DE102004058399B4 - pump - Google Patents

Abstract

Pump (10) for delivering hydrogen-containing gas, comprising:
a motor (29);
a motor housing (11) defining a motor chamber (13) for receiving the motor (29);
a rotor (33) that rotates in accordance with the rotation of the motor (29);
a pump housing (14) defining a pump chamber (17) for receiving the rotor (33); and
a partition wall (12) located between the pump housing (14) and the motor housing (11), wherein the pump housing (14) and the motor housing (11) are attached to each other via the partition wall (12)
the motor housing (11) is opened towards the partition (12) and the pump housing (14) is opened towards the partition (12), the partition (12) closing the motor housing (11) and the pump housing (14) .
characterized in that
the motor housing (11) is opened exclusively in the direction of the partition wall (12), and
the engine chamber (13) filled with inert gas and ...

Description

The The present invention relates to a pump which is a fluid by sucking a rotor into a pump chamber sucks and the fluid through an outlet from the pump chamber leaves.

In a fuel cell system according to the prior art, the electrical Energy using hydrogen gas and oxidizing gas as reactive Gas is generated during the production of electrical energy produces water. To the generated Water from the fuel cell will be the hydrogen gas and the oxidizing gas is supplied to the fuel cell in an amount greater than is a consumption amount required to generate the electrical energy. Therefore contains the hydrogen gas discharged from the fuel cell (the so-called Hydrogen off-gas) unreacted hydrogen gas. The omission of unreacted hydrogen gas deteriorates fuel consumption of the fuel cell system. Therefore, the hydrogen off-gas is circulated and returned to the fuel cell to to improve the fuel consumption of the fuel cell system.

As a means for forcibly circulating the hydrogen off-gas in the fuel cell system, a pump is used (see Japanese Patent Laid-Open Publication No. 2003-151592 ). That is, the fuel cell system of the aforementioned publication sucks the hydrogen off-gas discharged from the fuel cell via a condenser separating gas from liquid to the pump. The engine draws the hydrogen exhaust gas into the pump chamber and mixes the sucked hydrogen off-gas with a fresh hydrogen gas supplied from a hydrogen tank. The hydrogen off-gas mixed with the fresh hydrogen gas is returned to an anode of the fuel cell. The ambient air serving as the oxidizing gas is supplied via a further pump to a cathode of the fuel cell.

The pump having such a function has been described in, for example, US Pat Japanese Patent Laid-Open Publication No. 2002-54587 proposed. The pump of this publication is an air pump that supplies air (oxidizing gas) to a fuel cell. The pump has a motor housing and a pump housing, which are integrally attached to each other. The motor housing defines a motor chamber that receives the motor. The pump housing defines a pump chamber that houses a rotor that rotates in accordance with the rotation of the motor. The motor chamber and the pump chamber are separated by a bottom wall (partition wall) of the motor housing through which a rotary shaft of the motor extends. At a portion of the bottom wall, where the rotary shaft is inserted, a sealing material is provided.

As described above, besides the pump (air pump) for sucking air and supplying it to the fuel cell in the fuel cell system, a pump (hydrogen pump) for sucking hydrogen gas (hydrogen off-gas) and supplying it to the fuel cell is provided. In this case, the pump (hydrogen pump) has substantially the same construction as that in the Japanese Patent Laid-Open Publication No. 2002-54587 disclosed pump (air pump), with the exception that the fluid to be sucked and supplied is not air but hydrogen gas.

However, when sucking and supplying hydrogen with the gas in the Japanese Patent Laid-Open Publication No. 2002-54587 The pump disclosed the following problems. That is, since the hydrogen off-gas has a characteristic of permeating through metal, the hydrogen off-gas often permeates the bottom wall (partition wall) of the motor housing separating the pump chamber from the motor chamber, and enters the motor chamber. Although a seal material is provided at a portion of the bottom wall of the motor housing through which the rotation shaft of the motor is inserted, there is a small gap that allows the rotation shaft to rotate. Therefore, the hydrogen exhaust gas passes through the small gap from the pump chamber into the engine chamber.

in the Generally will be during of the assembly air enclosed in the engine chamber. Therefore, the oxygen contained in the air in the engine chamber and the in the hydrogen exhaust gas that has entered the engine chamber included Hydrogen react with each other and water in the engine chamber produce. When water is generated, as described above is, can Components (such as a motor) in the motor chamber corrode. As a result, the performance of the pump can be degraded.

A pump according to the preamble of claim 1 is known from US Pat. No. 6,471,494 B1 known. Other pumps are in the DE 197 09 206 A1 . EP 0 472 933 A2 and US 5,263,825 A disclosed.

It It is an object of the present invention to provide a generic pump to improve that with less effort or less Cost of corrosion in the engine compartment of the unit is prevented.

These Task is with a pump with the features of the claim 1 solved.

Further Aspects and advantages of the invention will become apparent from the following Description in conjunction with the accompanying drawings, which illustrate by means of examples the principles of the invention. The invention, together with its objects and advantages of Best with reference to the description below of the presently preferred embodiment together with the accompanying drawings, in which:

1 Fig. 10 is a sectional view illustrating a hydrogen pump according to an embodiment of the present invention; and

2 an enlarged partial sectional view of 1 is, which explains the state in which the hydrogen gas is the engine chamber of in 1 enters shown pump.

With reference to 1 and 2 An embodiment of the present invention will now be described.

1 shows a hydrogen pump, which is a type of a pump used in a fuel cell system. That is, the pump in this embodiment is a pump for a fluid containing hydrogen. The hydrogen pump 10 from this embodiment is formed by a motor section M and a pump section P. The motor section M has a substantially cup-shaped motor housing 11 which has a closed first end (left end off 1 ) and an open second end (right end in 1 ), and he has a partition (separating element) 12 attached to the motor housing 11 coupled to close the opening. The inner surface of the motor housing 11 and the inner surface of the partition 12 define a motor chamber 13 , The engine chamber 13 is filled with inert gas (such as nitrogen) G

The pump section P has a substantially oval, cup-shaped pump housing 14 which has an open first end (left end in 1 ) and a bearing block (separating element) 16 did that with screws 15 to the pump housing 14 coupled to close the opening. The inner surface of the pump housing 14 and the inner surface of the bearing block 16 define a pump chamber. In this embodiment, the separation form 12 and the storage block 16 a partition. The motor housing 11 is open in the direction of the partition and the pump housing 14 is open towards the partition. The partition closes the motor housing 11 and the pump housing 14 ,

A substantially oval, cup-shaped gearbox 18 is at a second end (right end in 1 ) of the pump housing 14 the pump section P secured with screws (not shown). The gearbox 18 is smaller than the pump housing 14 , The outer surface of the second end of the pump housing 14 and the inner surface of the transmission housing 18 define a gear chamber 19 , The outer surface of the separation 12 and the outer surface of the bearing block 16 are secured together with screws (not shown) so that the motor section M is integrated with the pump section P. An O-ring 20 is between the motor housing 11 and the separation 12 , the pump housing 14 and the storage block 16 , the pump housing 14 and the transmission housing 18 , and between the separation 12 and the storage block 16 arranged as a sealing member to keep the inside tight from the outside.

At a bottom section 21 of the motor housing 11 there is a warehouse 22 , The warehouse 22 is coaxial with the motor housing 11 and is inside the motor chamber 13 facing. The warehouse 22 supports a first end (left end in 1 ) a drive shaft (rotary shaft) 23 rotatable. A second end of the drive shaft 23 extends through a in the separation 12 trained through hole 12a one in the storage block 16 trained through hole 16a and one in a bottom section 24 of the pump housing 14 trained through hole 24a into the interior of the transmission chamber.

The second end of the drive shaft 23 is through a warehouse 25 that is at the bottom section 24 of the pump housing 14 is rotatably supported, and the central portion of the drive shaft 23 is through one in the storage block 16 provided bearing 26 rotatably supported. A motor rotor 27 is in the engine chamber 13 on the drive shaft 23 secured. A motor stator 28 is so on the motor housing 11 secured, which is the motor stator 28 on the outer peripheral side of the motor rotor 27 located. The motor rotor 27 and the motor stator 28 form an electric motor 29 ,

A driven shaft 30 parallel to the drive shaft 23 runs, is located in the pump chamber 17 of the pump section P. The ends of the drive shaft 30 are through one in the bottom section 24 of the pump housing 14 provided bearing 31 and by one in the storage block 16 provided bearing 32 rotatably supported. A twin-bladed drive rotor 33 and a two-blade driven rotor 34 are in the pump chamber 17 to the drive shaft 23 or to the drive shaft 30 secured. A second end (right end) of the driven shaft 30 extends through the bottom section 24 of the pump housing 14 in the same way as the second end (right end) of the drive shaft 23 into the interior of the transmission chamber 19 , One to the second end of the drive shaft 23 secured drive gear 35 and one to the two te end of the driven shaft 30 secured driven gear 36 are in the transmission chamber 19 engaged with each other.

A sealing ring (sealing material) 37 is located in the storage block 16 next to the camp 26 at the drive rotor 33 facing side to the gap between the drive shaft 23 and the storage block 16 to seal. The sealing ring 37 is located between the inner surface of the through hole 16a and the drive shaft 23 , In the same way there is a sealing ring (sealing material) 37 in the storage block 16 next to the camp 32 at the driven rotor 34 facing side to the gap between the driven shaft 30 and the storage block 16 to seal. In this embodiment, there is also a sealing ring 37 in the bottom section 24 of the pump housing 14 next to the camp 25 at the drive rotor 33 facing side to the gap between the drive shaft 23 and the pump housing 14 to seal. In the same way there is a sealing ring (sealing material) 37 in the bottom section 24 of the pump housing 14 next to the camp 31 at the driven rotor 34 facing side to the gap between the driven shaft 30 and the pump housing 14 to seal.

The hydrogen pump 10 is positioned so that an imaginary plane representing the axes of the drive shaft 23 and the driven shaft 30 contains, runs horizontally. An inlet (not shown) is in the ceiling of the pump housing 14 of the pump portion P is formed around the discharged from the fuel cell, not shown, hydrogen gas into the pump chamber 17 to suck. An outlet 38 is in the bottom portion of the pump chamber 17 formed by the rotation of the rotors 33 . 34 sucked hydrogen gas from the pump chamber 17 omit. Therefore, it will be from the inlet into the pump chamber 17 sucked hydrogen exhaust gas through the outlet 38 discharged and returned to the fuel cell. As described above, the hydrogen pump repeats 10 the suction and delivery process, in which hydrogen exhaust gas into the pump chamber 17 sucked and then left out.

Now, the operation of the above-described hydrogen pump (pump) will be described. 10 described. The operation, which is carried out when the hydrogen exhaust gas in the pump chamber 17 the engine chamber 13 will be discussed mainly later.

In a case where the hydrogen pump 10 Repeat the suction and feed operation of hydrogen exhaust gas, as described above, a part of the from the inlet into the pump chamber 17 sucked hydrogen exhaust the engine chamber 13 over the through hole 16a of the storage block 16 and over the through hole 12a the separation 12 enter, as in 2 is shown. That is, although the sealing ring 37 in the through hole 16a of the storage block 16 is located between the sealing ring 37 and the drive shaft 23 a small gap formed around the rotation of the drive shaft 23 to enable.

In addition, between the through hole 12a the separation 12 and the peripheral surface of the drive shaft 23 a gap formed around the rotation of the drive shaft 23 to enable. Therefore, this can be done in the pump chamber 17 sucked hydrogen exhaust the engine chamber 13 enter through these columns. Since the hydrogen (hydrogen) gas has the characteristic of permeating through metal, the hydrogen exhaust gas can pass through the bearing block 16 and by the separation 12 penetrate, which are made of metal material (for example, an aluminum alloy), and it can into the motor chamber 13 enter.

However, since in this embodiment, the motor chamber 13 is filled with inert gas (nitrogen) G, that is, there is no remaining air (oxidizing gas), generates the hydrogen gas, which is the engine chamber 13 no water by reaction with the air (the oxidizing gas). Therefore, even if the hydrogen exhaust is the engine chamber 13 enters that water is not generated by a reaction with air (the oxidizing gas). Therefore, it prevents components such as the electric motor 29 in the engine chamber 13 corrode. As a result, the performance of the hydrogen pump is prevented 10 deteriorated.

The inert gas (nitrogen) G in the engine chamber 13 gets through in the through hole 16a of the storage block 16 located sealing ring 37 prevented from entering the pump chamber 17 to escape. The O-rings 20 , which serve as the sealing elements, prevent the inert gas (nitrogen) G, which is the through hole 12a the separation 12 happens from the contact portion between the motor housing 11 and the separation 12 and the contact portion between the partition 12 and the storage block 16 escapes to the outside. The O-rings 20 Also, prevent water from entering the engine chamber 13 from the contact portion between the motor housing 11 and the separation 12 and from the contact portion between the partition 12 and the storage block 16 enters.

• (1) Selbst wenn Wasserstoffabgas die Motorkammer 13 von der Pumpenkammer 17 betritt, ist die Motorkammer 13 mit dem inerten Gas (Stickstoff) G gefüllt, dass heißt, es gibt dort keine Luft (Oxidationsgas). Daher wird in der Motorkammer 13 kein Wasser durch eine Reaktion zwischen Wasserstoff und Luft erzeugt. Dementsprechend wird verhindert, dass Bauteile, wie zum Beispiel der Elektromotor 29 in der Motorkammer 13, durch Wasser korrodieren, und es wird zuverlässig verhindert, dass sich die Leistung der Wasserstoffpumpe 10 verschlechtert.
• (2) Da die Diffusionsgeschwindigkeit des Stickstoffs, das die Motorkammer 13 als das inerte Gas G füllt, langsamer (um circa 1/3) als die der Luft ist, entweicht der Stickstoff nicht einfach von der Motorkammer 13. Daher wird die Leistung der Wasserstoffpumpe 10 für eine lange Zeitspanne beibehalten.
• (3) Das Dichtungsmaterial, das in diesem Ausführungsbeispiel der Dichtungsring 37 ist, befindet sich in dem Durchgangsloch 16a des Lagerblocks 16, durch den sich die Antriebswelle 23 erstreckt. Daher verhindert der Dichtungsring 37 zuverlässig, dass das inerte Gas G in der Motorkammer 13 dort in die Pumpenkammer 17 entweicht, wo sich die Antriebswelle 23 in dem Lagerblock 16 erstreckt (durch das Durchgangsloch 16a).
• (4) Das Dichtungselement, das in diesem Ausführungsbeispiel der O-Ring 20 ist, befindet sich an dem Kontaktabschnitt zwischen dem Motorgehäuse 11 und der Abtrennung 12. Daher wird zuverlässig verhindert, dass das inerte Gas G in der Motorkammer 13 von dem Kontaktabschnitt zwischen dem Motorgehäuse 11 und der Abtrennung 12 nach außen entweicht. Der O-Ring 20 verhindert zudem, dass das Wasser die Motorkammer 13 von außen über den Kontaktabschnitt betritt.
• (5) Das Dichtungselement, das in diesem Ausführungsbeispiel der O-Ring 20 ist, befindet sich an dem Kontaktabschnitt zwischen der Abtrennung 12 und dem Lagerblock 16. Daher wird zuverlässig verhindert, dass das inerte Gas G in der Motorkammer 13 von dem Kontaktabschnitt zwischen der Abtrennung 12 und dem Lagerblock 16 nach außen entweicht. Der O-Ring 20 verhindert zudem, dass Wasser die Motorkammer 13 von außen über den Kontaktabschnitt betritt.

The preferred embodiment has the following advantages.

• (1) Even if hydrogen gas exhausted the engine mer 13 from the pump chamber 17 enters, is the engine chamber 13 filled with the inert gas (nitrogen) G, that is, there is no air (oxidizing gas). Therefore, in the engine chamber 13 no water generated by a reaction between hydrogen and air. Accordingly, it prevents components such as the electric motor 29 in the engine chamber 13 , corrode by water, and it is reliably prevents the performance of the hydrogen pump 10 deteriorated.
• (2) Because the diffusion rate of nitrogen, which is the engine chamber 13 As the inert gas G fills, slower (by about 1/3) than that of the air, the nitrogen does not simply escape from the engine chamber 13 , Therefore, the power of the hydrogen pump 10 maintained for a long period of time.
• (3) The sealing material, in this embodiment, the sealing ring 37 is located in the through hole 16a of the storage block 16 through which the drive shaft 23 extends. Therefore, the seal ring prevents 37 Reliable that the inert gas G in the engine chamber 13 there in the pump chamber 17 escapes, where the drive shaft 23 in the storage block 16 extends (through the through hole 16a ).
• (4) The sealing element, in this embodiment, the O-ring 20 is located at the contact portion between the motor housing 11 and the separation 12 , Therefore, it is reliably prevented that the inert gas G in the engine chamber 13 from the contact portion between the motor housing 11 and the separation 12 escapes to the outside. The O-ring 20 also prevents the water from the engine chamber 13 enters from outside via the contact portion.
• (5) The sealing element, in this embodiment, the O-ring 20 is located at the contact portion between the partition 12 and the storage block 16 , Therefore, it is reliably prevented that the inert gas G in the engine chamber 13 from the contact portion between the partition 12 and the storage block 16 escapes to the outside. The O-ring 20 also prevents water from the engine chamber 13 enters from outside via the contact portion.

The The invention can be carried out in the following ways.

In the preferred embodiment, the partition is separated by the partition (partition) 12 that the opening of the motor housing 11 closes, and through the bearing block (separating element) 16 formed, which is the opening of the pump housing 14 closes. However, the partition can only through the bearing block 16 be educated. In this case, the storage block closes 16 the opening of the motor housing 11 and the opening of the pump housing 14 ,

In the preferred embodiment, the O-ring 20 used as the sealing member located at the contact portion between the motor housing 11 and the separation 12 located. However, instead of the O-ring 20 Also, another seal member may be used as long as the seal member prevents the inert gas G from leaking to the outside through the contact portion and the water enters via the contact portion.

In the preferred embodiment, the sealing material is the sealing ring 37 is, in the through hole 16a of the storage block 16 , However, the sealing ring can 37 also in the through hole 12a the separation 12 are located.

In the present embodiment, the motor chamber 13 filled with the inert gas G, which is nitrogen. However, any inert gas other than nitrogen (e.g., argon, helium, neon, xenon, and krypton) may be used as long as the inert gas does not react with hydrogen to produce water. The engine chamber 13 may be filled with mixed gas (for example, nitrogen and neon), which is the mixture of various inert gases G.

In the preferred embodiment, the present invention is a hydrogen pump 10 which circulates hydrogen gas (hydrogen off-gas) in the fuel cell system. However, the present invention may be embodied as any pump (hydrogen pump) different from the pump used in the fuel cell system as long as the pump sucks and supplies fluid containing hydrogen.

The present examples and embodiments are to be regarded as illustrative and not restrictive and that The invention is not limited to the details given herein, but rather can be within the scope and equivalence of the enclosed claims be modified.

A pump has a motor and a motor housing. The motor housing defines a motor chamber for receiving the motor. The engine chamber is filled with inert gas. A rotor rotates in accordance with the rotation of the motor. A pump housing defines a pump chamber for receiving the rotor. Between the pump housing and the motor housing is a partition. The pump housing and the motor housing are attached to each other via the partition wall. Therefore, even if hydrogen halide Any fluid escaping from the pump chamber into the engine chamber prevents water from being generated in the engine chamber.

Claims (6)

Pump ( 10 ) for delivering hydrogen-containing gas, comprising: an engine ( 29 ); a motor housing ( 11 ), which is a motor chamber ( 13 ) for picking up the engine ( 29 ) Are defined; a rotor ( 33 ), which is in accordance with the rotation of the engine ( 29 ) turns; a pump housing ( 14 ), which has a pump chamber ( 17 ) for receiving the rotor ( 33 ) Are defined; and a partition ( 12 ) located between the pump housing ( 14 ) and the motor housing ( 11 ), wherein the pump housing ( 14 ) and the motor housing ( 11 ) over the partition wall ( 12 ) are attached to each other, wherein the motor housing ( 11 ) towards the partition ( 12 ) is open and the pump housing ( 14 ) towards the partition ( 12 ) is opened, wherein the partition ( 12 ) the motor housing ( 11 ) and the pump housing ( 14 ), characterized in that the motor housing ( 11 ) exclusively in the direction of the partition ( 12 ), and the engine chamber ( 13 ) is filled with inert gas and sealed so that the inert gas can not escape to the outside. Pump ( 10 ) according to claim 1, characterized in that the inert gas is at least one of nitrogen, argon, helium, neon, xenon and krypton. Pump ( 10 ) according to claim 1, characterized by a rotary shaft ( 23 ), which is the rotation of the engine ( 29 ) to the rotor ( 33 ), whereby the partition wall ( 12 ) a through hole ( 12a ), through which the rotary shaft ( 23 ), and a seal ( 37 ), which extends between the inner surface of the through hole ( 12a ) and the rotary shaft ( 23 ) is located. Pump ( 10 ) according to claim 1, characterized by a sealing element ( 20 ) located at a contact portion between the motor housing ( 11 ) and the partition ( 12 ) is located. Pump ( 10 ) according to claim 1, characterized in that the partition wall ( 12 ) has a plurality of separating elements, which are placed on each other, and in that a sealing element ( 20 ) on at least a portion of a portion between the adjacent partition members, a portion between the motor housing (10) 11 ) and the adjacent separator and a portion between the pump housing ( 14 ) and the adjacent partition. Pump ( 10 ) according to one of claims 1 to 5, characterized in that the pump ( 10 ) is incorporated in a fuel cell system.