JP2007100667A - Vacuum pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum pump preventing excessive wear of the blade by improving a lubricating condition of a sliding part of the blade. <P>SOLUTION: This pump is provided with a pump housing 1 including a cylinder, a rotor 2 rotatably and eccentrically provided in the cylinder and having a rotor groove part 7 formed in a diameter direction, and a blade 3 slidably mounted in the rotor groove part 7 and sliding on an inner circumference part of the cylinder on a tip thereof during rotation of the rotor 2, and an oil groove 8 is formed on an side surface part of the rotor groove part 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vacuum pump that is mounted mainly on trucks and passenger cars and generates a vacuum at a pressure lower than atmospheric pressure.

2. Description of the Related Art Conventionally, a vacuum pump for a vehicle servo brake device is known as a negative pressure generation source of a vacuum brake booster mounted on a diesel vehicle. As this type of vacuum pump, an eccentric type vacuum pump is widely used (for example, refer to Patent Document 1). In such an eccentric vacuum pump, an eccentric rotor is rotatably provided in a cylindrical cylinder formed in a pump housing, and a blade is passed through a guide groove formed radially on the outer periphery of the rotor. Can come and go freely.
Japanese Patent Laid-Open No. 2002-106486 (page 3-5, FIG. 1-10)

  By the way, in the above-described conventional vacuum pump, when the blade enters and exits the guide groove in the rotor, the blade side surface receives a load generated by the sliding resistance of the blade and the cylinder, the internal pressure due to the pump action, and the like. Normally, the engine oil supplied into the vacuum pump generates an oil film between the blade side and the guide groove of the rotor, reducing wear on the sliding surface. When the equipment that uses the negative pressure of the vacuum pump is operating, the engine oil that stays in the vacuum pump and generates an oil film is discharged together with the sucked air. There was a problem that the wear of the blade was promoted. Further, if the supply amount of the engine oil for lubrication is increased, the internal pressure of the pump is increased and the noise of the vacuum pump is increased. Therefore, it is difficult to increase the engine oil for lubrication.

  The present invention has been created in view of the above points, and its purpose is to improve the lubrication state of the sliding portion of the blade, thereby preventing the occurrence of excessive wear of the blade. To provide a pump.

  In order to solve the above-described problems, a vacuum pump according to the present invention includes a pump housing having a cylindrical cylinder, a rotor that is eccentrically rotated within the cylinder, and has a guide groove formed in a radial direction. A blade is slidably attached to the guide groove, and has a blade whose tip is in sliding contact with the inner peripheral portion of the cylinder when the rotor rotates, and has an oil groove on a side surface of the guide groove. By providing an oil groove on the side surface of the rotor guide groove, the engine oil on the back of the blade is pumped when the pump chamber is compressed, where the load on the sliding part between the blade and the rotor guide groove is the largest. Thus, the blade can be forcibly supplied to the sliding portion of the guide groove of the blade and the rotor, the lubrication state of the sliding surface can be improved, and the wear of the blade side surface portion can be reduced.

  Moreover, as for the oil groove | channel mentioned above, it is desirable to form multiple pieces in one side part. As a result, engine oil can be efficiently supplied to the sliding portion of the guide groove of the rotor.

  Moreover, it is desirable that the oil groove described above is provided on the side surface portion of the guide groove on the side opposite to the rotation direction. This makes it possible to reliably supply engine oil to the sliding part on the blade back side.

  In addition, it is desirable that the plurality of oil grooves described above be evenly arranged along the rotation axis of the rotor. Alternatively, the plurality of oil grooves described above are desirably arranged at target positions with respect to the center position along the rotation axis of the rotor. Thereby, it becomes possible to supply engine oil uniformly to the whole sliding part of the guide groove of a rotor. Further, the sliding state of the blade and rotor guide groove side surfaces is stabilized, and the surface pressure can be reduced.

  Hereinafter, a vacuum pump according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings. FIG. 1 is an axial sectional view of a vacuum pump according to an embodiment. FIG. 2 is a radial cross-sectional view of a vacuum pump according to an embodiment. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

  As shown in these drawings, the vacuum pump according to this embodiment includes a pump housing 1, a rotor 2, blades 3, and a frame 5. The pump housing 1 is for forming a pump chamber, and has a cylindrical cylinder. One axial end surface of the pump housing 1 is open, and the opening is closed by the frame 5. A bearing 9 is disposed on the other axial end surface, and a shaft 6 is supported by the bearing 9. The rotor 2 is fitted to the shaft 6 by a fitting method such as a spline, and a blade 3 that slides in the rotor groove 7 as a guide groove of the rotor 2 as the rotor rotates is disposed.

  The frame 5 is partially formed with a suction port 50, and a check valve 52 is attached to the opposite side of the pump housing 1 via the suction port 50. The check valve 52 discharges air in the cylinder of the pump housing 1 and blocks the flow of air in the reverse direction.

  The rotor 2 is fitted to a shaft 6 supported by a bearing 9 provided in the pump housing 1, and rotates together with the shaft 6. The rotor 2 has a rotor groove portion 7 as a plurality of guide grooves formed in the radial direction, and a blade 3 is provided in each rotor groove portion 7. The plurality of blades 3 are slidably inserted into the respective rotor groove portions 7, and when the rotor 2 rotates, the rotor grooves 7 protrude radially outwards by the action of centrifugal force, and the tips (outer peripheral ends) are cylinders. It reciprocates in the rotor groove 7 while making sliding contact with the inner periphery 4. Further, one or a plurality of oil grooves 8 are provided on the side surface portion of the rotor groove portion 7 in the counter-rotating direction. In a state where the tip of each blade 3 is in sliding contact with the cylinder inner peripheral portion 4, a space defined by the cylinder inner peripheral portion 4, the outer peripheral portion of the rotor 2 and the two blades 3 adjacent in the circumferential direction, and the frame 5 is formed. It becomes the pump chamber 10.

  Further, the bearing 9 described above is disposed at a position deviated from the center position of the cylinder on the axial end surface of the pump housing 1, and two points are provided by the metal bearing 11 attached to the frame 5 concentrically with the bearing 9. The supported rotor 2 rotates by receiving a driving force of an engine (not shown) via a gear 12 at the tip of the shaft 6. When the rotor 2 rotates in this manner, the volume of the pump chamber 10 defined by the cylinder inner peripheral portion 4, the adjacent two blades 3, and the frame 5 changes, and the compressed internal air is reduced to the smallest volume. By discharging from the discharge port 54, it operates as a vacuum pump.

  Thus, in the vacuum pump of the present embodiment, the oil groove 8 is provided in the sliding surface direction (counter-rotation direction) of the blade 3 that slides in the radial direction of the rotor groove portion 7 during rotation. When the pump 3 is slid, especially when the pump 3 is compressed due to a load applied to the blade 3 and the sliding condition becomes poor, the chamber surrounded by the blade 3 and the rotor groove 7 is also compressed, and the side of the rotor groove 7 is compressed. Since the engine oil for lubrication can be forcibly supplied to the sliding portion from the provided oil groove 8, wear of the sliding portion can be reduced.

  In particular, by providing a plurality of oil grooves 8 as shown in FIG. 3, engine oil can be efficiently supplied to the sliding portion on the side surface of the rotor groove portion 7. Further, by providing the oil groove 8 on the side surface portion of the rotor groove portion 7 on the side opposite to the rotation direction, the engine oil can be reliably supplied to the sliding portion on the blade rear surface side. Further, as shown in FIG. 3, a plurality (three) of oil grooves 8 are evenly arranged along the shaft (rotating shaft) 6 of the rotor 2 and are subject to a central position along the shaft 6. (In FIG. 3, the central oil groove 8 is formed corresponding to the central position along the shaft 6, and the upper oil groove 8 and the lower oil groove 8 are located at this central position. The engine oil can be uniformly supplied to the entire sliding portion of the rotor groove portion 7. Further, the sliding state between the blade 3 and the side surface of the rotor groove 7 is stabilized, and the surface pressure can be reduced.

  In addition, by supplying engine oil directly to the rotor groove 7 and the sliding part of the blade 3, the amount of engine oil in the whole vacuum pump can be reduced, and the noise for exhausting the engine oil is reduced. can do.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the embodiment described above, the half-moon shaped oil groove 8 is provided on the counter-rotating side of the rotor groove portion 7 as shown in FIG. Further, as shown in FIG. 3, in the present embodiment, the oil groove 8 is formed in a direction substantially perpendicular to the shaft 6, but may be formed so as to form a predetermined angle with respect to the vertical direction.

It is an axial sectional view of the vacuum pump of one embodiment. It is radial direction sectional drawing of the vacuum pump of one Embodiment. It is the III-III sectional view taken on the line of FIG. It is the IV-IV sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pump housing 2 Rotor 3 Blade 4 Cylinder inner peripheral part 5 Frame 6 Shaft 7 Rotor groove part 8 Oil groove 9 Bearing 10 Pump chamber 11 Metal bearing 12 Gear 50 Suction port 52 Check valve 54 Discharge port

Claims (5)

A pump housing having a cylindrical cylinder;
A rotor that is eccentrically provided in the cylinder and is rotatably provided with a guide groove formed in a radial direction;
A blade that is slidably attached to the guide groove, and whose tip is in sliding contact with the inner periphery of the cylinder when the rotor rotates,
And having an oil groove on a side surface of the guide groove. In claim 1,
The oil pump has a plurality of oil grooves formed on one side portion. In claim 1 or 2,
2. The vacuum pump according to claim 1, wherein the oil groove is provided on a side surface portion of the guide groove on the side opposite to the rotation direction. In claim 2,
The vacuum pump, wherein the plurality of oil grooves are evenly arranged along a rotation axis of the rotor. In claim 2,
The vacuum pump, wherein the plurality of oil grooves are disposed at a target position with respect to a center position along a rotation axis of the rotor.

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