CN100379990C - vane pump - Google Patents

Abstract

The present invention relates to vane pump which is provided with vane rotors (9) which freely rotate and are contained in a stator (8), and vanes (16) which are freely held and come out and in a plurality of gaps (15), wherein the gaps (15) are formed in the positions with rough equal spaces on the periphery parts of the vane rotors in the circumferential direction from the radiation direction. If the length L in the circumferential direction of each weight reducing part (18) between two adjacent gap forming parts (17 and 17) is longer than the length L1 in the circumferential direction of each gap forming part (17), even the weight reducing parts of adjacent vane rotors are embedded with the gap forming parts on a part feeder, the weight reducing parts and the gap forming parts are not tightly embedded so as to form a movable embedding state so as to prevent rotors carried by the part feeder from interconnecting and the efficiency of automatic installation operation from descending.

Description

vane pump

technical field

The present invention relates to a vane pump used as an oil pressure supply source of a power steering device of a vehicle.

Background technique

Various products have been provided as vane pumps for vehicles, and one of them is known as the invention described in Japanese Patent Application Laid-Open No. 9-324767 issued by the Japanese Patent Office.

In this vane pump, a stator is accommodated inside a pump casing, and a vane rotor is rotatably provided in the stator to form a pressure chamber between an outer peripheral surface and an inner peripheral surface of the stator.

On the outer peripheral portion of the vane rotor, a plurality of slits are formed radially at positions at equal intervals in the circumferential direction, and thin-plate-shaped vanes are supported in each of the slits so that they can move freely in and out toward the inner peripheral surface of the stator. . The rotor is connected to a drive shaft inserted into the pump casing. The drive shaft transmits rotational force from the crankshaft of the engine through the timing belt through the driven pulley attached to the outer end side.

In addition, when the vane rotor rotates according to the rotation of the drive shaft, the pressure of the back pressure chamber for each vane protrudes from the gap, and the tip of each vane rotates while slidingly contacting the inner peripheral surface of the stator. Therefore, the working fluid flowing into the pump chamber between the vanes from the suction port formed in the pump casing is discharged to the discharge port while being compressed by the vanes, thereby acting as a pump.

Therefore, in the above-mentioned conventional vane pump, recently, there are notches formed at intervals on the outer peripheral surface of the rotor other than the slit forming portion where the slits are formed, for example, rotors formed by trimming sintered alloys. The material meets the requirements for cost reduction, and at the same time, by realizing the expansion of the volume of the pressure chamber, it exerts the effect of reducing the pulsation of the pump.

However, when notches are formed at intervals on the outer peripheral surface of the rotor, and when the length in the circumferential direction of each notch is almost the same as the length in the circumferential direction of the convex slit forming part, a plurality of rotors processed by sintering will not be produced in the production line. Stored on the part feeder, and slightly interfere with each other on the same plane and transport, the other gap forming part adjacent to the notch part of one rotor is in a state of being tightly fitted and connected to each other.

Therefore, when the interconnected rotors are conveyed to the automatic mounting device by the parts feeder, the workability of the automatic mounting is deteriorated.

Contents of the invention

The present invention is made in view of the above-mentioned existing technical problems. In the first aspect of the present invention, a notch is formed in a portion other than the slit forming portion that forms the slit on the outer peripheral surface of the rotor, and at the same time, the two adjacent The circumferential length of the notch between the slit forming parts is longer than the circumferential length of each of the slit forming parts.

According to the present invention, since the length of the notch in the circumferential direction is set to be longer than the length of the respective slit forming portions in the circumferential direction, when loading and transporting a plurality of sintered and molded rotors on the component feeder, even if the rotors are close to each other, Slightly interfering with the notch of one rotor and fitting the gap forming portion of the other adjacent rotor, it is not a tight fit but is in a so-called loose fitting state, and the rotors are transported in a state of being separated from each other without being connected to each other.

As a result, each rotor can be smoothly transported to the automatic mounting device by the parts feeder, and a decrease in mounting workability can be prevented.

In a second aspect of the present invention, the circumferential length of the slit forming portion is set to be at least three times the opening length of the slit.

According to the present invention, even if the length of the slit forming portion in the circumferential direction is made as small as possible by the notch portion formed on the outer peripheral surface of each rotor, since its length is three times or more the opening length of the slit, it is still possible to sufficiently ensure The rigidity of the gap forming part. Therefore, the pushing action (pumping action) of each vane as the rotor rotates can sufficiently resist the large load acting on the vane in the direction opposite to the rotation direction, preventing deformation of the slit forming portion.

According to the third aspect of the present invention, a first chamfer is formed on each outer end edge of each slit forming portion formed convexly by the notch in the rotor rotation direction and on the opposite side to the rotation direction, and at the same time, A second chamfer is formed between the root of the slit forming portion and the connecting portion with the notch, and the radius of curvature of the second chamfer is set to be larger than that of the first chamfer.

According to the present invention, as described above, when the notches and slit forming portions of the adjacent rotors are fitted together during the transportation of the respective rotors by the parts feeder, even if the first chamfered portion of one rotor and the second chamfered portion of the other rotor When the two chamfered parts are in contact, since the radius of curvature of the second chamfered part is larger than that of the first chamfered part, they cannot be tightly fitted to each other, and often simply form a separable state. Therefore, the automatic mounting work is further facilitated.

A fourth aspect of the present invention is characterized in that, based on the slit of the slit forming portion, the length of the portion of the rotor opposite to the rotation direction is set to be longer than the length of the portion of the rotor on the rotation direction side.

According to the present invention, since the portion on the opposite side to the rotation direction of the rotor has higher rigidity, it is possible to sufficiently counteract and support a large load in the direction opposite to the rotation direction of the blades, thereby improving the durability of the rotor.

Description of drawings

1 is a longitudinal sectional view showing a vane pump according to a first embodiment of the present invention;

Fig. 2 is the A-A line sectional view of Fig. 1;

Fig. 3 is a front view of the vane rotor and stator provided in this embodiment;

Fig. 4 is the B-B line sectional view of Fig. 3;

Fig. 5 is an enlarged view of part C of Fig. 3;

Fig. 6 is an enlarged view of a main part showing a second embodiment of the present invention.

Detailed ways

Next, embodiments of the vane pump of the present invention will be described in detail with reference to the drawings.

The vane pump is a pump suitable as a supply source of oil pressure for a hydraulic machine such as a power steering device of a vehicle. As shown in Fig. 1, it is mainly driven by a pump casing 1 fixed to a cylinder block of an internal combustion engine with screws, a pump main body 2 arranged in the pump casing 1, and a drive unit with one end side inserted inside the pump casing 1. Axis 3 constitutes.

Described pump housing 1 is shown in Figure 1 and Figure 2, is made up of block-shaped pump body 6 with suction passage 4 and discharge passage 5 and the pump cover 7 that is combined with its pump body 6, in this pump body 6 and pump cover A space for placing the pump main body 2 is provided between 7 .

As shown in FIGS. 1 to 3 , the pump main body 2 includes a stator 8 accommodated inside the pump cover 7 , a vane rotor 9 rotatably provided inside the stator 8 , and vane rotors 9 arranged on both sides of the stator 8 . A pair of side panels 10,11.

The stator 8 is positioned on the pump housing 1 with positioning pins 13, 13 fitted in a pair of small semicircular pin slots 8b, 8c formed at a position of approximately 180° on the outer peripheral surface as shown in Fig. 3 In the circumferential direction, at the same time, the inner peripheral surface 8a is formed in a substantially elliptical shape.

The vane rotor 9 is integrally formed into a substantially disc shape by sintered alloy, and a substantially annular pump chamber 14 is partitioned between the outer peripheral surface and the inner peripheral surface 8 a of the stator 8 . In addition, in the center of the vane rotor 9, a zigzag hole 9b is formed through which the front end 3a of the driving shaft 3 passes through the side plates 10 and 11 in a zigzag shape. At the same time, on the outer peripheral portion, ten slits 15 are radially formed at positions at equal intervals in the circumferential direction. Each of the slits 15 holds thin-plate-shaped blades 16 slidably radially inside, and at the same time, a hole is formed at the bottom so that the front end 16a of each blade 16 protrudes from the opening end of the slit 15 toward the inner peripheral surface 8a of the stator 8. Back pressure chamber 15a.

In addition, as shown in FIGS. 3 to 6, the vane rotor 9 is formed with an arc-shaped lightening portion 18, which is a notch at a portion other than the slit forming portion 17 forming the slits 15 on the outer peripheral surface. .

The slit forming portions 17, as shown in FIG. 5 , are respectively formed in a convex shape due to the existence of each lightening portion 18, and at the same time, the circumference of each lightening portion 18 between the adjacent two slit forming portions 17, 17 The length L in the direction is set to be longer than the length L1 in the circumferential direction of each slit forming portion 17 .

The entire circumferential length L1 of the slit forming portion 17 is set to be at least three times the opening length L2 of the slit 15 . In addition, the slit 15 is formed at a substantially central position in the circumferential direction of the slit forming portion 17, and based on the slit 15, a portion 17a of the vane rotor 9 on the opposite side to the rotation direction and a portion 17b on the rotation direction side thereof The lengths L3 and L4 in the circumferential direction are substantially the same.

In the vane rotor 9, as shown in FIG. 5, an arc-shaped first chamfer 17c is formed on each outer edge of each slit forming portion 17 in the vane rotor rotation direction (arrow direction) and on the opposite side to the rotation direction. At the same time, an arc-shaped second chamfer 17d is formed between the root of the slit forming portion 17 and the connecting portion of the weight reducing portion 18, and the radius of curvature R of the second chamfer 17d is larger than the first The radius of curvature of the chamfered portion 17c is large.

Furthermore, in the vane rotor 9, an annular third chamfer 17e is formed in the inner circumferential direction of the slit forming portion 17 and the weight reducing portion 18 on the outer peripheral portion to prevent the Burns prone to occur.

The other end protruding from the pump body 6 of the drive shaft 3 is equipped with a driven wheel 19 for transmission of drive, and the power of the engine will be transmitted by the belt outside the figure wound on the driven wheel 19 .

The side plate 10 on the one side is crimped with the end face of the pump body 6. On the crimped portion, as shown in FIG. There are 4 connections to the suction passage.

Between the outer peripheral surface of the pump body 2 and the inner peripheral surface of the pump cover 7 , a pressure chamber 22 into which hydraulic fluid discharged from a discharge port 21 formed on the pump body 2 flows is provided. The pressure chamber 22 is connected in parallel to the discharge passage 5 provided in the pump body 6 and the discharge passage 24 formed on the radially opposite side of the discharge passage 5 .

A variable throttling device 25 is provided in the passage 5 , and a discharge valve 26 that follows the pressure difference between the front and back of the variable throttling device 25 is provided at the upstream end of the discharge passage 24 .

The variable throttling device 25 includes: a slide valve placement hole 27 formed on the end face of the pump body 6 on the side of the pressure chamber 22; the slide valve placement hole 27 is freely placed in the slide valve placement hole 27, and the channel is increased or decreased according to its advance and retreat position. A spool valve 28 with an opening area of 5; a spring 29 pressing the spool valve 28 toward the pressure chamber 22 side.

The variable throttling device 25 advances and retreats by balancing the oil pressure of the pressure chamber 22 acting on one end of the slide valve 28 and the elastic force of the spring 29. At the same time, the slide valve 28 is set at the initial position in contact with the side plate 10 to discharge the passage. 5 has the largest opening area. One discharge port 21 formed in the pump body 2 opens at a position opposite to the end surface of the slide valve 28 in the side plate 10 .

The discharge valve 26 includes: a spool valve placement hole 30 formed on the end face of the pump body 6 on the pressure chamber 22 side; a spool valve 31 which is freely placed in the spool valve placement hole 30; The spool valve 31 presses against the pressure chamber 22 side; the discharge port 33 opens in the pressure chamber 22 according to the retraction amount thereof when the spool valve 31 retreats, and constitutes the opening end of the discharge passage 24 .

The pressure on the downstream side of the variable throttle device 25 on the bottom 30 a side of the spool valve placement hole 30 is introduced through the pressure introduction passage 23 . One end of the spool valve 31 faces the side of the pressure chamber 22. Therefore, due to the pressure before and after the variable throttle device 25 before and after the spool valve 31, the discharge valve 26 will increase and decrease according to the pressure difference between the front and rear of the spool valve 31. The flow rate discharged from the discharge port 33 to the discharge passage 24 .

Therefore, according to this embodiment, when the rotational speed of the drive shaft 3 (vane rotor 9) is low, the discharge valve 26 closes the discharge port 33 by the force of the spring 32 since the variable throttle device 25 is in a state where the discharge passage 5 is opened to the maximum. , so corresponding to the increase of the rotational speed, the supply flow rate of the discharge passage 5 also increases.

When the rotation speed of the drive shaft 3 is high to a certain extent, when the front and rear differential pressure of the variable throttling device 25 exceeds the set value, because the slide valve 31 of the discharge valve 26 that follows the front and rear differential pressure opens the discharge port 33, from the discharge Since the hydraulic oil is discharged from the passage 24, an increase in the amount of oil supplied to the discharge passage 5 can be suppressed.

Furthermore, when the rotational speed of the drive shaft 3 is increased from this state, the spool valve 28 of the variable throttle device 25 is retreated against the elastic force of the spring 29 by the oil pressure of the working oil on the side of the pressure chamber 22, and the discharge rate is gradually reduced. The opening area of the channel 5. As a result, the amount of oil supplied to the discharge passage 5 gradually decreases, and a so-called blow-down characteristic is obtained.

According to this embodiment, since the plurality of weight reduction portions 18 are formed at intervals on the outer peripheral surface of the vane rotor 9, reduction of metal material and reduction of pulsation can be achieved.

Furthermore, since the length L in the circumferential direction of each lightening portion 18 is set to be longer than the length L1 in the circumferential direction of each slit forming portion 17, even when a plurality of vane rotors 9 sintered and molded are transported by a parts feeder, the Even if the weight-reducing portion 18 of one vane rotor 9 is fitted with the slit forming portion 17 of the other adjacent vane rotor 9, the so-called movable fitting state is formed because the tight fitting cannot be performed, and the mutual vane rotors 9 cannot be connected, and can be Shipped separately from each other.

As a result, each rotor can be smoothly sent to the automatic mounting device by the parts feeder, and deterioration of mounting workability can be prevented.

In addition, even if the length L1 in the circumferential direction of the slit forming portion 17 generated by the lightening portion 18 is made as small as possible, since the length L1 is set to be three times or more the opening length L2 of the slit 15, it is possible to The rigidity of the slit forming portion 17 is sufficiently ensured.

Thereby, utilizing the push-out action (pump action) of each vane 16 following the rotation of the vane rotor 9, it is possible to fully resist the large load acting on the vane 16 in the direction opposite to the direction of rotation, and improve the supporting strength of the vane 16. At the same time, deformation of the slit forming portion 17 can be prevented.

Since the radius of curvature of the second portion 17d of the slit forming portion 17 is set to be larger than the radius of curvature of the first portion 17c, as described above, in the transportation of the parts feeder with each vane rotor 9, the blades that are adjacent to each other will be damaged. When the weight-reducing portion 18 and the slit forming portion 17 of the rotor 9 are fitted, they are not tightly fitted to each other, and are always in a state where they can be easily separated. Thus placing jobs becomes easier.

6 shows a second embodiment, in which the length L3 of the portion 17a of the vane rotor 9 on the opposite side to the rotation direction is set relative to the rotation direction of the vane rotor 9 based on the position where the slit 15 of the slit forming portion 17 is formed. The length L4 of the side portion 17b is long.

Therefore, since the rigidity of the portion 17a opposite to the rotation direction of the vane rotor 9 becomes greater, it can sufficiently counteract a large load in the opposite direction of rotation generated by the vanes 16, thereby improving the durability of the rotor.

The present invention is not limited to the structures of the respective embodiments described above, and for example, the depth and the length in the circumferential direction of the weight reducing portion 18 may be arbitrarily changed.

Claims (3)

1. A vane pump comprising: a stator housed in a pump casing; a rotor free to rotate housed in the stator and driven to rotate by a drive shaft; a plurality of slits along the outer circumference of the rotor Formed in the radial direction; blades, which are freely held in the respective slits toward the inner peripheral surface of the stator, are characterized in that they are formed on the outer peripheral surface of the rotor other than the slit forming portion that forms the slit. forming a notch, and at the same time, setting the circumferential length of the notch between the two adjacent slit forming parts to be longer than the circumferential length of each of the slit forming parts, A first chamfer is formed on each outer end edge of the rotor rotation direction and the opposite side to the rotation direction of each slit forming portion formed into a convex shape by each notch, and at the same time, at the base of the slit forming portion A second chamfered portion is formed between the connecting portion with the notch portion, and the radius of curvature of the second chamfered portion is set to be larger than that of the first chamfered portion. 2. The vane pump according to claim 1, wherein the circumferential length of the slit forming portion is set to be at least three times the opening length of the slit. 3. The vane pump according to claim 1 or 2, wherein the length of the portion on the side opposite to the rotation direction of the rotor is set to be longer than the length of the portion on the side of the rotation direction, based on the gap of the gap forming portion. Long length.

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