JP5479869B2 - Electric vane pump - Google Patents

Description

  The present invention relates to an electric vane pump.

  As a conventional electric vane pump, there is a type in which a pump chamber is formed by rotating a pump rotor provided with a vane in a cam ring, and a pump chamber is formed by the vane, the cam ring, and the pump rotor, and the sucked hydraulic oil is discharged at a high pressure (for example, , See Patent Document 1).

JP 2008-057483 A

  However, in the case of the electric vane pump described above, when the oil temperature of the hydraulic oil is relatively low, such as during cold start, the viscosity of the hydraulic oil is high and the fluidity is poor. Due to the fact that it was not formed, there was a problem that the performance of the electric vane pump deteriorated at the beginning of the start.

  The present invention has been made paying attention to such problems, and an object thereof is to improve the performance of an electric vane pump at the initial stage of starting.

The present invention is an electric vane pump, in which a coil is wound, a motor rotor whose outer periphery is covered by the stator and rotated by a rotating magnetic field formed by the stator, and a rotation that rotates integrally with the motor rotor. Non-magnetic pump rotor having a shaft and a plurality of slits opened on the outer peripheral surface and rotating integrally with the rotary shaft, and a soft magnetic cam ring in which the pump rotor is accommodated in an inner cam surface And a space between the outer peripheral surface of the pump rotor and the cam surface of the cam ring, which is slidably received in the slit, and divides the space into a plurality of pump chambers whose volumes change according to the rotation of the pump rotor. e Bei a vane of the magnetic body, and a pump housing of soft magnetic material provided with a storage portion for storing the cam ring, the inner periphery of the housing portion of the pump housing It is brought into contact with the outer peripheral surface of the cam ring and is brought into contact with a portion of the pump housing to the stator, characterized in that.

According to the present invention, when a current is passed through the coil at the start of the electric vane pump, the stator is magnetized to become a magnet, and the pump housing and cam ring that are in contact with the stator are also magnetized to become magnets. As a result, the pump rotor, which is a non-magnetic material, is not affected by the magnetized cam ring, while only the vane, which is a soft magnetic material, is pulled in the direction of exiting the slit due to the influence of the magnetized cam ring.

  Therefore, even if the electric vane pump is started in the cold state, the pump chamber can be formed by reliably bringing the vane into contact with the cam ring, so that a desired discharge pressure can be obtained from the initial stage of the start. The performance of the vane pump can be improved.

It is sectional drawing of an electric vane pump. It is an II-II arrow line view of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  With reference to FIG.1 and FIG.2, the structure of the electric vane pump 1 by this embodiment used as a hydraulic pressure supply source of hydraulic equipment is demonstrated.

  FIG. 1 is a sectional view of an electric vane pump 1 according to the present embodiment. 2 is a view taken in the direction of arrows II-II in FIG.

  As shown in FIG. 1, the electric vane pump 1 includes a rotating shaft 5 that is rotatably supported by bearings 4 attached to a pump housing 2 and a motor housing 3, respectively. A vane pump 6 that discharges high-pressure hydraulic fluid to various hydraulic devices is provided on the distal end side (left side in the figure) of the rotary shaft 5, and the rotary shaft 5 is rotated on the base end side (right side in the figure) of the rotary shaft 5. A motor 7 for operating the vane pump 6 is provided.

  The vane pump 6 includes a pump rotor 61 formed of an annular nonmagnetic material that is fixed to the rotating shaft 5 and rotates integrally with the rotating shaft 5, and an annular soft magnetic material that accommodates the pump rotor 61 therein. And a cam ring 62 configured as described above.

  In the present embodiment, the non-magnetic material means a material that does not interact with a magnetic field, such as aluminum. The soft magnetic material refers to a magnetic material, such as carbon steel (having a low carbon content) or pure iron, whose magnetization is easily aligned in the magnetic field direction with respect to an external magnetic field and has a small residual magnetization retention force. On the other hand, a magnetic material, such as a permanent magnet, that is difficult to magnetize even when an external magnetic field is applied and that retains its residual magnetization strongly once magnetized is called a ferromagnetic material.

  Here, as shown in FIG. 2, the pump rotor 61 is formed with a plurality of slits 63 that are opened in the outer peripheral surface 61a in a radial pattern at predetermined intervals. A soft magnetic vane 64 having a rectangular cross section is slidably accommodated in each slit 63, and the vane pump is rotated by the vane 64 and the slit 63 at the base end portion of the slit 63. A back pressure chamber 63a into which the discharge pressure of 6 is guided is defined. In this embodiment, the rotating shaft 5 rotates counterclockwise in FIG.

  The vane 64 is pushed out in a direction (outer diameter direction of the vane pump 6) to exit from the slit 63 by the discharge pressure acting on the back pressure chamber 63a when the rotating shaft 5 rotates, and an elliptical cam on the inner periphery of the cam ring 62 It contacts the surface 62a. A plurality of pump chambers 65 are defined by the outer peripheral surface 61 a of the pump rotor 61, the cam surface 62 a of the cam ring 62, and the adjacent vane 64 by the vane 64 coming into contact with the cam surface 62 a of the cam ring 62.

  The volume of the pump chamber 65 increases in the region A and decreases in the region B when the rotary shaft 5 rotates. That is, the volume of the pump chamber 65 expands and contracts as the rotating shaft 5 rotates. Hereinafter, the area A in which the volume of the pump chamber 65 increases is referred to as “suction area”, and the area B in which the volume decreases in the pump chamber 65 is referred to as “discharge area”.

  A description will be given with reference to FIG. 1 again.

  The pump cover 8 is disposed in contact with one end face (left side in the figure) of the pump rotor 61 and the cam ring 62, and the side plate 9 is disposed in contact with the other end face (right side in the figure).

  On the surface of the pump cover 8 in contact with the pump rotor 61, two arc-shaped suction ports (not shown) that open corresponding to the suction region and guide the hydraulic oil to the pump chamber 65 are formed in a groove shape.

  In the side plate 9, two arc-shaped discharge ports 92 that open corresponding to the discharge region and guide the hydraulic oil discharged from the pump chamber 65 to the high-pressure chamber 91 are formed therethrough.

  As each pump rotor 61 rotates, each pump chamber 65 sucks hydraulic oil from the suction port in the suction region, and discharges the hydraulic oil through the discharge port 92 in the discharge region.

  A pump housing recess (housing portion) 21 for housing the pump rotor 61, the cam ring 62, and the side plate 9 is formed on one end surface of the pump housing 2 made of a soft magnetic material. The outer peripheral surface of the cam ring 62 is in contact with the inner peripheral surface of the pump housing recess 21.

  A bearing housing recess 22 for housing the bearing 4 and a stator housing recess 23 for housing a stator of the motor 7 to be described later are formed on the other end surface of the pump housing 2. A protrusion 23a that is a part of the stator housing recess 23 and is formed on the outer periphery of the pump housing 2 is in contact with a laminated steel plate of a stator core described later.

  The motor 7 is an annular motor rotor 71 fixed to the rotating shaft 5 and rotating integrally with the rotating shaft 5, and a circle provided so as to cover the periphery of the motor rotor 71 at a predetermined interval in the radial direction. And an annular stator 72.

  On the outer periphery of the motor rotor 71, a plurality of permanent magnets are arranged at predetermined intervals in the circumferential direction of the motor rotor 71. The outer periphery of the motor rotor 71 is a magnetic pole in which the N pole and the S pole are alternately switched in the circumferential direction.

  The stator 72 is formed by connecting a plurality of stator cores 721 in an annular shape. The stator core 721 includes a soft magnetic laminated steel plate 722 that is laminated and integrated. The laminated steel plate 722 has a T shape in a plan view (when viewed from the axial direction of the rotating shaft 5), and has an arcuate yoke portion 722 a formed on the outer peripheral side of the motor 7, and the yoke portion 722 a to the motor 7. , And a tooth portion 722b that is insulated by an insulator (insulating material) 723 formed of an insulating synthetic resin. A coil 724 is wound around the tooth portion 722b via an insulator 723. The protruding portion 23 a of the pump housing 2 is in contact with the yoke portion 722 a of the laminated steel plate 722.

  The motor housing 3 includes an outer peripheral wall 31 formed on the outer periphery of the stator 72, a stator housing recess 32 that houses the stator 72, and a bearing housing recess 33 that houses the bearing 4. Hold.

  By controlling energization of the coil 724 according to the rotational position of the motor rotor 71, the stator 72 attracts and repels the permanent magnet of the rotor. As a result, the rotating shaft 5 rotates together with the motor rotor 71. Thus, the motor rotor 71 is rotated by the rotating magnetic field formed by the stator 72.

  Next, the effect of the electric vane pump 1 according to the present embodiment will be described.

  When the electric vane pump 1 is started in a cold place or when the electric vane pump 1 is driven and restarted after a long time has elapsed, the hydraulic oil temperature is relatively low and the hydraulic oil viscosity is low. Since it is high, the fluidity of the hydraulic oil becomes poor. Therefore, when the electric vane pump 1 is started in such a cold state, even if the pump rotor 61 is rotated by the motor 7, the vane 64 is not pushed out in the direction of exiting the slit 63, and the pump chamber 65 is not formed. A desired discharge pressure may not be obtained in the initial stage of startup.

  Therefore, in the present embodiment, the motor rotor 71 is made of a nonmagnetic material, and the vane 64, the cam ring 62, and the pump housing 2 are made of a soft magnetic material. Then, the inner peripheral surface of the pump housing recess 21 of the pump housing 2 and the outer peripheral surface of the cam ring 62 were brought into contact with each other, and the protruding portion 23a of the pump housing 2 and the yoke portion 722a of the laminated steel plate 722 were brought into contact with each other.

  Accordingly, when a current is passed through the coil 724 when the electric vane pump 1 is started, the laminated steel plate 722 is magnetized, and the pump housing 2 in contact with the laminated steel plate 722 is magnetized. The cam ring 62 that contacts the pump housing 2 is also magnetized. As a result, the pump rotor 61 that is a non-magnetic material is not affected by the magnetized cam ring 62, while only the vane 64 that is a soft magnetic material is affected by the magnetized cam ring 62 in the direction of exiting from the slit 63. Be pulled.

  Therefore, even if the electric vane pump 1 is started in a cold state, the tip of the vane 64 can be reliably brought into contact with the cam surface 62a of the cam ring 62 to form the pump chamber 65. The discharge pressure can be obtained.

  Note that the present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  For example, in the above embodiment, the entire cam ring 62 is made of a soft magnetic material, but only the portion near the suction region may be made of a soft magnetic material, and the other portions may be made of a non-magnetic material. Further, a soft magnetic material may be embedded in the vicinity of the suction region. This is because, if the pump chamber 65 can be formed by bringing the tip of the vane 64 into contact with the cam surface 62a of the cam ring 62 in the suction region, a desired discharge pressure can be obtained from the beginning of the start.

2 Pump housing 5 Rotating shaft 21 Pump housing recess (housing portion)
61 pump rotor 61a outer peripheral surface 62 cam ring 62a cam surface 63 slit 64 vane 65 pump chamber 71 motor rotor 72 stator 722 laminated steel plate 723 insulator (insulating material)
724 coil

Claims (2)

A stator around which a coil is wound;
A motor rotor whose outer periphery is covered by the stator and rotated by a rotating magnetic field formed by the stator;
A rotating shaft that rotates integrally with the motor rotor;
A non-magnetic pump rotor that includes a plurality of slits that open to the outer peripheral surface and rotates integrally with the rotating shaft;
A soft magnetic cam ring in which the pump rotor is housed in an inner cam surface;
A soft magnetic material that is slidably accommodated in the slit and divides a space between an outer peripheral surface of the pump rotor and a cam surface of the cam ring into a plurality of pump chambers whose volumes change according to the rotation of the pump rotor. With the vane
A soft magnetic pump housing comprising an accommodating portion for accommodating the cam ring;
Bei to give a,
Abutting the inner peripheral surface of the accommodating portion of the pump housing and the outer peripheral surface of the cam ring, and contacting a part of the pump housing to the stator;
An electric vane pump characterized by that. It said stator comprises a laminated steel plate integrated by stacking steel plates of soft magnetic material,
A portion of the pump housing abuts against the laminated steel plate of the stator;
The electric vane pump according to claim 1.

Images