JPH10103256A - Gear pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly feed lubricant in a bearing in a simple constitution even if high pressure is applied to either a suction port or discharge port. SOLUTION: Movable members 12, which have an orifice section 12a at a part, are axially and slidably arranged in the lubrication grooves 4b, 5b arranged in the inner peripheries of bearings 4 and 5 in their axial directions. Since this movable member 12 is constituted so as to be displaced to the side of the port wherein the pressure becomes low energized by the differential pressure working on both ports, to whichever port, a suction port or a discharge port, high pressure is applied, the bearings can be properly lubricated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear pump suitably used for transferring a high-viscosity fluid such as a polymer such as a molten synthetic resin or a chemical.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional gear pump includes a pair of gears 2 and 3 in an eyeglass hole 10 provided in a body 1.
Are housed in mesh with each other, and a drive shaft 2a on which one gear 2 is mounted and a driven shaft 3a on which the other gear 3 is mounted are supported by bearings 4 and 5 disposed in the body 1. Both ends of the body 1 are covered with a pair of a front cover 6 and a rear cover 7, and a suction port 8 is provided on a side where the teeth of the gears 2 and 3 gradually separate from each other, and a side where the teeth gradually meet. Are provided with discharge ports 9 respectively. And drive shaft 2
a, when the two gears 2 and 3 are synchronously and reversely driven through
The liquid sucked from the suction port 8 is used for the gears 2 and 3 and the body 1.
It is possible to perform a well-known pumping action of confining in a volume space formed between them and moving the space to the discharge port 9 side.

[0003] On the other hand, recently, self-lubrication type gear pumps in which the bearings 4 and 5 are self-lubricated by using a hydraulic fluid have been relatively frequently used. The pump shown in FIG. 5 is also of that type, and lubrication extending along the axis and opening at both end surfaces of the bearings 4 and 5 is provided on the inner periphery of the bearings 4 and 5 disposed on the rear cover 7 side. Grooves 4a, 5a
The starting ends of these lubrication grooves 4a, 5a extend further perpendicularly and open to the discharge port 9. A return hole 1b extending along the axis and opening at both end surfaces of the body 1 is provided within the thickness of the body 1 and at a position facing the axis of the lubrication grooves 4a, 5a. The end of 1b is opened to the suction port 8. Further, the inner surface 7b of the rear cover 7 is provided with a return groove 7a having both ends facing the ends of the lubrication grooves 4a and 5a and the start end of the return hole 1b. A return line composed of the discharge side lubrication grooves 4a and 5a, the return groove 7a and the return hole 1b is formed, and a part of the liquid of the discharge port 9 is supplied to the bearings 4 and 5 through the return line. It is supplied and then returned to the suction port 8. Similarly, the bearing 4 disposed on the front cover 6 side,
5, a recirculation system composed of lubrication grooves 4b and 5b, a recirculation groove 6a and a recirculation hole 1c is formed, and a part of the liquid of the discharge port 9 is supplied to the bearings 4 and 5 through the recirculation system. Supply to
Thereafter, the suction port 8 is returned to the suction port 8.

In such a configuration, as shown in FIG. 5, lubrication grooves 4a, 5a, 4b, 5b in the bearings 4, 5 are provided.
The large-diameter portion 14 is formed near the end of the front and rear covers 6 and 7 and formed as an orifice portion 11 so that the working fluid does not flow smoothly into the large-diameter portion 14 without obstructing the inside of the large-diameter portion 14. The working fluid is positively lubricated into the bearings 4 and 5 by setting an appropriate liquid pool state.

[0005]

However, for example, in the case of a gear pump or the like used after an extruder, the hydraulic fluid is pressure-fed from the extruder to the gear pump in a high pressure state, and the pressure on the suction port side is often increased by the pressure on the discharge port side. May be higher than the pressure. Assuming that the pressure on the suction port side is Ps, the pressure on the discharge port side is Pd, and the pressure in the bearing is Pm, the inside of the gear pump is in a pressure state of Pd <Pm <Ps. When the pressure Ps on the suction port side is higher than the pressure Pd on the discharge port in the pressure state of Pd <Ps, the lubrication path of the hydraulic fluid is in the pressure state of Pd> Ps in which the pressure on the discharge port side is high. It becomes the reverse route to the case. At this time, if the orifice portion in the lubrication groove is fixed to the front and rear cover side, the hydraulic fluid is throttled at the inflow start end side, and the large-diameter portion of the lubrication groove does not stay in the liquid state, and as a result, The liquid does not actively flow into the inner circumferential portion of the bearing. For this reason, poor lubrication is caused in the bearing, causing problems such as damage and seizure of the shaft and the bearing.

The present invention has been made in view of such a problem, and it is possible to quickly supply the lubricating liquid into the bearing even when the suction port side or the discharge port side is in a high pressure state. It is intended to provide a gear pump.

[0007]

In order to achieve the above object, the present invention employs the following configuration. That is, in the gear pump of the present invention, a pair of gears are accommodated in an eyeglass hole provided in the body so as to be synchronously and reversely rotatable in a meshing state, and a discharge port and a suction port are provided on a side where the teeth gradually mesh and a side where the teeth gradually separate. A gear pump comprising a port, and a lubrication groove provided in the inner periphery of a bearing for supporting the shaft of the gear along the axial direction, the lubrication groove having one end communicating with a discharge port and the other end communicating with a suction port. A movable member having an orifice part is slidably disposed in the groove along the axial direction.

With this configuration, when one of the pressures of the discharge port and the suction port becomes relatively high with respect to the other, the movable member is applied by the differential pressure acting on both ends thereof. It is urged to slide in the lubrication groove, and is displaced to the port side where the pressure becomes low. Therefore, in any case, the transfer fluid will flow to the orifice portion after passing through the large-diameter portion in the lubrication groove, and the large-diameter portion will have an appropriate liquid pool regardless of the use condition of the pump. The lubrication effect is maintained in the proper state.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. Parts common to those in FIG. 5 are denoted by the same reference numerals. This gear pump, as shown in FIG.
A pair of gears 2 and 3 respectively mounted on a driving shaft 2a and a driven shaft 3a are housed in an eyeglass hole 10 provided in the body 1 in a meshing state with each other. Are rotatably supported by slide bearings 4 and 5 which also serve as sliding seals on the tooth side surfaces. Both ends of the body 1 are sealed by a front cover 6 and a rear cover 7. Then, with the synchronous reverse rotation of the gears 2 and 3 under meshing, the volume space surrounded by the gears 2 and 3 and the inner periphery of the body is moved, and the suction port provided on the side where the teeth are gradually separated from each other. A well-known pumping action of sucking liquid from the port 8 and gradually discharging the liquid to a discharge port 9 provided on the side where the teeth mesh with each other is performed.

On the other hand, a bearing 4 disposed on the rear cover 7 side,
On the inner periphery of 5, lubrication grooves 4a, 5a extending along the axis and opening at both end surfaces of the bearings 4, 5 are engraved, and the starting ends of these lubrication grooves 4a, 5a extend further at right angles. Discharge port 9
It is open to. A return hole 1b extending along the axis and opening at both end surfaces of the body 1 is provided within the thickness of the body 1 and at a position facing the axis of the lubrication grooves 4a, 5a. The end of 1b is opened to the suction port 8. Further, the lubrication groove 4 is provided on the inner surface 7b of the rear cover 7.
A return groove 7a having both ends facing the ends of a, 5a and the start of the return hole 1b is provided. A recirculation system composed of the lubrication grooves 4a, 5a, the recirculation groove 7a and the recirculation hole 1b is formed. A part of the liquid of the discharge port 9 is supplied to the bearings 4, 5 through the recirculation system. Thereafter, the suction port 8 is returned to the suction port 8.

Similarly, the lubrication grooves 4b and 5b, the recirculation grooves 6a, and the bearings 4 and 5 disposed on the front cover 6 side are also provided.
A recirculation system composed of a recirculation hole 1c is provided. A part of the liquid of the discharge port 9 is supplied to the bearings 4 and 5 through the recirculation system, and then returned to the suction port 8. ing.
In such a configuration, as shown in FIG. 2, in the present embodiment, the movable member 12 having an orifice portion 12a is partially provided in the lubrication grooves 4a, 5a, 4b, and 5b.
a, 5a, 4b, and 5b are provided so as to be slidable in the axial direction between both stoppers 13 projecting upward from both ends.

Next, the operation of this embodiment will be described.
When the discharge port 9 side is higher in pressure than the suction port 8 side, as shown by the imaginary line in FIG. 3, the movable member 12 is urged by the differential pressure acting on both ports 8 and 9 to move through the lubrication groove 4a. It slides toward the rear cover 7 which is the low pressure side, and is locked by the stopper 13. At this time, in the lubrication groove 4a, a large diameter portion 15 is formed on the gear 2 side and an orifice portion 12a is formed on the rear cover 7 side, and the hydraulic fluid flowing in from the discharge port 9 passes through the large diameter portion 15 and passes through the orifice. The large-diameter portion 15 circulates with the portion 12a, and the large-diameter portion 15 is in a high-pressure liquid pool state, and the working fluid flows around the inner circumference of the bearing. On the other hand, when the suction port 8 side has a higher pressure than the discharge port 9 side, the movable member 12
As shown by a solid line in FIG. 3, the lubrication groove 4 a slides in the lubrication groove 4 a toward the gear 2, which is a low pressure side, and is locked by the stopper 13. At this time, in the lubrication groove 4a, the large diameter portion 15 is formed on the rear cover 7 side and the orifice portion 12a is formed on the gear 2 side, and the hydraulic fluid flowing from the suction port 8 side flows from the large diameter portion 15 to the orifice portion 12a. And the large-diameter portion 15 is in a state of a high-pressure liquid pool, and the working fluid flows around the inner circumference of the bearing.

That is, the discharge port 9 or the suction port 8
When any one of the pressures becomes relatively high with respect to the other, the movable member 12 is urged by the differential pressure acting on both ends thereof and slides in the lubrication grooves 4a, 5a, 4b, and 5b. To the port side where the pressure becomes low. Therefore,
In any case, the transfer fluid is lubricated grooves 4a, 5a, 4b, 5
After passing through the large-diameter portion in b, the fluid flows to the orifice portion 12a, so that an appropriate lubrication operation is performed regardless of the use state of the gear pump.

With such a structure, the lubricating grooves 4a, 5a of the movable member 12 having an orifice portion 12a in part are provided.
a, 4b, and 5b, the appropriate bearing lubrication action can be performed even when either the suction port 8 or the discharge port 9 becomes high pressure, and seizure of the bearings 4, 5 can be reliably performed over a long period of time. This can be prevented. With such a configuration, the throttling effect and the flow rate can be changed only by replacing the movable members 12 having different orifice diameters. Therefore, the entire bearings 4 and 5 are replaced every time for various purposes and applications. It is not necessary to do so, and it is possible to respond flexibly with only the minimum required specification change.

Further, lubrication grooves 4a, 5a,
Since the stoppers 13 are provided at both ends in 4b and 5b, even if the stopper 13 is at the slide end, a passage for allowing the hydraulic fluid to flow into each port 8 and 9 can be secured, and the hydraulic fluid can be quickly supplied to each port 8, 9 It is possible to flow into. Further, if the stoppers 13 are provided on the bearings 4 and 5 as described above, the movable member 12 can be disposed not only on the rear cover 7 but also on the front cover 6 having a gap between the bearings 4 and 5. Becomes possible.

The form of the movable member 12 is shown in FIG.
As shown in FIG.
A notch 12b may be provided together with a. When such a structure is disposed on the rear cover 7 side, since the hydraulic fluid flows from the orifice portion 12a to the respective ports through the notches 12b, a stopper is provided in the lubrication grooves 4a, 5a. There is no need to provide them.

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

[0018]

The present invention is embodied in the form described above and has the following effects. The gear pump according to the present invention is a gear pump in which a lubrication groove having one end communicating with the discharge port and the other end communicating with the suction port is provided along the axial direction on the inner periphery of the bearing. A movable member having an orifice portion is provided so as to be slidable along the axial direction.

With such a structure, a proper bearing lubricating action can be performed even when either the suction port or the discharge port is at a high pressure through the behavior of the movable member partially having an orifice portion in the lubrication groove. It is possible to reliably prevent seizure of the bearing and the like for a long period of time. In addition, with such a configuration, the throttling effect and the flow rate can be changed simply by exchanging the movable members having different orifice diameters, so that it is flexible with only the minimum necessary specification change for various purposes and applications. Can be handled.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention, with a part thereof broken away.

FIG. 2 is a perspective view showing a bearing in the embodiment.

FIG. 3 is an explanatory view of the operation.

FIG. 4 is an operation explanatory view showing another embodiment of the present invention.

FIG. 5 is a view corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Body 2 ... Gear 2a ... Shaft 3 ... Gear 3a ... Shaft 4 ... Bearing 5 ... Bearing 4a, 4b, 5a, 5b ... Lubrication groove 8 ... Suction port 9 ... Discharge port 10 ... Eyeglass hole 12a ... Orifice part 12 ... Movable Element

Claims (1)

[Claims] A pair of gears are accommodated in a pair of eyeglasses provided in a body so as to be synchronously and reversely rotatable in a meshing state, and a discharge port and a suction port are respectively provided on a side where teeth are gradually meshed and gradually separated. Provided on the inner periphery of the bearing that supports the shaft of the gear,
In a gear pump, one end of which is connected to a discharge port and the other end of which is connected to a suction port, a lubricating groove is provided along the axial direction, wherein a movable member having an orifice part in the lubricating groove is formed along the axial direction. A gear pump characterized by being slidably disposed.