial direction of the drive shaft 16, the cylinder 6 is also provided in the direction orthogonal to the axial direction of the drive shaft 16. The cylinder 6 of this embodiment is divided into a portion for accommodating one piston 8 and a portion for accommodating the other piston 8, and the divided cylinder 6 includes a partition wall 64 and a drive shaft on the center side. 16 is connected by a connecting member 65 inserted therethrough.
[0061]
In this embodiment, the two pistons 8 can be reciprocated by converting the rotation of the drive shaft 16 into a reciprocating motion in the orthogonal direction without having a crank mechanism having a crank and a connecting rod. As a result, the hermetic pump device that reciprocates in the direction perpendicular to the drive shaft 16 can be reduced in size. Moreover, since the vibration accompanying the reciprocating motion of the piston 8 is canceled by the opposing operation of the piston 8, the hermetic pump device can be reduced in vibration.
[0062]
On the other hand, this embodiment employs a structure in which the restraining member holder 63 is supported by the cylindrical fixing member 67 via the sliding bearing 66 in the isolation space 13 in the first bellows 12. The cylindrical fixing member 67 is fixed to the partition wall 64 and the coupling member 65. With this structure, the piston 8 connected to the restraining member holder 63 can be prevented from slidingly contacting the cylinder 6, so that no sliding powder is generated between the piston 8 and the cylinder 6, and the fluid discharged from the hermetic pump device is discharged. There are no defects to contaminate.
[0064]
In the above embodiment, the present invention is applied to a pump for circulating hydrogen. However, for example, a pump for pumping gas such as flammable gas and toxic gas other than hydrogen, and liquid pumping such as flammable liquid and toxic liquid. It may be applied to an industrial pump.
In the above embodiment, an example in which metal is used as the material of the pump unit 1 has been shown. However, part or all of the constituent members of the pump unit 1 may be configured using resin or rubber. That is, for example, the first and second bellows 12 and 27 and the like may be configured using resin or rubber according to the applied working fluid.
In the above embodiment, an example in which the cylinder 6 having a cylindrical shape is formed inside the cylindrical case 4 is shown, but a cylinder is formed by inserting and fixing a cylinder liner member inside the case. Also good.
[Brief description of the drawings]
FIG. 1 is a sectional view of a pump unit in a hermetic pump device (first embodiment).
FIG. 2 is an exploded perspective view of a pump unit (first embodiment).
FIG. 3 is an exploded perspective view of the drive mechanism (first embodiment).
FIG. 4 is a schematic explanatory view of a drive mechanism (first embodiment).
FIG. 5 is an exploded perspective view of the first and second sliding guides (first embodiment).
FIG. 6 is an explanatory view of a labyrinth groove formed on the outer peripheral surface of a piston (first embodiment).
FIG. 7 is an exploded perspective view of the valve mechanism (first embodiment).
FIG. 8 is a schematic explanatory diagram of a drive mechanism (second embodiment).
FIG. 9 is an explanatory view of a piston detent means formed on a cylinder and a piston (third embodiment).
FIG. 10 is an explanatory view of a reverse injection hole formed in a piston (fourth embodiment).
FIG. 11 is a sectional view of the pump unit as seen from the drive shaft side (eighth embodiment).
FIG. 12 is a sectional view taken along the drive shaft of the pump unit (Eighth embodiment)).
[Explanation of symbols]
  1 Pump unit
  2 Electric motor
  3 Casing (fixing member)
  6 cylinders
  6a Convex (Convex provided on the inner peripheral wall of the cylinder)
  7 First working chamber
  8 Piston
  8a Groove (groove along the axial direction provided on the outer peripheral wall of the piston)
10 Drive mechanism
11 Second working chamber
12 1st bellows (expandable member)
13 Isolation space
14 Connecting members
16 Drive shaft
17 Face Cam
18 Laura
19 Roller holder
24 First sliding guide
24a Spline protrusion (protrusion that fits into the groove)
25 Second sliding guide
25a Spline groove (groove along the axial direction)
26 Sliding bearing
27 Second bellows (second elastic member)
28 Second isolation space
31 Labyrinth groove
32 Inlet
34 Discharge port
36 Suction valve
37 Discharge valve
38 Suction Reed Valve
39 Discharge reed valve
41 Valve ring (valve)
42 Suction valve restraining ring (valve seat)
43 Discharge valve holding ring (valve seat)
51 Cam groove
52 Cam Rotor
53 Guide pin
54 Guide pin holder
56 Reverse injection hole (Reverse injection means)
61 Elliptical cam
62 Restraint member
63 Restraint member holder
66 plain bearings
67 Cylindrical fixing member

Claims (16)

A cylindrical cylinder;
A piston that is disposed in the cylinder, reciprocates in the cylinder to change the volume in the cylinder, and performs a fluid suction and compression operation;
An elastic member that elastically expands and contracts along the reciprocating direction of the piston and forms an isolation space inside the piston;
A drive mechanism disposed inside the isolation space for reciprocally driving the piston in the cylinder;
In a hermetic pump device comprising :
The drive mechanism is
The pistons are arranged to face each other, and are arranged in the isolation space formed between the pistons,
A rotationally driven drive shaft;
A face cam that rotates integrally with the drive shaft and projects in a rib shape around the drive shaft;
It has a roller along the axial cam surface of the face cam, and a roller holder that transmits the axial displacement of the roller to the piston,
A hermetic pump device, wherein the opposed pistons are provided so as to face each other. A cylindrical cylinder;
A piston that is disposed in the cylinder, reciprocates in the cylinder to change the volume in the cylinder, and performs a fluid suction and compression operation;
An elastic member that elastically expands and contracts along the reciprocating direction of the piston and forms an isolation space inside the piston;
A drive mechanism disposed inside the isolation space for reciprocally driving the piston in the cylinder;
In a hermetic pump device comprising :
The drive mechanism is
The pistons are arranged to face each other, and are arranged in the isolation space formed between the pistons,
A rotationally driven drive shaft;
A cam rotor that rotates integrally with the drive shaft and has a cam groove formed on the outer periphery;
A guide pin holder having a guide pin inserted into the cam groove, and transmitting an axial displacement of the guide pin to the piston;
A hermetic pump device, wherein the opposed pistons are provided so as to face each other. In the hermetic pump device according to claim 1 or 2 ,
Means for reciprocating the piston and preventing rotation of the piston are:
A first sliding guide having a substantially cylindrical shape connected and fixed to the piston;
A second sliding guide that is connected and fixed to a casing that houses the cylinder, and fits on an outer periphery or an inner periphery of the first sliding guide;
One sliding portion of the first sliding guide and the second sliding guide is provided with a groove along the axial direction,
The other sliding portion of the first sliding guide and the second sliding guide is provided with a convex portion that fits into the groove,
A hermetic pump device, wherein a sliding bearing capable of sliding in a rotational direction and an axial direction is disposed between one of the first sliding guide or the second sliding guide and the drive shaft. In the hermetic pump device according to any one of claims 1 to 3 ,
The space formed between the piston and the casing that houses the cylinder expands and contracts along the reciprocating direction of the piston, and forms a second isolation space that covers the periphery of the drive shaft. A hermetic pump device in which members are arranged. In the hermetic pump device according to any one of claims 1 to 4 ,
The piston is supported by the drive shaft so that it does not slide against the cylinder. In the hermetic pump device according to claim 1 or 2 ,
Means for reciprocating the piston and preventing rotation of the piston are:
A groove along the axial direction provided on one of the inner peripheral wall of the cylinder or the outer peripheral wall of the piston;
It is provided on the other of the inner peripheral wall of the cylinder or the outer peripheral wall of the piston, and includes a convex part that fits into the groove,
A hermetic pump device in which a sliding bearing capable of sliding in the rotational direction and the axial direction is disposed between the piston and the drive shaft. In the hermetic pump device according to any one of claims 1 to 6 ,
A hermetic pump device characterized in that a change in volume of a space sandwiched between the pistons operating in opposition is also used as a second working chamber for suctioning and compressing fluid. The hermetic pump device according to claim 5 ,
A sealed pump device characterized in that a labyrinth groove along a circumferential direction is provided on an outer peripheral surface of the piston. In the hermetic pump device according to claim 1 or 2 ,
A hermetic pump device, wherein the drive shaft rotates 180 degrees so that the opposed pistons reciprocate once. The hermetic pump device according to claim 9 , wherein
A hermetic pump device, wherein the drive shaft rotates 90 degrees so that the opposed pistons are moved forward or backward by one. A cylindrical cylinder;
A piston that is disposed in the cylinder, reciprocates in the cylinder to change the volume in the cylinder, and performs a fluid suction and compression operation;
An elastic member that elastically expands and contracts along the reciprocating direction of the piston and forms an isolation space inside the piston;
A drive mechanism disposed inside the isolation space for reciprocally driving the piston in the cylinder;
In a hermetic pump device comprising :
The drive mechanism is
The piston is arranged in the isolated space between the pistons, which are opposed to each other.
A rotationally driven drive shaft;
An elliptical cam having an elliptical shape that rotates integrally with the drive shaft;
A constraining member that exhibits a chain shape surrounding the periphery of the elliptical cam, and converts the rotation of the elliptical cam into a reciprocating stroke;
A restraining member holder that transmits a reciprocating stroke by the restraining member to the piston;
A hermetic pump device, wherein the opposed pistons are provided so as to face each other. The hermetic pump device according to claim 11 ,
The constraining member holder is fixed to the piston, and is supported by a cylindrical fixing member via a sliding bearing in the isolation space in the telescopic member. In the hermetic pump device according to claim 1 or 2 ,
When a suction port that guides suction fluid to a first working chamber formed between the cylinder and the piston is provided on the outer peripheral side of the cylinder,
The suction valve that guides the fluid sucked from the suction port to the first working chamber and prevents the fluid compressed in the first working chamber from flowing out is configured using a plate-like suction reed valve. And
The closed pump device, wherein an open end of the suction reed valve is provided toward the drive shaft. In the hermetic pump device according to claim 1 or 2 ,
When a discharge port for guiding the compressed fluid compressed in the first working chamber formed between the cylinder and the piston to the outside is provided on the outer peripheral side of the cylinder,
The discharge valve that guides the fluid compressed in the first working chamber to the outside of the cylinder and prevents the fluid from flowing into the first working chamber uses a plate-like discharge reed valve. Is composed of,
The closed pump device according to claim 1, wherein an open end of the discharge reed valve is provided toward a side different from the drive shaft. In the hermetic pump device according to claim 1 or 2 ,
The expansion / contraction member is divided and provided between the opposed pistons, and a connecting member that connects the divided expansion / contraction members is fixed to a fixing member. A cylindrical cylinder;
A piston that is disposed in the cylinder, reciprocates in the cylinder to change the volume in the cylinder, and performs a fluid suction and compression operation;
An elastic member that elastically expands and contracts along the reciprocating direction of the piston and forms an isolation space inside the piston;
A drive mechanism disposed inside the isolation space for reciprocally driving the piston in the cylinder;
In a hermetic pump device comprising :
The piston is provided with reverse injection means for guiding a part of the fluid compressed by the piston into the piston and blowing out the fluid from the outer peripheral surface of the piston toward the top of the piston. Pump device.

Images