JP2020122455A - Geared pump or geared motor - Google Patents

Abstract

To suppress breakage of a gear.SOLUTION: A geared pump (1) comprises a pair of gears which are helical gears; a casing which houses the pair of gears; a first member which comes into slide contact with the pair of gears; and a second member which comes into slide contact with the pair of gears. The inside space of the casing is sectioned into a high-pressure region and a low-pressure region. The first member has a first groove (53) communicating with the high-pressure region. The second member has a second groove (63) communicating with the high-pressure region. While one of a low pressure region-side end (53b) of the first groove (53) and a low pressure region-side end (63b) of the second groove (63) communicates with a tooth groove (13) between a pair of adjacent teeth of the respective gears, the other of the low pressure region-side end (53b) of the first groove (53) and the low pressure region-side end (63b) of the second groove (63) communicates with the tooth groove (13) that the one of the low pressure region-side end (53b) of the first groove (53) and the low pressure region-side end (63b) of the second groove (63) communicates with.SELECTED DRAWING: Figure 7

Description

The present disclosure relates to a gear motor or gear pump.

As a conventional gear pump, there is one that includes a pair of gears that mesh with each other and a pair of movable side plates that are adjacent to both side surfaces of these gears and each have a high-pressure introduction groove on its sliding surface (see Patent Document 1). ..

JP2012-77686A

However, when using a helical gear as a pair of gears of the above conventional gear pump, the helical gear has twisted teeth, so when the tooth space moves from the low pressure region to the high pressure region, the movable side plate on one side is There is a moment when only the high-pressure introduction groove provided in the point where it communicates with the tooth groove of the gear. In this case, the pressure of the high-pressure working fluid in the high-pressure introduction groove propagates from the high-pressure introduction groove provided on the movable side plate on one side to the movable side plate on the other side, and a water hammer near the movable side plate on the other side. May occur. As a result, there is a problem that the impact load of the water hammer acts on the meshing point of the gear and the gear is damaged. Particularly, at the end of the gear, an edge is formed by the tooth surface and the end face of the gear, and since the thickness is thin and the strength is low, the gear is easily damaged.

The present disclosure proposes a gear pump or a gear motor that can suppress damage to a gear.

The gear pump or gear motor of the present disclosure is
A pair of gears that are bevel gears,
A casing having an internal space for housing the pair of gears,
A first member slidably contacting one end face of the pair of gears in the axial direction;
A second member that is in sliding contact with the other end surface of the pair of gears in the axial direction,
The internal space of the casing is divided into a high pressure region and a low pressure region by the pair of gears,
The first member has a first groove that is provided on a first sliding surface that is in sliding contact with the pair of gears and that communicates with the high pressure region.
The second member has a second groove that is provided on a second sliding surface that is in sliding contact with the pair of gears and that communicates with the high pressure region.
One of the low-pressure region side end of the first groove and the low-pressure region side end of the second groove communicates with a tooth groove between a pair of adjacent teeth of each gear. While the first groove is in the low pressure region side end and the second groove in the low pressure region side end, the other of the first groove and the low pressure region side end is One of the end portion of the second groove on the low pressure region side communicates with the tooth groove.

According to the present disclosure, even when one of the first groove and the second groove communicates with one tooth groove first, one of the first groove and the second groove communicates with the tooth groove. While doing so, the other of the first groove and the second groove communicates with the tooth groove. As a result, even if the pressure of the high-pressure working fluid propagates from only one side of the first member provided with the first groove or the second member provided with the second groove to the tooth space, the high pressure is applied to the first member. It becomes difficult to propagate to the other side of the member or the second member. As a result, the occurrence of water hammer near the first member or the second member is suppressed, so that damage to the gear can be suppressed.

In the gear pump or the gear motor of one embodiment,
The end portion of the first groove on the low pressure region side and the end portion of the second groove on the low pressure region side communicate with the tooth groove substantially at the same time.

According to the above-described embodiment, the first groove and the second groove communicate with the tooth groove of the gear substantially at the same time, so that the high-pressure working fluid flowing into the tooth groove from each of the first groove and the second groove is The pressure collides near the center of the gear tooth width. As a result, a water hammer occurs near the center of the tooth width of the gear. Further, the strength of the tooth near the center of the tooth width is higher than the strength of the tooth near the end of the tooth width having an edge formed by the end surface and the tooth surface of the gear. Therefore, as compared with the case where the pressure of the high-pressure working fluid propagates to the first member or the second member and water hammer occurs near the end of the tooth width of the gear, the gear loss can be suppressed.

In the gear pump or the gear motor of one embodiment,
An imaginary circle passing through the outermost point of the end of the first groove on the low pressure region side around the rotation center of each gear is defined as a first imaginary circle, and the low pressure region of the second groove around the rotation center. If the virtual circle passing through the outermost point of the side end is the second virtual circle,
The end of the one tooth surface of each gear on the first virtual side on the first virtual circle is closer to the first member side than the end of the one tooth surface on the second virtual circle is on the second member side. The first angle θ1 is deviated in the delay direction with respect to the rotation direction of each gear,
The end of the first groove on the low pressure region side is set to be offset from the end of the second groove on the low pressure region side by a second angle θ2 in the delay direction with respect to the rotation direction of each gear. Has been done,
An angle range of the arc portion of the first virtual circle in the tooth groove viewed from the rotation center is θ3, and an angle range of the arc portion of the second virtual circle in the tooth groove viewed from the rotation center. Is θ4,
θ1-θ4<θ2<θ1+θ3
The relationship is established.

In the gear pump or the gear motor of one embodiment, the first angle θ1 and the second angle θ2 are substantially equal.

In the gear pump or the gear motor of one embodiment,
The first groove is provided on the outer peripheral edge of the first member,
The second groove is provided on the outer peripheral edge of the second member.

According to the above embodiment, since the first groove is provided on the outer peripheral edge of the first member, it is easy to process the first groove by cutting. Similarly, since the second groove is provided on the outer peripheral edge of the second member, the second groove can be easily processed by cutting.

In the gear pump or the gear motor of one embodiment,
The amount of angular position deviation between the end point of the tooth tip of the gear on the side of the first member and the end point of the tooth tip on the side of the second member with respect to the center of rotation of the gear is on the low pressure region side of the first groove. It is substantially equal to the shift amount of the angular position with respect to the rotation center between the end portion and the end portion of the second groove on the low pressure region side.

It is a sectional view of a gear pump concerning a 1st embodiment of this indication. FIG. 2 is a sectional view taken along line II-II of FIG. 1. It is the top view which looked at the 1st side plate concerning a 1st embodiment from a pair of drive gear and a driven gear side. It is the top view which looked at the 2nd side plate concerning a 1st embodiment from a pair of drive gear and a driven gear side. It is a perspective view of the gear pump which concerns on 1st Embodiment. It is a typical top view which looked at the drive gear of a 1st embodiment from the 1st side plate side. It is a typical development view of the side surface of a drive gear along the 1st virtual circle and the 2nd virtual circle in a 1st embodiment. It is the typical top view which looked at the drive gear of a 2nd embodiment from the 1st side plate side. It is a typical development view of the side surface of a drive gear along the 1st virtual circle and the 2nd virtual circle in a 2nd embodiment. It is sectional drawing of the gear pump which concerns on 3rd Embodiment of this indication.

Hereinafter, a gear pump according to an embodiment of the present disclosure will be described with reference to the accompanying drawings. In the attached drawings, the same components are designated by the same reference numerals.

[First Embodiment]
FIG. 1 is a sectional view of a gear pump 1 according to the first embodiment. The gear pump 1 of the present embodiment sucks a working fluid (working oil in the present embodiment), pressurizes it, and discharges it to a hydraulic device (for example, a hydraulic device).

Referring to FIG. 1, a gear pump 1 according to the present embodiment is arranged in a casing 30, a pair of driving gears 10 and a driven gear 20 that mesh with each other, a casing 30 that houses the pair of the driving gears 10 and a driven gear 20, and a casing 30. Bearing members 40A and 40B. The gear pump 1 includes a first side plate 50 that is in sliding contact with one end surface (right side in FIG. 1) of the pair of drive gears 10 and the driven gears 20 in the axial direction, and the pair of drive gears 10 and the driven gears 20 in the axial direction. The second side plate 60 is in sliding contact with the other end surface (left side in FIG. 1). The first side plate 50 is an example of a first member according to the present disclosure. The second side plate 60 is an example of the second member according to the present disclosure.

The drive gear 10 and the driven gear 20 are helical gears. The teeth 11 of the drive gear 10 and the teeth 21 of the driven gear 20 are configured to mesh with each other. The twist angle of the teeth 11 of the drive gear 10 is the same as the twist angle of the teeth 21 of the driven gear 20, and the twist direction of the teeth 11 of the drive gear 10 is opposite to the twist direction of the teeth 21 of the driven gear 20. ..

The drive gear 10 has a drive shaft 12 extending in the axial direction of the drive gear 10 from both sides of the drive gear 10 in the axial direction. A drive source (not shown) such as a motor is mechanically connected to one end (right side in FIG. 1) of the drive shaft 12. The driven gear 20 has a driven shaft 22 that extends in the axial direction of the driven gear 20 from both sides of the driven gear 20 in the axial direction.

The casing 30 includes a body 30a that accommodates the pair of drive gears 10 and the driven gears 20, a mounting 30b that is screwed to the body 30a, and a cover 30c that is screwed to the body 30a.

The bearing member 40A has a bearing 41A that supports the drive shaft 12 and a bearing 42A that supports the driven shaft 22. A gasket 43A is provided on the surface of the bearing member 40A facing the first side plate 50. The gasket 43A is for limiting the range in which the pressure of the high-pressure working fluid flowing between the first side plate 50 and the bearing member 40A acts. The first side plate 50 is pressed against the pair of drive gears 10 and driven gears 20 by the pressure of the high-pressure working fluid that has flowed into a portion between the first side plate 50 and the bearing member 40A.

The bearing member 40B has a bearing 41B that supports the drive shaft 12 and a bearing 42B that supports the driven shaft 22. A gasket 43B is provided on the surface of the bearing member 40B that faces the second side plate 60. The gasket 43B is for limiting the range in which the pressure of the high-pressure working fluid flowing between the second side plate 60 and the bearing member 40B acts. The second side plate 60 is pressed against the pair of drive gears 10 and driven gears 20 by the pressure of the high-pressure working fluid that has flowed into a portion between the second side plate 60 and the bearing member 40B.

The first side plate 50 and the second side plate 60 are arranged in the casing 30 so as to sandwich the pair of drive gear 10 and driven gear 20. The first side plate 50 is provided between the bearing member 40A and the pair of drive gears 10 and driven gears 20. The second side plate 60 is provided between the pair of drive gear 10 and driven gear 20, and the bearing member 40B.

The first side plate 50 has a first sliding surface 50a that is in sliding contact with the pair of drive gear 10 and the driven gear 20, and a non-sliding surface 50b that is located on the opposite side. The first side plate 50 is pressed in the direction away from the pair of drive gear 10 and driven gear 20 by the pressure of the working fluid acting on the first sliding surface 50a. On the other hand, in the first side plate 50, the pressure of the high-pressure working fluid introduced between the first side plate 50 and the bearing member 40A acts on the non-sliding surface 50b, so that the pair of drive gears 10 and driven gears. It is pressed in a direction approaching 20.

The shape of the gasket 43A is set so that the force acting on the non-sliding surface 50b is slightly larger than the force acting on the first sliding surface 50a. As a result, the first side plate 50 is appropriately attached to the end faces of the pair of drive gears 10 and the driven gears 20 so that the gap between the end faces of the pair of drive gears 10 and the driven gears 20 and the first side plate 50 becomes small. It is pressed by force. As a result, leakage of high-pressure working fluid to the low-pressure side is suppressed.

The second side plate 60 has a second sliding surface 60a that is in sliding contact with the pair of drive gear 10 and the driven gear 20, and a non-sliding surface 60b that is located on the opposite side. The second side plate 60 is pressed in the direction away from the pair of drive gear 10 and driven gear 20 by the pressure of the working fluid acting on the second sliding surface 60a. On the other hand, in the second side plate 60, the pressure of the high-pressure working fluid introduced between the second side plate 60 and the bearing member 40B acts on the non-sliding surface 60b, so that the pair of drive gears 10 and the driven gears. It is pressed in a direction approaching 20.

The shape of the gasket 43B is set so that the force acting on the non-sliding surface 60b is slightly larger than the force acting on the second sliding surface 60a. As a result, the second side plate 60 is appropriately attached to the end faces of the pair of drive gears 10 and the driven gears 20 so that the gap between the end faces of the pair of drive gears 10 and the driven gears 20 and the second side plate 60 becomes small. It is pressed by force. As a result, leakage of high-pressure working fluid to the low-pressure side is suppressed.

FIG. 2 is a sectional view taken along line II-II of FIG.

Referring to FIG. 2, the casing 30 has an internal space 31 for housing the pair of drive gears 10 and driven gears 20.

The internal space 31 of the casing 30 has a cross-sectional shape configured by two circular shapes that partially overlap each other. The inner space 31 of the casing 30 is formed by the pair of drive gear 10 and driven gear 20, the bearing members 40A and 40B, the gaskets 43A and 43B, the first side plate 50, and the second side plate 60 (shown in FIG. 1). , And is divided into a high pressure region 31a and a low pressure region 31b.

The casing 30 includes a suction passage 32 that communicates with a low pressure region 31b of the internal space 31 and a discharge passage 33 that communicates with a high pressure region 31a of the internal space 31.

When the drive gear 10 (not shown) mechanically connected to the drive shaft 12 rotates the drive gear 10 around the rotation center C1 (see arrow R1 in the drawing), the driven gear 20 meshed with the drive gear 10 rotates the rotation center C2. It rotates around (see arrow R2 in the figure). As a result, the working fluid is transported from the suction passage 32 to the discharge passage 33 via the internal space 31 (see arrow A in the figure).

FIG. 3 is a plan view of the first side plate 50 according to the present embodiment as viewed from the pair of drive gears 10 and driven gears 20.

Referring to FIG. 3, the first side plate 50 is an 8-shaped plate-shaped member formed of two circular shapes that partially overlap each other. The first side plate 50 has a drive-side first shaft hole 51 through which the drive shaft 12 (shown in FIG. 1) is inserted and a driven-side first shaft hole 52 through which the driven shaft 22 (shown in FIG. 1) is inserted. Prepare The drive-side first shaft hole 51 is arranged coaxially with the drive shaft 12 (shown in FIG. 1 ). In other words, the drive-side first shaft hole 51 is arranged coaxially with the rotation center C1 of the drive gear 10. The driven-side first shaft hole 52 is arranged coaxially with the driven shaft 22 (shown in FIG. 1 ). In other words, the driven-side first shaft hole 52 is arranged coaxially with the rotation center C2 of the driven gear 20.

In addition, the first side plate 50 includes a drive-side first high-pressure introduction groove 53 provided on the outer peripheral edge of the first sliding surface 50a of the first side plate 50 and an outer peripheral edge of the first sliding surface 50a of the first side plate 50. And the driven-side first high-pressure introduction groove 54 provided in the. The drive-side first high-pressure introduction groove 53 and the driven-side first high-pressure introduction groove 54 are examples of the first groove according to the present disclosure.

The drive-side first high-pressure introduction groove 53 is provided on the drive gear 10 side (upper side in FIG. 3) of the first side plate 50, and extends along the circumferential direction of the rotation center C1 of the drive gear 10. An end portion 53 a of the drive-side first high-pressure introduction groove 53 on the high-pressure region 31 a side communicates with the discharge passage 33. The end portion 53b of the drive-side first high-pressure introduction groove 53 on the low-pressure region 31b side does not communicate with the suction passage 32. The drive-side first high-pressure introduction groove 53 introduces a high-pressure working fluid to the low-pressure side to reduce the bearing load acting on the bearings 41A and 41B (shown in FIG. 1).

The driven-side first high-pressure introduction groove 54 is provided on the driven gear 20 side (lower side in FIG. 3) of the first side plate 50 and extends along the circumferential direction of the rotation center C2 of the driven gear 20. The end 54 a of the driven-side first high-pressure introduction groove 54 on the high-pressure region 31 a side communicates with the discharge passage 33. An end portion 54b of the driven-side first high-pressure introduction groove 54 on the low-pressure region 31b side does not communicate with the suction passage 32. The driven-side first high-pressure introduction groove 54 introduces a high-pressure working fluid to the low-pressure side to reduce the bearing load acting on the bearings 42A and 42B (shown in FIG. 1).

FIG. 4 is a plan view of the second side plate 60 according to the present embodiment as viewed from the pair of drive gear 10 and driven gear 20.

Referring to FIG. 4, the second side plate 60 is an 8-shaped plate-shaped member formed of two circular shapes that partially overlap each other. The second side plate 60 has a drive-side second shaft hole 61 through which the drive shaft 12 (shown in FIG. 1) is inserted and a driven-side second shaft hole 62 through which the driven shaft 22 (shown in FIG. 1) is inserted. Prepare The drive side second shaft hole 61 is arranged coaxially with the drive shaft 12 (shown in FIG. 1 ). In other words, the drive side second shaft hole 61 is arranged coaxially with the rotation center C1 of the drive gear 10. The driven-side second shaft hole 62 is arranged coaxially with the driven shaft 22 (shown in FIG. 1 ). In other words, the driven-side second shaft hole 62 is arranged coaxially with the rotation center C2 of the driven gear 20.

Further, the second side plate 60 includes a drive-side second high-pressure introduction groove 63 provided on the outer peripheral edge of the second sliding surface 60a of the second side plate 60, and an outer peripheral edge of the second sliding surface 60a of the second side plate 60. And the driven-side second high-pressure introduction groove 64 provided in the. The drive-side second high-pressure introducing groove 63 and the driven-side second high-pressure introducing groove 64 are examples of the second groove according to the present disclosure.

The drive-side second high-pressure introduction groove 63 is provided on the drive gear 10 side (upper side in FIG. 4) of the second side plate 60 and extends along the circumferential direction of the rotation center C1 of the drive gear 10. An end portion 63 a of the drive-side second high-pressure introduction groove 63 on the high-pressure region 31 a side communicates with the discharge passage 33. The end portion 63b of the drive-side second high-pressure introduction groove 63 on the low-pressure region 31b side does not communicate with the suction passage 32. The drive-side second high-pressure introducing groove 63 introduces a high-pressure working fluid to the low-pressure side to reduce the bearing load acting on the bearings 41A and 41B (shown in FIG. 1).

The driven-side second high-pressure introduction groove 64 is provided on the driven gear 20 side (lower side in FIG. 4) of the second side plate 60, and extends along the circumferential direction of the rotation center C2 of the driven gear 20. An end portion 64a of the second driven high pressure introduction groove 64 on the high pressure region 31a side communicates with the discharge passage 33. The end portion 64b of the driven-side second high-pressure introduction groove 64 on the low-pressure region 31b side does not communicate with the suction passage 32. The driven-side second high-pressure introduction groove 64 introduces a high-pressure working fluid to the low-pressure side to reduce the bearing load acting on the bearings 42A and 42B (shown in FIG. 1).

FIG. 5 is a perspective view of the gear pump 1 according to this embodiment. The casing 30 is not shown in FIG.

Referring to FIG. 5, the ends of the teeth 11 of the drive gear 10 on the first side plate 50 side are closer to the rotation direction R1 of the drive gear 10 than the ends of the teeth 11 of the drive gear 10 on the second side plate 60 side are. Is set on the delay side. Similarly, the end of the tooth 21 of the driven gear 20 on the side of the first side plate 50 lags behind the end of the tooth 21 of the driven gear 20 on the side of the second side plate 60 in the rotational direction R2 of the driven gear 20. It is set on the direction side.

In the present embodiment, the end portion 53b on the low pressure region 31b side (shown in FIG. 3) of the drive-side first high-pressure introduction groove 53 provided on the first side plate 50 is the second drive-side portion provided on the second side plate 60. The end portion 63b of the high pressure introduction groove 63 on the low pressure region 31b side (shown in FIG. 4) is set on the delay direction side with respect to the rotation direction R1 of the drive gear 10. Similarly, an end portion 54b of the driven-side first high-pressure introduction groove 54 provided in the first side plate 50 on the low-pressure region 31b side (shown in FIG. 3) has a driven-side second high-pressure introduction provided in the second side plate 60. It is set on the delay direction side with respect to the rotation direction R2 of the driven gear 20 with respect to the end portion 64b of the groove 64 on the low pressure region 31b side (shown in FIG. 4).

Further, as shown in FIG. 5, the teeth 11 of the drive gear 10 are provided with a tooth surface 11a on the non-meshing side. The tooth surface 11 a on the non-meshing side of the drive gear 10 is a tooth surface that does not transmit torque to the teeth 21 of the driven gear 20. Similarly, the teeth 21 of the driven gear 20 include a tooth surface 21a on the non-meshing side. The tooth surface 21 a on the non-meshing side of the driven gear 20 is a tooth surface that does not transmit torque to the teeth 11 of the drive gear 10.

FIG. 6 is a schematic top view of the drive gear 10 of the present embodiment viewed from the first side plate 50 side. Hereinafter, the drive gear 10 side of the gear pump 1 will be described, but the driven gear 20 side of the gear pump 1 (not shown) also has the same configuration. Specifically, the driven-side first high-pressure introducing groove 54 has the same configuration as the driving-side first high-pressure introducing groove 53, and the driven-side second high-pressure introducing groove 64 is the driving-side second high-pressure introducing groove. It has the same structure as 63.

As shown in FIG. 6, in the following description, with the rotation center C1 of the drive gear 10 as the center, the outermost point P1 of the drive-side first high-pressure introduction groove 53 from the rotation center C1 of the drive gear 10 (shown in FIG. 3). ), and a virtual circle passing through) is defined as a first virtual circle VC1. Similarly, with a rotation center C1 of the drive gear 10 as the center, a virtual circle passing through the outermost point P2 (shown in FIG. 4) of the drive-side second high-pressure introduction groove 63 from the rotation center C1 of the drive gear 10 Two virtual circles VC2. In the present embodiment, the drive-side first high-pressure introducing groove 53 is provided on the outer peripheral edge of the first side plate 50, and the drive-side second high-pressure introducing groove 63 is provided on the outer peripheral edge of the second side plate 60. The first high-pressure introduction groove 53 and the drive-side second high-pressure introduction groove 63 overlap each other in a top view. Similarly, the first virtual circle VC1 and the second virtual circle VC2 overlap in a top view.

Referring to FIG. 6, the tooth 11 of the drive gear 10 includes a tooth surface 11a on the non-meshing side and a tooth tip 11b.

FIG. 7 is a schematic development view of the side surface of the drive gear 10 along the first virtual circle VC1 and the second virtual circle VC2 in the present embodiment.

With reference to FIGS. 6 and 7, the end point 11a1 of the tooth surface 11a on the first side plate 50 side (upper side in FIG. 7) on the first virtual circle VC1 corresponds to the tooth surface 11a on the second virtual circle VC2. The end point 11a2 on the side of the second side plate 60 (lower side in FIG. 7) is deviated from the rotation direction R1 of the drive gear 10 by the first angle θ1 in the delay direction.

The end point 11a1 of the tooth flank 11a on the first side plate 50 side on the first virtual circle VC1 is a line segment LS1 forming the tooth flank 11a at the end face of the drive gear 10 facing the first side plate 50, and a first virtual It means the intersection with the circle VC1.

The end point 11a2 of the tooth flank 11a on the second side plate 60 side on the second virtual circle VC2 is a line segment LS2 that constitutes the tooth flank 11a at the end face of the drive gear 10 that faces the second side plate 60, and a second virtual The intersection with the circle VC2.

In the present embodiment, the end point 11a1 of the tooth surface 11a on the first side plate 50 side coincides with the addendum 11b in a top view. Further, the end point 11a2 of the tooth surface 11a on the second side plate 60 side coincides with the addendum 11b in a top view.

In other words, in the present embodiment, the deviation amount of the angular position between the end point of the tooth tip 11b on the first side plate 50 side and the end point of the tooth tip 11b on the second side plate 60 side with respect to the rotation center C1 of the drive gear 10 is It is equal to 1 angle θ1.

Further, the end portion 53b of the drive-side first high-pressure introduction groove 53 on the low-pressure region 31b side is closer to the rotation direction R1 of the drive gear 10 than the end portion 63b of the drive-side second high-pressure introduction groove 63 on the low-pressure region 31b side. The second angle θ2 is deviated to the delay direction side.

In other words, in the present embodiment, the rotation of the drive gear 10 between the end portion 53b of the drive-side first high-pressure introduction groove 53 on the low-pressure area 31b side and the end portion 63b of the drive-side second high-pressure introduction groove 63 on the low-pressure area 31b side. The amount of deviation of the angular position with respect to the center C1 is equal to the second angle θ2.

As shown in FIG. 6, the angle range of the arc portion VC11 in the tooth groove 13 between the pair of adjacent teeth 11 of the drive gear 10 in the first virtual circle VC1 viewed from the rotation center C1 of the drive gear 10 is θ3. When the angle range of the arc portion VC21 in the tooth groove 13 of the second virtual circle VC2 viewed from the rotation center C1 of the drive gear 10 is θ4, the gear pump 1 of the present embodiment
θ1-θ4<θ2<θ1+θ3
The relationship is established.

Specifically, in the present embodiment, the first angle θ1 and the second angle θ2 are substantially equal. In addition to the case where the first angle θ1 and the second angle θ2 are completely equal, the phrase “substantially equal” includes a case where the difference between the first angle θ1 and the second angle θ2 is within the manufacturing tolerance range.

In the present embodiment, since the first angle θ1 and the second angle θ2 are substantially equal to each other, when the drive gear 10 rotates, the drive-side first high-pressure introduction groove 53 provided in the first side plate 50 and the second side plate. The drive-side second high-pressure introduction groove 63 provided in 60 communicates with the tooth groove 13 almost at the same time. After that, the pressure of the high-pressure working fluid propagates from the drive-side first high-pressure introducing groove 53 and the drive-side second high-pressure introducing groove 63 to the tooth groove 13 (see arrow W in FIG. 7), and the tooth width of the tooth groove 13 is changed. A water hammer occurs near the center.

The high pressure of the water hammer generated near the center of the tooth width of the tooth groove 13 propagates to the meshing portion of the pair of drive gears 10 and the driven gears 20, and the teeth of the meshing line of the pair of drive gears 10 and the driven gears 20. An impact load acts on the drive gear 10 and the driven gear 20 near the center of the width.

Further, in the present embodiment, the first virtual circle VC1 and the second virtual circle VC2 overlap each other in a top view, so the angle range θ3 and the angle range θ4 are equal.

According to the above configuration, as shown in FIG. 7, since the relationship of θ1-θ4<θ2 is established, even if the drive-side second high-pressure introducing groove 63 communicates with the tooth groove 13 first, the drive The drive-side first high-pressure introducing groove 53 communicates with the tooth groove 13 while the second side high-pressure introducing groove 63 communicates with the tooth groove 13.

Similarly, as shown in FIG. 7, since the relationship of θ2<θ1+θ3 is established, even if the drive-side first high-pressure introduction groove 53 communicates with the tooth groove 13 first, the drive-side first high-pressure introduction The drive-side second high-pressure introduction groove 63 communicates with the tooth groove 13 while the groove 53 communicates with the tooth groove 13.

As a result, the pressure of the high-pressure working fluid is applied only from one side of the first side plate 50 provided with the drive-side first high-pressure introduction groove 53 or the second side plate 60 provided with the drive-side second high-pressure introduction groove 63. Even if it propagates to the tooth space 13, it becomes difficult for the high pressure to reach the other side of the first side plate 50 or the second side plate 60. As a result, the occurrence of water hammer near the first side plate 50 or the second side plate 60 is suppressed, and thus damage to the drive gear 10 and the driven gear 20 can be suppressed.

Further, in the present embodiment, the driven-side first high-pressure introducing groove 54 has the same configuration as the driving-side first high-pressure introducing groove 53, and the driven-side second high-pressure introducing groove 64 is the driving-side second high-voltage. It has the same structure as the introduction groove 63. Therefore, even when the driven-side second high-pressure introduction groove 64 communicates with the tooth groove of the driven gear 20 first, while the driven-side second high-pressure introduction groove 64 communicates with the tooth groove of the driven gear 20, Further, the driven-side first high-pressure introduction groove 54 communicates with the tooth groove of the driven gear 20. Similarly, even when the driven-side first high-pressure introducing groove 54 communicates with the tooth groove of the driven gear 20 first, while the driven-side first high-pressure introducing groove 54 communicates with the tooth groove of the driven gear 20, In addition, the driven-side second high-pressure introduction groove 64 communicates with the tooth groove of the driven gear 20.

As a result, the pressure of the high-pressure working fluid is applied only from one side of the first side plate 50 provided with the driven-side first high-pressure introduction groove 54 or the second side plate 60 provided with the driven-side second high-pressure introduction groove 64. Even if it propagates to the tooth space of the driven gear 20, it becomes difficult for the high pressure to reach the other side of the first side plate 50 or the second side plate 60. As a result, the occurrence of water hammer near the first side plate 50 or the second side plate 60 is suppressed, and thus damage to the drive gear 10 and the driven gear 20 can be suppressed.

According to the above-described embodiment, since the first angle θ1 and the second angle θ2 are substantially equal to each other, the drive-side first high-pressure introducing groove 53 and the drive-side second high-pressure introducing groove 63 are the tooth grooves 13 of the drive gear 10. To communicate at substantially the same time. The pressures of the high-pressure working fluids that have flowed into the tooth groove 13 from the drive-side first high-pressure introducing groove 53 and the drive-side second high-pressure introducing groove 63 collide with each other in the vicinity of the center of the tooth width of the tooth groove 13, and A water hammer occurs near the center of the tooth width of 13 (see arrow W in FIG. 7 ). The strength of the tooth 11 of the drive gear 10 near the center of the tooth width is higher than the strength of the tooth 11 of the drive gear 10 near the end of the tooth width. Similarly, the strength near the center of the tooth width of the tooth 21 of the driven gear 20 is higher than the strength near the end of the tooth width of the tooth 21 of the driven gear 20. Therefore, the pressure of the high-pressure working fluid propagates to the first side plate 50 or the second side plate 60, and compared with the case where a water hammer occurs near the end of the tooth width of the drive gear 10, the drive gear 10 and the driven gear are driven. The loss of the gear 20 can be suppressed.

Similarly, according to the above embodiment, the driven-side first high-pressure introducing groove 54 having the same configuration as the driving-side first high-pressure introducing groove 53 and the driven-side having the same configuration as the driving-side second high-pressure introducing groove 63 are provided. The second high-pressure introduction groove 64 communicates with the tooth groove of the driven gear 20 at substantially the same time. The pressures of the high-pressure working fluids flowing into the tooth spaces from the driven-side first high-pressure introduction groove 54 and the driven-side second high-pressure introduction groove 64 collide with each other near the center of the tooth width of the tooth spaces of the driven gear 20, A water hammer occurs near the center of the tooth width of the tooth groove of the driven gear 20. The strength of the tooth 21 of the driven gear 20 near the center of the tooth width is higher than the strength of the tooth 21 of the driven gear 20 near the end of the tooth width. Similarly, the strength near the center of the tooth width of the tooth 11 of the drive gear 10 is higher than the strength near the end of the tooth width of the tooth 11 of the drive gear 10. Therefore, as compared with the case where the pressure of the high-pressure working fluid propagates to the first side plate 50 or the second side plate 60 and water hammer occurs near the end of the tooth width of the driven gear 20, the driven gear 20 and the drive gear are driven. The loss of the gear 10 can be suppressed.

When a high pressure is generated in the vicinity of the first sliding surface 50a of the first side plate 50, the force acting on the first sliding surface 50a of the first side plate 50 exceeds the force acting on the non-sliding surface 50b, and the first side plate 50 may separate from the pair of drive gear 10 and driven gear 20. As a result, the high-pressure working fluid leaks between the first side plate 50 and the pair of drive gear 10 and driven gear 20, which may reduce the discharge amount of the working fluid and reduce the volumetric efficiency.

According to the above-described embodiment, the water hammer pressure generated near the center of the tooth width decreases due to diffusion and leakage before reaching the first sliding surface 50a of the first side plate 50. This suppresses the force acting on the first sliding surface 50a of the first side plate 50 from exceeding the force acting on the non-sliding surface 50b of the first side plate 50. Generation of a gap between the gear 10 and the driven gear 20 is suppressed. As a result, it is possible to prevent the working fluid from leaking and reducing the discharge amount, so that it is possible to suppress a decrease in volumetric efficiency.

Similarly, when a high pressure is generated near the second sliding surface 60a of the second side plate 60, the force acting on the second sliding surface 60a of the second side plate 60 exceeds the force acting on the non-sliding surface 60b, The second side plate 60 may be separated from the pair of drive gear 10 and driven gear 20. As a result, the high-pressure working fluid leaks between the second side plate 60 and the pair of drive gear 10 and driven gear 20, which may reduce the discharge amount of the working fluid and reduce the volumetric efficiency.

According to the above-described embodiment, the water hammer pressure generated near the center of the tooth width decreases due to diffusion and leakage before reaching the second sliding surface 60a of the second side plate 60. This suppresses the pressure acting on the second sliding surface 60a of the second side plate 60 from exceeding the pressure acting on the non-sliding surface 60b of the second side plate 60. Generation of a gap between the gear 10 and the driven gear 20 is suppressed. As a result, it is possible to prevent the working fluid from leaking and reducing the discharge amount, so that it is possible to suppress a decrease in volumetric efficiency.

According to the above-described embodiment, since the drive-side first high-pressure introduction groove 53 is provided on the outer peripheral edge of the first side plate 50, the drive-side first high-pressure introduction groove 53 can be easily processed by cutting. Similarly, since the drive-side second high-pressure introducing groove 63 is provided on the outer peripheral edge of the second side plate 60, the drive-side second high-pressure introducing groove 63 can be easily processed by cutting.

[Second Embodiment]
The second embodiment is the same as the first embodiment except for the first side plate and the second side plate, and FIGS. 1 and 2 are incorporated. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 8 is a schematic top view of the drive gear 10 according to the second embodiment as viewed from the first side plate 50 side. Hereinafter, the drive gear 10 side of the gear pump 1 will be described, but the driven gear 20 side of the gear pump 1 (not shown) also has the same configuration. Specifically, the driven-side first high-pressure introducing groove 54 has the same configuration as the driving-side first high-pressure introducing groove 53, and the driven-side second high-pressure introducing groove 64 is the driving-side second high-pressure introducing groove. It has the same structure as 63.

Referring to FIG. 8, the drive-side first high-pressure introduction groove 53 of the present embodiment is provided inside the outer peripheral edge of the first sliding surface 50a of the first side plate 50 in the radial direction of the rotation center of the drive gear 10. ing. Similarly, the drive-side second high-pressure introduction groove 63 of the present embodiment is provided on the radially inner side of the rotation center C1 of the drive gear 10 with respect to the outer peripheral edge of the second side plate 60. Further, the drive-side first high-pressure introducing groove 53 and the drive-side second high-pressure introducing groove 63 are provided so as not to overlap in a top view. Specifically, the drive-side second high-pressure introduction groove 63 is arranged radially inside the rotation center C1 of the drive gear 10 with respect to the drive-side first high-pressure introduction groove 53.

FIG. 9 is a schematic development view of the side surface of the drive gear 10 along the first virtual circle VC1 and the second virtual circle VC2 in the present embodiment.

Referring to FIGS. 8 and 9, an angular range of the arc portion VC11 in the tooth groove 13 between the pair of adjacent teeth 11 of the drive gear 10 of the first virtual circle VC1 viewed from the rotation center C1 of the drive gear 10. θ3 is larger than the angular range θ4 when the arc portion VC21 in the tooth groove 13 of the second virtual circle VC2 is viewed from the rotation center C1 of the drive gear 10.

The second embodiment has the same effects as the first embodiment.

[Third Embodiment]
The third embodiment is the same as the first embodiment except for the first bearing member 150 and the second bearing member 160. In the third embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 10 is a sectional view of the gear pump 101 according to the third embodiment.

Referring to FIG. 10, the gear pump 101 according to the present embodiment has a first bearing member 150 and a second bearing member 160 that are in sliding contact with the pair of drive gear 10 and driven gear 20. The first bearing member 150 of the present embodiment is an example of the first member according to the present disclosure. The second bearing member 160 of the present embodiment is an example of the second member according to the present disclosure.

The first bearing member 150 has a first sliding surface 150a that is in sliding contact with the pair of drive gears 10 and driven gears 20, and a non-sliding surface 150b opposite to the first sliding surface 150a. The first bearing member 150 includes a bearing 151 that supports the drive shaft 12 of the drive gear 10, a bearing 152 that supports the driven shaft 22, and a gasket 153 provided on the non-sliding surface 150 b of the first bearing member 150. Have and.

The gasket 153 is for limiting the range in which the pressure of the high-pressure working fluid that flows between the first bearing member 150 and the mounting 30b acts. The first bearing member 150 is pressed against the pair of drive gears 10 and driven gears 20 by the pressure of the working fluid flowing into a part between the first bearing member 150 and the mounting 30b.

The second bearing member 160 has a second sliding surface 160a that is in sliding contact with the pair of drive gear 10 and the driven gear 20, and a non-sliding surface 160b opposite to the second sliding surface 160a. The second bearing member 160 has a bearing 161 that supports the drive shaft 12 of the drive gear 10 and a bearing 162 that supports the driven shaft 22. A gasket 163 is provided on the non-sliding surface 160 b of the second bearing member 160.

The gasket 163 is for limiting the range in which the pressure of the high-pressure working fluid flowing between the second bearing member 160 and the cover 30c acts. The second bearing member 160 is pressed against the pair of drive gear 10 and driven gear 20 by the pressure of the working fluid that has flowed into a portion between the second bearing member 160 and the cover 30c.

Further, the first sliding surface 150a of the first bearing member 150 is provided with a driving-side first high-pressure introducing groove 154 and a driven-side first high-pressure introducing groove 155. The drive-side first high-pressure introducing groove 154 of this embodiment has the same configuration as the drive-side first high-pressure introducing groove 53 (shown in FIG. 3) of the first embodiment, and detailed description thereof will be omitted. .. Further, the driven-side first high-pressure introduction groove 155 of the present embodiment has the same configuration as the driven-side first high-pressure introduction groove 54 (shown in FIG. 3) of the first embodiment, and a detailed description thereof will be given. Omit it.

Further, the second sliding surface 160a of the second bearing member 160 is provided with a drive-side second high-pressure introduction groove 164 and a driven-side second high-pressure introduction groove 165. The drive-side second high-pressure introducing groove 164 of this embodiment has the same configuration as the drive-side second high-pressure introducing groove 63 (shown in FIG. 4) of the first embodiment, and detailed description thereof will be omitted. .. Further, the driven-side second high-pressure introduction groove 165 of the present embodiment has the same configuration as the driven-side second high-pressure introduction groove 64 (shown in FIG. 4) of the first embodiment, and a detailed description thereof will be given. Omit it.

In this embodiment, the same operational effects as those of the first embodiment are obtained.

Although the embodiments have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims.

For example, although the case where the present disclosure is applied to a gear pump has been described in the above-described first and second embodiments, the present disclosure may be applied to a gear motor configured similarly to the gear pump.

DESCRIPTION OF SYMBOLS 1... Gear pump 10... Drive gear 11... Tooth 11a... Tooth surface 11a1, 11a2... End point 11b... Tooth tip 12... Drive shaft 13... Tooth groove 20... Driven gear 21... Tooth 21a... Tooth surface 22... Followed shaft 30... Casing 30a...Body 30b...Mounting 30c...Cover 31...Internal space 31a...High pressure region 31b...Low pressure region 32...Suction passage 33...Discharge passage 40A, 40B...Bearing member 41A, 41B... Bearing 42A, 42B... Bearing 43A, 43B... Gasket 50... 1st side plate 50a... Sliding surface 50b... Non-sliding surface 51... Drive side 1st shaft hole 52... Driven side 1st shaft hole 53... Drive side 1st high pressure introduction groove 53a... End part 53b... End part 54 ... driven side first high-pressure introduction groove 54a ... end portion 54b ... end portion 60 ... second side plate 60a ... sliding surface 60b ... non-sliding surface 61 ... drive side second shaft hole 62 ... driven side second shaft hole 63 ... Drive-side second high-pressure introducing groove 63a...End 63b...End 64...Driven-side second high-pressure introducing groove 64a...End 64b...End VC1...First virtual circle VC2...Second virtual circle 101...Gear pump 150... 1st bearing member 151... Bearing 152... Bearing 153... Gasket 154... Drive side 1st high pressure introduction groove 155... Driven side 1st high pressure introduction groove 160... 2nd bearing member 161... Bearing 162... Bearing 163... Gasket 164... Drive side Second high pressure introducing groove 165... Second high pressure introducing groove on driven side

Claims (6)

A pair of gears (10, 20) that are helical gears,
A casing (30) having an internal space (31) for accommodating the pair of gears (10, 20);
A first member (50, 150) that is in sliding contact with one end surface of the pair of gears (10, 20) in the axial direction;
A second member (60, 160) that is in sliding contact with the other end surface of the pair of gears (10, 20) in the axial direction,
The internal space (31) of the casing (30) is divided into a high pressure region (31a) and a low pressure region (31b) by the pair of gears (10, 20),
The first member (50, 150) is provided on a first sliding surface (50a, 150a) that is in sliding contact with the pair of gears (10, 20), and a first groove (communicating with the high pressure region (31a) ( 53, 54, 154, 155),
The second member (60, 160) is provided on a second sliding surface (60a, 160a) that is in sliding contact with the pair of gears (10, 20), and a second groove (communicating with the high pressure region (31a) ( 63, 64, 164, 165),
The low pressure region (31b) end portion (53b, 54b) of the first groove (53, 54, 154, 155) and the low pressure region (31b) of the second groove (63, 64, 164, 165). While one of the side ends (63b, 64b) communicates with the tooth groove (13) between the pair of adjacent teeth (11, 21) of each gear (10, 20). , The end (53b, 54b) of the first groove (53, 54, 154, 155) on the low pressure region (31b) side and the low pressure region (31b) of the second groove (63, 64, 164, 165). )-Side end portions (63b, 64b) and the other of the first grooves (53, 54, 154, 155) on the low pressure region (31b) side and the second end portion (53b, 54b). One of the ends (63b, 64b) of the grooves (63, 64, 164, 165) on the low pressure region (31b) side communicates with the tooth groove (13). , Gear pump (1, 101) or gear motor. A gear pump (1, 101) or gear motor according to claim 1,
The low pressure region (31b) end portion (53b, 54b) of the first groove (53, 54, 154, 155) and the low pressure region (31b) of the second groove (63, 64, 164, 165). The gear pump (1, 101) or the gear motor, characterized in that the side end portions (63b, 64b) communicate with the tooth groove (13) substantially at the same time. A gear pump (1, 101) or gear motor according to claim 1,
With the center of rotation (C1, C2) of each gear (10, 20) as the center, the maximum position of the end (53b, 54b) of the first groove (53, 54, 154, 155) on the low pressure region (31b) side. An imaginary circle passing through the outer point (P1) is defined as a first imaginary circle (VC1), and the low pressure region (31b) of the second groove (63, 64, 164, 165) is centered on the rotation center (C1, C2). If a virtual circle passing through the outermost point (P2) of the side end portions (63b, 64b) is defined as a second virtual circle (VC2),
The end point (11a1) of the one tooth surface (11a) of each gear (10, 20) on the first member (50, 150) side on the first virtual circle (VC1) is the second virtual circle ( With respect to the rotation direction (R1, R2) of each gear (10, 20) than the end point (11a2) of the one tooth surface (11a) on the second member (60, 160) side on VC2). , Is offset by the first angle θ1 in the delay direction,
The end portion (53b, 54b) of the first groove (53, 54, 154, 155) on the low pressure region (31b) side is the low pressure region (31b) of the second groove (63, 64, 164, 165). ) Side end portions (63b, 64b) with respect to the rotational direction (R1, R2) of each of the gears (10, 20), the second angle θ2 is shifted to the delay direction side,
The angle range of the arc portion (VC11) in the tooth groove (13) of the first virtual circle (VC1) viewed from the rotation center (C1, C2) is θ3, and the second virtual circle (VC2) is If the angle range of the arc portion (VC21) in the tooth groove (13) viewed from the rotation center (C1, C2) is θ4,
θ1-θ4<θ2<θ1+θ3
The gear pump (1, 101) or the gear motor, characterized in that A gear pump (1, 101) or gear motor according to claim 3,
The gear pump (1, 101) or the gear motor, wherein the first angle (θ1) and the second angle (θ2) are substantially equal to each other. A gear pump (1) or gear motor according to any one of claims 1 to 4,
The first groove (53, 54, 154, 155) is provided on the outer peripheral edge of the first member (50, 150),
The gear pump (1, 101) or the gear motor, wherein the second groove (63, 64, 164, 165) is provided on the outer peripheral edge of the second member (60, 160). A gear pump (1, 101) or gear motor according to claim 5,
The gear at the end point of the tooth tip (11b) of the gear (10, 20) on the first member (50, 150) side and the end point of the tooth tip (11b) on the second member (60, 160) side. The deviation amount of the angular position of (10, 20) with respect to the rotation center (C1, C2) is determined by the end portion (53b, 54b) of the first groove (53, 54, 154, 155) on the low pressure region (31b) side. And the amount of deviation of the angular position of the second groove (63, 64, 164, 165) from the low pressure region (31b) side end (63b, 64b) with respect to the rotation center (C1, C2). Gear pump (1, 101) or gear motor, characterized in that they are equal.

Images