JP2007009787A - Motor-integrated internal gear pump and electronic equipment - Google Patents

Abstract

An object of the present invention is to maintain a small and inexpensive function as a motor-integrated internal gear pump, and to make it more inexpensive and highly reliable.
A motor-integrated internal gear pump 80 includes a pump unit 81 that sucks and discharges hydraulic fluid, and a motor unit 82 that drives the pump unit 81. The pump portion 81 includes an inner rotor 1 having teeth on the outer periphery, an outer rotor 2 having teeth that mesh with the teeth of the inner rotor 1, and pump casings 3 and 4 that house the inner rotor 1 and the outer rotor 2. With. The motor unit 82 includes a rotor 11 and a stator 12 that rotates the rotor 11. The rotor 11 and the outer rotor 2 are formed by sharing a permanent magnet member 112 containing magnet powder in resin.
[Selection] Figure 1

Description

  The present invention relates to a motor-integrated internal gear pump and an electronic device.

  The internal gear type pump has long been known as a pump that pumps out sucked liquid against pressure, and is particularly popular as a hydraulic source pump and an oil supply pump.

  The internal gear type pump has a spur gear-shaped inner rotor with teeth on the outer periphery and an annular outer rotor with teeth on the inner periphery and the width of which is almost the same as the inner rotor. It is configured. A pump casing having a flat inner surface facing the both side surfaces of the rotors through a slight gap is provided so as to accommodate both rotors. The number of teeth of the inner rotor is usually one less than the number of teeth of the outer rotor, and rotates in the same manner as the power transmission gear in a state where they are meshed with each other. By the change of the tooth gap area accompanying this rotation, the liquid confined in the tooth gap is sucked and discharged, thereby functioning as a pump. If one of the inner and outer rotors is driven, the other will also rotate by meshing. The center of rotation of both rotors is off and it is necessary to pivotally support each rotor. The pump casing is provided with an opening to a flow path communicating with the outside called a suction port and a discharge port. The suction port is provided so as to communicate with a tooth groove having a larger volume, and the discharge port is provided so as to communicate with a tooth groove having a smaller volume. As a rotor tooth profile, an arc is applied to a part of the outer rotor tooth profile, and a trochoid curve is generally applied to the tooth profile of the inner rotor.

  Since the internal gear pump rotates with the inner rotor and the outer rotor meshing with each other, when one rotor is driven to rotate, the other rotor also rotates. The motor unit is integrated on the outer peripheral side of the pump unit, the rotor of the motor unit is integrated with the outer rotor, and the method of driving the outer rotor with the motor unit can be shorter than the structure in which the pump unit and the motor unit are connected in the axial direction. Therefore, it can be said to be a form suitable for miniaturization.

  As an internal gear type pump having such a structure, there is an internal gear pump disclosed in Japanese Patent Laid-Open No. 2-277993 (Patent Document 1). In Patent Document 1, an outer gear (rotor) is mounted on the outer periphery of a stator (stator) mounted inside a motor casing so as to be in contact with the stator at a predetermined interval in the radial direction. An internal gear is formed by combining an outer rotor) and an inner gear (corresponding to the inner rotor) meshed with the outer gear, and both end surfaces of the internal gear are liquid-tightly closed with a closing plate. Each of the closing plates comprises an internal gear pump provided with a suction port and a discharge port communicating with the internal gear. The closing plate (pump casing) includes a front casing (front casing) and a rear casing (rear casing), disc-shaped thrust bearings are disposed between both casings and both sides of the internal gear pump, and the outer gear Both sides are supported by this thrust bearing, and both ends of the support shaft are fixed to both casings, and the inner gear is rotatably supported on this support shaft via a radial bearing. Is provided between the rotor and the stator, and at the same time, a liquid supply path is provided to lubricate each bearing portion and return it to the suction side.

JP-A-2-2777983

  However, in the inscribed gear pump of Patent Document 1, the outer gear and the rotor are formed of different members, which causes a problem of increasing the size and cost.

  Further, Patent Document 1 does not disclose the materials of the rotor, outer gear, inner gear, and closing plate that constitute the inscribed gear pump, nor does it disclose use in electronic equipment. If this inscribed gear pump is used in an electronic device such as a personal computer or a server, it is suitable for mass production, long life, high precision maintenance, low sliding friction, low cost, and light weight. Is required. In addition, as the working fluid that flows in the pump section when used in electronic equipment, an antifreeze such as ethylene glycol is used in consideration of the storage temperature of the electronic equipment, so the compatibility between the internal gear pump and the antifreeze must also be considered I found out that

  An object of the present invention is to obtain a motor-integrated internal gear pump and electronic equipment that are small, inexpensive, and highly reliable while utilizing the function of an internal gear that is suitable for a high head.

  A first aspect of the present invention for achieving the above-mentioned object includes a pump part that sucks and discharges hydraulic fluid and a motor part that drives the pump part, and the pump part forms teeth on the outer periphery. An inner rotor, an outer rotor formed with teeth that mesh with teeth of the inner rotor, and a pump casing that houses the inner rotor and the outer rotor. The motor unit includes a rotor and the rotation In a motor-integrated internal gear pump configured to include a stator for rotating a rotor, the rotor and the outer rotor are formed by a permanent magnet member containing magnet powder in a resin. It is in.

A more preferable specific configuration example in the first aspect of the present invention is as follows.
(1) While using water or a liquid containing water as a component as a working fluid sucked into and discharged from the pump unit, a shared member of the rotor and the outer rotor is formed with a ferrite bonded magnet containing ferrite magnet powder. thing.
(2) The shared member of the rotor and the outer rotor is formed of a member having a strong magnetic force on the outer peripheral side and a weak magnetic force on the inner peripheral side, and the stator is installed on the outer periphery of the shared member. thing.
(3) In (1), an antifreeze containing water and organic matter is used as the working fluid.
(4) In (1), the common member is formed of a PPS / ferrite bonded magnet in which ferrite magnet powder is contained in a PPS resin.
(5) In the above (1), the pump casing is constituted by joining two casings each including a first casing and a second casing so as to face the first casing and the second casing. Shoulder portions projecting inwardly are respectively formed on both sides of the outer peripheral portion of the common member, annular projecting portions projecting in the axial direction from the inner peripheral tooth portions, and the annular projecting portions are formed as the first projecting portion. It fits to the outer peripheral surface of each shoulder part of a casing and a said 2nd casing, and the said stator was installed in the outer periphery outer side of the said shared member.
(6) In the above (1), the pump casing is formed of PPS carbon fiber resin containing carbon fiber in PPS resin or PPS glass fiber resin containing glass fiber in PPS resin.
(7) In (1), the inner rotor is formed of PPS carbon fiber resin or POM resin containing carbon fiber in PPS resin.
(8) In (5), the first casing and the second casing are formed of PPS carbon fiber resin containing carbon fiber in PPS resin.
(9) In the above (8), a sealing portion that extends the outer peripheral portion of either the first casing or the second casing in the axial direction to seal between the rotor and the stator. Forming and mounting the stator on the outside of the sealing portion.

  The second aspect of the present invention includes a pump unit that sucks and discharges hydraulic fluid, and a motor unit that drives the pump unit, and the pump unit includes an inner rotor having teeth formed on an outer periphery thereof, An outer rotor having teeth that mesh with teeth of the inner rotor formed on the inner periphery, a pump casing that houses the inner rotor and the outer rotor, and the motor unit includes a rotor and a stator that rotates the rotor In the motor-integrated internal gear pump configured to include the PPS resin / ferrite bonded magnet in which the PPS resin contains ferrite magnet powder, the rotor is formed.

A more preferable specific configuration example in the second aspect of the present invention is as follows.
(1) The pump casing is formed of PPS carbon fiber resin containing carbon fiber in PPS resin, and the inner rotor is formed of PPS carbon fiber resin containing carbon fiber in PPS resin.

  According to a third aspect of the present invention, there is provided an electronic apparatus in which the motor-integrated internal gear pump according to any one of the above is mounted as a liquid circulation source and an antifreeze composed of water and organic matter is used as a working liquid.

  According to the present invention, it is possible to obtain a motor-integrated internal gear pump and an electronic device that are small, inexpensive, and highly reliable while utilizing the function of an internal gear that is suitable for a high head.

  Hereinafter, a motor-integrated internal gear pump according to an embodiment of the present invention, a manufacturing method thereof, and an electronic device will be described with reference to FIGS.

  First, the entire motor-integrated internal gear pump of this embodiment will be described with reference to FIGS. 1 is a longitudinal sectional view of a motor-integrated internal gear pump 80 according to an embodiment of the present invention, FIG. 2 is a front view showing a left half surface of the pump 80 of FIG. 1 in section, and FIG. 3 is a pump of FIG. 80 is an exploded perspective view of the pump portion in FIG. 80, and FIG. 4 is a cross-sectional view showing a method for joining the casings of the pump 80 in FIG.

  The pump 80 includes a pump unit 81 that sucks and discharges hydraulic fluid, a motor unit 82 that drives the pump unit 81, and a control unit 83 that controls the motor unit 82. It is a gear type pump.

  The pump 81 includes a resin inner rotor 1, a resin outer rotor 2, a resin front casing (first casing) 3, a resin rear casing (second casing) 4, and a metal inner shaft. 5. The front casing 3 and the rear casing 4 are members that form a pump casing. In other words, the pump casing member is composed of two separate pump casing members. The back casing 4 includes a sealing portion 6, a flange portion 18, and a cover 13. The inner shaft 5 constitutes an inner rotor support shaft, and in the present embodiment, the inner shaft 5 is composed of a separate member from the front casing 3 or the rear casing 4.

  The motor unit 82 includes a rotor 11 made of permanent magnets, a stator 12, and a sealing unit 6. The sealing unit 6 is shared by the pump unit 81 and the motor unit 82.

  The inner rotor 1 of the pump portion 81 has a shape similar to a spur gear, and has teeth 1a having a trochoidal curve as an outline on the outer periphery. Strictly speaking, this tooth surface has a slight gradient in the axial direction, and forms a so-called “draft gradient” that assists the blanking during injection molding. The inner rotor 1 has a shaft hole 1b having a smooth inner surface penetrating in the axial direction at the center. Both end surfaces 1c of the inner rotor 1 are flat and smoothly finished, and slide between the inner surfaces 25 and 26 which are the end surfaces of the shoulder portion 22 projecting inward from the front casing 3 and the rear casing 4. Is forming.

  The inner rotor 1 is made of a synthetic resin having a self-lubricating property and having a property such that swelling deformation and corrosion due to water or a solution containing water are negligible. Specifically, it is made of PPS carbon fiber resin containing carbon fiber in PPS (polyphenylene sulfide) resin. Accordingly, the inner rotor 1 having sufficient strength and wear resistance as the inner rotor 1 can be obtained. A POM (polyacetal) resin may be used instead of the PPS carbon fiber resin. POM has a low frictional resistance and a low sliding resistance, so that the pump efficiency can be improved. Moreover, since it is soft as a material, an impact load can be relieved and the vibration noise by a motion of a rotor is suppressed. Although these materials have water absorption and moisture permeation, there is no problem because they are used as the inner rotor 1. Further, although deformation due to high-temperature water absorption occurs, if the tooth profile is compensated for this, the deformation can be absorbed. The gap between the rotors 1 and 2 is enlarged at low temperatures. However, when antifreeze composed of water and organic substances is used as the working fluid, the viscosity of the antifreeze increases and the pump efficiency is improved and the performance is reduced. Can be prevented.

  The outer rotor 2 has an annular internal gear shape having substantially the same tooth width as that of the inner rotor 1, and has one tooth having a tooth shape formed by an arc or the like more than the inner rotor 1. The teeth 2a of the outer rotor 2 have substantially the same cross-sectional shape in the axial direction as a spur gear, but have a slight gradient in the axial direction, which is a so-called “draft gradient” that assists punching during injection molding. You may have. In this case, the same draft is given to the inner rotor 1, the direction of the gradient between the inner rotor 1 and the outer rotor 2 is reversed, and the outer rotor 2 Both 1 and 2 are meshed so that the diameter of the internal teeth also increases. Thereby, the meshing surfaces of both 1 and 2 can be prevented from coming into contact with each other due to the position in the axial direction. Both end surfaces 2b of the tooth portion of the outer rotor 2 are finished flat and smooth, form surfaces that slide between the flat inner surfaces 25 and 26 of the front casing 3 and the rear casing 4, and function as thrust bearings.

  The outer rotor 2 has substantially the same width as the inner rotor 1 except for the outer peripheral portion, and the outer rotor 2 is disposed outside the inner rotor 1 so that both end faces of the inner rotor 1 and the outer rotor 2 are substantially coincident with each other. . An annular projecting portion 21 projecting in the axial direction is formed on the outer peripheral portion of the outer rotor 2 from the tooth portion (a portion having the same tooth width as that of the inner rotor 1 located on the inner side). The inner periphery of the overhang portion 21 is formed as a smooth surface and constitutes a surface that slides between the outer peripheral surfaces 27 and 28 of the shoulder portion 22.

  The outer rotor 2 and the inner rotor 1 are configured to rotate by being sandwiched between the front casing 3 and the rear casing 4 in a meshed state. A bearing portion of the inner shaft 5 having a smooth outer periphery is fitted into the central shaft hole of the inner rotor 1 with a slight gap, whereby the inner rotor 1 is rotatably supported on the inner shaft 5. . The inner shaft 5 does not rotate because it is closely fitted to the front casing 3 and the rear casing 4.

  A permanent magnet is integrated as the rotor 11 of the motor portion 82 on the outside of the outer rotor 2. In the present embodiment, the outer rotor 2 and the rotor 11 are formed as an integral member from a resin mixed with magnet powder. In other words, the rotor 11 of the motor part 82 and the outer rotor 2 of the pump part 81 are configured by a common member 112 that is one member made of a permanent magnet member containing magnet powder. As a result, the rotor 11 and the outer rotor 2 can be manufactured in a small size and at low cost. The rotor 11 is configured such that alternating polarities are given in the radial direction, and NS poles are alternately arranged along the circumference when viewed from the outer circumference side.

  In the present embodiment, the shared member 112 is formed of a ferrite bonded magnet containing ferrite magnet powder. Accordingly, even when water or a liquid containing water as a component is used as the working fluid, the magnet is not corroded or rusted and can be manufactured at a low cost. The common member 112 is formed of a PPS / ferrite bonded magnet containing ferrite magnet powder in PPS resin. As a result, the magnetic characteristics of the motor part 82 as the rotor 11 are improved, a highly accurate tooth profile as the pump part 81 can be formed, and the low friction and low wear sliding characteristics in the part functioning as the bearing part are achieved. In addition, the moldability is good, and the corrosion resistance stability in water can be good.

  In this embodiment, the common member 112 is formed in a cylindrical shape so that the magnetic force on the outer peripheral side is strong and the magnetic force on the inner peripheral side is weak, and the stator 12 is installed on the outer periphery of the common member 112. Therefore, it can be easily magnetized from the outer periphery, and the function as the rotor 11 can be sufficiently exhibited even if a ferrite bond magnet that is generally cheaper and weak in magnetic force than a neodymium magnet or the like is used.

  Further, in the present embodiment, shoulder portions 22 projecting inward so as to face the front casing 3 and the rear casing 4 are formed, respectively, and the shafts are arranged on both sides of the outer peripheral portion of the common member 112 more than the inner peripheral tooth portions. The annular projecting portion 21 projecting in the direction is formed, and the annular projecting portion 21 is formed so as to be fitted to the outer peripheral surfaces 27 and 28 of the respective shoulder portions 22 of the front casing 3 and the rear casing 4. The portion functioning as 11 can be increased in the axial direction, and from this point of view, it is helpful to use a ferrite bond magnet that is inexpensive and weak in magnetic force.

  It is also conceivable that the outer rotor 2 and the rotor 11 are shared as a composite structure of the outer peripheral portion including the projecting portion of the outer rotor 2 being a PPS / ferrite bonded magnet and the tooth portion being a PPS carbon fiber. In that case, the complex PPS / ferrite bonded magnet that is difficult to be molded is made a simple cylindrical shape, and the tooth portion that requires precision is made of PPS resin, so that there is no hard ferrite grain on the meshing surface with the inner rotor 1. The tooth profile is low loss and low wear.

  The inner shaft 5 includes a cylindrical bearing portion 51 having an outer diameter slightly smaller than the inner diameter of the shaft hole 1b of the inner rotor 1 and slightly longer in the axial direction than the tooth width of the inner rotor 1, and both end surfaces of the bearing portion 51. And a fitting portion 53 having an outer diameter that is smaller than the outer diameter of the bearing portion 51. Specifically, the axial length of the bearing portion 51 located at the center of the inner shaft 5 is slightly longer (for example, 0.05 to 0.1 mm) than the tooth width of both rotors. There are cylindrical fitting portions 53 on both sides of the bearing portion 51 and are concentric with the bearing portion 51. In addition, the bearing part 51 and the fitting part 53 are the names of the part of the inner shaft 5 manufactured from the same metal material, and are integral. Since the inner shaft 5 is made of a metal material, it is superior in terms of strength and dimensional accuracy compared to the inner rotor 1, outer rotor 2, front casing 3 and rear casing 4 made of synthetic resin. ing.

  The inner shaft 5 also has a function as a structural material that connects the front casing 3 and the rear casing 4. The fitting portion 53 is inserted and fixed in fitting holes 27 a and 28 a formed in the flat inner surfaces 25 and 26 of the casings 3 and 4. In this state, the step surfaces (both end surfaces of the bearing portion 51) 51a serving as the boundary between the bearing portion 51 and the fitting portion 53 are in close contact with the flat inner surfaces 25 and 26 of the casing. Therefore, the length of the bearing portion 51 matches the distance (interval) between the two flat inner surfaces 25, 26, and both rotors 1, 2 are flat inner surfaces 25, which are axial end surfaces of the front casing 3 and the rear casing 4. 26 is built in with a slight gap. The fitting holes of the front casing 3 and the rear casing 4 are eccentric with respect to the outer peripheral surfaces 27 and 28 of the shoulder portion 22 in accordance with the meshing of the rotors 1 and 2.

  The shoulder portions 22 of the front casing 3 and the back casing 4 are formed to protrude inward so as to face each other. The outer peripheral surfaces 27 and 28 of the shoulder portion 22 are fitted to the inner peripheral surface of the projecting portion 21 of the outer rotor 2 with a slight gap, and the shoulder portions 22 of the front casing 3 and the rear casing 4 are fitted to both sides of the outer rotor 2. Is supported rotatably and acts as a radial bearing. The shoulder portions 22 of the front casing 3 and the back casing 4 are in a positional relationship as if they were cut out from a part of the same cylinder.

  The front casing 3 constituting one of the two pump casing members has openings called the suction port 8 and the discharge port 10 on the flat inner surface 25 thereof. The suction port 8 and the discharge port 10 are located on the inner side of the root circle of the inner rotor 1 and the root circle of the outer rotor 2 (because the outer rotor 2 is an internal gear, the root diameter is larger than the tip diameter). Is also formed with an opening having a contour on the outside. The suction port 8 faces the working chamber 23 whose volume increases, and the discharge port 10 faces the working chamber 23 whose volume decreases. Further, the working chamber 23 at the moment when the maximum volume is reached is configured so that neither of the ports 8 and 9 faces, or is kept in communication with a slight cross-sectional area.

  The suction port 8 and the discharge port 10 are communicated with a suction port 7 and a discharge port 9 which are opened to the outside through an L-shaped channel from the back of the port groove. A communication passage 9 a is provided in the middle of the flow path from the discharge port 10 to the discharge port 9 and communicates with the internal space 24 that branches and faces the outer periphery of the outer rotor 2. The internal space 24 is a space surrounded by the front casing 3 and the back casing including the sealing portion 6.

  The thin cylindrical sealing portion 6 is provided between the outer periphery of the rotor 11 via a minute gap (for example, a gap of 1 mm or less), and the rotor 11 can rotate together with the outer rotor 2.

  The rear casing 4 constituting one of the two casing members forms a cylindrical sealing portion 6 extending in the axial direction covering the outer side of the outer rotor 2 from the outer peripheral portion than the portion constituting the flat inner surface 26 thereof. Then, the axial rigidity on the sealing portion 6 side is made more flexible than the flat inner surface 26 side, and the front casing 3 constituting one of the two casing members is joined on the distal end side of the sealing portion 6. That is, the sealing part 6 is a part of the back casing 4 and refers to a thin plate part that extends in the front direction in a cylindrical shape from the outer peripheral part rather than the part where the flat inner surface and the shoulder part are formed.

  The front casing 3 and the back casing 4 are in contact with a cylindrical surface called a fitting surface 16 and are fitted with a degree of freedom to move in the axial direction while restricting the radial direction. The fitting surface 16 is constituted by a fitting surface between the inner periphery of the tip portion of the sealing portion 6 and the outer periphery of the outer annular portion 29 formed on the inner surface side of the front casing 3. A concave portion is provided in the inner periphery of the front end portion of the sealing portion 6 adjacent to the fitting surface 16, and the confidentiality between the front casing 3 and the rear casing 4 is maintained by inserting the O-ring 14 in the concave portion. Be drunk. With this configuration, the front casing 3 and the rear casing 4 can have a combined structure in which confidentiality is maintained while maintaining the degree of freedom in the axial direction.

  The front casing 3 and the back casing 4 are made of PPS carbon fiber resin containing carbon fiber in PPS resin. The front casing 3 and the rear casing 4 using PPS carbon fiber resin have low water absorption, small deformation due to water absorption, small thermal deformation, corrosion resistance to antifreeze, and heat resistance. Since PPS carbon fiber resin is an insulating material, it is effective in preventing electric leakage, has little moisture permeation, and has good slidability at the bearing portion, so that it has little wear and can be expected to have a long life and high reliability. Moreover, it can be molded with high accuracy.

  Near the outer periphery of the front casing 3, a plurality of welding protrusions 41 are provided in an annular shape toward the back side, and a flange groove 18 of the rear casing 4 facing the annular shape is formed with a welding groove 42 into which the welding protrusion 41 is inserted. Yes. In the present embodiment, as shown in FIG. 4, the tip end portion of the welding projection 41 is formed on an inclined surface, and the bottom portion of the welding groove 42 has an inclined surface that matches the inclined surface, and welding tools 43 and 44 are provided. Is pressed against the outer peripheral portion of the front casing 3 and the flange portion 18 of the rear casing 4 from both sides, and minute vibrations are applied while applying force to the welding tools 43 and 44. Specifically, the welding tools 43 and 44 are attached to an ultrasonic welding machine to apply ultrasonic vibration. As a result, the contact surfaces of the casings 3 and 4 generate heat by micro-vibration friction and melt and melt together, and when the temperature drops after the vibration stops, they resolidify and become one. Therefore, the welding tool 43 and 44 are formed in a shape that allows the welding tool 43 and 44 to be in close contact with each other so that the surface on the back side of the welding projection 41 of the front casing 3 and the surface on the back side of the welding groove 42 of the back casing 4 are flat and open.

  The groove for inserting the welding tool 44 on the rear casing 4 side is an annular groove for inserting the stator 12 after welding, and is smaller and simpler than the case where a structure such as a groove only for welding is provided. Can be made into any shape.

  By the time when the welding is completed, there is no contact other than the contact between the welding projection 41 and the welding groove 42 and the contact between the step of the inner shaft 5 and the contact between the flat inner surfaces 25 and 26 and restraining the axial movement. Moreover, the sealing part 6 is thin and is flexible compared with a flat inner surface, a shoulder part, and the welding part vicinity including the structure of the vicinity. By doing so, at the time of welding, the positional relationship of each member is determined in the following order.

  First, the fitting portion 53 of the inner shaft 5 is inserted into the rear casing 4, the inner rotor 1 and the outer rotor 2 are fitted to the inner shaft 5, and the front casing 3 fitted with the O-ring 14 is fitted into the rear casing 4. Match. In this state, welding jigs 43 and 44 are applied from both sides of both casings 4 and 5, and ultrasonic vibration is applied while pressing with a predetermined force. Thereby, the contact part of the welding protrusion 41 and the welding groove 42 melt | dissolves, and the front casing 3 and the back casing 4 displace to the direction which mutually approaches. In this process, the stepped surface 51 a of the inner shaft 5 is in close contact with the flat inner surfaces 25 and 26. When the welding is further advanced, the sealing portion 6 of the back casing 4 and the periphery thereof are elastically deformed and the welding proceeds deeply. When the vibration is stopped while the force is applied to the welding jigs 43 and 44, the melted welded portion is reduced in temperature and solidified, and the shape is determined in that state. After that, even if the welding jig is removed, the stepped surface 51a of the inner shaft 5 remains in close contact with the flat inner surfaces 25 and 26, and the force for the contact remains applied as a reaction force for elastic deformation around the sealing portion 6. It becomes.

  The inner shaft 5 is made of metal, and is more easily dimensional accuracy in the axial direction than the resin casing members 3 and 4. Moreover, there exists an advantage which can ensure the dimension of a tooth width direction in the center part nearest to the tooth part of the rotors 1 and 2. FIG. Compared to the method of obtaining the accuracy of the distance between the flat inner surfaces 25 and 26 only by the dimensional accuracy of the casings 3 and 4 via the outer periphery of the sealing portion 6 etc. without depending on the accuracy of the inner shaft 5, It is much easier to maintain accuracy. Therefore, according to the structure of this embodiment, the effect of maintaining appropriately the clearance of the tooth | gear part end surface which has a big influence on pump performance and reliability is high.

  Although the welding protrusion 41 is formed in an annular shape, it is not provided continuously around the circumference, but has a shape lacking a part from the circumference as shown in FIG. The reason is to limit the area more than one round and concentrate the pressing force at the time of welding to ensure the welding, and by arranging the suction channel and the discharge channel in the missing part This is to avoid interference between the welding tool 43 and these flow paths.

  By the action of the fitting surface 16, the positioning accuracy in the radial direction of the two casings can be combined well, and the axial position can be maintained by the close contact between the inner shaft 5 and the flat inner surfaces 25, 26. Further, the internal space 24 is sealed by the O-ring 14, and except for the suction port 8 and the discharge port 10, since it has a simple structure without any other holes or mating surfaces communicating with the outside world, the sealability is also good. Therefore, it is possible to reliably prevent liquid leakage.

  The cover 13 is formed by integral molding so as to be folded back from the outer periphery of the front side flange 18 of the sealing portion 6 connected to the back casing 4 to the back side. The cover 13 covers the outer periphery of the stator 12 of the motor unit 82 and serves to prevent electric shock, maintain aesthetics, and prevent noise.

  At a position outside the sealing portion 6 and facing the rotor 11, a stator 12 wound around a comb-like iron core is press-fitted into the outer periphery of the sealing portion 6. The stator 12 is fitted into an annular groove formed between the sealing portion 6 and the cover 13. Since the motor part 82 composed of the rotor 11 and the stator 12 is arranged on the outer peripheral side of the pump part 81 composed of the inner rotor 1 and the outer rotor 2 and is not arranged in the axial direction, the pump 80 can be made thinner and smaller. It has been.

  The control unit 83 is for controlling the motor unit 82 and includes a DC brushless motor driving inverter electronic circuit. By providing the motor part 82 on the outer peripheral side of the pump part 81 as described above, the control part 83 can be installed on the back side of the pump part 81 where the suction port 7 and the discharge port 9 are not provided.

  On the circuit board 31, a power element 32, which is a main electronic component, is mounted to constitute an inverter circuit for driving a DC brushless motor. The circuit board 31 is fixed to the back casing 4 by caulking through a protrusion 45 provided on the back side of the back casing 3 in a hole provided in the center thereof. The power element 32 is in contact with the back casing 4 through the circuit board 31. Thereby, the heat generated in the inverter circuit can be radiated to the working fluid in the pump unit 81 through the back casing 4. One end of the winding of the stator 12 is connected to the circuit board 31, and a power line 33 that supplies power from the outside, a rotation output line 34 that transmits information about the rotation speed in pulses, and a common ground line thereof are connected. The

  A DC brushless motor is constituted by a motor unit 82 having a rotor 11 and a stator 12 made of permanent magnets, and a control unit 83 having an inverter electronic circuit. A structure in which the rotor 11 is inside the thin sealing portion 6 and the stator 12 is outside the sealing portion 6 is called a canned motor. In the canned motor, the rotational power is transmitted to the inside of the sealing portion 6 called a can by using magnetic force without requiring a shaft seal or the like, and therefore the volume that is sent out by the volume change of the working chamber 23 while isolating the working fluid from the outside. Suitable for pump structure.

  About the shape of the pump 80, the objective of this invention can be better achieved by making it into the dimensional relationship shown in FIG. When the width of the inner rotor 1 and the tooth width of the outer rotor 2 are 1, the inner rotor has an outer diameter of 1.7 to 3.4, the outer rotor has an overhanging portion inner diameter of 2.5 to 5, and the outer rotor has an overhang. The axial length of the part is set to a dimension of 0.4 to 0.8.

  If the outer diameter of the inner rotor 1 is larger than this range, the ratio of internal leakage in the end face clearance (reverse flow from the side communicating with the high-pressure discharge port to the side communicating with the suction port, reducing the pump performance) Increase and decrease pump performance. On the other hand, if it is smaller than this range, the flow velocity in the area of the opening communicating with the working chamber and the suction or discharge port is increased, the pressure loss is increased, and the pump performance is also lowered.

  The inner diameter of the overhanging portion 21 of the outer rotor 2 needs to be geometrically larger than the outer diameter of the inner rotor 1. At the same time, if it is larger than this range, the frictional force and internal leakage from the bearing surface are increased, so that the pump performance is lowered.

  If the axial length of the outer rotor overhanging portion 21 is smaller than this range, the bearing surface pressure increases and frictional wear may increase, which may reduce the pump life and reliability. On the other hand, if it is larger than this range, it will be easy to cause a single contact due to errors such as cylindricity and concentricity of the bearing surface, which is not a good idea.

  The rotational speed of the inner rotor is preferably in the range of 2500 to 5000 revolutions per minute. If the rotational speed is slower than this range, the ratio of the amount of internal leakage to the transport flow rate increases and the pump efficiency decreases. On the other hand, if it is faster than this range, vibration noise generated by the pump will increase.

  Next, the operation of the pump 80 will be described with reference to FIGS.

  By supplying 12 V DC to the power line 33 and supplying a current to the motor drive circuit of the control unit 83, a current is sent to the winding of the stator 12 through the power element 32. Thereby, the motor part 82 is started and it controls to rotate the motor part 82 with the set rotational speed. Since the power element 32 outputs the rotation information of the rotor 11 as a pulse from the rotation output line 34, the host control device that receives the signal can check the operation state of the pump 80.

  When the rotor 11 of the motor unit 82 rotates, the outer rotor 2 integrated with the rotor 11 rotates, and the inner rotor 1 meshed with the rotor 11 is also transmitted to rotate in the same manner as a general internal gear. The working chamber 23 formed in the tooth spaces of the two rotors 1 and 2 expands and contracts in volume as the rotors 1 and 2 rotate. At the lower end in FIG. 2 where the teeth of the inner rotor 1 and the outer rotor 2 are engaged to the deepest, the volume of the working chamber 23 is minimized and maximized at the upper end. Accordingly, when the rotor rotates counterclockwise in FIG. 2, the volume of the right half working chamber increases while moving upward, and the volume of the left half working chamber decreases while moving downward. Since all the sliding parts that pivotally support both rotors 1 and 2 are immersed in the working fluid, the friction is small and abnormal wear can be prevented.

  The working fluid is sucked from the suction port 7 through the suction port 8 into the working chamber 23 whose volume is being expanded. The working chamber 23 having the maximum volume is displaced from the outline of the suction port 8 due to the rotation of the rotor, completes the suction, and then communicates with the discharge port 10. From there, the volume of the working chamber 23 is reduced, and the working fluid in the working chamber 23 is sent out from the discharge port 10. The delivered hydraulic fluid is sent out from the discharge port 9 to the outside. Since there is a communication passage 9a branched in the middle of the discharge flow path, the internal pressure of the internal space 24 is maintained at the discharge pressure.

  In this embodiment, since the suction flow path is short, the suction negative pressure is small and cavitation can be prevented. Further, since a relatively high discharge pressure acts on the inner surface of the sealing portion 6 and pushes it outward, even the thin sealing portion 6 is deformed inward and comes into contact with the rotor 11. Can be avoided. At the same time, leakage from a gap as a radial bearing formed on the projecting portion 21 of the outer rotor 2 can be reduced. The reason for this is that leakage from this gap enhances the outward force by the action of centrifugal force, but if the internal pressure of the inner space 24 that is the outer periphery is high, the action of pushing it back works.

  The heat of the power element 32 that needs to be cooled due to heat generated by the operation passes through the wall surface of the back casing 4 that is in contact with the circuit board 31, moves to the working fluid flowing through the internal space 24, and is released to the outside. Is done. Since the working fluid in the internal space 24 is constantly stirred and sequentially replaced by minute leakage from the radial bearing surface, heat can be efficiently removed. Thus, in order to cool the inside of the pump 80 efficiently, a heat sink and a cooling fan for cooling the power element 32 are not required. Similarly, heat generated by motor loss generated in the rotor 11 and the stator 12 can be efficiently carried away, and an abnormal temperature rise can be prevented.

  Next, an electronic apparatus having the above-described pump 80 will be described with reference to FIG. FIG. 6 is a perspective view showing the overall configuration of the personal computer with the personal computer main body placed vertically, and the electronic device shown in FIG. 4 is an example of a desktop personal computer.

  The personal computer 60 includes a personal computer main body 61A, a display device 61B, and a keyboard 61C. The liquid cooling system 69 is built in the personal computer main body 61A together with the CPU (central processing unit) 62, and the liquid pool 63, the pump 80, the heat exchanger 65, the heat radiating plate A66, and the heat radiating plate B67 are connected in this order by pipes. It consists of a closed loop system. The purpose of installing this liquid cooling system 69 is mainly to carry the heat generated by the CPU 62 built in the personal computer main body 61A to the outside and maintain the temperature rise of the CPU 62 below a specified value. Since the liquid cooling system 69 that uses water or a liquid mainly composed of water as a heat medium, for example, an antifreeze liquid composed of water and organic matter (ethylene glycol, etc.) has a higher heat carrying capacity and less noise than the air cooling system, It is suitable for cooling the CPU 62 that generates a large amount of heat.

  The liquid reservoir 63 is filled with a liquid to be fed (working fluid) and air. The liquid reservoir 63 and the pump 80 are juxtaposed, and the outlet of the liquid reservoir 63 and the suction port of the pump 80 are connected by a pipe line. A heat exchanger 65 is installed in close contact with the heat radiating surface of the CPU 62 via heat conductive grease. The discharge port of the pump 80 and the inlet of the heat exchanger 65 are communicated with each other by a pipe line. The heat exchanger 65 is communicated with the heat radiating plate A66 through a conduit, the heat radiating plate A66 is communicated with the heat radiating plate B67 via the conduit, and the heat radiating plate B67 is communicated with the liquid reservoir 63 via the conduit. The heat radiating plate A66 and the heat radiating plate B67 are installed so as to radiate heat from different surfaces of the personal computer main body 61A.

  The power line 33 is drawn from the DC 12V power supply normally provided in the personal computer 60 to the pump 80, and the rotation output line 34 is connected to the electronic circuit of the personal computer 60 which is a host control device.

  The operation of the liquid cooling system 69 will be described. When electric power is sent along with the activation of the personal computer 60, the pump 80 is activated and the liquid to be delivered begins to circulate. The liquid to be fed is sucked into the pump 80 from the liquid pool 63, pressurized by the pump 80, and sent to the heat exchanger 65. The liquid to be fed sent from the pump 80 to the heat exchanger 65 absorbs heat generated by the CPU 62 and the liquid temperature rises. Further, the liquid to be delivered exchanges heat with the outside air (heat is radiated to the outside air) by the next heat radiating plate A66 and the heat radiating plate B67, and returns to the liquid pool 63 after the liquid temperature is lowered. Thereafter, this is repeated and the cooling of the CPU 62 is continued.

  Since the pump 80 is an internal gear type that is a kind of positive displacement pump, it has the ability to make the suction port have a negative pressure even when it is activated in a dry state (no liquid condition). Therefore, it has a self-priming capability of sucking liquid without priming even if it passes through a pipe line higher than the liquid level inside the liquid reservoir 63 or even if the pump 80 is at a position higher than the liquid level. In addition, since the internal gear pump 80 has a higher pressurization capacity than a centrifugal pump or the like, it can also be applied to conditions in which the pressure loss passing through the heat exchanger 65 and the heat radiating plates 66 and 67 increases. In particular, when the heat generation density of the CPU 62 is high, it is necessary to bend and lengthen the flow path inside the heat exchanger 65 in order to expand the heat exchange area, and this is necessary in a liquid cooling system using a centrifugal pump or the like. Although the pressure loss increases and application becomes difficult, the liquid cooling system 69 of the present embodiment can cope with this.

  In the liquid cooling system 69 of the present embodiment, the liquid temperature is lowered via the heat radiating plates 66 and 67 immediately after the outlet of the heat exchanger 65 where the liquid to be delivered becomes the highest temperature, so that the liquid reservoir 63 and the pump 80 are used. The temperature of is kept relatively low. Therefore, the internal parts of the pump 80 are easier to ensure reliability than in a high temperature environment.

  As a result of the operation of the liquid cooling system 69, the temperature of each part through which the liquid circulates is determined and is monitored by a temperature sensor (not shown). In the case where it is confirmed that the cooling capacity is insufficient due to a temperature rise above a specified level, an increase in the rotational speed of the pump 80 is commanded to prevent an excessive temperature in advance. Conversely, when the cooling is excessive, the rotational speed is suppressed. The rotation output transmitted by the pump 80 is constantly monitored. If the rotation output is interrupted and the change in liquid temperature is abnormal, it is determined that the pump 80 is out of order and the personal computer 60 shifts to an emergency operation. In the emergency operation, the hardware is prevented from being fatally damaged after performing minimum operations such as reducing the CPU speed and saving the program during operation.

It is a longitudinal cross-sectional view of the motor integrated internal gear type pump of one Embodiment of this invention. FIG. 2 is a front view showing a cross section of a left half surface of the pump of FIG. 1. It is a disassembled perspective view of the pump part of the pump of FIG. It is sectional drawing which shows the joining method of the casing of the pump of FIG. It is a dimension figure of the inner rotor and outer rotor of the pump of FIG. It is explanatory drawing of the electronic device provided with the cooling system which has a pump of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Inner rotor, 1a ... Teeth, 1b ... Shaft hole, 1c ... End face, 2 ... Outer rotor, 2a ... Teeth, 2b ... End face, 3 ... Front casing, 4 ... Rear casing, 5 ... Inner shaft, 6 ... Sealing Portion 7: Suction port 8 ... Suction port 9 ... Discharge port 9a ... Communication path 10 ... Discharge port 11 ... Rotor 12 ... Stator 13 ... Cover 14 ... O-ring 16 ... Fitting 18, flange portion, 21, overhang portion, 22, shoulder portion, 23, working chamber, 24, inner space, 25, flat inner surface of the front casing, 26, flat inner surface of the rear casing, 27, 28, shoulder portions Outer peripheral surface, 27a and 28a ... fitting hole, 29 ... outer annular portion, 31 ... circuit board, 32 ... power element, 33 ... power line, 34 ... rotating output line, 41 ... welding projection, 42 ... welding groove, 43 ... welding Tool 44 ... Welding tool 51 ... Bearing part 51a ... Step surface 53 ... Fitting , 60 ... PC, 61A ... PC body, 61B ... Display device, 61C ... Keyboard, 62 ... CPU, 63 ... Puddle, 65 ... Heat exchanger, 66 ... Heat sink A, 67 ... Heat plate B, 69 ... Liquid Cooling system (cooling system), 80 ... motor-integrated internal gear pump, 81 ... pump unit, 82 ... motor unit, 83 ... control unit, 112 ... common member.

Claims (13)

A pump unit that sucks and discharges hydraulic fluid; and a motor unit that drives the pump unit,
The pump unit includes an inner rotor having teeth formed on the outer periphery, an outer rotor having teeth that mesh with teeth of the inner rotor formed on the inner periphery, and a pump casing that houses the inner rotor and the outer rotor.
In the motor-integrated internal gear pump, the motor unit is configured to include a rotor and a stator that rotates the rotor.
A motor-integrated internal gear pump characterized in that the rotor and the outer rotor are shared by a permanent magnet member containing magnet powder in resin.   2. The motor-integrated internal gear pump according to claim 1, wherein water or a liquid containing water as a component is used as a working fluid sucked into and discharged from the pump unit, and the rotation is performed by a ferrite bonded magnet containing ferrite magnet powder. A motor-integrated internal gear pump characterized by forming a common member for the child and the outer rotor.   2. The motor-integrated internal gear pump according to claim 1, wherein a shared member of the rotor and the outer rotor is formed of a member having a strong magnetic force on the outer peripheral side and a weak magnetic force on the inner peripheral side. A motor-integrated internal gear pump, wherein the stator is installed on the outer periphery of the member.   3. The motor-integrated internal gear pump according to claim 2, wherein an antifreezing liquid containing water and organic matter is used as the hydraulic fluid.   3. The motor-integrated internal gear pump according to claim 2, wherein the common member is formed of a PPS / ferrite bonded magnet in which ferrite magnet powder is contained in PPS resin.   3. The motor-integrated internal gear pump according to claim 2, wherein the pump casing is configured by joining two casings including a first casing and a second casing, and the first casing and the second casing are combined. Shoulder portions projecting inward so as to face each other are formed on the casing, annular projecting portions projecting in the axial direction from the inner peripheral tooth portions are formed on both sides of the outer peripheral portion of the common member, and the annular projecting portions are formed. The motor-integrated inscribed type, wherein the stator is installed outside the outer periphery of the common member, and the portion is fitted to the outer peripheral surface of each shoulder portion of the first casing and the second casing Gear type pump.   3. The motor-integrated internal gear pump according to claim 2, wherein the pump casing is formed of PPS carbon fiber resin containing carbon fiber in PPS resin or PPS glass fiber resin containing glass fiber in PPS resin. A motor-integrated internal gear pump.   3. The motor-integrated internal gear pump according to claim 2, wherein the inner rotor is formed of PPS carbon fiber resin or POM resin containing carbon fiber in PPS resin. .   7. The motor-integrated internal gear pump according to claim 6, wherein the first casing and the second casing are formed of PPS carbon fiber resin containing carbon fiber in PPS resin. Internal gear pump.   10. The motor-integrated internal gear pump according to claim 9, wherein an outer peripheral portion of any of the first casing and the second casing is extended in an axial direction to seal between the rotor and the stator. A motor-integrated internal gear pump characterized by forming a sealing portion to be stopped and mounting the stator on the outside of the sealing portion. A pump unit that sucks and discharges hydraulic fluid; and a motor unit that drives the pump unit,
The pump unit includes an inner rotor having teeth formed on the outer periphery, an outer rotor having teeth that mesh with teeth of the inner rotor formed on the inner periphery, and a pump casing that houses the inner rotor and the outer rotor.
In the motor-integrated internal gear pump, the motor unit is configured to include a rotor and a stator that rotates the rotor.
A motor-integrated internal gear pump, wherein the rotor is formed of a PPS resin / ferrite bonded magnet containing ferrite magnet powder in PPS resin.   12. The motor-integrated internal gear pump according to claim 11, wherein the pump casing is made of PPS carbon fiber resin containing carbon fiber in PPS resin, and the inner part is made of PPS carbon fiber resin containing carbon fiber in PPS resin. A motor-integrated internal gear pump characterized by forming a rotor.   An electronic apparatus comprising the motor-integrated internal gear pump according to any one of claims 1 to 12 as a liquid circulation source, and an antifreeze composed of water and organic matter as the working liquid.

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