JP6770370B2 - Vane pump - Google Patents

Description

The present invention relates to a vane pump.

Patent Document 1 describes a vane pump having a notch formed on a side surface of a cam ring in contact with a side plate and facing a suction recess formed in the side plate. In the vane pump described in Patent Document 1, a suction port is formed by a suction recess and a notch.

Japanese Unexamined Patent Publication No. 2006-125210

In the vane pump described in Patent Document 1, hydraulic oil is sucked into the pump chamber partitioned between the vanes through the suction port as the rotor rotates. At this time, as the vane approaches the end of the suction port, the opening area of the suction port leading to the pump chamber becomes smaller. When the opening area of the suction port is reduced in this way, the flow velocity of the hydraulic oil sucked into the pump chamber becomes high, and cavitation is likely to occur.

The present invention has been made in view of the above problems, and an object of the present invention is to suppress the occurrence of cavitation in a vane pump.

The first invention is an inner peripheral cam surface in which a rotor driven to rotate, a plurality of vanes provided on the rotor so as to reciprocate in the radial direction of the rotor, and tips of the plurality of vanes are in sliding contact with each other as the rotor rotates. A cam ring having a rotor, a first side member and a second side member arranged across the cam ring, a rotor, a cam ring, adjacent vanes, a pump chamber partitioned by the first side member and the second side member, and the like. A suction port formed in the cam ring to guide the working fluid to the pump chamber, and an opening area increasing portion formed in the vicinity of the end of the suction port in the rotation direction of the rotor to increase the opening area of the suction port opening facing the pump chamber. The opening area increase portion is formed only within a range corresponding to the distance between adjacent vanes from the end of the suction port in the rotation direction of the rotor toward the start end side .

In the first invention, when the pump chamber approaches the end of the suction port as the rotor rotates, the opening area of the pump chamber can be increased, so that the flow velocity of the working fluid sucked into the pump chamber through the suction port. Can be suppressed from increasing. Further, in the first invention, the opening area increasing portion is formed only within the range corresponding to the distance between the adjacent vanes from the end end side of the suction port toward the start end side, so that the tip end portion of the vane and the inside of the cam ring are formed. Since the sliding distance can be shortened while the contact area with the peripheral cam surface is small, and the opening area of the opening of the pump chamber can be increased when the pump chamber is started to be closed, the tip of the vane can be increased. It is possible to suppress the occurrence of cavitation while more reliably preventing seizure between the portion and the inner peripheral cam surface of the cam ring.

The second invention is that the opening area increasing portion is formed so as to gradually increase the opening area from the start end side of the suction port in the rotation direction of the rotor toward the end side of the suction port in the rotation direction of the rotor. It is a feature.

In the second invention, the change in the flow rate of the working fluid sucked into the pump chamber can be made gentle, and pulsation and the like can be suppressed.

In a third aspect of the invention, the suction port has a notch formed in at least one of the end faces of the cam ring in contact with the first side member and the second side member, and the opening area increasing portion is provided in the notch, and the cam ring is provided. It is characterized in that the width of the notch in the axial direction of is inclined so as to gradually increase toward the end side.

The fourth invention is characterized in that the opening area increasing portion is a through hole formed near the end of the suction port and penetrating the inner and outer peripheral surfaces of the cam ring.

In the fourth invention, since the opening area increasing portion is formed by the through hole, the cam ring can be easily manufactured.

A fifth invention is an inner peripheral cam surface in which a rotor driven to rotate, a plurality of vanes provided on the rotor so as to reciprocate in the radial direction of the rotor, and tips of the plurality of vanes are in sliding contact with each other as the rotor rotates. A cam ring having a rotor, a first side member and a second side member arranged across the cam ring, a rotor, a cam ring, adjacent vanes, a pump chamber partitioned by the first side member and the second side member, and the like. A suction port formed in the cam ring to guide the working fluid to the pump chamber, and an opening area increasing portion formed in the vicinity of the end of the suction port in the rotation direction of the rotor to increase the opening area of the suction port opening facing the pump chamber. The opening area increasing portion is formed so as to gradually increase the opening area from the start end side of the suction port in the rotation direction of the rotor toward the end side of the suction port in the rotation direction of the rotor. It has a notch formed on at least one of the end faces of the cam ring in contact with the first side member and the second side member, the opening area increasing portion is provided in the notch, and the width of the notch in the axial direction of the cam ring ends. It is characterized in that it is formed so as to gradually increase toward the side .

According to the present invention, the occurrence of cavitation can be suppressed in the vane pump.

It is sectional drawing of the vane pump which concerns on embodiment of this invention. It is a front view of the rotor, vane and cam ring which concerns on embodiment of this invention, and shows the state which assembled the rotor, vane and cam ring. It is a front view of the 1st side plate which concerns on embodiment of this invention. It is a side view of the cam ring, the 1st side plate and the 2nd side plate which concerns on embodiment of this invention, and shows the state which the 1st side plate and the 2nd side plate are assembled to the cam ring. It is a rear view of the cam ring which concerns on embodiment of this invention. It is a front view of the 2nd side plate which concerns on embodiment of this invention. It is a figure which shows the pump chamber near the side port which concerns on embodiment of this invention. It is a figure which shows the state which the pump chamber moved from the position of FIG. 7a. It is a figure which shows the modification of the vane pump which concerns on embodiment of this invention. It is a figure which shows the modification of the vane pump which concerns on embodiment of this invention. It is a figure which shows the modification of the vane pump which concerns on embodiment of this invention.

Hereinafter, the vane pump 100 according to the embodiment of the present invention will be described with reference to the drawings. The vane pump 100 is used as a hydraulic supply source for a hydraulic device 1 (for example, a power steering device, a transmission, etc.) mounted on a vehicle. Here, the vane pump 100 in which hydraulic oil is used as the hydraulic fluid will be described, but other fluids such as hydraulic water may be used as the hydraulic fluid.

As shown in FIG. 1, the vane pump 100 includes a drive shaft 10, a rotor 20 connected to the drive shaft 10, a plurality of vanes 30 provided on the rotor 20, and a cam ring 40 accommodating the rotor 20 and the vanes 30. To be equipped.

The drive shaft 10 is rotatably supported by the pump body 50 and the pump cover 60. When the power of the engine or an electric motor (not shown) is transmitted to the drive shaft 10, the rotor 20 rotates with the rotational drive of the drive shaft 10.

In the following, the direction along the rotation center axis of the rotor 20 is also referred to as "axial direction", the radial direction of the rotor 20 is also simply referred to as "diameter direction", and the direction in which the rotor 20 rotates during normal operation of the vane pump 100 is simply "rotation". Also called "direction".

Further, the vane pump 100 further includes first and second side plates 70 and 80 as first and second side members arranged so as to sandwich the rotor 20 and the cam ring 40 in the axial direction. The first and second side plates 70 and 80 have side surfaces 70a and 80a that abut the rotor 20 and the cam ring 40, respectively. The pump chamber 41 is partitioned by the rotor 20, the cam ring 40, the adjacent vanes 30, the first side plate 70 and the second side plate 80.

FIG. 2 is a front view of the rotor 20, vane 30, and cam ring 40 assembled and viewed from the side of the pump cover 60. As shown in FIG. 2, a plurality of slits 22 having openings 21 on the outer peripheral surface are formed radially at predetermined intervals in the rotor 20. The opening 21 of the slit 22 is formed in a raised portion 23 that rises radially outward from the outer circumference of the rotor 20.

The vane 30 is slidably inserted into each slit 22. The tip portion 31 of the vane 30 faces the inner peripheral surface 40a of the cam ring 40. The base end portion 32 of the vane 30 is located in the slit 22, and a back pressure chamber 24 is formed by the slit 22 and the vane 30 on the base end portion 32 side of the vane 30.

When the rotor 20 rotates, centrifugal force acts on the vane 30. By this centrifugal force, the vane 30 is pushed out in the direction of protruding from the slit 22, and the tip portion 31 of the vane 30 is pressed against the inner peripheral surface 40a of the cam ring 40.

The inner peripheral surface 40a of the cam ring 40 is formed in a substantially oval shape. Hereinafter, the inner peripheral surface 40a is also referred to as an “inner peripheral cam surface 40a”.

Since the inner peripheral cam surface 40a of the cam ring 40 is formed in a substantially oval shape, the vane 30 reciprocates in the radial direction with respect to the rotor 20 as the rotor 20 rotates. As the vane 30 reciprocates, the pump chamber 41 repeats expansion and contraction.

In the present embodiment, the vane 30 reciprocates twice while the rotor 20 makes one rotation, and the pump chamber 41 repeats expansion and contraction twice. That is, the vane pump 100 alternately has two expansion regions 42a and 42c in which the pump chamber 41 expands and two contraction regions 42b and 42d in which the pump chamber 41 contracts in the rotational direction.

See FIG. 1 again. The pump body 50 is formed with a housing recess 51 that houses the rotor 20, the cam ring 40, and the first side plate 70. The first side plate 70 is arranged on the bottom surface 51a of the accommodating recess 51.

An annular groove 52 is formed on the bottom surface 51a of the accommodating recess 51. The annular groove 52 and the first side plate 70 form a high-pressure chamber 53 into which the hydraulic oil discharged from the pump chamber 41 flows. The hydraulic oil discharged from the pump chamber 41 is supplied to the hydraulic equipment 1 through the high pressure chamber 53.

FIG. 3 is a front view of the first side plate 70 as viewed from the side of the cam ring 40. As shown in FIGS. 1 and 3, the first side plate 70 is formed with a through hole 71 penetrating the first side plate 70 at the center thereof. The drive shaft 10 is inserted through the through hole 71.

The first side plate 70 is provided with two discharge ports 72 for guiding the hydraulic oil discharged from the pump chamber 41 to the high pressure chamber 53. The discharge port 72 is provided so as to be located in each of the contraction regions 42b and 42d.

The pump chamber 41 contracts while the pump chamber 41 (see FIG. 2) passes through the contraction regions 42b, 42d. As the pump chamber 41 contracts, the pressure of the hydraulic oil in the pump chamber 41 rises, and the hydraulic oil in the pump chamber 41 is discharged from the discharge port 72. That is, the hydraulic oil in the pump chamber 41 is discharged from the discharge port 72 while the pump chamber 41 passes through the contraction regions 42b and 42d. Since the hydraulic oil is discharged in the contraction regions 42b and 42d in this way, the contraction regions 42b and 42d are also referred to as "discharge regions".

The vane 30 is pushed most into the slit 22 when moving from the contraction region 42d to the expansion region 42a and from the contraction region 42b to the expansion region 42c, at which time the volume of the pump chamber 41 is minimized. The hydraulic oil for the minimum capacity of the pump chamber 41 is not discharged from the pump chamber 41 while the pump chamber 41 passes through the contraction regions 42d and 42b, and remains in the pump chamber 41. As described above, the minimum volume of the pump chamber 41 does not function as a pump and is also called a dead volume.

The first side plate 70 is formed with two back pressure passages 73 (see FIGS. 1 and 3) for guiding hydraulic oil from the high pressure chamber 53 to the back pressure chamber 24 (see FIGS. 1 and 2). As shown in FIG. 3, the back pressure passage 73 is formed in an arc shape centered on the through hole 71 so as to be located in the expansion regions 42a and 42c. As a result, hydraulic oil is guided from the high pressure chamber 53 to the back pressure chamber 24 passing through the expansion regions 42a and 42c. Therefore, the vane 30 passing through the expansion regions 42a and 42c has a slit 22 due to the pressure in the back pressure chamber 24. It protrudes from (see FIG. 3) and is pressed against the inner peripheral surface 40a of the cam ring 40.

As described above, in the present embodiment, the vane 30 is pressed in the direction of protruding from the slit 22 not only by the centrifugal force generated by the rotation of the rotor 20 but also by the pressure in the back pressure chamber 24.

See FIG. 1 again. The inner diameter of the accommodating recess 51 of the pump body 50 is larger than the outer diameter of the cam ring 40. A fluid chamber 54 extending from the outer circumference of the second side plate 80 to the outer circumference of the first side plate 70 is formed between the cam ring 40 and the pump body 50.

The opening of the accommodating recess 51 is sealed by the pump cover 60. The pump cover 60 is fixed to the pump body 50 by bolts (not shown). A second side plate 80 is arranged between the pump cover 60 and the cam ring 40.

A low pressure chamber 61 is formed in the pump cover 60. The low pressure chamber 61 is connected to the tank 2 through a low pressure passage. When the vane pump 100 operates, the hydraulic oil in the tank 2 is supplied to the low pressure chamber 61 through the low pressure passage. The low pressure chamber 61 communicates with the fluid chamber 54, and the hydraulic oil in the tank 2 is supplied to the fluid chamber 54 through the low pressure chamber 61.

The cam ring 40 and the second side plate 80 are provided with a side port 81 as a suction port for guiding the hydraulic oil in the low pressure chamber 61 to the pump chamber 41. Further, the cam ring 40 and the first side plate 70 are provided with a side port 74 as a suction port for guiding the hydraulic oil in the fluid chamber 54 to the pump chamber 41. The side ports 74 and 81 are provided so as to be located in the expansion regions 42a and 42c, respectively.

The pump chamber 41 expands while the pump chamber 41 passes through the expansion regions 42a, 42c (see FIG. 2). With the expansion of the pump chamber 41, the pressure in the pump chamber 41 decreases, and the hydraulic oil is sucked into the pump chamber 41 from the side ports 74 and 81. That is, the hydraulic oil is sucked into the pump chamber 41 from the side ports 74 and 81 while the pump chamber 41 passes through the expansion regions 42a and 42c. As described above, since the hydraulic oil is sucked into the pump chamber 41 in the expansion regions 42a and 42c, the expansion regions 42a and 42c are also referred to as "suction regions".

FIG. 4 is a side view of the first side plate 70 and the second side plate 80 assembled to the cam ring 40 and viewed from the outside in the radial direction. As shown in FIGS. 3 and 4, two recesses 75 are formed on the side surface 70a of the first side plate 70. The recessed portion 75 opens in the outer peripheral surface 70b of the first side plate 70.

FIG. 5 is a rear view of the cam ring 40 as viewed from the side of the first side plate 70. As shown in FIGS. 4 and 5, two notches 43 are provided on the end surface 40b of the cam ring 40 in contact with the first side plate 70. The notch 43 is located in the expansion regions 42a and 42c, and is formed from the outer peripheral surface 40d of the cam ring 40 to the inner peripheral cam surface 40a.

As shown in FIG. 4, when the first side plate 70 is assembled to the cam ring 40, the recessed portion 75 of the first side plate 70 faces the notch 43 of the cam ring 40. The hydraulic oil in the fluid chamber 54 (see FIG. 1) is guided to the pump chamber 41 through a port formed by the recess 75 and the notch 43. That is, in the present embodiment, the recessed portion 75 of the first side plate 70 and the notch 43 of the cam ring 40 correspond to the side port 74.

FIG. 6 is a front view of the second side plate 80 as viewed from the side of the pump cover 60. As shown in FIGS. 4 and 6, the outer peripheral surface 80b of the second side plate 80 is provided with two recessed portions 82. The recessed portion 82 is formed from the side surface 80a of the second side plate 80 to the side surface 80c of the second side plate 80 opposite to the side surface 80a.

As shown in FIGS. 2 and 4, two notches 44 are provided in the end surface 40c of the cam ring 40 in contact with the second side plate 80. The notch 44 is formed from the outer peripheral surface 40d of the cam ring 40 to the inner peripheral cam surface 40a so as to be located in the expansion regions 42a and 42c.

As shown in FIG. 4, when the second side plate 80 is assembled to the cam ring 40, the recessed portion 82 of the second side plate 80 faces the notch 44 of the cam ring 40. The hydraulic oil in the low pressure chamber 61 (see FIG. 1) is guided to the pump chamber 41 through a port formed by the recess 82 and the notch 44. As described above, in the present embodiment, the recessed portion 82 of the second side plate 80 and the notch 44 of the cam ring 40 correspond to the side port 81.

As shown in FIG. 4, the notches 43 and 44 of the cam ring 40 have openings of the side ports 74 and 81 that open into the pump chamber 41 near the ends of the side ports 74 and 81 in the rotation direction of the rotor 20. Inclined portions 45 and 46 are formed as an opening area increasing portion for increasing the area. Specifically, in the inclined portions 45 and 46, the widths of the notches 43 and 44 in the axial direction of the cam ring 40 gradually increase toward the end side in the vicinity of the ends of the side ports 74 and 81 in the rotation direction of the rotor 20, respectively. It is formed so as to be large.

The "starting end" of the side port 81 means the end portion 81a of the end portions of the side port 81 that the pump chamber 41 that has moved into the expansion regions 42a and 42c first reaches with the rotation of the rotor 20. To do. Further, the “termination” of the side port 81 means the end 81b of the end of the side port 81, to which the pump chamber 41 moving in the expansion regions 42a and 42c finally reaches with the rotation of the rotor 20. To do. That is, when the vane pump 100 operates, the pump chamber 41 that has moved into the expansion regions 42a and 42c reaches the start end of the side port 81, so that the pump chamber 41 and the side port 81 communicate with each other. When the pump chamber 41 passes through the end of the side port 81, the communication between the pump chamber 41 and the side port 81 is cut off.

Similarly, the “starting end” of the side port 74 refers to the end portion 74a of the end portion of the side port 74 that the pump chamber 41 that has moved into the expansion regions 42a and 42c first reaches with the rotation of the rotor 20. means. The "termination" of the side port 74 means the end 74b of the ends of the side port 74, where the pump chamber 41 moving within the expansion regions 42a, 42c arrives later as the rotor 20 rotates.

As shown in FIG. 7, the inclined portions 45 and 46 have a distance d between the vanes 30 adjacent to each other from the end of the side ports 74 and 81 in the rotation direction of the rotor 20 toward the start end side (pump in the circumferential direction of the rotor 20). It is formed in the range D corresponding to the length of the chamber 41 (see FIG. 7a).

Next, the operation of the vane pump 100 will be described.

When the power of the engine or an electric motor (not shown) is transmitted to the drive shaft 10, the rotor 20 rotates with the rotational drive of the drive shaft 10. The vane 30 reciprocates with respect to the rotor 20 as the rotor 20 rotates, and the pump chamber 41 repeats expansion and contraction.

The hydraulic oil in the tank 2 is guided to the pump chamber 41 passing through the expansion regions 42a and 42c through the low pressure chamber 61 and the side port 81, or through the low pressure chamber 61, the fluid chamber 54 and the side port 74. The hydraulic oil in the pump chamber 41 passing through the contraction regions 42b and 42d is discharged from the discharge port 72 to the high pressure chamber 53.

When the notches 43 and 44 are not provided with the inclined portions 45 and 46, the pump chamber 41 approaches the end of the side ports 74 and 81 (specifically, the position shown in FIG. 7a to the position shown in FIG. 7b). The opening area of the notches 43 and 44 for sucking the hydraulic oil into the pump chamber 41 (opening area of the pump chamber 41) gradually decreases as the hydraulic oil is sucked into the pump chamber 41. At this time, the flow velocity of the hydraulic oil sucked into the pump chamber 41 increases as the opening area of the notches 43 and 44 (opening area of the pump chamber 41) becomes smaller, so that the pump chamber 41 ends the side ports 74 and 81. Cavitation is more likely to occur as it approaches, that is, when the pump chamber 41 is closed.

Therefore, in the vane pump 100 of the present embodiment, inclined portions 45, 46 are provided near the end ends of the side ports 74, 81. As a result, the opening area of the pump chamber 41 can be increased when the pump chamber 41 approaches the end of the side ports 74 and 81, that is, when the pump chamber 41 starts to be closed. Therefore, in the vane pump 100, the opening area of the pump chamber 41 can be increased when the pump chamber 41 is started to be closed, so that an increase in the flow velocity of the hydraulic oil sucked into the pump chamber 41 through the side port 74 is suppressed. it can. Therefore, the occurrence of cavitation can be suppressed.

Further, as described above, in the vane pump 100, when the back pressure of the back pressure chamber 24 acts on the vane 30 with the rotation of the rotor 20, the tip portion 31 of the vane 30 is pressed against the inner peripheral surface 40a of the cam ring 40. Sliding. As shown in FIG. 7a, in the range D in which the inclined portions 45, 46 of the cutouts 43, 44 are formed, the tip portion of the vane 30 is compared with the area E in which the inclined portions 45, 46 are not formed. The area of contact between 31 and the inner peripheral surface 40a of the cam ring 40 is small. Therefore, when the vane 30 moves within the range D, seizure is likely to occur between the tip portion 31 of the vane 30 and the inner peripheral surface 40a of the cam ring 40. Therefore, in the vane pump 100, by forming the inclined portions 45 and 46 only near the ends of the side ports 74 and 81, the vane 30 has a small contact area between the tip portion 31 of the vane 30 and the inner peripheral surface 40a of the cam ring 40. The sliding distance in the state is shortened. As a result, it is possible to prevent the tip portion 31 of the vane 30 and the inner peripheral surface 40a of the cam ring 40 from being seized.

The inclined portions 45, 46 are more preferably formed within a range corresponding to the distance d between the adjacent vanes 30 from the end end side of the side ports 74, 81 toward the start end side. According to this configuration, the vane 30 is connected to the tip portion 30a of the vane 30 until the pump chamber 41 is started to be closed, that is, until the vane 30 moves to the boundary between the range D and the range E shown in FIG. 7a. The cam ring 40 slides in a state where the contact area with the inner peripheral surface 40a is large. Further, when the pump chamber 41 is started to be closed (when the pump chamber 41 moves to a range corresponding to the terminal distance d of the side ports 74 and 81), the opening of the pump chamber 41 is opened by the inclined portions 45 and 46. The opening area can be increased. Therefore, according to this configuration, the sliding distance can be shortened when the contact area between the tip portion 30a of the vane 30 and the inner peripheral surface 40a of the cam ring 40 is small, and when the pump chamber 41 is started to be closed. Since the opening area of the opening of the pump chamber 41 can be increased, seizure between the tip portion 31 of the vane 30 and the inner peripheral surface 40a of the cam ring 40 can be more reliably prevented, and when the pump chamber 41 is closed. It is possible to suppress the occurrence of cavitation.

According to the above embodiment, the following effects are obtained.

The vane pump 100 is formed near the end of the side ports 74 and 81 in the rotation direction of the rotor 20, and is an inclined portion that increases the opening area of the openings of the notches 43 and 44 facing the pump chamber 41 of the side ports 74 and 81. It includes 45 and 46. As a result, when the closing of the pump chamber 41 is started, the opening area of the pump chamber 41 can be increased, so that an increase in the flow velocity of the hydraulic oil sucked into the pump chamber 41 through the side port 74 can be suppressed. Therefore, the occurrence of cavitation can be suppressed.

Further, in the vane pump 100, the inclined portions 45 and 46 are formed near the end ends of the side ports 74 and 81. As a result, the distance between the tip portion 31 of the vane 30 and the inner peripheral surface 40a of the cam ring 40 can be shortened while the contact area is small, and the tip portion 31 of the vane 30 and the inner peripheral surface 40a of the cam ring 40 are seized. Can be prevented.

Further, in the vane pump 100, the inclined portions 45 and 46 are formed within a range corresponding to the distance d between the adjacent vanes 30 from the end of the side ports 74 and 81 toward the start end side. As a result, the sliding distance between the tip portion 30a of the vane 30 and the inner peripheral surface 40a of the cam ring 40 can be shortened while the contact area is small, and when the pump chamber 41 is started to be closed, the pump chamber 41 can be closed. Since the opening area of the opening can be increased, the occurrence of cavitation can be suppressed while more reliably preventing seizure between the tip portion 31 of the vane 30 and the inner peripheral surface 40a of the cam ring 40.

Further, the opening area increasing portion (inclined portions 45, 46) gradually opens from the start end side of the side ports 74, 81 in the rotation direction of the rotor 20 toward the end side of the side ports 74, 81 in the rotation direction of the rotor 20. It is formed to increase the area. As a result, the change in the flow rate of the hydraulic oil sucked into the pump chamber 41 can be made gentle, and pulsation and the like can be suppressed.

A modified example of the embodiment of the present invention will be described below.

In the above embodiment, the opening area increasing portion is formed by the inclined portions 45, 46 that gradually increase the opening area from the start end side to the end side of the side ports 74, 81, as shown in FIG. The opening area increasing portion may have a shape in which the opening areas of the cutouts 43 and 44 are gradually increased.

Further, if the tip portion 31 of the vane 30 and the inner peripheral surface 40a of the cam ring 40 are not seized, the inclined portions 45 and 46 are formed from the start end to the end end of the cutouts 43 and 44 as shown in FIG. May be good.

Further, although the inclined portions 45 and 46 are formed as the opening area increasing portion, as shown in FIG. 10, the through hole 47 penetrating the inner and outer peripheral surfaces of the cam ring 40 may be used as the opening area increasing portion. According to this configuration, the shapes of the notches 43 and 44 can be simplified, so that the cam ring 40 can be easily manufactured.

The configuration, action, and effect of the embodiment of the present invention configured as described above will be collectively described.

In the vane pump 100, a rotor 20 driven to rotate, a plurality of vanes 30 provided on the rotor 20 so as to reciprocate in the radial direction of the rotor 20, and tips 31 of the plurality of vanes 30 slide with the rotation of the rotor 20. A cam ring 40 having an inner peripheral cam surface 40a in contact with the rotor 20, a first side member (first side plate 70) and a second side member (second side plate 80) arranged so as to sandwich the rotor 20 and the cam ring 40, and a rotor 20. , Cam ring 40, adjacent vanes 30, pump chamber 41 partitioned by first side member (first side plate 70) and second side member (second side plate 80), and pump chamber 41 formed in cam ring 40. A suction port (side port 74, 81) for guiding the working fluid and a suction port (side port 74, 81) formed near the end of the suction port (side port 74, 81) in the rotation direction of the rotor 20 and facing the pump chamber 41. It is characterized by including an opening area increasing portion (inclined portions 45, 46, through hole 47) for increasing the opening area of the opening of 81).

According to this configuration, when the pump chamber 41 approaches the end of the suction port (side ports 74, 81) as the rotor 20 rotates, the opening area of the pump chamber 41 can be increased, so that the suction port can be increased. It is possible to suppress an increase in the flow velocity of the working fluid sucked into the pump chamber 41 through (side ports 74 and 81). Therefore, the occurrence of cavitation can be suppressed. Further, since the opening area increasing portion (inclined portion 45, 46, through hole 47) is formed near the end of the suction port (side port 74, 81), the tip portion 31 of the vane 30 and the inner peripheral cam of the cam ring 40 are formed. The sliding distance between the surface 40a and the surface 40a in a small contact area can be shortened, and the tip 31 of the vane 30 and the inner peripheral cam surface 40a of the cam ring 40 can be prevented from seizing.

In the vane pump 100, the opening area increasing portion (inclined portion 45, 46) is a suction port (side port 74, 81) in the rotation direction of the rotor 20 from the start end side of the suction port (side port 74, 81) in the rotation direction of the rotor 20. ) Is formed so as to gradually increase the opening area toward the end side.

According to this configuration, the change in the flow rate of the working fluid sucked into the pump chamber 41 can be made gentle, and pulsation and the like can be suppressed.

In the vane pump 100, the suction port (side port 74, 81) is at least one of the end faces 40b, 40c of the cam ring 40 in contact with the first side member (first side plate 70) and the second side member (second side plate 80). The cutouts 43, 44 formed in the cam ring 40 are provided, and the opening area increasing portions (inclined portions 45, 46) are provided in the cutouts 43, 44, and the width of the cutouts 43, 44 in the axial direction of the cam ring 40 ends. It is characterized in that it is formed so as to gradually increase toward the side.

The vane pump 100 is characterized in that the opening area increasing portion (through hole 47) is a through hole 47 formed near the end of the suction port (side ports 74, 81) and penetrating the inner and outer peripheral surfaces of the cam ring 40.

According to this configuration, since the opening area increasing portion (through hole 47) is formed by the through hole 47, the cam ring 40 can be easily manufactured.

In the vane pumps 100 and 200, the opening area increasing portion is formed within a range corresponding to the distance between the adjacent vanes 30 from the end of the suction port (side ports 74 and 81) in the rotation direction of the rotor 20 toward the start end side. It is characterized by being done.

According to this configuration, the opening area increasing portions (inclined portions 45, 46, through holes 47) correspond to the distance between the vanes 30 adjacent to each other from the end of the suction port (side ports 74, 81) toward the start end side. By forming it within the range, the sliding distance can be shortened when the contact area between the tip portion 30a of the vane 30 and the inner peripheral surface 40a of the cam ring 40 is small, and when the pump chamber 41 is started to be closed. Since the opening area of the opening of the pump chamber 41 can be increased, seizure between the tip portion 31 of the vane 30 and the inner peripheral surface 40a of the cam ring 40 can be more reliably prevented, and the occurrence of cavitation can be suppressed. Can be done.

Although the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above embodiments. Absent.

100 ... vane pump, 10 ... drive shaft, 20 ... rotor, 22 ... slit, 24 ... back pressure chamber, 30 ... vane, 31 ... tip, 40 ... Cam ring, 40a ... Inner circumference cam surface, 41 ... Pump chamber, 43,44 ... Notch, 45,46 ... Inclined part (opening area increase part), 47 ... Through hole (opening) Area increase part), 50 ... pump body, 60 ... pump cover, 70 ... first side plate (first side member), 72 ... discharge port, 73 ... back pressure passage, 74 , 81 ... Side port (suction port), 74, 81 ... Notch, 74b, 81b ... End (termination), 80 ... Second side plate (second side member)

Claims (5)

Rotationally driven rotor and
A plurality of vanes provided on the rotor so as to be reciprocating in the radial direction of the rotor,
A cam ring having an inner cam surface on which the tips of the plurality of vanes are in sliding contact with each other as the rotor rotates.
The first side member and the second side member arranged so as to sandwich the rotor and the cam ring,
A pump chamber partitioned by the rotor, the cam ring, adjacent vanes, the first side member and the second side member.
A suction port formed in the cam ring to guide the working fluid to the pump chamber,
An opening area increasing portion formed near the end of the suction port in the rotation direction of the rotor and increasing the opening area of the opening of the suction port facing the pump chamber is provided .
The vane pump is characterized in that the opening area increasing portion is formed only within a range corresponding to the distance between the adjacent vanes from the end end side of the suction port to the start end side in the rotation direction of the rotor . The opening area increasing portion is formed so as to gradually increase the opening area from the start end side of the suction port in the rotation direction of the rotor toward the end side of the suction port in the rotation direction of the rotor. The vane pump according to claim 1. The suction port
It has a notch formed in at least one of the end faces of the cam ring in contact with the first side member and the second side member.
The claim is characterized in that the opening area increasing portion is provided in the notch and is formed so as to be inclined so that the width of the notch in the axial direction of the cam ring gradually increases toward the end side. 2. The vane pump according to 2. The vane pump according to claim 1, wherein the opening area increasing portion is a through hole formed in the vicinity of the end of the suction port and penetrating the inner and outer peripheral surfaces of the cam ring. Rotationally driven rotor and
A plurality of vanes provided on the rotor so as to be reciprocating in the radial direction of the rotor,
A cam ring having an inner cam surface on which the tips of the plurality of vanes are in sliding contact with each other as the rotor rotates.
The first side member and the second side member arranged so as to sandwich the rotor and the cam ring,
A pump chamber partitioned by the rotor, the cam ring, adjacent vanes, the first side member and the second side member.
A suction port formed in the cam ring to guide the working fluid to the pump chamber,
An opening area increasing portion formed near the end of the suction port in the rotation direction of the rotor and increasing the opening area of the opening of the suction port facing the pump chamber is provided.
The opening area increasing portion is formed so as to gradually increase the opening area from the start end side of the suction port in the rotation direction of the rotor toward the end side of the suction port in the rotation direction of the rotor.
The suction port
It has a notch formed in at least one of the end faces of the cam ring in contact with the first side member and the second side member.
The vane pump is characterized in that the opening area increasing portion is provided in the notch and is formed so as to be inclined so that the width of the notch in the axial direction of the cam ring gradually increases toward the terminal side.

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