JP2017223197A - Hydraulic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic device which can excellently secure a large seal region and makes flow of working fluid in a low pressure side channel unlikely to be disordered.SOLUTION: A hydraulic device comprises: a pair of helical gears; and a housing 2 including a hydraulic chamber 6 in which the gears are accommodated in a meshed state of the gears. With a meshing part of the gears defined as a boundary, one side of the hydraulic chamber 6 is set to a low pressure side and the other side is set to a high pressure side. The housing 2 includes: a low pressure side channel which is opened in the hydraulic chamber 6 at the low pressure side; and a high pressure side channel which is opened in the hydraulic chamber 6 at the high pressure side. The low pressure side channel is formed as a groove-like channel 31 in which a portion formed in a region where the gear is projected in a radial direction is opened on an inner face of the hydraulic chamber 6. An edge of an opening 32 of the groove-like channel 31 is made narrower gradually in a direction in which a tooth interval between the pair of gears becomes narrower gradually. In the low pressure side channel, working fluid flows into the groove-like channel 31 in a direction from a wider opening to a narrower opening of the groove-like channel 31 or flows out of the groove-like channel 31 in a direction from the narrower opening to the wider opening of the groove-like channel 31.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a hydraulic device including a pair of gears whose tooth portions mesh with each other, and more particularly, to a hydraulic device using a helical gear as the pair of gears.

  Conventionally, as the hydraulic device, a pair of gears is appropriately rotated by a drive motor, and a hydraulic pump that pressurizes and discharges the working liquid by a rotating operation of the gears, or a pre-pressurized working liquid is introduced to the gears. There is known a hydraulic motor that rotates the rotating shaft and uses the rotational force of the rotating shaft as power.

  In such a hydraulic apparatus, generally, a pair of gears meshing with each other is housed in a housing, and each rotating shaft extending outward from both end faces of each gear is provided with the housing. And a structure that is rotatably supported by bearing members that are housed inside and disposed on both sides of each gear. Conventionally, as disclosed in Patent Document 1 below, a hydraulic device using a helical gear as the pair of gears is known.

  As described in Patent Document 1, the hydraulic device is accommodated in a casing having a spectacle hole and the spectacle hole, and abuts on the inner peripheral surface of the spectacle hole so that the spectacle hole is high-pressured. A pair of helical gears partitioned into a space and a low-pressure space, and a communication path communicating with the low-pressure space of the eyeglass hole, the communication path including a first flow path that opens to the outside of the casing; A second passage that extends along the axial direction of the helical gear between the low pressure space of the spectacle hole and the first passage, and has a larger passage than the first passage; Yes.

  An opening extending along the axial direction of the helical gear is formed at the boundary between the low pressure space of the spectacle hole and the second flow path, and the opening extends from the spectacle hole to the spectacle hole. When the first flow path side is viewed, the opening width of the pair of helical gears on the far side has a wider width than the opening width on the side of the pair of helical gears on which the tooth lines approach. doing.

  According to this hydraulic device, since the opening width of the pair of helical gears on the far side is wider than the opening width of the pair of helical gears on the side where the pair of helical gears approaches, Utilizing the area where the helical gear teeth are far away and not used for sealing, the seal area where the helical gear teeth of the pair of helical gears approach is viewed from the eyeglass hole side as much as possible. The area sealed by the inner peripheral surface of the spectacle hole and the helical gear (seal area) can be made a large area by moving to the path (suction flow path) side, and the second flow path It is said that the opening area can be increased.

  In this way, for example, when used as a hydraulic pump, the working liquid is drawn from the space surrounded by the tooth surface of the helical gear and the inner peripheral surface of the eyeglass hole. Cavitation can be prevented while preventing leakage to the flow path) side, and when used as a hydraulic motor, it is surrounded by the tooth surface of the helical gear and the inner peripheral surface of the eyeglass hole. It is possible to prevent an increase in pressure loss in the second flow path (diffusion flow path) while preventing the working liquid from leaking from the created space to the first flow path (suction flow path) side. .

Japanese Patent Laid-Open No. 2006-70209

  By the way, the first flow path (suction flow path) in the hydraulic device disclosed in Patent Document 1 is in a region where the outer peripheral surfaces of the pair of helical gears are projected in the radial direction. It is a round hole with a circular cross section formed so as to open to the outer surface of the housing and the other to open to the second flow path (diffusion flow path). On the other hand, the second flow path is a groove-shaped flow path formed along the axial direction of the helical gear so as to open to the inner peripheral surface of the eyeglass hole.

  Therefore, the working liquid that flows into the groove-shaped second flow path from the first flow path having a round hole flows into the second flow centering on the first flow path at the connection portion between the first flow path and the second flow path. It will circulate so as to diffuse in the path, but at that time, the flow path cross-sectional area suddenly increases (increases stepwise) when moving from the first flow path to the second flow path, The flow of the working liquid is likely to be disturbed (unevenness). As a result, there is a problem that cavitation is likely to occur when the pair of helical gears are rotated at high speed. If the flow unevenness or cavitation occurs in the working liquid, the performance of the hydraulic device is lowered, leading to a problem that the predetermined performance is not exhibited.

  Thus, in the hydraulic device of Patent Document 1, the region sealed by the inner peripheral surface of the spectacle hole and the helical gear as described above can be a large region, and the second While there is an effect that the opening area of the flow path can be increased, there is a problem that the flow of the working liquid in the suction flow path on the low pressure side is likely to be disturbed (unevenness) and cavitation is likely to occur. .

  The present invention has been made in view of the above circumstances, and can ensure the large sealing area described above as in the conventional case, and is more disturbed by the flow of the working liquid in the low-pressure side channel than in the conventional case. It is an object of the present invention to provide a hydraulic device that is less likely to cause the problem.

The present invention for solving the above problems is as follows.
A pair of helical gears each having a rotation shaft provided so as to extend outward from both end faces and meshing teeth with each other;
A housing having a hydraulic chamber in which the pair of gears are housed in mesh;
A bearing member disposed on each side of each gear in the housing, and rotatably supporting the rotation shaft of each gear;
The hydraulic chamber has two arcuate inner circumferential surfaces along the outer circumferential surface of the meshed gear, one on the low pressure side and the other on the high pressure side with the meshing portion of the pair of gears as a boundary And the housing includes a low-pressure channel that opens to the inner surface of the low-pressure hydraulic chamber, and a high-pressure channel that opens to the inner surface of the high-pressure hydraulic chamber,
Each of the gears is a hydraulic device configured to rotate in sliding contact with its inner peripheral surface in a hydraulic chamber on the low pressure side,
In the low-pressure side flow path, a portion formed in a region obtained by projecting the outer peripheral surface of the gear in the radial direction is in a hydraulic pressure chamber inner surface corresponding to an intermediate position between the shafts of the pair of gears in the axial direction of the gear. Formed as a groove-like flow path that does not open on the outer surface in the radial direction of the housing, while opening along
At least a part of the opening of the groove-shaped flow path has an opening width in a direction perpendicular to the axis of the gear, and a tooth space between the pair of gears in sliding contact with the peripheral surface of the hydraulic chamber on the low pressure side. Toward the direction of gradually narrowing, gradually narrowing,
In the low-pressure side flow channel, the working liquid flows into the groove-shaped flow channel from the wide opening width of the groove-shaped flow channel toward the narrower side, or wider from the narrower opening width of the groove-shaped flow channel. The present invention relates to a hydraulic device formed so as to flow out from the groove-shaped channel toward the direction.

  According to this hydraulic device, one hydraulic chamber is set to the low pressure side and the other hydraulic chamber is set to the high pressure side with the meshing portion of the pair of gears as a boundary, and each gear is set to the low pressure side hydraulic pressure. Rotates while sliding in contact with its inner peripheral surface in the room.

  A groove-like flow path that forms a low-pressure side flow path is opened along the axial direction of the gear at a portion corresponding to the intermediate position between the shafts of the pair of gears on the low-pressure side hydraulic pressure chamber surface. And at least a part of the opening of the groove-like channel has an opening width in a direction perpendicular to the axis of the gear, and the teeth between the pair of gears slidably contact the peripheral surface of the hydraulic chamber on the low pressure side. The streak interval gradually narrows in the direction of gradually narrowing. The concept of gradually narrowing includes not only the case of narrowing continuously but also the case of narrowing in stages. Further, the edge of the opening may be formed in a smooth straight line or curved line, or a stepped, zigzag or corrugated shape.

  In the low-pressure channel, the working liquid flows into the groove-shaped channel from the wider opening width of the groove-shaped channel toward the narrower one, or the groove-shaped channel having the smaller opening width. It is formed so as to flow out from the groove-like channel toward the wider side. That is, when the hydraulic device is a pump, the low-pressure side channel is configured such that the working liquid flows into the grooved channel from the wider opening width of the grooved channel toward the narrower side. On the other hand, when the hydraulic device is a motor, the low-pressure side flow path causes the working liquid to flow out from the groove-shaped flow path from the narrowest opening width of the groove-shaped flow path. Formed.

  Thus, according to the hydraulic device of the present invention, at least a part of the opening of the groove-like channel that opens to the low pressure side hydraulic pressure chamber inner surface has a width between the teeth of the pair of gears. Since the streak interval is gradually narrowed in the direction of gradually narrowing, the tooth streaks of the gears that are in sliding contact with the peripheral surface of the hydraulic chamber on the low pressure side are as close as possible to the opening edge of the groove-like flow path. The region sealed (sealed region) by the low pressure side hydraulic pressure chamber peripheral surface and the helical gear can be made as large as possible. And by ensuring such a large sealing area, it is possible to prevent the working liquid from leaking from the high pressure side to the low pressure side, so that the sealing performance can be further improved.

  Further, the groove-shaped flow path is a groove-shaped flow path that opens to the inner surface of the hydraulic pressure chamber, but does not open to the outer surface in the radial direction of the housing. The working liquid flows into the groove-shaped channel from the wide opening width of the groove-shaped channel toward the narrower side, or the groove-shaped channel opens toward the wider side from the narrower opening width of the groove-shaped channel. In the hydraulic device according to the present invention, the flow of the working liquid in the groove-like flow path is almost uniform and does not easily cause a large turbulence. Even if the pair of gears are rotated at a high speed, problems such as cavitation hardly occur.

  In this invention, it is preferable that the opening edge part of the said groove-shaped flow path is along the tooth trace of a pair of said gears which slidably contacts the hydraulic chamber surrounding surface of the said low voltage | pressure side in at least one part. In this way, the tooth streaks of the gears that are in sliding contact with the peripheral surface of the hydraulic chamber on the low pressure side can be set closer to the opening edge of the groove-like flow path, and the hydraulic chamber on the low pressure side can be set. The seal area sealed by the peripheral surface and the helical gear can be a larger area.

  And the opening part of such a groove-shaped flow path can be V-shaped, U-shaped, or parabolic in the whole edge shape (contour shape) seen from the said hydraulic pressure chamber.

  Furthermore, in the present invention, it is more preferable that the opening edge of the groove-like channel is entirely along the tooth traces of the pair of gears that are in sliding contact with the peripheral surface of the hydraulic chamber on the low pressure side. In this way, the tooth streaks of the gears that are in sliding contact with the peripheral surface of the hydraulic chamber on the low pressure side can be set closer to the opening edge of the groove-like flow path, and the hydraulic chamber on the low pressure side can be set. The sealing area sealed by the peripheral surface and the helical gear can be made larger.

  Further, in the present invention, the groove depth of the groove-like flow path is gradually increased in a direction in which a tooth space between the pair of gears slidably contacting the low pressure side hydraulic chamber circumferential surface is gradually reduced. Preferably it is shallow.

  As described above, according to the hydraulic device according to the present invention, the opening width of at least a part of the opening portion of the groove-like channel that opens to the low pressure side hydraulic chamber inner surface is between the pair of gears. As the tooth trace interval of the gear is gradually narrowed in the direction of gradually narrowing, the tooth trace of each gear slidingly contacting the peripheral surface of the hydraulic pressure chamber on the low pressure side is as much as possible at the opening edge of the groove-like flow path The seal area sealed by the low pressure side hydraulic chamber inner circumferential surface and the helical gear can be made as large as possible. And by ensuring such a large sealing area, it is possible to prevent the working liquid from leaking from the high pressure side to the low pressure side, so that the sealing performance can be further improved.

  Further, the groove-shaped flow path is a groove-shaped flow path that opens to the inner surface of the hydraulic pressure chamber, but does not open to the outer surface in the radial direction of the housing. The working liquid flows into the groove-shaped channel from the wide opening width of the groove-shaped channel toward the narrower side, or the groove-shaped channel opens toward the wider side from the narrower opening width of the groove-shaped channel. In the hydraulic device according to the present invention, the flow of the working liquid in the groove-like flow path is almost uniform and does not easily cause a large turbulence. Even if the pair of gears are rotated at a high speed, problems such as cavitation hardly occur.

It is the plane sectional view showing the hydraulic pump concerning one embodiment of the present invention, and is a sectional view of an arrow CC direction in Drawing 4. It is the front sectional view showing the hydraulic pump concerning this embodiment, and is a sectional view of an arrow AA direction in Drawing 1. In the plane sectional view shown in FIG. 1, a pair of helical gears are omitted from the plane sectional view. It is the side view which showed the 2nd housing of the hydraulic pump which concerns on this embodiment, and is the side view of the arrow BB direction in FIG. FIG. 4 is a plan sectional view showing a hydraulic pump according to another embodiment of the present invention, and is a plan sectional view showing a pair of helical gears omitted as in FIG. 3. FIG. 5 is a plan sectional view showing a hydraulic pump according to still another embodiment of the present invention, and is a plan sectional view showing a pair of helical gears omitted as in FIG. 3.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The apparatus of this example is a hydraulic pump 1, and as shown in FIGS. 1 to 4, a housing 2 and a pair of helical gears (hereinafter simply referred to as “gears”) 10, 20 provided in the housing 2. Rotation shafts 11 and 12 extending along the axial direction from both end faces of the gear 10, rotation shafts 21 and 22 similarly extending along the axial direction from both end faces of the gear 20, and Bushings 13 and 14 as bearing members that are provided on both sides and rotatably support the rotating shafts 11 and 12, respectively, and bushes that are also provided on both sides of the gear 20 and rotatably support the rotating shafts 21 and 22 respectively. 23, 24.

  The housing 2 includes three members, a first housing 3, a second housing 4, and a third housing 5. As shown in FIG. 1, the first housing 3 is located on the left side, and the second housing 4 is located in the center. The third housing 5 is continuously provided in a state of being positioned on the right side, and is integrally fastened by a mounting bolt or the like. It should be noted that the space between the first housing 3 and the second housing 4 and the space between the second housing 4 and the third housing 5 are sealed in a liquid-tight manner by seals 7 and 8, respectively.

  The second housing 4 includes a hydraulic chamber 6 disposed in a state where the pair of gears 10 and 20 mesh with each other. The hydraulic chamber 6 has two arc-shaped inner peripheral surfaces along the outer peripheral surfaces of the meshed gears 10 and 20, and the cross-sectional shape in the direction orthogonal to the axis of the gears 10 and 20 is substantially numeric. 8 has a shape of a letter “8”, and is open to both end faces of the second housing 4.

  The first housing 3 is formed with support holes 16 and 26 into which the bushes 14 and 24 are inserted, respectively, and the third housing 5 is provided with a through hole 15 and the bush 23 into which the bush 13 is inserted. A support hole 25 to be inserted is formed. The through hole 15 and the support hole 16 are coaxially formed at positions corresponding to the rotary shafts 11 and 12, respectively. Similarly, the support holes 25 and 26 are coaxial at positions corresponding to the rotary shafts 21 and 22, respectively. Formed on top.

  Thus, as described above, the rotary shafts 11 and 12 are rotatably supported by the bushes 13 and 14, and the rotary shafts 21 and 22 are rotatably supported by the bushes 23 and 24. The rotating shaft 11 extends outward through the through hole 15, and an oil seal 17 fitted into the large-diameter portion on the opening side of the through hole 15 connects the outer peripheral surface of the rotating shaft 11 and the through hole 15. The space is sealed.

  One of the pair of gears 10 and 20 is a drive gear 10 and the other is a driven gear 20. The output shaft of an electric motor, for example, is connected to the rotary shaft 11, and is rotated in the direction indicated by arrow D by the electric motor. Is done. In this example, the tooth portion of the drive gear 10 is left-handed and the tooth portion of the driven gear 20 is right-handed.

  As described above, the pair of gears 10 and 20 are disposed in the hydraulic chamber 6 in a state of being engaged with each other. The hydraulic chamber 6 is connected to the high pressure side with the meshing portion of the gears 10 and 20 as a boundary. Divided into low pressure side. Further, the gears 10 and 20 are configured to slide in contact with the inner peripheral surface on the low pressure side of the hydraulic chamber 6 and rotate in the rotation direction. The region between the contact portion and the inner peripheral surface of the hydraulic chamber 6 is the low pressure side region, and the meshing portion from the portion where the tooth portions of the gears 10 and 20 are separated from the inner peripheral surface of the hydraulic chamber 6. The region up to is the high pressure side region. Actually, in the region on the low pressure side, the pressurization of the hydraulic oil starts when the teeth of the gears 10 and 20 are in sliding contact with the inner peripheral surface of the hydraulic chamber 6.

  The housing 2 includes a suction flow path 30 that is a low-pressure-side flow path that opens to the inner surface of the low-pressure side hydraulic chamber 6, and a high-pressure-side flow path that opens to the inner surface of the high-pressure side hydraulic chamber 6. The discharge flow path 40 is formed. The suction flow path 30 includes a communication path 33 formed in the first housing 3 and a groove-shaped flow path 31 formed in the second housing 4. In FIG. 2, the groove-like flow path 31 opens on the left end face of the second housing 4, and on the inner surface of the hydraulic chamber 6 corresponding to the intermediate position between the pair of gears 10 and 20. It is a groove-shaped channel formed so as to open along the axial direction of the gears 10 and 20, and is not open on the outer surface of the second housing 4 in the radial direction of the gears 10 and 20. As described above, the groove-like flow path 31 is a flow path formed in the second housing 4, but is a flow path formed in a region in which the outer peripheral surfaces of the gears 10 and 20 are projected in the radial direction. In other words.

  Further, as shown in FIG. 3, in the opening 32 of the groove-shaped channel 31, a part of the edge on both sides sandwiching the virtual central axis L parallel to the axis of the gears 10 and 20 is on the low pressure side. Along the tooth traces of the pair of gears 10 and 20 that are in sliding contact with the inner peripheral surface of the hydraulic pressure chamber 6, in other words, the direction orthogonal to the virtual central axis L (same as the axis of the gears 10 and 20). The width (opening width) of the liquid pressure chamber 6 is gradually narrowed in a direction in which the tooth gap between the pair of gears 10 and 20 slidably contacting the inner peripheral surface of the hydraulic pressure chamber 6 is gradually narrowed. The shape of the opening 32 viewed from the inside of the pressure chamber 6 is V-shaped, U-shaped, or parabolic. In addition, the two-dot chain line shown in FIG. 3 represents the tooth trace of each gear 10 and 20.

  In addition, as shown in FIG. 2, the groove depth of the groove-like flow path 31 is such that the interval between the pair of gears 10 and 20 slidably contacting the inner peripheral surface of the hydraulic chamber 6 on the low pressure side is gradually increased. It gradually becomes shallower in the direction of narrowing.

  On the other hand, one side of the communication path 33 opens to the right end surface of the first housing 3 and is connected to the opening of the groove-shaped flow path 31, and the other side is the outer surface of the first housing 3 (in the radial direction). Open to the outer surface. An opening (supply port) 34 formed on the outer surface of the first housing 3 is connected to a hydraulic oil supply source through a pipe as appropriate. Thus, the hydraulic oil supplied to the communication path 33 from the supply port 34 flows into the groove-like flow path 31, and at this time, the hydraulic oil has a wide opening width in the groove-like flow path 31. It flows into the groove-shaped channel 31 from one side toward the narrower side.

  Further, one of the discharge passages 40 opens on the inner surface of the hydraulic chamber 6 corresponding to the intermediate position between the shafts of the pair of gears 10 and 20, and the other is the outer surface of the second housing 4. The opening (discharge port) 41 formed on the outer surface of the second housing 4 is connected to a hydraulic device through piping as appropriate.

  According to the hydraulic pump 1 of the present example having the above configuration, the supply port 34 of the first housing 3 is connected to a hydraulic oil supply source through an appropriate pipe, and the discharge port 41 is connected to an appropriate pipe. Then, the electric gear is connected to the hydraulic equipment as appropriate, and an electric motor is connected to the rotating shaft 11 of the driving gear 10, and then the driving gear 10 is rotated in the arrow D direction by the electric motor.

  As a result, the driven gear 20 meshed with the drive gear 10 rotates together with the drive gear 10, and hydraulic oil flows into the hydraulic chamber 6 from the communication path 33 and the groove-shaped flow path 31 by the rotation of the gears 10 and 20. The hydraulic oil in the region sandwiched between the inner peripheral surface of the hydraulic chamber 6 and the tooth portions of the gears 10 and 20 is transferred to the discharge flow path 40 side by the rotation of the gears 10 and 20, and the hydraulic chamber 6 is from the meshing portion where the tooth portions of the gears 10 and 20 mesh with each other in the rotational direction of the gears 10 and 20 until the tooth portions are in sliding contact with the inner peripheral surface of the hydraulic chamber 6. The region between them is the low pressure region (low pressure side), and the region between the part where the teeth of the gears 10, 20 are separated from the inner peripheral surface of the hydraulic chamber 6 and the meshing portion is the high pressure region (high pressure side). . Then, the hydraulic oil pressurized to a high pressure is supplied from the discharge port 41 to the hydraulic equipment through the pipe.

  In the hydraulic pump 1 of this example, the groove-like flow path 31 forming the suction flow path 30 opens to the inner surface of the hydraulic chamber 6 corresponding to the intermediate position between the pair of gears 10 and 20. The opening 32 of the groove-like flow path 31 is such that at least a part of both side edges sandwiching a virtual center axis L parallel to the axis of the gears 10 and 20 is in the low pressure side hydraulic chamber 6. Since it is provided along the tooth traces of the pair of gears 10 and 20 that are in sliding contact with the inner peripheral surface, the tooth traces of the gears 10 and 20 that are in sliding contact with the inner peripheral surface of the low pressure side hydraulic chamber 6 are as much as possible. That is, it can be set as close as possible to the edge of the opening 32 of the groove-shaped flow path 31, and the inner peripheral surface of the low-pressure side hydraulic chamber 6 and the teeth of the gears 10, 20 The sealing area sealed by can be a large area. Thus, by ensuring such a large sealing area, it is possible to prevent the hydraulic oil from leaking from the high pressure side to the low pressure side, and the sealing performance can be further improved.

  The groove-like channel 31 is a groove-like channel that opens to the inner surface of the hydraulic chamber 6 but does not open to the outer surface of the second housing 4 in the radial direction. 33 is formed so that the hydraulic oil flowing into the groove-like channel 31 from the communication passage 33 flows in a direction from the wider opening width of the groove-like channel 31 toward the narrower one. Since the groove depth of the flow path 31 is gradually shallower in the same direction, in the hydraulic pump 1 of this example, the flow of hydraulic oil in the groove-shaped flow path 31 is unlikely to be greatly disturbed and free from stagnation. It is almost uniform. For this reason, in the hydraulic pump 1 of this example, in order to increase the discharge pressure (output), even if the gears 10 and 20 are rotated at a high speed, problems such as cavitation hardly occur.

  As mentioned above, although one specific embodiment of this invention was described, the specific aspect which this invention can take is not limited to this aspect at all.

  For example, in the above example, in the opening portion 32 of the groove-like channel 31, a part of the edge portions on both sides of the virtual center axis L is slidably contacted with the inner peripheral surface of the low-pressure side hydraulic chamber 6. Although it was along the tooth traces of the pair of gears 10 and 20, it is not limited to such a mode, and a width of a part of the edge portion in a direction orthogonal to the central axis L is the liquid. It is good also as what was gradually narrowed toward the direction where the tooth-gap space | interval between a pair of gearwheels 10 and 20 which slidably contacts with the internal peripheral surface of the pressure chamber 6 becomes narrow gradually. Although such an aspect cannot be said to be a more preferable aspect, the tooth streaks of the gears 10 and 20 that are in sliding contact with the inner peripheral surface of the low-pressure side hydraulic chamber 6 are replaced with the openings of the groove-like flow path 31. Therefore, the seal area sealed by the inner peripheral surface of the low-pressure side hydraulic chamber 6 and the teeth of the gears 10 and 20 can be made a correspondingly large area. be able to.

  On the other hand, as a more preferable aspect, as shown in FIG. 5, in the opening portion 32 ′ of the groove-shaped channel 31 ′, the entire edge portions on both sides of the virtual center axis L are in sliding contact with each other. The thing along the tooth trace direction of the gearwheels 10 and 20 can be mentioned. According to this aspect, compared with the above example, the flow of the hydraulic oil in the groove-like flow path 31 can be made even more uniform without any stagnation.

  Furthermore, as shown in FIG. 6, the opening 32 ″ of the groove-shaped channel 31 ″ has an edge formed in a step shape, and the entire shape (contour shape) of the edge is V-shaped (U It may be formed in a letter shape or a parabolic shape). Alternatively, the edge of the opening 32 ″ may be formed in a zigzag shape or a wave shape instead of the step shape.

  Similarly, in the opening portion 32 ′ of the groove-like channel 31 ′ shown in FIG. 5, the edge portion may be formed in a stepped shape, a zigzag shape, or a corrugated shape.

  Further, in the above example, the groove depth of the groove-like flow path 31 is set in such a direction that the interval between the pair of gears 10 and 20 slidably contacting the inner peripheral surface of the low-pressure side hydraulic chamber 6 is gradually reduced. However, the present invention is not limited to such a mode, and the groove depth of the groove-like channel 31 may be made substantially constant as shown by a one-dot chain line in FIG. . In this aspect, the hydraulic oil flow in the channel 31 is more likely to stagnate than the hydraulic pump 1 in the above example, but this can be sufficiently achieved for the purpose of the present invention. .

  In the above example, the communication passage 33 is configured such that the other side opens to the outer surface of the first housing 3 in the radial direction. However, the present invention is not limited to this mode. You may comprise so that it may open to the left end surface of the 1st housing 3, as shown with a dashed-two dotted line. Also according to such an aspect, the flow of the hydraulic oil flowing into the groove-like flow path 32 from the communication path 33 can be changed from a wider opening width of the groove-like flow path 31 to a narrower one. The flow of hydraulic oil in the channel 31 can be made smooth.

  In the above example, the discharge passage 40 that is the high-pressure side passage opens on the inner surface of the hydraulic chamber 6 corresponding to the intermediate position, one of which is between the shafts of the pair of gears 10 and 20. Although the other side is configured to open to the outer surface of the second housing 4, the present invention is not limited to such an embodiment, and the discharge channel 40 is similar to the suction channel 30 in the first housing. 33 and a groove-like channel formed in the second housing 4, and the hydraulic oil in the groove-like channel is directed from the narrower opening width of the groove-like channel to the wider one. It may be configured to flow out. By adopting such a configuration, even in the high-pressure side flow channel, the flow of the hydraulic oil flowing out from the groove-shaped flow channel to the communication channel flows from the narrower opening width of the groove-shaped flow channel to the wider one. It is possible to make the flow of hydraulic oil in the groove-like flow path smooth.

  In the above example, the housing 2 is composed of the first housing 3, the second housing 4, and the third housing 5, the bushes 14 and 24 are provided in the first housing 3, and the bushes 13 and 23 are provided in the third housing. Although the configuration is adopted, the configuration of the housing 2 is not limited to such a mode. As an example, the second housing 4 may be provided with bushes 13 and 23.

  In the above example, the present invention is embodied as a hydraulic pump that uses oil as the working liquid. However, the aspects that the present invention can take are not limited to such a hydraulic pump, and the present invention includes a coolant pump and the like. In addition, it can be embodied as a hydraulic pump using a liquid mainly composed of water as a working liquid. Further, the present invention can be embodied not as a hydraulic pump but as a hydraulic motor.

DESCRIPTION OF SYMBOLS 1 Hydraulic pump 2 Housing 3 1st housing 4 2nd housing 5 3rd housing 6 Hydraulic chamber 10, 20 (helical) gear 11, 12, 21, 22, Rotating shaft 13, 14, 23, 24 Bush 30 Low pressure side Channel 31 Groove-shaped channel 32 Opening 33 Communication channel 40 High-pressure side channel

Claims (5)

A pair of helical gears each having a rotation shaft provided so as to extend outward from both end faces and meshing teeth with each other;
A housing having a hydraulic chamber in which the pair of gears are housed in mesh;
A bearing member disposed on each side of each gear in the housing, and rotatably supporting the rotation shaft of each gear;
The hydraulic chamber has two arcuate inner circumferential surfaces along the outer circumferential surface of the meshed gear, one on the low pressure side and the other on the high pressure side with the meshing portion of the pair of gears as a boundary And the housing includes a low-pressure channel that opens to the inner surface of the low-pressure hydraulic chamber, and a high-pressure channel that opens to the inner surface of the high-pressure hydraulic chamber,
Each of the gears is a hydraulic device configured to rotate in sliding contact with its inner peripheral surface in a hydraulic chamber on the low pressure side,
In the low-pressure side flow path, a portion formed in a region obtained by projecting the outer peripheral surface of the gear in the radial direction is in a hydraulic pressure chamber inner surface corresponding to an intermediate position between the shafts of the pair of gears in the axial direction of the gear. Formed as a groove-like flow path that does not open on the outer surface in the radial direction of the housing, while opening along
At least a part of the opening of the groove-shaped flow path has an opening width in a direction perpendicular to the axis of the gear, and a tooth space between the pair of gears in sliding contact with the peripheral surface of the hydraulic chamber on the low pressure side. Toward the direction of gradually narrowing, gradually narrowing,
In the low-pressure side flow channel, the working liquid flows into the groove-shaped flow channel from the wide opening width of the groove-shaped flow channel toward the narrower side, or wider from the narrower opening width of the groove-shaped flow channel. A hydraulic apparatus, wherein the hydraulic apparatus is formed so as to flow out from the groove-shaped channel toward the direction.   The opening edge portion of the groove-shaped flow path is along at least a part of the pair of gear teeth slidingly contacting the peripheral surface of the hydraulic chamber on the low pressure side. Hydraulic device.   2. The hydraulic device according to claim 1, wherein the opening edge of the groove-like channel is formed in a V shape, a U shape, or a parabolic shape when viewed from the hydraulic pressure chamber. .   2. The hydraulic pressure according to claim 1, wherein the opening edge portion of the groove-like flow passage is entirely along the tooth traces of the pair of gears that are in sliding contact with the peripheral surface of the hydraulic pressure chamber on the low pressure side. apparatus. The groove depth of the groove-like flow path is gradually shallower in a direction in which the tooth space between the pair of gears slidably contacting the low pressure side hydraulic chamber circumferential surface is gradually narrowed. The hydraulic apparatus according to claim 1, wherein the hydraulic apparatus is one of the first to fourth aspects.

Images