WO2018198371A1

WO2018198371A1 - Vane pump

Info

Publication number: WO2018198371A1
Application number: PCT/JP2017/017075
Authority: WO
Inventors: 雅之長島
Original assignee: 株式会社ミクニ
Priority date: 2017-04-28
Filing date: 2017-04-28
Publication date: 2018-11-01

Abstract

A pump chamber 16 is defined by disposing a rotor 15 having vanes 17 inside a housing space 10 of a pump housing 2, and an output shaft 13 of a motor 3 affixed to the underside of the pump chamber 16 is inserted and affixed in a shaft hole 15b of the rotor 15. The rotor 15 is rotatively driven by the motor 3 and air is drawn in and discharged by means of vanes 17 effecting volumetric change in the pump chamber 16. The rotor 15 and vanes 17 are made of a carbon material, and when drilling the shaft hole 15b of the rotor 15, an excess thickness part 15c is left without the shaft hole penetrating therethrough in the upward direction. The excess thickness part 15c blocks wear particles generated on the upper side of the rotor 15, thereby ensuring against a situation wherein the wear particles enter a bearing 14 of the motor 3, positioned lower than the rotor 15, via the space between the shaft hole 15b and the output shaft 13.

Description

Vane pump

The present invention relates to a vane pump, and more particularly, a rotor is disposed in a housing space of a pump housing to define a pump chamber, and a tip of a vane provided so as to be able to appear and retract on an outer peripheral surface as the rotor rotates is accommodated. The present invention relates to a vane pump that sucks and discharges air by changing the volume of a pump chamber while being in sliding contact with the inner peripheral surface of a space.

As this type of vane pump, for example, Patent Document 1 describes a vacuum pump for supplying negative pressure to a vehicle brake assist device. FIG. 5 is a cross-sectional view showing the vacuum pump of Patent Document 1. As shown in FIG. A cam ring 105 is fixed to the upper surface of the pump base 102 of the vacuum pump 101 and closed on both upper and lower sides by a lower plate 103 and an upper plate 104. The upper surface of the pump base 102 includes these members 103 to 105. A bottomed cylindrical silencing housing 106 is fixed.

A cylindrical rotor 108 is disposed at an eccentric position of the accommodating space 107 in the cam ring 105, and a crescent-shaped pump chamber 109 is defined in the accommodating space 107 by the rotor 108. A motor 110 is fixed to the lower surface of the pump base 102, and an output shaft 110a is disposed in the motor 110 along an axis L extending in the vertical direction, and can be rotated by a pair of upper and lower bearings 110b (only the upper side is shown). It is supported. The output shaft 110a protrudes upward from the motor 110, passes through the pump base 102 and the lower plate 103, and is inserted into a shaft hole 108a that penetrates the rotor 108 in the vertical direction. Has been.

When the rotor 108 is rotationally driven by the motor 110, a plurality of vanes 111 provided on the outer peripheral surface of the rotor 108 so as to be able to project and retract are brought into sliding contact with the inner peripheral surface of the accommodating space 107, and the pump is divided into a plurality of sections. The volume of the chamber 109 is gradually changed.

As a result, the air from the brake assist device is sucked into the pump chamber 109 through the pneumatic hose 112, the suction passage 113, and the suction port 103a of the lower plate 103, and the discharge port 104a of the upper plate 104 passes through the pump chamber 109. Is discharged from the discharge passage 114 to the outside. The reason why air is passed through the silencing housing 106 is to reduce noise by reducing air pulsation that occurs in synchronization with suction and discharge.

JP 2013-60841 A

By the way, this type of vane pump may be required to operate without lubrication depending on its application and the like, and the vacuum pump of Patent Document 1 also has self-lubricating properties so that it can function even without lubrication. The carbon rotor and vane are used.

However, carbon with poor wear resistance is significantly worn by sliding contact in the accommodation space 107 as compared with a normal metal material, and a relatively large amount of wear powder is generated in the accommodation chamber 107. The wear powder generated mainly in the pump chamber 109 is discharged together with air through the discharge port 104a, but the wear powder generated between the upper and lower side surfaces of the rotor 108 and the lower plate 103 and the upper plate 104 is There is a problem in that it enters into the bearing 110b of the motor 110 located directly below and causes troubles such as sticking.

The present invention has been made to solve such problems, and the object of the present invention is to use a rotor or vane made of a material having poor wear resistance, such as carbon, even if these are used. It is an object of the present invention to provide a vane pump that can prevent troubles caused by wear powder by preventing the wear powder of the rotor and vane from entering the motor.

In order to achieve the above object, the vane pump of the present invention has a cylindrical rotor disposed in an accommodation space defined in the pump housing, and an upper side surface and a lower side surface of the accommodation space on the upper side surface and the lower side surface of the rotor. And a pump chamber is defined between the outer peripheral surface of the rotor and the inner peripheral surface of the accommodating space, and the output shaft of the motor disposed on the lower side of the pump housing is connected to the lower surface of the accommodating space. Inserting and fixing in the shaft hole of the rotor through the rotor, the rotor is driven to rotate by the motor, and the tip of the vane provided on the outer peripheral surface of the rotor is slidably brought into contact with the inner peripheral surface of the accommodating space In a vane pump that sucks and discharges air by changing the volume of the pump chamber, the rotor and the vane are made of a self-lubricating material, and the shaft hole of the rotor is directed upward by a shield provided at the top of the rotor. Characterized in that it is closed by (claim 1).

As another aspect, it is preferable that an upper plate made of aluminum is disposed on the upper side surface of the accommodation space opposite to the upper side surface of the rotor (claim 2).

According to the vane pump of the present invention, even when a rotor or vane made of a material having poor wear resistance, such as carbon, is used, it is possible to suppress the situation where the wear powder of these rotor and vane enters the motor. Troubles caused by wear powder can be avoided in advance.

It is a perspective view which shows the vacuum pump of embodiment. It is a disassembled perspective view which shows a vacuum pump. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1 showing a rotor and vanes in the accommodation space. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3, showing a connection portion between the rotor and the output shaft. FIG. 5 is a cross-sectional view corresponding to FIG. 4 showing a vacuum pump of Patent Document 1.

Hereinafter, an embodiment in which the present invention is embodied in a vane type vacuum pump will be described.
1 is a perspective view showing a vacuum pump according to the present embodiment, FIG. 2 is an exploded perspective view showing a vacuum pump, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1 showing a rotor and vanes in an accommodation space.

The vacuum pump 1 of this embodiment is mounted on a vehicle in order to generate a negative pressure to be supplied to the vehicle brake assist device. In each figure, the vacuum pump 1 is shown in a posture when installed in the vehicle, and in the following description, the vehicle is mainly used to represent front and rear, left and right, and up and down directions.

As a whole, the vacuum pump 1 has a pump housing 2 as a center, a motor 3 fixed to the lower side, and a silencer housing 4 fixed to the upper side.

The pump housing 2 is manufactured by aluminum die casting and has a cylindrical shape extending in the vertical direction. An inner peripheral wall 6 (inner peripheral surface) is formed so as to have a double inner / outer positional relationship with respect to the outer peripheral wall 5. . The lower part of the inner peripheral wall 6 is closed by a bottom wall 7 (lower side surface) formed integrally, and an upper plate 8 (upper side surface) made of aluminum is fixed to the upper opening of the inner peripheral wall 6 by screws 9. A housing space 10 is defined by the inner peripheral wall 6, the bottom wall 7 and the upper plate 8. The storage space 10 in a plan view has a track shape with the long side in the front-rear direction and the short side in the left-right direction.

A motor 3 is fixed to the lower surface of the pump housing 2 with screws 12, and an output shaft 13 is disposed in the motor 3 along an axis L extending in the vertical direction. A pair of upper and lower bearings 14 (the upper side is shown in FIG. 4). ) Is rotatably supported. The output shaft 13 protrudes upward from the motor 3 and is connected to a rotor 15 disposed in the accommodation space 10 to rotate the rotor 15 in a predetermined direction (counterclockwise in plan view). . The connection structure of the output shaft 13 to the rotor 15 will be described in detail later.

The lower surface (lower side surface) of the rotor 15 opposes the bottom wall 7 of the accommodating space 10 via a minute clearance, and the upper surface (upper side surface) of the rotor 15 opposes the upper plate 8 via a minute clearance. Yes. As a result, pump chambers 16 having a crescent shape in plan view are defined on both front and rear sides of the rotor 15 in the accommodation space 10.

A vane groove 15a is formed in six equally divided portions on the outer peripheral surface of the rotor 15 over the entire vertical width of the rotor 15, and a plate-like vane 17 is centered around the axis L in each vane groove 15a. It is arranged to be able to appear and retract in the inside and outside direction. The vertical width of each vane 17 is substantially the same as the vertical width of the rotor 15, and the tip (outer peripheral end) is inclined with respect to the base end (inner peripheral end) in the rotational direction of the rotor 15.

The silencer housing 4 is fixed to the upper surface of the pump housing 2 by screws 19, and although not shown, an expansion chamber and a resonance chamber for reducing pulsation of air discharged from the vacuum pump 1 are formed in the silencer housing 4. Has been.

As shown in FIG. 3, a connector 20 for supplying power to the motor 3 and a nipple 21 connected to a brake assist device via a pneumatic hose (not shown) are provided on the front side of the outer peripheral wall 5 of the pump housing 2. Yes. The nipple 21 communicates with a suction port 22 that opens into one of the pump chambers 16 via a first suction path 23a. The suction port 22 is an annular second suction path 23b (imaginary) formed on the lower surface of the upper plate 8. Via a suction port 22 that opens into the other pump chamber 16 via a line).

In addition, discharge ports (not shown) are opened in the accommodating spaces 10 in the pump chambers 16, and these discharge ports communicate with the outside from the discharge path 28 via the expansion chamber and the resonance chamber in the silencer housing 4. Yes.

Therefore, when the rotor 15 is rotationally driven in the accommodation space 10 by the motor 3, the vanes 17 gradually change the volume of the pump chambers 16 divided into a plurality while the tips of the vanes 17 are in sliding contact with the inner peripheral surface of the accommodation space 10. . Thus, air from the brake assist device is sucked into one pump chamber 16 from one suction port 22 through the pneumatic hose and nipple 21 and the first suction passage 23a, and the other through the second suction passage 23b. The suction port 22 is sucked into the other pump chamber 16.

In each pump chamber 16, air is transferred from the suction port 22 side to the discharge port side by the vane 17, and flows into the silencer housing 4 through the discharge path 28 from each discharge port. Air pulsation is relaxed in the process of flowing through the expansion chamber and the resonance chamber, and then air is discharged to the outside.

An annular space 24 is formed between the inner peripheral wall 6 and the outer peripheral wall 5 of the pump housing 2, and the annular space 24 communicates with the outside through gaps 25 formed on both front and rear sides of the outer peripheral wall 5. ing. Although not shown, an engine cooling fan is disposed in front of the vacuum pump 1, and a part of the cooling air is sent to the vacuum pump 1. The cooling air flows into the annular space 24 from the front gap 25 and branches to the left and right, flows through both the left and right sides of the inner peripheral wall 6, joins, and is discharged from the rear gap 25 to the outside. Due to the circulation of the cooling air, the temperature rise of the vacuum pump 1 is suppressed.

Further, at this time, the upper plate 8 is also exposed to the cooling air, and the upper plate 8 is made of aluminum having good heat conduction like the pump housing 2. For this reason, the heat in the accommodation space 10 is diffused to the outside through the large area of the upper plate 8, and the temperature rise of the vacuum pump 1 can be further reliably suppressed.

On the other hand, mounting flanges 27 having buffer members 26 are integrally formed on both the left and right sides of the pump housing 2, and the vacuum pump 1 is fixed to the vehicle body via these mounting flanges 27.

Incidentally, as described above, the vacuum pump 1 that supplies negative pressure to the brake assist device cannot lubricate the sliding contact between the rotor 15 and the vane 17 in the accommodating space 10 with oil. As with the vacuum pump 101 of FIG. 1, a carbon rotor 15 and vane 17 having self-lubricating properties are employed so that they can function even without lubrication.

As described in [Problems to be Solved by the Invention], in Patent Document 1, the carbon rotor 108 and the vane 111 are worn by the sliding contact in the housing space 107, and the wear powder is located immediately below. This causes a problem that it enters the bearing 110b of the motor 110 and causes trouble.

In view of such problems, the present inventor has focused on the following points. Since wear powder generated mainly in the pump chamber 109 is discharged to the outside together with air through the discharge port 104a, most of the wear powder entering the bearing 110b is generated on the upper and lower sides of the rotor 108 ( Mainly due to wear on the upper and lower side surfaces of the rotor 108 and the upper and lower ends of the vane 111). In Patent Document 1, wear powder generated on the upper side of the rotor 108 reaches the bearing 110b through a minute clearance between the shaft hole 108a of the rotor 108 and the output shaft 110a. The wear powder that enters 110b can be almost halved.

Under such a point of view, in the vacuum pump 1 of the present embodiment, measures are taken at the connecting portion between the rotor 15 and the output shaft 13, and the structure will be described in detail below.
4 is a cross-sectional view taken along the line IV-IV in FIG. 3 showing a connection portion between the rotor 15 and the output shaft 13.

A boss 29 is projected upward from the top of the motor 3 around the output shaft 13, and a cylindrical tube 30 is projected downward from the bottom surface of the bottom wall 7 of the pump housing 2. Yes. The cylindrical portion 30 is fitted on the boss portion 29 with an O-ring 31 interposed therebetween, whereby the pump housing 2 and the motor 3 are positioned on the axis L.

The output shaft 13 of the motor 3 protrudes upward from the shaft hole 29 a of the boss portion 29, and the upper portion is positioned in the accommodation space 10 through the cylindrical portion 30 of the pump housing 2 and the shaft hole 7 a of the bottom wall 7. A shaft hole 15b is formed in the rotor 15 along the axis L from below, and the upper portion of the output shaft 13 is inserted into the shaft hole 15b and the relative rotation is restricted by the rotation-preventing member 32 (" Equivalent to “Insert / Fix”).

For example, the shaft hole 15b is drilled, but does not penetrate the rotor 15 upward, leaving the surplus portion 15c on the upper side. In the present embodiment, the surplus portion 15c functions as a shielding portion that closes the shaft hole 15b upward, and the upper portion and the lower side of the rotor 15 are separated from each other by the presence of the surplus portion 15c. It is completely defined by the surplus portion 15c without communicating through the minute clearance between the hole 15b and the output shaft 13.

Accordingly, it is possible to prevent the abrasion powder generated on the upper side of the rotor 15 from being blocked by the surplus portion 15c and entering the bearing 14 of the motor 3 positioned below through a minute clearance between the shaft hole 15b and the output shaft 13. Is done. This wear powder enters the pump chamber 16 on the outer peripheral side through a minute clearance between the upper surface of the rotor 15 and the lower surface of the upper plate 8, and is discharged to the outside together with air through the discharge port.

As a result, the wear powder that may enter the bearing 14 is almost halved only to the one generated mainly on the lower side of the rotor 15. Can be resolved.

This is the end of the description of the embodiment, but the aspect of the present invention is not limited to this embodiment. For example, in the above-described embodiment, the present invention is applied to the vacuum pump 1 that sucks and discharges air to generate a negative pressure, but the type of the vane pump is not limited to this. For example, it may be embodied as an air pump that operates by supplying discharged air to an actuator.

Further, in the above embodiment, the pump chambers 16 are defined on both the front and rear sides of the rotor 15 disposed in the accommodating space 10, and air is sucked and discharged, but the internal structure of the vane pump is not limited to this. For example, as shown in FIG. 4 of Patent Document 1, a single pump chamber may be defined by arranging a rotor at an eccentric position in the accommodation space. Even in this case, the same effect as the embodiment can be obtained by forming the surplus portion without penetrating the shaft hole of the rotor.

In the above embodiment, the rotor 15 and the vane 17 are made of carbon. However, the present invention is not limited to this, and any material having a self-lubricating property may be used.
Moreover, in the said embodiment, when the shaft hole 15b was drilled in the rotor 15, it left the surplus part 15c and it was made to function as a shielding part, However, it is not restricted to this. For example, the shaft hole 15b may be formed by penetrating the rotor 15 and then the lid member (shielding portion) may be fixed to the upper surface of the rotor 15 to close the shaft hole 15b.

In the above embodiment, the output shaft 13 of the motor 3 is inserted into the shaft hole 15b and the rotation is restricted by the anti-rotation member 32. However, the output shaft 13 is inserted into the shaft hole 15b and May be completely fixed.
Moreover, in the said embodiment, although the vacuum pump 1 was installed with the upright attitude | position with respect to the vehicle body, you may apply when installing with an inclination attitude | position. Even in this case, wear powder intrudes into the bearing 14 of the motor 3, so that the same effect can be obtained by adopting the configuration of the present embodiment.

1 Vacuum pump (vane pump)
3 Motor 2 Pump housing 6 Inner peripheral wall (inner peripheral surface)
7 Bottom wall (lower side)
8 Upper plate (upper side)
DESCRIPTION OF SYMBOLS 10 Storage space 13 Output shaft 15 Rotor 15b Shaft hole 15c Surplus part (shielding part)
16 Pump room 17 Vane

Claims

A cylindrical rotor is disposed in a housing space defined in the pump housing, and an upper surface and a lower surface of the housing space are opposed to an upper surface and a lower surface of the rotor, respectively, and an outer peripheral surface of the rotor A pump chamber is defined between the housing space and the inner peripheral surface of the housing space, and an output shaft of a motor disposed on the lower side of the pump housing passes through the lower surface of the housing space to form a shaft hole of the rotor The pump chamber is inserted and fixed inside, and the rotor is driven to rotate by the motor, and the tip of a vane provided on the outer circumferential surface of the rotor is slidably brought into contact with the inner circumferential surface of the housing space. In the vane pump that sucks and discharges air by changing the volume of
The rotor and the vane are made of a self-lubricating material,
The vane pump, wherein the shaft hole of the rotor is closed upward by a shielding portion provided at an upper portion of the rotor.
2. The vane pump according to claim 1, wherein an upper plate made of aluminum is disposed as an upper side surface of the accommodation space facing the upper side surface of the rotor.