JP2004270509A - Air pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air pump that suitably supports a drive shaft where an eccentric part such as a cam is mounted with two bearings and allows center alignment of the bearings to be performed easily. <P>SOLUTION: A drive shaft 2 where a cam 3 is mounted is supported at two points by two bearings 4 and 5 on both sides. A pump housing that includes the bearings 4 and 5 is divided at a place substantially along the center of a rotation axis of the drive shaft 2 into a first housing part 21 and a second housing part 22 joined to the first housing part 21 with joint bolts 8. The first housing part 21 and the second housing part 22 support the two bearings 4 and 5. The drive shaft 2 is thereby suitably supported by the bearings 4 and 5, and also the centers of the bearings 4 and 5 tend to align easily to allow the center alignment work of the bearings 4 and 5 to be performed easily and efficiently. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an air pump.
[0002]
[Prior art]
An eccentric part such as a cam body and a crank part is provided on the drive shaft to which the output of the motor is transmitted, and the piston connected to this eccentric part is slid in the cylinder to supply compressed air and discharge air. An air pump for performing a vacuum state is known.
[0003]
As shown in FIG. 6, a conventional air pump has a motor 53 attached to a pump housing 51 via a motor bracket 52, a cam body 54 attached to an output drive shaft 53a of the motor 53, and bearings for receiving the cam body 54. A piston rod 56 is connected via a cam bearing 55, and a piston 58 is slid in a cylinder 57 connected to a pump housing 51 to send and discharge air from a compression chamber 59 in which a valve body and the like are housed. ing. The end of the output drive shaft 53a of the motor 53 is not supported, but the cam body 54 that performs eccentric rotation is supported in a cantilevered state. In addition, many air pumps having a cantilever structure similar to this are disclosed (for example, Patent Document 1).
[0004]
However, in such a structure in which the cam body 54 performing the eccentric rotation is supported in a cantilever state, since the vibration accompanying the eccentric rotation of the cam body 54 is large, the output drive shaft 53a of the motor 53 is rotatably supported. As a result, the bearings 53b, 53c and the motor 53 have a shorter life. Further, when the bearings 53b and 53c are to be replaced, each component such as the cam body 54 and the motor 53 must be removed, which is troublesome and poor in workability.
[0005]
As a structure to cope with this, as shown in FIGS. 7 and 8, a drive shaft 73 connected to an output shaft 71a of a motor 71 and having a cam body 72 as an eccentric portion is mounted on a bearing such as two bearings. It is conceivable that two points are supported from both sides at 74 and 75. That is, a bearing 74 for rotatably supporting one end of a drive shaft 73 to which a cam body 72 is attached is attached to a housing 77 to which a cylinder 76 is attached, so as to cover an opening provided on a side of the housing 77. A bearing 75 for rotatably supporting the other end of the drive shaft 73 is attached to the attached motor guide 78, and the bearings 74, 75 support two points from both sides to support the motor shaft 78 in a double-supported state. A motor 71 is attached to the motor guide 78 via a collar 79, and an end of the drive shaft 73 is externally fitted to an output drive shaft 71 a of the motor 71, and is fixed with a set screw 81.
[0006]
According to this configuration, the drive shaft 73 to which the cam body 72 is attached is supported by the bearings 74 and 75 in a double-supported state, so that the vibration caused by the eccentric rotational movement of the cam body 72 can be suppressed, and The adverse effects of the vibrations on 74 and 75 can be kept small, and the life is extended. Further, even when the bearings 74 and 75 are replaced, the cam body 72 does not need to be removed, so that the trouble of removing the cam body 72 can be saved.
[0007]
[Patent Document 1]
Japanese Utility Model Publication No. 3-32791
[Problems to be solved by the invention]
However, in the conventional air pump shown in FIGS. 7 and 8, one bearing 74 is supported by the housing 77, the other bearing 75 is supported by the motor guide 78, and the bearings 74 and 75 are individually separated by separate members. Due to the supporting structure, there is a problem that it takes a lot of trouble and time to align the two bearings 74 and 75.
That is, when assembling or replacing the bearings 74 and 75, the mounting position of the motor guide 78 with respect to the housing 77 must be strictly adjusted. Further, the bearing 74 is fitted in the housing 77 and the bearings 74 and 75 are fitted in the motor guide 78. Since the bearings 74 and 75 are not precisely positioned just by being fitted, respectively, In order to smooth the rotation of the bearings 74 and 75, the outer and inner races of the bearings 74 and 75 must be adhered to the housing 77, the motor guide 78, and the drive shaft 73 in a well-positioned state. It takes much time and effort, resulting in a decrease in workability.
[0009]
The present invention solves the above-mentioned problem, and a drive shaft having an eccentric portion such as a cam body can be favorably supported by two bearings in a double-supported state. It is an object of the present invention to provide an air pump which can be performed without applying too much air.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides an air pump for supplying or discharging air by providing an eccentric portion on a drive shaft to which the output of a motor is transmitted, and sliding a piston connected to the eccentric portion in a cylinder. Wherein the drive shaft provided with the eccentric portion is supported by two bearings at two points from both sides, and the pump housing holding the two bearings is mounted on a surface substantially along the rotation axis of the drive shaft. The first and second split housings are divided into a first split housing and a second split housing coupled to the first split housing by coupling means. The first and second split housings are used to connect the two bearings. It is characterized by being pinched.
[0011]
According to this configuration, the drive shaft to which the eccentric portion such as the cam body is attached can be favorably supported by the two bearings in a double-supported state, and the work of aligning these bearings can be performed without much trouble. It can be carried out.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention according to claim 1 is an air pump that supplies or discharges air by providing an eccentric portion on a drive shaft to which an output of a motor is transmitted, and sliding a piston connected to the eccentric portion in a cylinder. The drive shaft provided with the eccentric portion is supported by two bearings at two points from both sides, and the pump housing holding the two bearings is divided into two parts by a surface substantially along the rotation axis of the drive shaft. And a first split housing and a second split housing coupled to the first split housing by coupling means, and the first and second split housings sandwich the two bearings. It is characterized by having made it.
[0013]
According to this configuration, the drive shaft provided with the eccentric portion can be supported at two points from both sides of the eccentric portion arrangement point by the two bearings, that is, favorably supported in a double-supported state. Then, the pump housing is divided into two parts along a surface along the rotation axis of the drive shaft, and the first divided housing and the second divided housing each form a portion for supporting two bearings. When the two bearings are sandwiched by the first and second split housings, the axes of the two bearings are easily aligned, and the work of centering the bearings can be performed without much trouble. it can.
[0014]
According to a second aspect of the present invention, in the air pump according to the first aspect, a shape of a receiving surface for receiving each of the two bearings in the first and second split housings is a semicircle or a square or a rhombus when two are combined. It is characterized by the following isosceles triangle.
[0015]
According to a third aspect of the present invention, in the air pump according to the first or second aspect, the drive shaft is connected to the output shaft of the motor via a joint having an uneven shape in a side view. .
[0016]
With this configuration, even when the axes of the drive shaft and the output shaft of the motor do not exactly coincide with each other, the rotation of the output shaft of the motor is favorably transmitted to the drive shaft.
Hereinafter, an air pump according to an embodiment of the present invention will be described with reference to the drawings.
[0017]
Here, the air pump according to this embodiment is used for supplying compressed air to the oxygen-enriched membrane. The oxygen-enriched membrane has a property that, when air is supplied, a gas having an increased oxygen concentration is discharged from the opposite side when passing through the membrane. A gas state having a high oxygen concentration can be created on the opposite side of the oxide film. The use of this air pump is not limited to this, and it can be used not only for various kinds of air supply but also for pressure reduction or vacuum pump for discharging air to the outside. .
[0018]
As shown in FIGS. 1 to 3, this air pump has a cam shaft 3 as an eccentric part attached to a drive shaft 2 to which an output shaft 1 a of a motor 1 is connected, and a drive shaft provided with the cam body 3. 2 is rotatably supported by two bearings 4, 5 in a double-supported state at two points from both sides of a place where the arrangement of the cam body 3 is arranged (eccentric part arrangement point).
[0019]
Then, the pump housing 20 (see FIG. 3) holding the two bearings 4, 5 is connected to a surface along the rotation axis of the drive shaft 2 (this embodiment is a horizontal plane, but is not limited to this). A first divided housing 21 in which the cylinder 7 is integrally formed, and a second divided housing 22 which is coupled below the first divided housing 21 by coupling bolts 8 as coupling means. The two bearings 4 and 5 are vertically held by semicircular bearing receiving surfaces 21a, 21b, 22a and 22b formed on the first and second split housings 21 and 22, respectively. Received in state. Further, the motor 1 is mounted on the second split housing 22 via the motor bracket 9, and the output shaft 1 a and the drive shaft 2 of the motor 1 are connected by a connecting screw 10 so as to rotate integrally. I have. Reference numeral 11 denotes a motor cover that covers a place where the motor 1 is provided.
[0020]
The cam body 3 is fixed to the drive shaft 2 by a set screw 12, and a piston rod 15 having a piston 14 mounted thereon is connected to the cam body 3 via a cam bearing 13. On the first split housing 21, a head cover 16 having an air introduction pipe 16a, an air introduction chamber 16b, an air exhaust chamber 16c, and an air exhaust pipe 16d, and a head plate 17 are fixed with screws. A valve seat 18 in which a tongue-shaped intake valve portion 18a and a discharge valve portion 18b are integrally formed is interposed between the first split housing 21 and the head cover 16. The air introduction passages 21c and 16e and the air discharge passages 21d and 16f formed at the upper end of the first split housing 21 and the head cover 16, respectively, form the suction valve portion 18a and the discharge valve portion 18b of the valve seat 18. At a position where the air introduction passage 21c of the first split housing 21 faces the intake valve portion 18a, the intake valve portion 18a is allowed to be deformed toward the intake side. A concave portion 21e is formed, and a concave portion 16g for allowing the exhaust valve portion 18b to be deformed toward the exhaust side is formed at a position where the air exhaust passage 16f of the head cover 16 faces the exhaust valve portion 18b. .
[0021]
In the above configuration, when the motor 1 is driven to move the piston 14 up and down in the cylinder 7, when the piston 14 is lowered, only the suction valve portion 18a is deformed into the recess 21e of the first split housing 21. Then, air is introduced into the cylinder 7, and by raising the piston 14 from this state, only the discharge valve portion 18b is deformed into the concave portion 16g of the head cover 16, and the air in the cylinder 7 is discharged into the air discharge pipe. It is discharged from 16d.
[0022]
According to the configuration described above, the drive shaft 2 provided with the cam body 3 as the eccentric portion is supported at two points from both sides of the cam body 3 by the two bearings 4 and 5, that is, favorably supported in a double-supported state. it can. Therefore, the vibration caused by the eccentric rotational movement of the cam body 3 can be suppressed, and the adverse effects of the vibration on the bearings 4 and 5 can be suppressed to a small extent, resulting in a long life. Further, even when the bearings 4 and 5 are replaced, the bearings 4 and 5 can be replaced very easily only by removing the connecting bolts 8 connecting the first divided housing 21 and the second divided housing 22. .
[0023]
Then, the pump housing 20 is divided into two parts by a surface along the rotation axis of the drive shaft 2, and the two bearings 4 and 5 are supported on the first divided housing 21 and the second divided housing 22, respectively. Since the bearing receiving surfaces 21a, 21b, 22a, and 22b are integrally formed, the relative positions of the bearing receiving surface 21a and the bearing receiving surface 21b in each of the split housings 21 and 22, and the bearing receiving surface 22a and the bearing are provided. The relative position with respect to the receiving surface 22b can be formed accurately. Therefore, when the two bearings 4 and 5 are sandwiched by the first and second split housings 21 and 22, the axes of the two bearings 4 and 5 can be easily aligned, and the centers of the bearings 4 and 5 can be easily adjusted. The matching operation can be performed efficiently without much trouble. Further, since the outer rings of the bearings 4 and 5 can be easily fixed to the first and second split housings 21 and 22 by tightening the coupling bolts 8, the centering is performed more strictly and the two bearings 4 and 5 are fixed. Even in the case of smooth rotation, only the inner rings of the bearings 4 and 5 formed of the bearings need to be bonded, so that labor and time can be saved.
[0024]
In the above embodiment, the shape of the bearing receiving surfaces 21a, 21b, 22a, 22b in each of the divided housings 21, 22 is semicircular as shown in FIG. However, as shown in FIGS. 4 (b) and 4 (c), as shown in FIGS. The bearing receiving surfaces 21a, 21b, 22a, and 22b may have a hypotenuse shape of an isosceles triangle such as a rhombus. In this case, the bearings 4, 5 and the bearing receiving surfaces 21a, 21b, 22a, 22b are in contact with each other without being affected by the accuracy of the perfect circle of the bearing receiving surfaces 21a, 21b, 22a, 22b. With these two points, the bearings 4 and 5 can be held securely, and cutting is not required from the point of working, and it can be formed only by molding, and there is an advantage that the manufacturing process can be simplified.
[0025]
Further, the connecting portion between the output shaft 1a and the drive shaft 2 of the motor 1 may be connected via joints 1b and 2a having a concave shape and a convex shape in a side view as shown in FIG. In this case, even when the axes of the drive shaft 2 and the output shaft 1a of the motor 1 do not exactly coincide with each other, these shafts can be connected relatively easily, and the rotation of the output shaft 1a of the motor 1 is driven. Good transmission to shaft 2. Therefore, the centering operation when the two bearings 4 and 5 are clamped by the first and second split housings 21 and 22 can be performed more easily and efficiently.
[0026]
Further, in the above embodiment, the pump housing 20 holding the two bearings 4 and 5 is divided into two parts by a surface along the rotation axis of the drive shaft 2, and a first divided housing 21 and a second divided housing 22 has been described, but the present invention is not limited to this. The pump housing is divided into two parts along a surface near the rotation axis of the drive shaft, and the first divided housing and the second divided housing are divided into two parts. It is also possible to interpose and connect a spacer between the divided housings.
[0027]
Further, in the above-described embodiment, the case where the cam body 3 as the eccentric part is provided on the drive shaft 2 has been described. However, the same operation and effect can be obtained by forming a crank-shaped part on a part of the drive shaft 2 itself. .
[0028]
【The invention's effect】
As described above, according to the present invention, the drive shaft provided with the eccentric portion is supported at two points from both sides by two bearings, and the pump housing holding the two bearings is substantially aligned with the rotation axis of the drive shaft. The first and second divided housings are divided into two parts along a plane along the first divided housing and a second divided housing coupled to the first divided housing by coupling means. By sandwiching the two bearings, the drive shaft provided with the eccentric portion can be favorably supported by the two bearings in a double-supported state, and the adverse effect due to vibration on the bearings can be suppressed. Long life. Further, when the two bearings are sandwiched by the first and second split housings, the axes of the two bearings are easily aligned with each other, and the work of aligning the bearings can be performed efficiently without much trouble. Can be done.
[0029]
In addition, by connecting the drive shaft to the output shaft of the motor via a joint having a concave-convex shape when viewed from the side, even when the axes of the drive shaft and the output shaft of the motor do not exactly coincide with each other, the motor can be used. Since the rotation of the output shaft is transmitted well to the drive shaft, positioning with respect to the motor can be performed relatively easily.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an air pump according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a state where a first split housing and a second split housing of the air pump are split.
FIG. 3 is a partially cutaway side view of the air pump.
FIGS. 4A to 4C are partially cutaway side views of the air pump.
FIG. 5 is a perspective view showing a connecting portion between an output shaft and a drive shaft of a motor of an air pump according to another embodiment of the present invention.
FIG. 6 is a partially cutaway front view of a conventional air pump.
FIG. 7 is a partially cutaway front view of another conventional air pump.
FIG. 8 is an exploded perspective view of the other conventional air pump.
[Explanation of symbols]
Reference Signs List 1 Motor 1a Output shaft 2 Drive shaft 3 Cam body (eccentric part)
4, 5 Bearing 8 Coupling bolt (coupling means)
13 Cam Bearing 14 Piston 15 Piston Rod 16 Head Cover 18 Valve Seat 18a Suction Valve 18b Discharge Valve 20 Pump Housing 21 First Split Housing

Claims (3)

An air pump for supplying or discharging air by providing an eccentric portion on a drive shaft to which the output of the motor is transmitted, and sliding a piston connected to the eccentric portion in a cylinder,
The drive shaft provided with the eccentric portion is supported at two points from both sides by two bearings,
The pump housing that holds the two bearings is divided into two parts along a surface substantially along the rotation axis of the drive shaft, and the first housing is connected to the first housing by coupling means. An air pump comprising two split housings, wherein the first and second split housings sandwich the two bearings. 2. The air according to claim 1, wherein the shape of the receiving surface of each of the first and second split housings that receives the two bearings is a semicircle or an isosceles triangle that is a square or a rhombus when the two are combined. 3. pump. The air pump according to claim 1, wherein the drive shaft is connected to an output shaft of the motor via a joint having an uneven shape when viewed from the side.

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