Motor direct drive air pump and related applications thereof

Abstract

A motor direct drive air pump comprises a housing, a first shaft, and a second shaft. The housing is formed with a left space and a right space; one of the spaces is a compression chamber having an air inlet and an air outlet; the other space has a transmission chamber and a driving chamber; stators are disposed in the driving chamber. A first shaft is disposed through a central partition of the housing; a first impeller is embedded at a portion of the first shaft located in the compression chamber, while a first gear is embedded at a portion of the first shaft located in the transmission chamber, and rotors are embedded at a portion of the first shaft located in the compression chamber. A second shaft is disposed through the central partition of the housing; a second impeller is embedded at a portion of the second shaft located in the compression chamber, while a second gear is embedded at a portion of the second shaft located in the transmission chamber, and the second impeller and the second gear are respectively coupled to the first impeller and the first gear. Therefore, a power outputted from a motor directly drives the first and the second impellers and allow the air pump to operate, without any additional coupling.

Description

FIELD OF THE INVENTION

The invention relates to an air pump, and more particularly to a motor direct drive air pump having a motor directly outputs power to drive the air pump, and the outputted power does not need to go through an additional coupling.

DESCRIPTION OF PRIOR ART

A conventional ventilation device usually comprises a housing with an air inlet and an air outlet, and has therein a pair of impellers that may be coupled to each other and rotate toward opposite directions, respectively. When one of the impellers passes by the air inlet, a fixed amount of air is captured between the impellers and the housing, then transported and allowed to exit via the air outlet by the rotating impellers. As the rotation of the impellers is repeated, the ventilation device may put out a fixed proportion of air.

A spiral pump of prior arts having a driving valve and a piston was disclosed in the U.S. Pat. No. 4,772,187. A plurality of arc-shaped surfaces are externally disposed on the driving valve, while a plurality of arc-shaped indentations are internally disposed on the main shaft of the driving valve, and the piston includes a plurality of semi-ellipsoid blades and a raised portion. When driven by an external force, the piston of the pump is allowed to spin, so that the liquid within the pump pushes the liquid around the inlet to the outlet under pressure.

A spiral compressor of prior arts having a spiral serrated male rotor and a spiral serrated female rotor that may be coupled together was disclosed in the U.S. Pat. No. 6,948,915. The compressor is connected to a housing, and the housing has a high-speed electric motor therein, the motor comprises a rotor, a stator, and an output shaft. The output shaft may drive at least a male rotor and a female rotor.

The U.S. Pat. No. 6,439,865 also discloses an air pump of prior arts, which comprises a chamber disposed in a housing, and has a suction portion, a pressurizing portion, and a conversion portion formed therein. The chamber has therein a pair of rotors that may be coupled to each other, and each of the rotors has at least three impellers disposed thereon; the impellers of the two rotors are disposed toward different directions, and thus defining spaces between the impellers in the air pump.

The underlying mechanism of the aforesaid compressors and air pumps is considerably similar to that of the ventilation device, in which a space is present and has pairs of impellers that may be coupled to each other disposed therein. The impellers or rotors are driven via an external driving device (such as a motor), so as to push the air or liquid in the space from an inlet to an outlet.

However, the ventilation devices of the prior arts must rely on a coupling linked to an external driving device (such as a motor), so as to be driven by a force and operate. This renders the overall size of the ventilation device needlessly large, and results in the fact that the ventilation device must be built with an excessive number of mechanical parts, thus the ventilation device not only occupies a lot of physical space, but also costs more to manufacture.

SUMMARY OF THE INVENTION

In light of the aforesaid problems, an air pump with smaller physical size and less mechanical parts is required, and the invention has proposed a novel and more advanced motor direct drive air pump in response to such requirement. The motor direct drive air pump of the invention comprises a housing, a first shaft, and a second shaft. The housing has a left cover, a right cover, and a central partition to form a left space and a right space, wherein one of the spaces is a compression chamber having at least an air inlet and an air outlet openly disposed on lateral walls thereof; the other space has a transmission chamber and a driving chamber, and stators are disposed in the driving chamber. Moreover, the first shaft is fittingly disposed through the central partition of the housing; a first impeller is embedded at a portion of the first shaft located in the compression chamber; a first gear is embedded at a portion of the first shaft located in the transmission chamber, and a rotor is embedded at a portion of the first shaft located in the driving chamber. Furthermore, the second shaft is fittingly disposed through the central partition of the housing; a second impeller is embedded at a portion of the second shaft located in the compression chamber; a second gear is embedded at a portion of the second shaft located in the transmission chamber, and the second impeller and the second gear are respectively coupled to the first impeller and the first gear. Therefore, a power outputted from a motor may directly drive the first impeller and the second impeller in the compression chamber and allow the air pump to operate, without needing to go through an additional coupling.

A primary objective of the invention is to propose a motor direct drive air pump having a smaller physical size.

Another objective of the invention is to propose a motor direct drive air pump having less mechanical parts.

Still another objective of the invention is to propose a motor direct drive air pump having less transmission loss over forces generated from a motor.

Still another objective of the invention is to propose a motor direct drive compressor having a smaller physical size.

Still another objective of the invention is to propose a motor direct drive compressor having less mechanical parts.

Still another objective of the invention is to propose a motor direct drive compressor having less transmission loss over forces generated from a motor.

A further objective of the invention is to propose a motor direct drive vacuum pump having a smaller physical size.

A further objective of the invention is to propose a motor direct drive vacuum pump having less mechanical parts.

A further objective of the invention is to propose a motor direct drive vacuum pump having less transmission loss over forces generated from a motor.

BRIEF DESCRIPTION OF DRAWINGS

The structure and the technical means adopted by the present invention to achieve the above and other objectives can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying diagrams, wherein:

FIG. 1 is a three-dimensional view that shows a motor direct drive air pump according to a first preferred embodiment of the invention.

FIG. 2 is an exploded view that shows a motor direct drive air pump according to a first preferred embodiment of the invention.

FIG. 3 is a sectional view that shows a motor direct drive air pump according to a first preferred embodiment of the invention.

FIGS. 4A to 4K are sketching views that show the allocation of bearings proposed in the invention.

FIG. 5 is a sectional view that shows a motor direct drive air pump according to a second preferred embodiment of the invention.

FIG. 6 is a sectional view that shows a motor direct drive compressor according to a third preferred embodiment of the invention.

FIG. 7 is a sectional view that shows a motor direct drive compressor according to a fourth preferred embodiment of the invention.

FIG. 8 is a sectional view that shows a motor direct drive air pump according to a seventh preferred embodiment of the invention.

FIG. 9 is a sectional view that shows a motor direct drive air pump according to a eighth Preferred embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A motor direct drive air pump is disclosed in the invention, which utilizes the principle of air transmission in air pumps understood by anyone of ordinary skill in the art, and will not be described in further details hereafter. Moreover, it should be noted that drawings mentioned in the following paragraphs are used to illustrate relevant structures of the invention, and are not necessarily drawn according to the actual sizes of the disclosed content.

The First Preferred Embodiment

A first preferred embodiment is shown in FIGS. 1, 2, and 3. A motor direct drive air pump 1 comprises a housing 10, a first shaft 11, and a second shaft 12. The housing 10 has a left cover 101, a right cover 102, and a central partition 103 to form a left space and a right space, and the right cover 102 may further include an optional cover 1021 to allow for further combination. One of the spaces is a compression chamber 104 having at least an air inlet 1041 and an air outlet 1042 openly disposed on lateral walls thereof; the other space has a transmission chamber 105 and a driving chamber 106, and stators 1061 are disposed in the driving chamber 106.

The first shaft 11 is fittingly disposed through the central partition 103 of the housing 10; a first impeller 13 is embedded at a portion of the first shaft 11 located in the compression chamber 104; a first gear 14 is embedded at a portion of the first shaft 11 located in the transmission chamber 105, and a rotor 1062 is embedded at a portion of the first shaft 11 located in the driving chamber 106. Furthermore, the second shaft 12 is fittingly disposed through the central partition 103 of the housing 10; a second impeller 15 is embedded at a portion of the second shaft 12 located in the compression chamber 104; a second gear 16 is embedded at a portion of the second shaft 12 located in the transmission chamber 105, and the second impeller 15 and the second gear 16 are respectively coupled to the first impeller 13 and the first gear 14. Therefore, a power outputted from a motor 17 may directly drive the first impeller 13 and the second impeller 15 in the compression chamber 104 and allow the air pump 1 to operate, without needing to go through an additional coupling.

In the aforesaid embodiment, the first impeller 13 and the second impeller 15 have the same number of blades, while in some other application the first impeller and the second impeller may have different number of blades. In addition, the motor direct drive air pump 1 may further comprise a control circuit (not shown) to control the operation of the motor 17.

Referring to FIG. 3, the central partition 103 may further comprise cylindrical flanges 1031 to the left, to the right, or to both directions thereof simultaneously, so that the left cover 101 or the right cover 102 may close over thereon.

FIGS. 4A to 4K show the allocation of bearings proposed in the invention, wherein a bearing 107 may be disposed in the central partition 103, the left cover 101, and the right cover 102, and the location of the bearing 107 may be freely arranged according to the requirements that arise from actual operation and mechanical balance of the air pump 1. For example, the bearing 107 may be disposed at where the first shaft 11 is embedded on the left cover 101, or at where the second shaft 12 is embedded on the left cover 101, or at where the first shaft 11 is embedded on the right cover 102, or at where the second shaft 12 is embedded on the right cover 102. The bearings 107 may also be disposed in pairs at where the first shaft 11 is embedded on the left cover 101 and on the central partition 103, or at where the second shaft 12 is embedded on the left cover 101 and on the central partition 103, or at where the first shaft 11 is embedded on a left side and a right side of the central partition 103, or at where the first shaft 11 is embedded on the right cover 102 and on the central partition 103, or at where the second shaft 12 is embedded on the right cover 102 and on the central partition 103.

The Second Preferred Embodiment

A second preferred embodiment is shown in FIG. 5, which is a sectional view of a motor direct drive air pump. The motor direct drive air pump 1 comprises a first housing 18, a second housing 19, a first shaft 11, and a second shaft 12. The first housing 18 has a left cover 101, a right cover 102, and a central partition 103 to form a left space and a right space, wherein one of the spaces is a transmission chamber 105; the other space is a compression chamber 104 with at least an air inlet (not shown) and an air outlet (not shown) openly disposed on lateral walls thereof. The second housing 19 is disposed outside of the right cover 102 for forming a driving chamber 106, and stators 1061 are disposed in the driving chamber 106.

The first shaft 11 is fittingly disposed into the transmission chamber 105, the compression chamber 104, and the driving chamber 106; a first impeller 13 is embedded at a portion of the first shaft 11 located in the compression chamber 104; a first gear 14 is embedded at a portion of the first shaft 11 located in the transmission chamber 105, and a rotor 1062 is embedded at a portion of the first shaft 11 located in the driving chamber 106. The second shaft 12 is fittingly disposed through the central partition 103; a second impeller 15 is embedded at a portion of the second shaft 12 located in the compression chamber 104; a second gear 16 is embedded at a portion of the second shaft 12 located in the transmission chamber 105, and the second impeller 15 and the second gear 16 are respectively coupled to the first impeller 13 and the first gear 14. Therefore, a power outputted from a motor 17 may directly drive the first impeller 13 and the second impeller 15 in the compression chamber 104 and allow the air pump 1 to operate, without needing to go through an additional coupling.

In the aforesaid embodiment, the first impeller 13 and the second impeller 15 have the same number of blades, while in some other application the first impeller and the second impeller may have different number of blades. In addition, the motor direct drive air pump 1 may further comprise a control circuit (not shown) to control the operation of the motor 17.

The central partition 103 may further comprise cylindrical flanges 1031 to the left, to the right, or to both directions thereof simultaneously, so that the left cover 101 or the right cover 102 may close over thereon.

According to the allocation of a bearing proposed in the invention, a bearing 107 may be disposed in the central partition 103, the left cover 101, the right cover 102, and the second housing 19, and the location of the bearing 107 may be freely arranged according to the requirements that arise from actual operation and mechanical balance of the air pump 1. For example, the bearing 107 may be disposed at where the first shaft 11 is embedded on the left cover 101, or at where the second shaft 12 is embedded on the left cover 101, or at where the first shaft 11 is embedded on the central partition 103, or at where the second shaft 12 is embedded on the central partition 103, or at where the first shaft 11 is embedded on the right cover 102, or at where the second shaft 12 is embedded on the right cover 102, or at where the first shaft 11 is embedded on the second housing 19, or at where the second shaft 12 is embedded on the second housing 19. Further, the bearing 107 may also be disposed in pairs to make the air pump 1 more balanced.

The Third preferred Embodiment

A third preferred embodiment is shown in FIG. 6, which is a sectional view of a motor direct drive compressor having identical characteristics as the aforesaid first embodiment. However, a compressor requires higher air impermeability than that of an air pump in order to provide compressed air of higher pressure. Therefore, seals 20 such as O-shaped rings are disposed at where the first shaft 11 and the second shaft 12 are fittingly disposed through the central partition 103 in this embodiment, and thinly-formed airtight rings 1011 may also be disposed at where the left cover 101 and the central partition 103 are joined if required. As a result, a power outputted from a motor may directly drive the first impeller and the second impeller in the compression chamber without going through an additional coupling, and allow the compressor to output compressed air from the air outlet.

The Fourth Preferred Embodiment

A fourth preferred embodiment is shown in FIG. 7, which is a sectional view of a motor direct drive compressor having identical characteristics as the aforesaid third embodiment. However, a compressor requires higher air impermeability than that of an air pump in order to provide compressed air of higher pressure. Therefore, seals 20 such as O-shaped rings are disposed at where the first shaft 11 and the second shaft 12 are fittingly disposed through the central partition 103 in this embodiment, and thinly-formed airtight rings 1021 may also be disposed at where the right cover 102 and the central partition 103 are joined if required. As a result, a power outputted from a motor may directly drive the first impeller and the second impeller in the compression chamber without going through an additional coupling, and allow the compressor to output compressed air from the air outlet.

The Fifth Preferred Embodiment

The invention further proposes a fifth preferred embodiment, which is a motor direct drive vacuum pump that has identical characteristics as the first and the fourth embodiments described above. The air inlet thereof is connected to an exterior pneumatic pipeline, when a power outputted from a motor directly drives the first impeller and the second impeller in the compression chamber, the vacuum pump is allowed to draw air from the exterior pneumatic pipeline via the air inlet and output the air via the air outlet, so as to make the exterior pneumatic pipeline vacuumed.

The Sixth Preferred Embodiment

The invention further proposes a sixth preferred embodiment, which is a motor direct drive vacuum pump that has identical characteristics as the third and the sixth embodiments described above. The air inlet thereof is connected to an exterior pneumatic pipeline, when a power outputted from a motor directly drives the first impeller and the second impeller in the compression chamber, the vacuum pump is allowed to draw air from the exterior pneumatic pipeline via the air inlet and output the air via the air outlet, so as to make the exterior pneumatic pipeline vacuumed.

The Seventh Preferred Embodiment

A seventh preferred embodiment is shown in FIG. 8, which is a sectional view of a motor direct drive air pump having identical characteristics as the aforesaid first embodiment, and further comprises a central partition 103 formed from a first partition 108 adjacent to the compression chamber 104 and a second partition 109 adjacent to the transmission chamber 105 in the housing 10, and a non-contact open space is formed at outside of where the first partition 108 and the second partition 109 are joined for facilitating airflow. A pair of seals 20 are disposed at where the first shaft 11 and the second shaft 12 are fittingly disposed through the first partition 108, such as O-shaped rings; a pair of bearings 107 are disposed at where the first shaft 11 and the second shaft 12 are fittingly disposed through the second partition 109. As a result, condensation of water vapor may be prevented and further facilitate the operation of the air pump 1.

In this embodiment, junctions between the first partition 108 and the second partition 109 may be located at four opposing corners between the first partition 108 and the second partition 109. Spacers 1031 are further disposed at the junctions, so that an open space is formed between the first partition 108 and the second partition 109. Otherwise, protrusions (not shown) may also be further extended from the junctions between the first partition 108 and the second partition 109, so that an open space is formed therebetween.

The Eighth Preferred Embodiment

A eighth Preferred embodiment is shown in FIG. 9, which is a sectional view of a motor direct drive air pump having identical characteristics as the aforesaid third embodiment, and further comprises a central partition 103 formed from a first partition 108 adjacent to the compression chamber 104 and a second partition 109 adjacent to the transmission chamber 105 in the housing 10, and a non-contact open space is formed at outside of where the first partition 108 and the second partition 109 are joined for facilitating airflow. A pair of seals 20 are disposed at where the first shaft 11 and the second shaft 12 are fittingly disposed through the first partition 108, such as O-shaped rings; a pair of bearings 107 are disposed at where the first shaft 11 and the second shaft 12 are fittingly disposed through the second partition 109. As a result, condensation of water vapor may be prevented and further facilitate the operation of the air pump 1.

In this embodiment, junctions between the first partition 108 and the second partition 109 may be located at four opposing corners between the first partition 108 and the second partition 109. Spacers (as shown in the seventh preferred embodiment)are further disposed at the junctions, so that an open space is formed between the first partition 108 and the second partition 109. Otherwise, protrusions (as shown in the eleventh preferred embodiment)may also be further extended from the junctions between the first partition 108 and the second partition 109, so that an open space is formed therebetween.

The Ninth Preferred Embodiment

The invention further proposes a Ninth Preferred embodiment, which is a motor direct drive compressor that has identical characteristics as the tenth embodiments described above. Because a compressor requires higher air impermeability than that of an air pump in order to provide compressed air of higher pressure, a pair of seals 20 such as O-shaped rings may be disposed at where the first shaft 11 and the second shaft 12 are fittingly disposed through the first partition 108 in this embodiment, and thinly-formed airtight rings 1011 may be further disposed at where the left cover 101 and the central partition 103 are joined if required.

The Tenth Preferred Embodiment

The invention further proposes a Tenth Preferred embodiment, which is a motor direct drive compressor that has identical characteristics as the twelfth embodiments described above. Because a compressor requires higher air impermeability than that of an air pump in order to provide compressed air of higher pressure, a pair of seals 20 such as O-shaped rings may be disposed at where the first shaft 11 and the second shaft 12 are fittingly disposed through the first partition 108 in this embodiment, and thinly-formed airtight rings 1011 may be further disposed at where the left cover 101 and the central partition 103 are joined if required.

The Eleventh Preferred Embodiment

The invention further proposes a Eleventh Preferred embodiment, which is a motor direct drive vacuum pump that has identical characteristics as the tenth and the thirteenth embodiments described above. The air inlet thereof is connected to an exterior pneumatic pipeline, when a power outputted from a motor directly drives the first impeller and the second impeller in the compression chamber, the vacuum pump is allowed to draw air from the exterior pneumatic pipeline via the air inlet and output the air via the air outlet, so as to make the exterior pneumatic pipeline vacuumed.

The Twelfth Preferred Embodiment

The invention further proposes an Twelfth Preferred embodiment, which is a motor direct drive vacuum pump that has identical characteristics as the twelfth and the fifteenth embodiments described above. The air inlet thereof is connected to an exterior pneumatic pipeline, when a power outputted from a motor directly drives the first impeller and the second impeller in the compression chamber, the vacuum pump is allowed to draw air from the exterior pneumatic pipeline via the air inlet and output the air via the air outlet, so as to make the exterior pneumatic pipeline vacuumed.

Although particular embodiments of the invention has been described in details for purposes of illustration, it will be understood by one of ordinary skill in the art that numerous variations will be possible to the disclosed embodiments without going outside the scope of the invention as disclosed in the claims.

Claims

1. A motor direct drive air pump, comprising:

a housing having a left cover, a right cover, and a central partition to form a left space and a right space, wherein one of the spaces is a compression chamber having at least an air inlet and an air outlet openly disposed on lateral walls thereof; the other space has a transmission chamber and a driving chamber, and stators are disposed in said driving chamber;

a first shaft being fittingly disposed through the central partition of the housing; a first impeller being embedded at a portion of the first shaft located in the compression chamber; a first gear being embedded at a portion of the first shaft located in the transmission chamber, and a rotor being embedded at a portion of the first shaft located in the driving chamber; and

a second shaft being fittingly disposed through the central partition of the housing; a second impeller being embedded at a portion of the second shaft located in the compression chamber; a second gear being embedded at a portion of the second shaft located in the transmission chamber, and the second impeller and the second gear are respectively coupled to the first impeller and the first gear;

therefore, a power outputted from a motor may directly drive the first impeller and the second impeller in the compression chamber and allow the air pump to operate, without needing to go through an additional coupling.

2. The motor direct drive air pump according to claim 1, further comprising a plurality of seals, said seals are disposed at where the left cover and the central partition are joined, and at where the first shaft and the second shaft are fittingly disposed through the central partition.

3. A motor direct drive air pump, comprising:

a first housing having a left cover, a right cover, and a central partition to form a left space and a right space, wherein one of the spaces is a transmission chamber; the other space is a compression chamber having at least an air inlet and an air outlet openly disposed on lateral walls thereof;

a second housing being disposed outside of the right cover for forming a driving chamber, and stators are disposed in said driving chamber;

a first shaft being fittingly disposed into the transmission chamber, the compression chamber, and the driving chamber; a first impeller being embedded at a portion of the first shaft located in the compression chamber; a first gear being embedded at a portion of the first shaft located in the transmission chamber, and a rotor being embedded at a portion of the first shaft located in the driving chamber; and

a second shaft being fittingly disposed through the central partition of the housing; a second impeller being embedded at a portion of the second shaft located in the compression chamber; a second gear being embedded at a portion of the second shaft located in the transmission chamber, and the second impeller and the second gear are respectively coupled to the first impeller and the first gear;

therefore, a power outputted from a motor may directly drive the first impeller and the second impeller in the compression chamber and allow the air pump to operate, without needing to go through an additional coupling.

4. The motor direct drive air pump according to claim 3, further comprising a plurality of seals, said seals are disposed at where the right cover of the first housing and the central partition are joined, and at where the first shaft and the second shaft are fittingly disposed through the central partition.

5. A motor direct drive air pump, comprising:

a housing having a left cover, a right cover, and a central partition to form a left space and a right space, wherein one of the spaces is a compression chamber having at least an air inlet and an air outlet openly disposed on lateral walls thereof; the other space has a transmission chamber and a driving chamber, and stators are disposed in the driving chamber;

a first shaft being fittingly disposed through the central partition of the housing; a first impeller being embedded at a portion of the first shaft located in the compression chamber; a first gear being embedded at a portion of the first shaft located in the transmission chamber, and a rotor being embedded at a portion of the first shaft located in the driving chamber; and

a second shaft being fittingly disposed through the central partition of the housing; a second impeller being embedded at a portion of the second shaft located in the compression chamber; a second gear being embedded at a portion of the second shaft located in the transmission chamber, and the second impeller and the second gear are respectively coupled to the first impeller and the first gear;

wherein the central partition of the housing is constructed via joining together a first partition adjacent to the compression chamber and a second partition adjacent to the transmission chamber, and a non-contact open space is formed at outside of where the first partition and the second partition are joined for facilitating airflow; pairs of seals are disposed at where the first shaft and the second shaft are fittingly disposed through the first partition, and pairs of bearings are disposed at where the first shaft and the second shaft are fittingly disposed through the second partition;

therefore, a power outputted from a motor may directly drive the first impeller and the second impeller in the compression chamber and allow the air pump to operate, without needing to go through an additional coupling.

6. A motor direct drive air pump, comprising:

a first housing having a left cover, a right cover, and a central partition to form a left space and a right space, wherein one of the spaces is a transmission chamber; the other space is a compression chamber having at least an air inlet and an air outlet openly disposed on lateral walls thereof;

a second housing being disposed outside of the right cover for forming a driving chamber, and stators are disposed in the driving chamber;

a first shaft being fittingly disposed into the transmission chamber, the compression chamber, and the driving chamber; a first impeller being embedded at a portion of the first shaft located in the compression chamber; a first gear being embedded at a portion of the first shaft located in the transmission chamber, and a rotor being embedded at a portion of the first shaft located in the driving chamber; and

a second shaft being fittingly disposed through the central partition of the housing; a second impeller being embedded at a portion of the second shaft located in the compression chamber; a second gear being embedded at a portion of the second shaft located in the transmission chamber, and the second impeller and the second gear are respectively coupled to the first impeller and the first gear;

wherein the central partition of the housing is constructed via joining together a first partition adjacent to the compression chamber and a second partition adjacent to the transmission chamber, and a non-contact open space is formed at outside of where the first partition and the second partition are joined for facilitating airflow; pairs of seals are disposed at where the first shaft and the second shaft are fittingly disposed through the first partition, and pairs of bearings are disposed at where the first shaft and the second shaft are fittingly disposed through the second partition;

therefore, a power outputted from a motor may directly drive the first impeller and the second impeller in the compression chamber and allow the air pump to operate, without needing to go through an additional coupling.