JPH0925883A - Gear pump or motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of early deterioration and damage to a seal member even with the frequent reversal of high-low pressure while securing appropriate pressure balance function. SOLUTION: An elastic seal member 8 mounted to a seal groove of a side plate is composed of a soft seal member 82 performing the function of substantially sealing a high-low pressure partition position making use of its elastic deformation, and a hard seal member 81 disposed on the inner circumferential side of the soft seal member 82 so as to function as a backup member for preventing the excessive deformation of the soft seal member 82. The soft seal member 82 is thereby prevented from being put in such action as to be dragged little by little into the V-shaped area of the seal groove so as to prevent early degradation and damage while securing sealing function in the high-low pressure partition position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear pump or motor of a type in which a high and low pressure region is reversed between a pair of inlets and outlets, such as a rotary motor.

[0002]

2. Description of the Related Art In a gear motor, a pair of gears meshing with each other is arranged in a case, and a pressure liquid is supplied to one of a pair of inlets and outlets that are opened in a meshing portion of both gears to flow from the inlet and outlet. While the liquid is confined in the tooth space of the gear, the liquid is forcibly pressed against the gear while moving to the other inlet / outlet, and at that time, rotational power is applied to the gear. In addition, the gear pump drives the gears in a synchronous reverse rotation,
The liquid sucked from one inlet / outlet is guided to the other inlet / outlet and discharged. In such a gear pump or motor, in order to improve volumetric efficiency and mechanical efficiency, the side surface of the gear must be surely sealed by the side plate, and the side plate is excessively pressed against the side surface of the gear and slides. The pressing force must also be appropriate so that the resistance does not increase.

Therefore, conventionally, as shown in FIG. 17, a seal groove b shown by hatching in the drawing is provided on the surface of the side plate a opposite to the gear side.
A seal member c made of a soft material shown in FIG. 18 is embedded in the seal groove b, and a pressure liquid is introduced from the gear side into a region surrounded by the side plate a, the seal member b, and a case (not shown) so that the side plate is properly formed. It is pushed back to the side surface of the gear by various forces, and it is properly attached to the side surface of the gear to make a sliding seal.

By the way, the high pressure region appearing on the gear side is
Gear mesh position and ± 18 in the circumferential direction from this mesh position
The pump / motor of the type in which the high and low pressures at the inlet and outlet are reversed by use is formed into a three-letter shape that connects a pair of high and low pressure partition positions that are rotated by 0 ° or more, and the high pressure region is the three-letter shape. Or, it appears inverted in one of the inverted three-letter shape. Therefore, as the seal member c, as shown in the figure, a seal member having a figure 8 shape and formed with angular protrusions d at four portions corresponding to the high and low pressure partition positions is used, and the high pressure region is 3 The hydraulic pressure can be balanced whether it is a letter shape or an inverted three-letter shape.

[0005]

By the way, the seal member c shown in FIG. 18 has a solid cross section.
Therefore, for example, when a high pressure in the shape of a letter 3 is generated on the gear side and the pressure liquid is introduced to the surface of the side plate on the side opposite to the gear, the seal member c is pressed against the high pressure liquid. Internal stress is generated, and this internal stress is transmitted in the longitudinal direction, and the mountain-shaped region c ₁ on the high-voltage side is separated by the high-low pressure partition position.
Applies a compressive force to the “<”-shaped region c ₂ on the low pressure side. Along with this, a pulling force acts on the "V" shaped area c ₂ on the opposite side. For this reason, when the high and low pressures are reversed and a repeated load is applied, the "V" shaped region c ₂ of the seal member flaps due to repeated compression / expansion in the directions of arrows e and f in the figure, causing early deterioration. together becomes, when the internal stress of the "V" shaped region c ₂ the sealing member acts as a compressive force reduces the sealing ability from the seal groove b for sealing member c is released to stress floats perpendicularly Or cause a problem of premature damage. Also, when the seal member c floats, the side plate a
Is improperly urged to the side surface of the gear, which causes a problem that causes a decrease in volumetric efficiency due to the occurrence of torque cross and the side plate a being pushed one side.

In order to eliminate such a problem, FIG.
Sealing member g shown in 9, Yamagata g ₁ is always high
Is L-shaped in cross section, and the other "V" -shaped region g ₂ is U-shaped in cross section as shown in FIG. That is, the thing, "V" seal member g in shaped region g ₂ fluid pressure is balanced by the external and internal U-shaped, the internal stress is not easily transmitted to the longitudinal direction of the seal member, the solid described above Problems such as the seal member c can be eliminated. However, since the high pressure also flows into the low pressure area through the inside of the U-shape, the pressure balance between the side plate a and the surface of the side plate a on the gear side is lost, and the side plate is strongly pressed against the side surface of the gear. For this reason, it also causes torque cross, and side leakage increases, which causes a problem that volumetric efficiency of the pump or motor is significantly reduced.

Therefore, in order to cope with such a problem, the seal member h shown in FIGS. 21 and 22 that the present inventor has recently proposed has a cross section U in which the mountain-shaped region h ₁ which is always high in pressure is crossed.
It is formed into a V shape, and the "V" shaped area h ₂ is made solid. However, the high and low pressures are reversed, and along with this, the protrusion i
From "V" shaped area h ₂ opposite to the pulling force compressive force or acts on the high pressure applied to the engagement side when the or acts, the protrusions i "V" over the shaped area h ₂ of the seal members h It must be given only by elastic strength. For this reason, the problem that this part is damaged in a short time cannot be wiped out.

The present invention has been made in view of such a problem, and the side plate is kept in contact with the side surface of the gear under proper pressure balance even when the high and low pressure regions are reversed by use. It is an object of the present invention to provide a hydraulic pump or motor capable of reliably improving the reliability and durability of the seal member.

[0009]

In order to achieve the above object, the present invention employs the following configuration.

That is, in the gear pump or motor of the present invention, a pair of gears that mesh with each other are arranged in the case, and the entire gear has a figure 8 shape between the gear side surfaces and the case, and the gears are connected to each other from the meshing position. A side plate having a seal groove formed by recessing the high- and low-pressure partition positions rotated by ± 180 ° or more in the circumferential direction in the radial direction on the side opposite to the gear is interposed, and an elastic seal member is mounted in the seal groove of the side plate. In the configuration in which the pressure liquid is introduced from the high pressure area on the gear side into the area surrounded by the side plate, the seal member and the case,
The elastic seal member is a hard seal member having a figure 8 shape substantially corresponding to the shape of the seal groove and having angular protrusions at high and low pressure partition positions, and a region where the high pressure and the low pressure are constantly high. And a soft seal member having angular protrusions at high and low pressure partitioning positions, and the hard seal member and the soft seal member are attached to the seal groove so that the latter closely contacts the outer circumference of the former. It is characterized by being attached.

As a concrete embodiment, the hard seal member and the soft seal member are provided more than the width and depth of the seal groove corresponding to the "V" shape region in which only the hard seal member is provided. The width and depth of the seal groove corresponding to the chevron region may be made wider and deeper.

In this case, in order to prevent the soft member from rising from the seal groove, the soft seal member is made to have a Z-shaped cross section, and the seal groove corresponding to the chevron region has a groove bottom side of the hard seal member. It is effective to let them dive into.

In particular, in order to facilitate the formation of the seal groove, the width-depth ratio of the seal groove corresponding to the V-shaped region is set to approximately 1: 1 and the width of the seal groove corresponding to the chevron region is set. It is desirable that the ratio of the depth to the depth is about 1: 1.

With such a structure, when a high pressure is applied to the gear side and the high pressure is introduced to the side surface of the side plate opposite to the gear side, the high pressure is applied to the seal groove corresponding to the chevron region. The high pressure liquid acts on the soft seal member. Then, by elastically deforming this soft seal member,
The protrusions arranged at the high and low pressure partitioning positions are preferably pressure-bonded to the angular recesses of the seal groove to clearly separate high pressure and low pressure. Moreover, such elastic deformation of the soft seal member is backed up by the hard seal member arranged on the inner periphery of the soft seal member and excessively elastically deformed to the extent that the soft seal member is pushed into the "V" shaped region of the seal groove. Absent. Therefore, even if the high and low pressures are frequently reversed, and the compression / pulling force is repeatedly applied to the elastic body seal member due to this, the seal portion arranged in the "V" shaped region of the seal groove may be prematurely fatigued or It is possible to effectively eliminate problems that lead to damage. This makes it possible to effectively enhance the durability of the elastic body seal member and achieve an ideal pressure balance regardless of the high pressure at either the inlet or the outlet, thereby effectively improving the volumetric efficiency and mechanical efficiency. .

In particular, the seal corresponding to the chevron region in which both the hard seal member and the soft seal member are disposed, rather than the width and depth of the seal groove corresponding to the "dogleg" region in which only the hard seal member is disposed. When the width and depth of the groove are made wider and deeper, a necessary and sufficient mounting space is secured for both seal members, and a proper mounting state can be realized.

In this case, when the soft seal member has a Z-shaped cross section and is made to penetrate into the groove bottom side of the hard seal member in the seal groove corresponding to the chevron region, hydraulic pressure is applied to the soft seal member. Even if an urging force acting in a direction of floating from the seal groove is generated due to the action, the soft seal member can be reliably retained in the seal groove. Therefore, it is possible to prevent the soft seal member from falling out of the seal groove and the increase in the side gap caused by the seal member widening the gap between the gear and the side plate due to this.

In particular, the width-depth ratio of the seal groove corresponding to the V-shaped region is approximately 1: 1 and the width-depth ratio of the seal groove corresponding to the chevron region is also approximately 1: 1. In this case, the seal groove can be properly formed on the side plate. That is,
Generally, a sintered product is used for this kind of side plate, and when such a groove is formed in the sintered product, the groove width and the groove depth are approximately 1:
This is because by setting it to 1, processing can be performed most easily and effectively.

As described above, according to the gear pump or the motor of the present invention, the elastic seal member is mainly the soft seal member for ensuring the sealing property at the high and low pressure partition positions, and the hard seal for backing up the soft seal member. Since it is composed of a member, it is necessary to secure an appropriate pressure balance state of the side plate to effectively improve the volumetric efficiency and mechanical efficiency of the pump or motor, and prevent early fatigue and damage of the seal member to reliably improve the durability. The excellent effect of being able to do is exhibited.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIG.
This will be described with reference to FIGS.

FIG. 1 is a vertical sectional view of the gear pump.
2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is a sectional view taken along line III-III in FIG.

This gear pump has a front case 1 and
A pair of gears 3 and 4 is provided between the body and the rear case 2
Are housed in a meshed state. The rear case 2 is the joining end surface 2
The eyeglass-shaped hole 21 is opened in a portion adjacent to a, and the bearing holes 22, 23 are formed in the inner end surface 21a of the hole 21.
And bushes 24 in their bearing holes 22 and 23, respectively.
25 is inserted. The front case 1 is also provided with bearing holes 12 and 13 at portions corresponding to the bearing holes 22 and 23, and the bushes 14 and 13 are similarly provided in the bearing holes 12 and 13.
15 is inserted. And the bushes 14, 24
The drive shaft 31 having the drive gear 3 mounted thereon is supported by the bushes 15, 25, and the driven shaft 41 having the driven gear 4 mounted thereon is supported by the bushes 15, 25. The rear cover 2, as shown in FIG.
A pair of entrances and exits 6 at positions facing the meshing portion O of the gears 3 and 4,
7 are opened.

Further, one side surface 3a of the gears 3, 4 is
4a and the rear case 2, and the other side surface 3b,
Side plates 5 are respectively disposed between the front case 1 and the front case 4b. The side plate 5 includes the side surfaces 3a of the gears 3 and 4,
3b, 4a, 4b for sealing the volume space, and as shown in FIG. 4, the overall contour has a shape in which gears 3, 4 meshing with each other are projected from the axial direction.
Two shaft holes 51 and 52 are punched out.

In FIG. 2, the liquid that has flowed in from one of the inlets / outlets 6 or 7 is allowed to flow out to the other of the inlets / outlets 7 or 6 so that it can function as a pump or a motor. In other words, when this pump / motor operates as a motor, the pressure liquid supplied to one of the inlets / outlets 6 and 7 is forcibly pressed against the gears 3 and 4 while the pressure liquid is confined in the tooth space, while the other inlet / outlet 7 is opened. 6, the rotational power is applied to the gears 3 and 4 in the meantime. Further, when performing a pumping action, the gears 3 and 4 are driven in a synchronous reverse rotation by an external power source to guide the liquid sucked from one of the inlets and outlets 7 to the other and discharge it.

In such a gear pump or motor, in order to enhance volumetric efficiency and mechanical efficiency, the gears 3, 4 are
It is necessary to surely seal the side surfaces 3a, 3b, 4a, 4b of the gears by the side plate 5, and moreover, the side plate 5 may be excessively pressed against the gear side surfaces 3a, 3b, 4a, 4b to increase the sliding resistance. The pressing force must be appropriate so that it will not occur. That is, when the gear pump or the motor is operated, for example, as shown in FIG. 5, the meshing position O of the gears 3 and 4 and ± 180 in the circumferential direction from this meshing position O.
A pair of high and low pressure partition positions P and Q that are rotated by more than °
The area in the shape of the letter 3 between and becomes high pressure as shown by the hatching in the figure. Also, when this rotates in the reverse direction,
It is inverted so as to be line-symmetric with respect to a straight line connecting the axes of the drive shaft 31 and the driven shaft 41, that is, to form an inverted three-letter shape. The high and low pressure partition positions at this time are R and S. In any case, since the side plate 5 tends to separate from the gear side surfaces 3a, 4a, 3b, 4b in this high pressure region, pressure balance for pushing it back is necessary.

Therefore, a seal groove 53 as shown by hatching in FIG. 4 is provided on the surface of the side plate 5 opposite to the gear side, and the elastic seal member shown in FIG. 6 is mounted in the seal groove 53. .

More specifically, the seal groove 53 is formed in a region where the high pressure and the low pressure are always high, that is, in a mountain-shaped region between the pair of high and low pressure partition positions P-R and Q-S. "1" between the first groove portion 53a to be formed and the other region, that is, between the high and low pressure partitioning positions P-Q and between R-S.
A second groove portion 53b which is formed in a character-shaped region and whose groove width and groove depth are set to about ½ of the groove width and groove depth of the first groove portion 53a, and the high and low pressure partitions. Position P,
Rear case holes 2 which are recessed radially in Q, R, and S
And a third groove portion 53c extending to the position 1. Further, a notch 54 is provided at the longitudinal end of the side plate 5, and the pressure liquid existing on the gear side surface of the side plate 5 is passed through the notch 54 along the thickness direction of the side plate 5 to the opposite gear side surface. I am trying to introduce it. A pressure introducing groove portion 53a ₁ wider than the notch 54 and extending in the radial direction is provided in the central portion of the _first groove portion 53a.

On the other hand, the elastic seal member 8 shown in FIG.
It is composed of a hard seal member 81 having a figure 8 shape and a soft seal member 82 having a chevron shape.

The hard seal member 81 is made of a hard plastic material or the like, and has a semi-circular shape that is fitted in the first groove portion 53a as a whole as shown in FIGS. First seal portion 81a and the second groove portion 5
"B" shaped second seal portion 81b fitted in 3b
And a third seal portion 81c, which is a rectangular protrusion fitted in the third groove portion 53c.
That is, the first seal portion 81a and the second seal portion 81b
Continuously form an 8-shaped endless sealing member, and the third sealing portion 81c constitutes an end-sealing member. In addition, in the hard seal member 81, the second groove portion 53b
The width dimension and the thickness dimension of the second seal portion 81b fitted to the first seal portion 8a are set to the first seal portion 8 fitted to the first groove portion 53a.
The width and the vertical dimension of 1a are set to about 1/2. Specifically, it is realized by making the surface 81 ₁ on the side opposite to the groove bottom flush with the surface 81 ₂ on the groove bottom side.

The soft seal member 82 is made of an appropriate soft material, and has a pair of separated mountain shapes as shown in FIGS. 11 to 13, and has the first groove portion 53a.
And a third seal portion 82c which is a semi-circular first seal portion 82a which is fitted to the third groove portion 53c and which is a square protrusion portion which is fitted to the third groove portion 53c. Moreover, this soft sealing member 82, the first to form a flange portion 82 ₁ a outer peripheral side position offset in a counter-groove bottom side, and displaced to the groove bottom side a inner peripheral side position A second brim portion 82 ₂ is formed on the ridge so that the cross-sectional shape is Z-shaped.

Then, first, the first groove portion 5 of the seal groove 53 is formed.
3a and the first groove of the soft seal member 82 in the third groove 53c.
Attach the seal part 82a and the third seal part 82c of
Then, the first seal portion 81a, the second seal portion 81b, and the third seal portion 81a of the hard seal member 81 are attached to the first groove portion 53a, the second groove portion 53b, and the third groove portion 53c of the seal groove 53.
The seal portion 81c is attached. In this case, as shown in FIG. 14, the first seal portion 81 of the hard seal member 81
a and the soft seal member 8 on the outer periphery of the third seal portion 81c.
The second seal portion 82a and the third seal portion 82c are in close contact with each other, and the first seal portion 8 of the hard seal member 81
The collar portion 82 ₂ of the soft seal member 81 is accommodated in the lower surface of the 1a and the third seal portion 81c in such a manner as to sneak into the groove bottom side.

With such a structure, when a high-pressure region as shown by hatching in FIG. 5 is generated on the gear side surface of the side plate 5 due to the operation of the gear pump or the motor, the liquid enters and exits. 6 or through the notch 54 as shown by the arrow in FIG. 15 to the opposite gear side surface of the side plate 5, respectively, and as a result, the opposite gear side surface is shaded in FIG. High pressure range is generated. Then, an appropriate reaction force is applied to the side plate 5 with respect to the high pressure region generated on the gear side surface. Therefore, the side plate 5 can be attached to the side surfaces 3a, 3b, 4a, 4b of the gears 3, 4 with an appropriate force,
The volumetric efficiency and mechanical efficiency can be effectively improved.

At this time, particularly high and low pressure partition positions P, Q, R,
Focusing on S, the pressure liquid introduced into the first groove portion 53a and the third groove portion 53c of the seal groove 53 causes the elastic force of the first seal portion 82a and the third seal portion 82c of the soft seal member 82 mainly. It is deformed, and in particular, the third seal portion 82c is preferably pressure-bonded to the inner wall of the third groove portion 53c of the seal groove 53 to clearly define high pressure and low pressure. Moreover, such a soft seal member 82 is backed up by the hard seal member 81 arranged on the inner periphery thereof and pushed further into the second groove portion 53b of the seal groove 53, which is in the V-shape. It does not cause excessive elastic deformation.
Further, since the hard seal member 81 has strength as a whole, the second seal portion 81b will not be deformed even if the third seal portion 81c receives a relatively large hydraulic pressure.
Therefore, even if the high and low pressures are frequently reversed, the elastic seal member arranged in the second groove portion 53b of the seal groove 53, which receives the compression / pulling force, is accompanied by this. It is possible to effectively eliminate the problem of fatigue or damage at an early stage, and reliably improve the durability of the elastic body seal member 8. This makes it possible to achieve an ideal pressure balance regardless of which of the inlet ports 6 and 7 has a high pressure, and it is possible to effectively improve the mechanical efficiency.

In particular, the mountain shape in which both the hard seal member 81 and the soft seal member 82 are arranged is larger than the width and depth of the second groove portion 53b having the V-shape in which only the hard seal member 81 is arranged. Since the width and depth of the first groove portion 53a to be formed are made wider and deeper, a necessary and sufficient mounting space can be secured for both seal members 81 and 82, and a proper mounting state is realized. It will be possible.

Moreover, by using such a structure, the soft seal member 82 is made to have a Z-shaped cross section, and is provided on the groove bottom side of the hard seal member 81 in the first groove portion 53a and the third groove portion 53c. Since the soft seal member 82 is submerged, even if hydraulic pressure acts on the soft seal member 82 to generate an urging force in the direction of floating from the first groove portion 53a and the third groove portion 53c, the floating is suppressed and the groove portions 53a, It can be securely stopped in 53c. For this reason, it is possible to prevent the soft seal member 82 from dropping out of the seal groove 8 and the increase in the side clearance caused by the seal member widening the clearance between the gear and the side plate due to this.

In the above embodiment, the first groove 5
It is desirable that the ratio of the groove width to the groove depth in each of 3a, the second groove portion 53b, and the third groove portion 53c is set to approximately 1: 1. This makes it possible to maximize the workability when the side plate 5 is a sintered product.

In addition, the specific configuration of each part is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[Brief description of drawings]

FIG. 1 is an overall vertical sectional view showing one embodiment of the present invention.

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

FIG. 3 is a sectional view taken along line III-III in FIG. 1;

FIG. 4 is a view showing a surface of the side plate on the side opposite to the gear according to the embodiment.

FIG. 5 is a view corresponding to FIG. 2 showing a state when a high pressure region is generated in the embodiment.

FIG. 6 is a perspective view showing an elastic seal member used in the same embodiment.

FIG. 7 is a plan view of a hard seal member that constitutes the elastic seal member.

FIG. 8 is a front view of the same.

FIG. 9 is a perspective view of the hard seal member as seen from the front side.

FIG. 10 is a perspective view of the hard seal member seen from the back side.

FIG. 11 is a plan view of a soft seal member that constitutes an elastic seal member.

FIG. 12 is a front view of the same.

FIG. 13 is a perspective view of the same.

14 is a sectional view taken along line XX in FIG.

15 is a cross-sectional view taken along the line YY in FIG.

FIG. 16 is a view corresponding to FIG. 3 showing a hydraulic pressure balance state of the embodiment.

FIG. 17 is a view of a conventional side plate viewed from the seal groove side.

FIG. 18 is a view showing a seal member mounted in a seal groove of the same side plate.

FIG. 19 is a view showing another conventional seal member.

20 is a cross-sectional view taken along the line AA in FIG.

FIG. 21 is a view showing still another conventional seal member.

22 is a partially enlarged cross-sectional view of FIG.

[Explanation of Codes] P, Q, R, S ... High and Low Pressure Partition Position 1 ... Front Case 2 ... Rear Case 3, 4 ... Gears 3a, 3b, 4a, 4b ... Gear Side 5 ... Side Plate 8 ... Elastic Seal Member 53 ... Seal groove 81 ... Hard seal member 81c ... Projection part (third seal part) 82 ... Soft seal member 82c ... Projection part (third seal part)

Claims (1)

[Claims] 1. A pair of gears that mesh with each other are provided in a case, and between the side faces of the gears and the case,
The entire shape is a figure of 8 and it is ± 180 in the circumferential direction from the meshing position.
A side plate having a seal groove formed by recessing the high- and low-pressure partitioning positions rotated by more than ° in the radial direction is formed on the side opposite to the gear, and an elastic body seal member is mounted in the seal groove of the side plate. And a structure in which a pressure liquid is introduced from a high-pressure region on the gear side into a region surrounded by a case, wherein the elastic seal member has a figure 8 shape substantially corresponding to the shape of the seal groove, and is located at a high / low pressure partition position. Consists of a hard seal member having angular protrusions and a soft seal member having angular protrusions at high and low pressure partitioning positions that form a chevron corresponding to a region where high pressure is always high even when high and low pressures are reversed. A gear pump or a motor, wherein a hard seal member and a soft seal member are mounted in a seal groove so that the latter is in close contact with the outer circumference of the former.