WO2018198368A1

WO2018198368A1 - Vane pump

Info

Publication number: WO2018198368A1
Application number: PCT/JP2017/017072
Authority: WO
Inventors: 崇寛小倉
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

In this vane pump, inner and outer walls constituting two layers are integrally formed in an annular shape in a pump housing (15), the lower section of an inner circumferential wall (22) is closed by a bottom wall (24) and the upper section is closed by an upper plate (27), and a track-shaped accommodation space (30) is thereby defined. A rotor (31) is arranged within the accommodation space (30) and a pump chamber (32) is thereby defined. When the rotor (31) is rotationally driven, a vane (33) on the outer circumference thereof causes the capacity of the pump chamber (32) to change and air is taken in and discharged. Openings (49) are formed on both the front and rear sides of the outer circumferential wall (16) of the pump housing (15), an annular space between the inner circumferential wall (22) and the outer circumferential wall (16) is made to function as a left-side ventilation path (50a) and a right-side ventilation path (50b), and heat within the accommodation space (30) is released to the exterior by cooling air flowing through the interior of said ventilation paths.

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 fluid 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. As shown in FIG. 4 of Patent Document 1, a cam ring closed on both sides by a lower plate and an upper plate is fixed to one side of the pump base of the vacuum pump so as to contain these members. A bottomed cylindrical housing is fixed to one side of the pump base.

A cylindrical rotor is disposed at an eccentric position of the accommodating space in the cam ring, and a crescent-shaped pump chamber is defined in the accommodating space by this rotor. A motor part is fixed to the other side of the pump base, and when the rotor is driven to rotate by this motor part, a plurality of vanes provided so as to be able to appear and retract on the outer peripheral surface of the rotor have their tips at the inner peripheral surface of the accommodation space. The volume of the pump chamber divided into a plurality is gradually changed while being in sliding contact.

Thus, air from the brake assist device is sucked into the pump chamber through the suction port, and further discharged from the pump port to the outside through the housing. The reason why air is passed through the housing 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 markedly worn by sliding contact within the accommodation space, and periodic rotor and vane replacement is required. In order to replace the parts, a complicated operation of disassembling and assembling the vacuum pump is required. Therefore, it is important to suppress the wear of the rotor and the vane as much as possible to extend the replacement interval.

However, if no lubrication is assumed, carbon or a similar material with poor wear resistance can only be used. Measures based on this were requested.

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 suppress wear of the rotor and vanes and can extend the replacement interval to improve durability.

In order to achieve the above object, the vane pump of the present invention has a cylindrical rotor disposed in a housing space defined in the pump housing, and one side surface and the other side surface of the housing space on one side surface and the other side surface of the rotor. The pump chamber is defined between the outer peripheral surface of the rotor and the inner peripheral surface of the housing space, and the tip of a vane provided on the outer peripheral surface of the rotor as the rotor rotates is provided. In a vane pump that sucks and discharges fluid by changing the volume of a pump chamber while sliding in contact with the inner peripheral surface of the storage space, the pump housing penetrates from one side to the other at a position close to the storage space and has cooling air inside. The ventilation path which distribute | circulates is formed (Claim 1).

As another aspect, it is preferable that a ventilation path is formed across a peripheral wall that forms the inner peripheral surface of the accommodation space (claim 2).

As another aspect, the pump housing is formed with an inner and outer double wall having an annular shape centering on the rotor, the inner peripheral wall functions as an inner peripheral surface, and communication holes are formed in the one and other outer peripheral walls, respectively. An annular space formed between the inner peripheral wall and the outer peripheral wall is opened to the outside through the communication holes, so that it penetrates from one side to the other across both sides of the inner peripheral wall. It is preferable that a first ventilation path and a second ventilation path are formed.

As another aspect, a motor portion that rotationally drives the rotor is fixed to the pump housing, and the output shaft of the motor portion is connected to the rotor through the bottom wall that functions as one side surface of the accommodation space, and the anti-motor of the pump housing A cover member that closes the annular space is fixed to the part side, and a third ventilation passage that connects the first ventilation path and the second ventilation path between the cover member that functions as the other side surface of the accommodation space and the cover member It is preferable to have a path (Claim 4).

As another aspect, the pump chamber has a function of sucking air as a fluid to generate negative pressure and discharging the sucked air to the outside, and the annular space is partitioned in the axial direction of the rotor by a partition wall, It is preferable that one of the divided sections functions as a first ventilation path and a second ventilation path, and the other functions as a silencing chamber that introduces air discharged from the pump chamber and exerts a silencing action.

As another aspect, it is preferable that at least one of the pair of communication holes on the outer peripheral wall is formed as a plurality of openings (Claim 6).

As another aspect, it is preferable that the inner peripheral wall, the outer peripheral wall, and the bottom wall of the pump housing are integrally formed (Claim 7).

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, wear of the rotor or vane can be suppressed, and the replacement interval can be extended. Durability can be improved.

It is a perspective view which shows the vacuum pump of embodiment. It is the II-II sectional view taken on the line of FIG. 1 which shows a vacuum pump. It is a disassembled perspective view which shows a vacuum pump. FIG. 4 is a perspective view corresponding to a cross section taken along line IV-IV in FIG. FIG. 5 is a perspective view corresponding to a cross section taken along the line V-V in FIG. 2, showing a preliminary noise reduction chamber of the pump housing. It is the perspective view which removed the upper plate which shows the relationship between the accommodation space of a pump housing, and the suction port of an upper plate. It is the VII-VII sectional view taken on the line of FIG. 2 which shows the relationship between the accommodation space of a pump housing, and a ventilation path. It is a perspective view equivalent to the VIII-VIII line section of Drawing 2 showing the introduction hole and the discharge hole provided in the silencer. FIG. 9 is a perspective view corresponding to a cross section taken along line IX-IX of FIG. 8 with a rotor and vanes showing an intake path and a discharge path of air into the pump chamber removed. It is a perspective view equivalent to the XX line section of Drawing 8 showing the discharge route of the air from a preliminary silence room to a silencer. It is a perspective view equivalent to the XI-XI line section of Drawing 8 showing the discharge route of the air from a silencer to the exterior.

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 a sectional view taken along the line II-II of FIG. 1 showing the vacuum pump, and FIG. 3 is an exploded perspective view showing the vacuum pump.

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 is shown in a posture when installed in a vehicle. Although not shown, a part of cooling air from an engine cooling fan arranged in front of the vacuum pump is shown by an arrow in FIG. As shown in FIG. 1, the vacuum pump 1 is sent. In the following description, the front / rear, left / right, and up / down directions are expressed with the vehicle as a main body.

As a whole, the vacuum pump 1 has a pump part 2 as a center, a motor part 3 fixed to the lower side thereof, and a muffler part 4 fixed to the upper side (non-motor part side).
The motor housing 5 of the motor unit 3 has a bottomed cylindrical shape that opens upward, and is manufactured by press-molding a steel plate. The opening of the motor housing 5 is closed by a disk-shaped housing cover 6 formed by press-molding a steel plate, and a flange 5a is formed around the opening. An output shaft 7 is disposed at the center in the motor housing 5 along an axis L extending in the vertical direction, and is rotatably supported by a pair of upper and

lower bearings

8 and 9. The upper portion of the output shaft 7 protrudes upward through a shaft hole 6a formed in the housing cover 6, and a cylindrical boss portion 6b is formed protruding upward from the housing cover 6 with the output shaft 7 as a center. .

In the motor housing 5, an armature (armature) 10 having a core and a winding and a commutator (commutator) 11 electrically connected to the winding are provided on the output shaft 7. Around the armature 10, a stator (stator) 12 having permanent magnets is disposed, and a brush unit 13 is disposed corresponding to the commutator 11.

A direct current supplied from the outside via a connector 21 to be described later is transmitted from a wiring (not shown) to the winding of the armature 10 via the brush of the brush unit 13 and the commutator 11, and the direction of the current flowing through the winding is output. It is switched according to the rotation angle of the shaft 7. As a result, a magnetic field corresponding to the rotation angle of the output shaft 7 is generated in the armature 10, and the output shaft 7 is rotated in a predetermined direction (counterclockwise in a plan view shown in FIG. 3) due to the interaction between the magnetic field and the magnetic force of the stator 12. Is driven to rotate.

The pump housing 15 of the pump unit 2 has a cylindrical shape extending in the vertical direction as a whole, and is manufactured by aluminum (light alloy material) die casting. The outer peripheral wall 16 of the pump housing 15 has an annular shape centering on the output shaft 7 of the motor unit 3, and the lower end of the pump housing 15 abuts on the flange portion 5 a of the motor housing 5 across the O-ring 17 and is fixed by screws 18. Yes. A pair of left and right mounting flanges 19 are integrally formed on the outer peripheral wall 16 of the pump housing 15, and the entire vacuum pump 1 is supported from the vehicle body side via a buffer member 20 attached to these mounting flanges 19. A connector 21 is provided at a front position of the outer peripheral wall 16 of the pump housing 15, and power is supplied from the connector 21 to the motor unit 3 through a wiring (not shown).

4 is a perspective view corresponding to a section taken along line IV-IV in FIG. 2 showing the arrangement of the rotor in the housing space of the pump housing 15, and FIG. 5 is a VV line in FIG. 2 showing the preliminary sound deadening chamber of the pump housing 15. It is a perspective view equivalent to a section.
As shown in FIGS. 2 to 5, an inner peripheral wall 22 (inner peripheral surface) is formed in the pump housing 15 so as to have a double inner / outer positional relationship with respect to the outer peripheral wall 16. An annular space between the outer peripheral wall 16 and the outer peripheral wall 16 is partitioned vertically by the partition wall 23 (in the axial direction of the rotor). As will be described in detail later, the annular space formed above the partition wall 23 in the pump housing 15 functions as the ventilation passages 50a to 50c having a cooling action (shown in FIGS. 4 and 6) and below the partition wall 23. The annular space formed on the side functions as a preliminary silencing chamber 40 that performs a silencing action in cooperation with the silencing section 4 (shown in FIGS. 5 and 9).

Further, the lower part in the inner peripheral wall 22 is closed by a bottom wall 24 (one side surface), and the upper part of the output shaft 7 of the motor unit 3 protrudes upward through a shaft hole 24a penetrating the bottom wall 24. ing. A cylindrical portion 24b having a cylindrical shape centering on the output shaft 7 is provided on the lower surface of the bottom wall 24 so as to protrude downward. The cylindrical portion 24b is O-ringed with respect to the boss portion 6b of the housing cover 6 of the motor portion 3. 25 and is fitted outside. The pump housing 15 and the motor unit 3 are positioned on the axis L by fitting the tube portion 24b and the boss portion 6b.

In the pump housing 15, an aluminum die-cast upper plate 27 (other side surface, lid member) is disposed so as to close the upper portion in the inner peripheral wall 22, and the periphery of the upper plate 27 is at the upper end of the inner peripheral wall 22. On the other hand, it is fixed by screws 29 in a state of being in contact with the O-ring 28 interposed therebetween. A housing space 30 is defined by the inner peripheral wall 22, the bottom wall 24, and the upper plate 27, and the housing space 30 centering on the output shaft 7 projecting inside has a long side in the front-rear direction and a left-right direction in the plan view. It has a track shape with short sides. Specifically, as shown in FIG. 4, the accommodation space 30 is formed in a cross-sectional track shape in which the ends of a pair of front and rear semicircular arc surfaces 30a are connected by a pair of left and right parallel surfaces 30b.

A cylindrical rotor 31 centering on the output shaft 7 is disposed in the accommodation space 30, and the lower surface (one side surface) of the rotor 31 is opposed to the bottom wall 24 of the accommodation space 30 through a minute clearance. The upper surface (other side surface) of the rotor 31 is opposed to the upper plate 27 via a minute clearance. As a result, pump chambers 32 each having a crescent shape in plan view are defined on both front and rear sides of the rotor 31 in the accommodation space 30.

As shown in FIG. 2, the rotor 31 is provided with a shaft hole 31 a along the axis L from below, and the output shaft 7 of the motor unit 3 is inserted into the shaft hole 31 a and is rotated relative to the rotation member 34. It is regulated. Since the shaft hole 31a does not penetrate the rotor 31 upward and leaves a surplus part 31b, the upper side and the lower side of the rotor 31 communicate with each other through a minute clearance between the shaft hole 31a and the output shaft 7. Without being done, it is completely partitioned off by the surplus part 31b.

As shown in FIGS. 3 and 4, vane grooves 31 c are formed in the equally divided six locations on the outer peripheral surface of the rotor 31 over the entire vertical width of the rotor 31, and each vane groove 31 c has a plate-like shape. The vanes 33 are arranged so as to be able to appear and retract in the inner and outer directions about the axis L, respectively. The vertical width of each vane 33 is substantially the same as the vertical width of the rotor 31, and the tip (outer peripheral end) is inclined with respect to the base end (inner peripheral end) in the rotational direction of the rotor 31.

When the rotor 31 is driven to rotate together with the output shaft 7 by the motor unit 3, each vane 33 receives a centrifugal force and generates air pressure in the outer circumferential direction (air pressure acting on the base end-air pressure acting on the tip end). receive. As a result, each vane 33 gradually changes the volume of the pump chamber 32 divided into a plurality of parts while sliding the tip thereof in sliding contact with the inner peripheral surface of the accommodation space 30 with the rotation of the rotor 31. Air is sucked into the pump chamber 32 from 35 and discharged from the pump chamber 32 to the discharge port 36.

The suction port 35 and the discharge port 36 are formed in pairs so as to correspond to the pump chambers 32 located on both the front and rear sides of the rotor 31, and the air from the suction port 35 to the discharge port 36 in each pump chamber 32. Transfer takes place.

6 is a perspective view with the upper plate 27 removed showing the relationship between the accommodation space 30 of the pump housing 15 and the suction port 35 of the upper plate 27, and FIG. 7 shows the relationship between the accommodation space 30 of the pump housing 15 and the ventilation path. 2 is a cross-sectional view taken along line VII-VII in FIG. 2, FIG. 8 is a perspective view corresponding to the cross section taken along line VIII-VIII in FIG. FIG. 9 is a perspective view corresponding to a cross section taken along line IX-IX in FIG. 8 from which a rotor 31 and a vane 33 showing an air intake path and a discharge path are removed.

As shown in FIGS. 6, 7, and 9, the pair of suction ports 35 are recessed in the lower surface of the upper plate 27 so as to face the respective pump chambers 32, and in detail, the rotor 31 in each pump chamber 32. It opens at a position on the counter-rotating side. As shown in FIG. 9, one suction port 35 communicates with a nipple 39 erected in the vicinity of the connector 21 through a first suction passage 37 formed in the pump housing 15, and the upper plate 27 It communicates with the other suction port 35 through an annular second suction passage 38 that is recessed so as to surround the accommodation space 30 on the lower surface.

As a result, both the suction ports 35 communicate with the nipple 39 via the first and

second suction passages

37 and 38. Further, although not shown, when the vacuum pump 1 is mounted on the vehicle, it is connected to the nipple 39 via the pneumatic hose. It will communicate with the connected brake assist device.
Therefore, when the volume of each pump chamber 32 is changed by each vane 33 as the rotor 31 rotates, the air from the brake assist device passes through the pneumatic hose, the nipple 39 and the first suction passage 37, and passes through one suction port 35. And is sucked into the other pump chamber 32 from the other suction port 35 through the second suction passage 38.

10 is a perspective view corresponding to the cross section taken along line XX of FIG. 8 showing the air discharge path from the preliminary muffler chamber to the muffler section 4, and FIG. 11 is the XI line of FIG. 8 showing the air discharge path from the muffler section 4 to the outside. It is a perspective view equivalent to a -XI line section.
As shown in FIG. 9, the pair of discharge ports 36 are formed on the inner peripheral surface of the inner peripheral wall 22 of the pump housing 15 so as to face the respective pump chambers 32. 31 is open at a position on the rotation side.

As described above, the annular preliminary sound deadening chamber 40 is formed below the partition wall 23 in the pump housing 15. Specifically, the preliminary silencing chamber 40 is formed so as to form an annular shape between the outer peripheral wall 16, the inner peripheral wall 22 and the lower cylindrical portion 24 b, and the preliminary silencing chamber 40 is connected to each pump via the discharge port 36. Each communicates with the inside of the chamber 32. As shown in FIG. 10, a discharge passage 41 is opened on one side of the preliminary muffler chamber 40. The discharge passage 41 passes through the pump housing 15 and the upper plate 27 and opens upward. A cylindrical sealing member 42 is disposed on the side.

On the other hand, as shown in FIGS. 2, 8, 10, and 11, the silencer 4 includes a silencer housing 43 having a bottomed cylindrical shape that opens downward, and a housing cover 44 (cover member) that closes the opening of the silencer housing 43. A silencing action is achieved by an expansion chamber 43a and a resonance chamber 43b (partially shown in FIG. 8) that are communicated with each other and are defined in the silencing housing 43. The outer periphery of the lower surface of the housing cover 44 is fixed by screws 46 in a state where the O cover 45 is in contact with the upper end of the outer peripheral wall 16 of the pump housing 15.

In this coupled state, the seal member 42 is elastically sandwiched between the upper surface of the upper plate 27 and the lower surface of the housing cover 44, and as a result, the preliminary silencing chamber 40 of the pump housing 15 connects the discharge passage 41 and the seal member 42. Via the expansion chamber 43a and the resonance chamber 43b in the silencer housing 43. As shown in FIGS. 8 and 11, a discharge hole 47 is opened near the seal member 42 on the housing cover 44, and the discharge hole 47 opens downward through the housing cover 44 and the pump housing 15. is doing.

Therefore, the air sucked into the pump chamber 32 through each suction port 35 is discharged from the pump chamber 32 through the discharge port 36 into the preliminary silencing chamber 40 by each vane 33 as the rotor 31 rotates. Then, it is discharged from the preliminary muffler chamber 40 through the discharge passage 41 and the seal member 42 into the muffler 4, and is discharged to the outside through the discharge hole 47 after flowing through the internal expansion chamber 43 a and the resonance chamber 43 b. Although pulsation that causes noise occurs in the air in synchronization with the suction and discharge by the vane 33 in each pump chamber 32, the pulsation is mitigated in the process of flowing through the preliminary silencing chamber 40, the expansion chamber 43a and the resonance chamber 43b. Therefore, noise associated with the operation of the vacuum pump 1 is suppressed.

By the way, the vacuum pump 1 that supplies negative pressure to the brake assist device by air suction / discharge cannot lubricate the sliding contact of the rotor 31 and the vane 33 in the accommodation space 30 with oil. A carbon rotor 31 and vane 33 having self-lubricating properties are employed so that they can function even in lubrication. However, as described in [Problems to be Solved by the Invention], carbon with poor wear resistance is markedly worn by sliding contact in the accommodation space 30, and the rotor 31 and the vane 33 need to be periodically replaced. Therefore, it is important to suppress the wear of the rotor 31 and the vane 33 as much as possible to extend the replacement interval.

In view of such a demand for the vacuum pump 1, the present inventor has paid attention to the fact that a decrease in temperature of the operating vacuum pump 1 leads to suppression of wear of the rotor 31 and the vane 33. That is, there is a correlation between the temperature range of the operating vacuum pump 1 and the wear of the rotor 31 and the vane 33, and the wear progresses as the temperature rises.

The vacuum pump disclosed in Patent Document 1 is not limited to the heat radiation of the rotor and vanes disposed in the housing space, but includes a cam ring, a lower plate, and an upper plate that define the housing space. Yes. For this reason, the heat generated by the sliding contact between the rotor and the vane and the heat transmitted from the motor unit 3 are trapped in the housing without being released to the outside, and the rotor and the vane cause wear due to temperature rise. .
As a countermeasure against such a problem, in this embodiment, a ventilation path is formed in the pump housing 15 so as to promote a temperature drop of the rotor 31 and the vane 33 in the accommodation space 30, and the configuration thereof will be described in detail below.

As shown in FIGS. 4, 6, and 7, a plurality of openings 49 (communication holes) extending in the horizontal direction are vertically arranged on both front and rear sides of the outer peripheral wall 16 of the pump housing 15. As described above, an annular space is formed on the upper side of the partition wall 23 in the pump housing 15 so as to surround the inner peripheral wall 22, and this annular space is closed by the housing cover 44 of the silencer 4. Each of the outer peripheral walls 16 is opened to the outside through openings 49 on both the left and right sides.

Hereinafter, for convenience of explanation, this annular space is regarded as a first ventilation path 50a and a second ventilation path 50b extending left and right across the inner peripheral wall 22 of the pump housing 15 as shown in FIGS. The first ventilation path 50a and the second ventilation path 50b form an arc shape along the inner peripheral wall 22 and penetrate the pump housing 15 from the front (one side) to the rear (the other), and the front side and the rear side are open. The portions 49 are connected to each other, and are hereinafter referred to as a left ventilation path 50a and a right ventilation path 50b.

As described above, since a part of the cooling air from the engine cooling fan disposed in front is sent to the vacuum pump 1, the cooling air flows from the front opening 49 to the left and

right ventilation paths

50 a and 50 b. After being introduced into the interior and flowing through the interior, they are discharged to the outside through the rear opening 49.

Further, since the upper plate 27 is located slightly below the upper end of the opening of the pump housing 15, a gap is formed between the upper surface of the upper plate 27 and the lower surface of the housing cover 44 of the silencer 4. Yes. For this reason, the left and

right ventilation paths

50a and 50b communicate with each other through this gap, and this gap also penetrates the pump housing 15 from the front to the rear, so that the opening on the rear side from the opening 49 on the front side. It functions as a third ventilation path 50c (upper ventilation path) for circulating cooling air toward the portion 49.

As a result, the accommodation space 30 in which the rotor 31 and the vane 33 are disposed is adjacent to the left and

right ventilation paths

50a and 50b via the inner peripheral wall 22 of the pump housing 15, and the upper ventilation path via the upper plate 27. Adjacent to 50c. Therefore, the heat in the accommodation space 30 is transmitted to the ventilation paths 50a to 50c via the inner peripheral wall 22 and the upper plate 27, and is released to the outside of the vacuum pump 1 by the cooling air flowing through the inside.

The left and

right ventilation passages

50 a and 50 b have an arc shape along the inner peripheral wall 22, and therefore are adjacent to the storage space 30 in a wide area corresponding to the inner peripheral surface of the storage space 30. Further, since the upper ventilation path 50 c is formed over the entire upper plate 27, the upper ventilation path 50 c is adjacent to the accommodation space 30 in a wide area corresponding to the upper surface of the accommodation space 30. Therefore, the heat in the accommodation space 30 is efficiently transmitted to the ventilation paths 50a to 50c through the wide area of the inner peripheral wall 22 and the upper plate 27. In addition, since the pump housing 15 and the upper plate 27 in which the inner peripheral wall 22 is formed are both made of aluminum having a good heat conductivity, the maximum heat radiation effect can be obtained.

In addition, the front and rear openings 49 of the pump housing 15 are always exposed to the cooling air flowing into and out of the ventilation passages 50a to 50c, and since the surface area is large, the pump housing 15 itself is also caused by the cooling air. To be cooled. As described above, the heat transmitted from the motor unit 3 to the pump housing 15 is also one of the factors that raise the temperature of the housing space 30, but since a part of the heat is carried away by the cooling air, the influence is reduced. Temperature rise in the accommodation space 30 is suppressed.

As a result, the temperature rise of the vacuum pump 1 in operation, particularly the temperature rise of the rotor 31 and the vane 33 in the accommodation space 30 can be suppressed. In particular, the air sucked and discharged by the vacuum pump 1 has a lower cooling action than liquids such as oil and fuel, and thus the temperature of the rotor 31 and the vane 33 tends to increase from the beginning. The heat rise using 50a to 50c can surely suppress the temperature rise. For this reason, the wear of the rotor 31 and the vane 33 can be suppressed. As a result, the replacement interval between the rotor 31 and the vane 33 due to the wear can be extended, and as a result, the durability of the vacuum pump 1 can be improved.

Furthermore, the pump housing 15 of the present embodiment has an inner peripheral wall 22, an outer peripheral wall 16 and a bottom wall 24 integrally formed, and this configuration also contributes to promotion of heat radiation from the accommodation space 30. That is, a part of the heat in the housing space 30 is radiated from the surface of the pump housing 15, but when the pump housing 15 is configured with these

walls

16, 22, and 24 as separate members, between the parts. Heat conduction is hindered at the joint surface, and the amount of heat released from the surface is reduced. According to the present embodiment, the integration of the outer peripheral wall 16, the inner peripheral wall 22, and the bottom wall 24 eliminates the joint surfaces between the components, thereby eliminating the heat conduction hindrance caused by the joint surfaces. For this reason, the amount of heat transmitted to the surface of the pump housing 15 and dissipated increases, and this point also contributes to the suppression of the temperature rise of the rotor 31 and the vane 33 and thus the suppression of wear.

On the other hand, the vacuum pump 1 includes the silencer 4 in order to suppress noise caused by air pulsation in the pump chamber 32. However, if the internal volume of the silencer 4 is increased for the purpose of higher silencing, the vacuum pump 1 It becomes a factor of the enlargement of the pump 1. In the present embodiment, an annular space that functions as the left and

right ventilation passages

50a and 50b is formed between the inner peripheral wall 22 and the outer peripheral wall 16 of the pump housing 15, so that no dead space is utilized below the annular space. Has occurred. Therefore, the space formed in this dead space is made to function as the preliminary silencing chamber 40. Therefore, without increasing the size of the vacuum pump 1, it is possible to realize a high silencing effect by expanding the entire internal volume including the silencing unit 4, thereby greatly reducing noise during operation of the vacuum pump 1. Another effect is also obtained.

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 embodiment, the present invention is applied to the vacuum pump 1 that sucks and discharges air as a fluid to generate a negative pressure, but the type of the vane pump is not limited to this. For example, the pump may be embodied as an air pump that operates by supplying discharged air to an actuator, or may be embodied as a pump that sucks and discharges liquid such as oil or fuel.

Further, in the above embodiment, the pump chambers 32 are defined on both the front and rear sides of the rotor 31 disposed in the accommodating space 30 and the 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 that of the embodiment can be obtained by forming the ventilation path in the vicinity of the accommodation space.

In the above embodiment, the pump housing 15 is made of aluminum die casting and the rotor 31 and the vane 33 are made of carbon. However, the material is not limited to these materials. Since the pump housing 15 may be made of a material having good heat conduction, it may be made of, for example, stainless steel or cast iron. The rotor 31 and the vane 33 are not necessarily made of a self-lubricating material. For example, the rotor 31 and the vane 33 may be made of aluminum on the premise of lubrication with oil, or limited to carbon even in the case of no lubrication. Alternatively, other self-lubricating materials such as resin may be used.

In the above embodiment, the left, right and upper ventilation paths 50a to 50c are formed in the pump housing 15 in order to suppress the temperature rise of the rotor 31 and the vane 33. However, it is not always necessary to form all of them. For example, the upper ventilation path 50c may be omitted, or only one of the left and

right ventilation paths

50a and 50b may be formed. Further, without forming the opening 49, it may be a simple communication hole through which the cooling air flows into and out of the ventilation paths 50a to 50c. The cooling air may be outside air. In the above embodiment, the structure in which the pump housing 15 is integrated with the cam ring and the lower plate is shown. However, the present invention is effective even if it is not integrated.

1 Vacuum pump (vane pump)
3 Motor part 7 Output shaft 15 Pump housing 16 Outer peripheral wall (outer peripheral surface)
22 Inner wall (inner wall)
24 Bottom wall (one side)
27 Upper plate (other side, cover member)
30 Housing Space 31 Rotor 32 Pump Chamber 33 Vane 40 Preliminary Silence Chamber 44 Housing Cover (cover member)
49 Opening (communication hole)
50a Left ventilation path (first ventilation path)
50b Right ventilation path (second ventilation path)
50c Upper ventilation path (third ventilation path)

Claims

A cylindrical rotor is disposed in a housing space defined in the pump housing, and one side surface and the other side surface of the housing space are opposed to one side surface and the other side surface of the rotor, respectively, and the outer peripheral surface of the rotor A pump chamber is defined between the inner space and the inner circumferential surface of the housing space, and the tip of a vane provided on the outer circumferential surface of the rotor as the rotor rotates is slid onto the inner circumferential surface of the housing space. In the vane pump that sucks and discharges the fluid by changing the volume of the pump chamber while making contact,
The vane pump according to claim 1, wherein a ventilation passage is formed in the pump housing so as to pass through from one side to the other at a position close to the accommodation space and to circulate cooling air therein.
2. The vane pump according to claim 1, wherein the ventilation path is formed across a peripheral wall that forms an inner peripheral surface of the housing space.
The pump housing is formed with an inner and outer double wall having an annular shape centered on the rotor, the inner peripheral wall functions as the inner peripheral surface, and the one and the other outer peripheral walls are each provided with a communication hole. An annular space formed between the inner peripheral wall and the outer peripheral wall is opened to the outside through the communication holes, so that the ventilation path serves as the ventilation path with the both sides of the inner peripheral wall sandwiched from the one to the other. 2. The vane pump according to claim 1, wherein a first ventilation path and a second ventilation path penetrating to the first are formed.
A motor unit that rotationally drives the rotor is fixed to the pump housing, and an output shaft of the motor unit is connected to the rotor through a bottom wall that functions as one side surface of the housing space. A cover member that closes the annular space is fixed to the motor unit side, and the first ventilation path and the second ventilation path are provided between the cover member that functions as the other side surface of the accommodation space and the cover member. The vane pump according to claim 3, further comprising a third ventilation path that allows communication.
The pump chamber sucks air as the fluid to generate a negative pressure, and has a function of discharging the sucked air to the outside,
The annular space is partitioned in the axial direction of the rotor by a partition wall, one of the sections functions as the first ventilation path and the second ventilation path, and the other introduces air discharged from the pump chamber. 5. The vane pump according to claim 3, wherein the vane pump functions as a silencing chamber that performs silencing.
The vane pump according to any one of claims 3 to 5, wherein at least one of the pair of communication holes of the outer peripheral wall is formed as a plurality of openings.
The vane pump according to claim 4, wherein the inner peripheral wall, the outer peripheral wall, and the bottom wall are integrally formed in the pump housing.