JPS591118Y2 - Gear pump or motor bearing mechanism - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a bearing mechanism for a gear pump or motor in which a pair of bearings butted against each other holds the shaft of a gear by a bush.

A bearing mechanism of this type, for example, as shown in FIG. 8, has been known in the past.

In other words, this bearing is a mechanism, a pair of bearings are bushes 1,
A hole 6 for inserting a positioning pin 5 is formed in each of the abutting surfaces 3 and 4 of the two bearings, and the positioning pin 5 is inserted into the hole 6 to position the bushes 1 and 2 of both bearings. That's what I do.

However, in this case, since the hole 6 is formed by machining, it is inevitable that some positional error will occur, and the positioning pin 5 and hole 6 must be loosely fitted in consideration of dimensional tolerances.

If the pin 5 and hole 6 are loosely fitted as shown above,
The relative relationship between the bushings of both bearings will be misaligned.

In this case, there is no problem as long as the bushes are deviated in the axial direction, but if the relative relationship between them is deviated in the direction orthogonal to the axis, the following problem arises.

That is, if both bushings shift in the direction perpendicular to the axis and the positions of the relief grooves 7 and 8 shift in that direction, pressure loss will occur when the trapped oil is discharged.

In addition, the locking pressure within the tooth groove changes intermittently, which causes noise and, in some cases, significantly reduces the volumetric efficiency.

In addition, if the relative relationship between the lobe surfaces 9 and 10 shifts in the above direction, the bushing seal may break.

However, since the bushings of both bearings are displaced in the axial direction, the above-mentioned drawbacks do not pose a problem.

Not only is this not a problem, but being able to move in the axial direction as described above is even more convenient because dimensional tolerances regarding the position of the hole 6, etc. can be corrected.

The purpose of this invention is to provide a mechanism in which the bushings of both bearings can move relative to each other in the axial direction, but prevent the bushings from moving in the direction perpendicular to the axis.

First, the first embodiment shown in FIGS. 1 to 4 will be described.

A gear 12.13 is housed inside the case body 11, and bushings 14 to 17 are arranged on both sides of the gear 12.13 as bearings for holding the gear shaft, and a cover 18. It is blocked by 19.

Note that the above-mentioned bearings are made up of sets of bushes 14, 15, and 16, and 17, respectively, and the configuration of each set is substantially the same, so that the bushes 14 and 15 side of the bearing will be explained below.

The bearing is a bush 14 located outside the case body 11.
．． A recessed surface 2° is formed around the hole into which the seal 15 is fitted, and an outer seal member 21 is fitted around the recessed surface 20.

The bearing installed in the case body 11 is a bushing 14.
．． The outside of 15 is formed in two stages.

That is, the relative position corresponding to the range where the inside of the tooth groove of the gears 12 and 13 is maintained at a low pressure is set at the same level as the cover joint surface of the case body 11, and the position corresponding to the range where the inside of the tooth groove is maintained at a high pressure. The corresponding relative position is set to the recessed surface 20.
are at the same level.

In addition, the outer side of each bearing has a rolled bushing 22.23 fitted into the bushing 14.15, which is on the same level as the cover joint surface.
And an inner seal member 24 is fitted around the relevant position corresponding to the range where the inside of the tooth groove is maintained at a low pressure.

On the outer surfaces of the bushes 14 and 15, the lever bearing has a high pressure area 25 between the outer seal member 21 and the inner seal member 24, and a low pressure area 26 within the inner seal member 24.

In addition, if the correspondence between the bushings 14 and 15 of the bearing is misaligned, the rope surfaces 27 and 28 of the bushings of both bearings will be misaligned.
It has been made clear in the above conventional explanation that the inner seal member 24 may break due to this.

In the high pressure area 25, the bearing has a concave notch 2 formed on the side surface of the bushing 14.15, that is, the side surface corresponding to the discharge side.
High pressure oil on the discharge side is introduced from 9, and this high pressure area 25
It balances the pressure in the tooth groove corresponding to the

Also, one end is opened to the recessed part 30.31 formed on the suction side of the inner surface of the bearing bushing 14.15, which is the contact surface with the gear, and the other end is opened to the outer surface of the bearing bushing 14.15. At the same time, parallel to the axis, the bearing enters the suction side into the low pressure area 26 via the oil passage hole 34 formed by the recesses 32, 33 formed in the abutting surfaces 39, 40 of the bushes 14, 15. Low pressure oil is introduced and balances the pressure in the tooth space corresponding to this low pressure area 26.

The low pressure oil introduced into the low pressure area 26 via the oil passage hole 34 passes through the groove 35.36 shown in FIG. It is then returned to the suction side.

In addition, the bearing numbers 43 and 44 in the figure are bushings 14 and 15.
This relief groove is formed at a position connected to the recessed notch 29 on the inner surface of the tooth groove, and is used to release the soaked oil in the tooth groove to the discharge side. It has been made clear in the conventional explanation that if the relationship deviates, the relief grooves 43 and 44 will be misaligned, resulting in pressure loss and noise.

The bearings configured as described above have the bushings 14 and 15.
Recesses 45 and 46, which are the gist of this invention, are formed.

That is, these four parts 45 and 46 have one end attached to the bushing 1.
The abutting surfaces 39.4.15 are open to the outer surfaces of the abutting surfaces 39.
40.

A positioning pin 47 is inserted into the hole formed by the concave portions 45, 46, and the bearing is positioned by this positioning pin 47 so that the bushes 14, 15 do not deviate from each other.

Both bearings thus positioned are bushes 14.
15 is movable relative to the pin 47 direction, that is, the axial direction.

As described above, the hole into which the positioning pin 47 is inserted is located in the recess 4.
5.46, but since the recesses 45 and 46 are formed in the abutting surfaces 39 and 40, they can be formed by casting and can maintain higher precision.

Therefore, the most important point in this invention is that the bearing has recesses 45.4B formed in the abutting surfaces 39 and 40 of the bushings 14 and 15, and the positioning pin 47 is inserted into the hole formed by these recesses. be.

Taking this point into consideration, the oil passage hole 3 that forms the circulation path for low-pressure oil
It is clear that a hollow positioning pin may be inserted into the locating pin 4, or even into the high-pressure oil circulation path as in the second embodiment shown in FIGS. 5-7.

Therefore, next, the second embodiment will be explained.

The outer sides of the bushings 49.50 housed in the case body 4B are made to protrude outward from the recessed surface 72 similar to the first embodiment and are at the same level as the cover joint surface of the case body 48.

On the outer surface of the bushing 49.50, which is on the same level as the cover joint surface, a groove 52.53 is formed halfway around the side path of the pump's discharge hole 51. An inner seal member 55 is fitted to the outer periphery of the bushing 49 and 50 on the suction hole 54 side.

The grooves 52 and 53 are formed wider than the inner seal member 55, so when the inner seal member 55 is fitted, a space is created within the groove 52 and 53, but this space is used as a passage. It is set at 56.

A high pressure area 58 is formed between the inner seal member 55 and an outer seal member 57 fitted around the recessed surface 72, and a low pressure area 59 is formed inside the inner seal member 55.

High pressure area 5B and low pressure area 5g on the outside as above
The inner surface of the bushing 49.50 has a configuration shown in FIG. 5.

That is, low pressure introduction holes 60 and 61 are formed on the suction hole 54 side of the case body 48.

The low pressure oil introduced from the low pressure introduction holes 60 and 61 reaches the low pressure area 59 via the periphery of the gear shaft, and is further returned to the suction hole 54 from the low pressure outlet hole 62 formed in the low pressure area 59. It is.

In addition, in the discharge hole 51111J, the high pressure introduction hole 6
3 is formed.

As is clear from FIG. 7, this high pressure introduction hole 63 is
Both bearings are formed by recesses 66 and 67 formed in abutting surfaces 64 and 65 of bushes 49 and 50.

That is, the recesses 66 and 67 have both ends open to both side surfaces of the bearing bush 49.50, and are positioned opposite to each other and parallel to the axis to form the abutment surface 64.65. In addition, the sides of the recesses 66 and 67 that contact the outside of the bushings 49 and 50 are large diameter portions 66a and 67a.

Therefore, when the bushings 49 and 50 of both bearings are butted together, the recesses 66 and 67 join together to form the high pressure introduction hole 63, but a hollow positioning pin 68 is inserted into the large diameter portions 66a and 671. So, this positioning pin 6
8, the bushings 49 and 50 of both bearings are positioned without being offset from each other.

Note that a plurality of notches 68a are formed at one end of the positioning pin 6B, that is, the side that contacts the cover (not shown) of the case body 4B, so as not to block the flow path of the high pressure introduction hole 63. There is.

The bearing has a concave portion 69.70 formed around the opening at one end of the high pressure introduction hole 63 on the inner surface of the bushing 49.50.
It opens in 6.

Further, the high pressure area 58 passes through the discharge hole 51 through a high pressure outlet hole 71 formed by a notch formed in the case body 48 and a bush 49,50.

However, when the gear is now rotated, the oil sucked in from the suction hole 54 passes around the gear and is discharged from the discharge hole 51.

At this time, the low pressure oil introduced from the low pressure introduction hole 60.61 is
The high-pressure oil that circulates as described above and is trapped in the tooth grooves on the discharge side is compressed during the rotation process of the gear and is forcibly fed into the high-pressure introduction hole 63.

The high-pressure oil sent into the high-pressure introduction hole is introduced into the high-pressure area 5B via the passage 56, and is also pushed out from the high-pressure outlet hole 71 to the discharge hole 51.

That is, the high pressure oil on the discharge hole 51 side flows through the high pressure introduction hole 63, the passage 56, the high pressure area 58, and the high pressure outlet hole 71.

As is clear from the above description, according to the mechanism of the bearing described in claim 1, the bearing has recesses formed on both abutting surfaces of the bushing, and a positioning pin is inserted into the hole formed by the recesses. Since the recess is inserted, the recess can be formed by casting, and positional errors will not occur.

In addition, since the recess is made parallel to the axis and the bushing of the bearing can be moved only in the axial direction, there is some dimensional error in the length of the positioning pin and the length of the recess. Even if there is, it will be corrected dynamically.

Moreover, since the bushes of both bearings are pressed against the side surfaces of the gear depending on the pressure in their high pressure area or low pressure area, the pressure balance can always be maintained in an optimal state.

According to the mechanism of the bearing described in claim 2, the positioning pin is inserted and hung using a part of the pressure oil path, so there is no need to form each of the recesses separately, and the bearing is more efficient. It is true.

[Brief explanation of the drawing]

Figures 1 to 4 show the first embodiment of this invention.
Figure 1 is a longitudinal side view of the case body and cover, Figure 2
The figure shows a perspective view of the bushing and positioning pin for one bearing.
Figures 3 and 4 show the inner and outer views of both bearings with their bushes butted against each other, and Figures 5 to 7 show the two bearings.
Fig. 5 is a sectional view of the bearing taken along the inner surface of the bushing, Fig. 6 is a side view of the case body with the cover removed, and Fig. 7 is a sectional view of one of the bearings taken along the inner surface of the bushing. FIG. 8 is a perspective view showing a conventional configuration. 14, 15.49.50... The bearing is a bush, 39.
40.64°65...butting surface, 45.46.66
, 67... recess, 47.6B... positioning pin.

Claims (2)

[Scope of utility model registration request] (1) A pair of bearings have bushings that butt each other, and each of these bearings holds the shafts of a pair of gears by the bushings.In a mechanism, the bearings of a gear pump or motor are arranged so that the bushings are butted against each other. A positioning pin is inserted into the hole formed by the above four parts of both bushings, and these bearings hold the bushings relative to each other only in the axial direction. The bearing of a gear pump or motor that makes it movable is a mechanism. (2) The bearing has a recess parallel to the axis on the butting surface of the bushing, with both ends open to both sides of the bushing.
A bearing for a gear pump or motor according to claim 1, wherein a hole formed by these recesses is used as a part of a pressure oil path, and a hollow positioning pin is inserted into the hole. is a mechanism.