JPH11210646A - Self-lubricating strengthening type of gear type quantitative pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the fixation of a fluid at the axial direction end face and the like of a gear, and the reduction and the variation of the discharge amount at the discharge port of a gear type quantitative pump. SOLUTION: A self-lubricating strengthening type of gear type quantitative pump discharges a fluid from a discharge port 9 at a constant flow rate by providing a gear couple 1 and 2 rotating at a constant speed while engaging each other, in a flow passage for force feeding communicating from a suction port 8 to a discharge port 9, and furthermore, the axial direction end faces of the gear couple 1 and 2 are lubricated by the fluid sucked from the suction port 8. The axial direction end faces of the gears 1 and 2 have ring form seal surfaces 10 in order to prevent the leaking of the fluid more than necessary at the shaft direction end surface of the gears 1 and 2, and recesses 11 formed at the inner sides in the radial direction of the seal surfaces 10 in order to prevent the stagnation and the fixation of the fluid at the axial direction end faces of the gears 1 and 2. Furthermore, flow passages 11, 12, 13, 14, and 15 in order to exhaust the fluid leaked at the axial end faces of the gears 1 and 2, to the outer side of the self-lubricating strengthening type of gear type quantitative pump rapidly, are also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for quantitatively feeding a relatively high-viscosity resin fluid which is easily solidified between a gear and a side plate on both sides of the gear and between the gear and a shaft surface during liquid feeding. The present invention relates to a suitable self-lubrication enhanced gear metering pump.

[0002]

2. Description of the Related Art Conventionally, a relatively high-viscosity resin fluid such as a resin fluid that can be melted, a resin fluid dissolved using a solvent, and a resin fluid containing a monomer is pumped as shown in FIG. A gear metering pump is used. FIG. 9 is a side sectional view of a conventional gear type metering pump. 9, reference numeral 101 denotes a driving gear, 102 denotes a driven gear, and 103 denotes a driving gear.
Is a drive shaft fixed to the drive gear 101; 104 is a driven shaft fixed to the side plate;
Denotes a side plate, and 107 denotes a casing.
FIG. 10 is a front view of the drive gear 101 of FIG. 9, and FIG.
FIG. 11 is a cross-sectional view taken along line XI-XI of FIG. Side plate 1
Fluid fed at a constant flow rate into the gear tooth space from the suction port provided in the drive gear 101 and the driven gear 10
While being held in the second tooth space, the drive gear 101 and the driven gear 102 rotate, and are sent to a discharge port side provided in the side plate 105. Subsequently, the gear type metering pump discharges the fluid at the discharge port at a constant flow rate to the left side of FIG. 9, and thereafter, the above-described steps are continuously repeated.

[0003] This gear type metering pump is a fluid to be pumped,
That is, it is lubricated by the fluid flowing from the suction port.
Specifically, the fluid that leaks into the gear metering pump from the gap between the gear and the side plate causes the drive gear 10
1. The driven gear 102, the drive shaft 103 and the driven shaft 104 are lubricated.

As shown in FIGS. 9 to 11, the conventional drive gear 101 and driven gear 102 have their axial end faces facing the side plates 105 and 106 formed on a single plane. Therefore, the axial end faces of the drive gear 101 and the driven gear 102 and the side plate 10
When the gap between the gears 5 and 106 is small, the leaked fluid becomes difficult to flow inside the gear type metering pump, such as between the axial end face of the gear and the side plate, and therefore,
The fluid solidifies. On the other hand, the axial end faces of the driving gear 101 and the driven gear 102 and the side plates 105, 10
When the gap between the pump and the pump is large, the leakage amount of the fluid leaking into the gear metering pump becomes too large, and the discharge amount at the discharge port of the gear metering pump decreases.
In addition, since the amount of fluid leakage varies due to fluctuations in the supply pressure and discharge pressure of the fluid to the gear metering pump and the change in viscosity, when the amount of fluid leakage is large, the discharge amount at the discharge port greatly varies. . In order to solve this problem, there has been proposed a gear type metering pump provided with an outflow passage for leaked fluid in a portion of the side plate adjacent to the gear (Japanese Patent Laid-Open No. Hei 6-74162).

[0005]

However, this pump is difficult to process because the side plate is processed, and the cost is high. Also, for example, it is difficult to clean the channel and replace parts when the channel is clogged.

[0006]

The gist of the present invention is that a fluid sucked from an inlet is conveyed to the outlet by a gear pair rotating at a constant speed while meshing with each other, and discharged from the outlet at a constant flow rate. In addition, a self-lubrication-enhanced gear type in which a part of fluid sucked from the suction port leaks from a gap between an axial end face of the gear pair and a side plate provided opposite to the end face to lubricate the gear. In the metering pump, an axial end face of at least one gear of the gear pair is formed between the gear and the side plate to prevent fluid from leaking from the suction port to an axial end face of the gear more than necessary. An annular sealing surface for sealing the gear, and a concave portion formed radially inward of the sealing surface in order to prevent stagnation and solidification of the fluid at the axial end surface of the gear, and A pump, wherein a flow path for rapidly discharging fluid that has leaked into the axial end faces of the pair from the recess to the outside of the pump are provided.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view of a first embodiment of a self-lubricating enhanced gear type metering pump (hereinafter, simply referred to as “pump”) according to the present invention. In FIG. 1, 1 is a driving gear, and 2 is a driven gear. These end faces are formed on the XY plane in the figure. Reference numeral 3 denotes a drive shaft fixed to the drive gear 1, and 4 denotes a driven shaft which is not fixed to the driven gear 2 but is fixed to the side plate. The central axes of the drive shaft 3 and the driven shaft 4 are oriented in the Z-axis direction. Reference numerals 5 and 6 denote side plates, and reference numeral 7 denotes a casing. Reference numeral 8 denotes a suction port for filling the gear groove with the fluid to be pumped, and 9 denotes a discharge port for discharging the fluid from the gear groove at a constant flow rate. Reference numeral 10 denotes an annular ring provided on the axial end faces of the drive gear 1 and the driven gear 2 for sealing between the gears and the side plates 5 and 6 so that excessive fluid does not leak to the axial end faces of the gears. Seal surface, 11 is the seal surface 10
The fluid (hereinafter, referred to as “lubricating fluid”) leaks from between the first and second side plates 5 and 6. 3 shows a recess provided for prevention. Reference numeral 12 denotes a lubrication groove provided in the drive shaft 3, which serves as a flow path for the lubricating liquid from the concave portion, and from which the lubricating liquid leaks to the side surface of the drive shaft 3 and the side plate 5.
And 6 can be lubricated. Reference numeral 13 denotes a lubricating liquid flow path from the concave portion, and indicates a lubrication groove provided on the driven shaft 4 for lubricating between the driven gear 2 and the driven shaft 4. Reference numeral 14 denotes a lubricating liquid discharge pipe formed inside the driving shaft 3 for discharging the lubricating liquid lubricating the driving shaft 3 from the pump. 2 shows a lubricating liquid discharge port provided in the side plate 6 for discharging from the side plate.

That is, the pump according to the present embodiment is lubricated by the lubricating liquid fed under pressure, that is, the lubricating liquid sucked from the suction port 8. More specifically, a part of the lubricating liquid to be pumped leaks as a lubricating liquid between the sealing surface 10 and the side plates 5 and 6 to the axial end faces of the respective gears, and the driving gear 1 and the driven gear 2 It flows into the recess while lubricating.
The lubricating liquid flows into the lubrication grooves 12 and 13 and the drive shaft 3
Then, the driven shaft 4 is lubricated and discharged from the lubricating liquid discharge pipe 14 or the lubricating liquid discharge port 15. The lubricating liquid moves through the pump by the filling pressure for filling the lubricating liquid from the suction port 8.

FIG. 2 is a sectional side view of the assembled pump. As shown in FIG. 2, the lubrication groove 12 is
The drive shaft 3 is spirally formed on a side surface (outer peripheral surface) of the drive shaft 3 in order to sufficiently spread the lubricating liquid between the drive shaft 3 and the side plates 5 and 6. The lubrication groove 12 is formed between the inner peripheral portion of the drive gear 1 as a starting point and both end surfaces of the drive shaft 3.
In the present embodiment, two lubrication grooves 12 extending to both end surfaces are formed apart from each other, but may be formed as one continuous groove. Further, the shape of the lubrication groove 12 is not particularly limited, and may be formed, for example, in a linear shape. On the other hand, four linear lubrication grooves 13 are formed on the side surface of the driven shaft 4. Each lubrication groove 13 is formed from the axial end face of the driven gear 2 as a starting point, passing through the inner peripheral portion of the driven gear 2 to the end face of the driven shaft 4. The lubricating liquid flowing through the lubrication groove 13 only lubricates between the driven gear 2 and the driven shaft 4, and the driven shaft 4 and the side plates 5 and 6
Since there is no need to lubricate between the two, the lubrication groove 13 is formed up to one end face of the driven shaft. The lubrication grooves 13 may be formed up to both end surfaces of the driven shaft, and the shape and the number thereof are not particularly limited. The lubrication groove 13 is formed in a gap 17 formed between the driven shaft 4 and the side plate 6 so that the lubricating liquid passing through the lubrication groove 13 is discharged to the outside of the pump.
Through the lubricating fluid discharge port 15. The lubrication groove 12 communicates with a lubricating fluid discharge pipe 14 via a gap 16 formed between the drive shaft 3 and the side plate 5.
FIG. 3 is a front view of only the drive gear 1, the driven gear 2, the drive shaft 3, the driven shaft 4, and the side plate 5 of the assembled pump as viewed from the direction III in FIG. As shown in FIG. 3, in order to secure the sealing force of the sealing surface 10, the radial length M of the sealing surface 10, that is, the distance from the tooth bottom of the driving gear 1 and the driven gear 2 to the inner peripheral edge of the sealing surface 10. The sealing surface 10 is formed so that the radial length is at least 5% of the radial length L from the tooth bottom to the outer peripheral surfaces of the drive shaft 3 and the driven shaft 4. Further, in order to prevent the lubricating liquid from solidifying between the sealing surface and the side plate, the sealing surface 10 is formed such that the length M is 10% or less of the length L.

FIG. 4 is a plan view of the drive gear 1, and FIG.
FIG. 5 is a sectional view of the drive gear 1 taken along line V-V. As shown in FIG. 4, in the present embodiment, a groove 22 is provided on the inner peripheral surface of the drive gear 1 so as to face the lubrication groove 12 provided on the gear shaft 3. The groove 22 is provided to facilitate the flow of the lubricating liquid from the recess 11 into the lubrication groove 12. As shown in FIG. 5, the seal surface 10 and the concave portion 11 are formed on both end surfaces of the drive gear 1 in the axial direction. Further, the concave portion 11 is formed such that the depth t with respect to the seal surface 10 is 50 μm or more so that the lubricating liquid does not stay and solidify in the concave portion 11 of the drive gear 1. Furthermore,
The gap between the sealing surface 10 and the side plates 5 and 6 is set to 5 μm or less in order to seal the space between the drive gear 1 and the side plates 5 and 6 so as not to leak more lubricant than necessary into the concave portion 11. Is set. Although only the drive gear 1 is shown in detail in the drawing, the driven gear 2
Are formed in substantially the same manner.

FIG. 6 is a side view of the drive shaft 3, and FIG.
FIG. Drive gear 1 through lubricating liquid discharge pipe 14
By rapidly discharging the lubricating liquid used for lubricating the drive shaft 3 from the pump, it is possible to prevent the lubricating liquid from solidifying in the lubrication groove 12 or the like.

As shown in FIGS. 1 to 7, the pump of the present embodiment rotates at a constant speed while lubricating fluid sucked from a suction port 8 provided in a side plate 5 while meshing with each other. The driving gear 1 and the driven gear 2 are fed into the tooth spaces at a constant flow rate. The lubricating fluid fed at a constant flow rate is held in the tooth grooves of the drive gear 1 and the driven gear 2 while the drive gear 1
And, by the rotation of the driven gear 2, it is sent to the side of the discharge port 9 provided in the side plate 5. Subsequently, the pump discharges the lubricating liquid at a constant flow rate at the discharge port 9, and thereafter, the above-described steps are continuously repeated.

The resin lubricating liquid which can be filled in the pump of the present embodiment is, for example, polycarbonate, polystyrene, polymethyl methacrylate, polymethyl acrylate, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride, polyfluoride. A mixed system of a resin such as vinyl and a monomer such as methyl methacrylate, ethyl methacrylate, vinyl chloride, vinyl acetate, and vinyl fluoride is exemplified. It is also possible to contain a solvent such as ascent or a photopolymerization initiator. However, it is not limited to the above.

FIG. 8 is an exploded perspective view of a second embodiment of the pump of the present invention. In FIG. 8, reference numeral 4 'denotes a driven shaft which is fixed to the driven gear 2 in a circumferentially stationary manner and is rotatable.
Reference numeral 3 'denotes a lubrication groove provided on the driven shaft 4' for lubricating the driven gear 2 and the driven shaft 4 '. 14 '
Denotes a lubricating fluid discharge pipe provided in the driven shaft 4 'for discharging the lubricating fluid lubricating the driven gear 2 and the driven shaft 4' from the pump. 23 is a groove provided on the inner peripheral surface of the driven gear 2. That is, the driven gear 2 and the driven shaft 4 'of the present embodiment have the same structure as the driving gear 1 and the driving shaft 3 of the first embodiment except that they have no driving force. The same reference numerals as those of the first embodiment indicate the same parts as those of the first embodiment.

[0016]

The present invention will be further described with reference to the following examples. Example 1 Using the rated 0.15 cc / rev pump shown in FIG.
Polymethyl methacrylate, methyl methacrylate, and fluorinated methacrylate were each used as a pumping liquid in a weight ratio of 45:
Using the resin solution mixed and stirred at a ratio of 35:20, the speed of 1 m / min while discharging the resin solution from the nozzle by driving the pump at three revolutions per minute with the resin supply pressure to the pump at 0.5 MPa. Was picked up. Irradiation with actinic light was carried out immediately before the pick-up to complete polymerization and solidification to form a filament, and the outer diameter and discharge pressure of the filament were measured. In the pump having the recesses of the dimensions shown in Experiment Nos. 1 to 4 in Table 1 on the gear end face, troubles such as stopping of the pump due to solidification of the solution did not occur. In addition, these gear pumps were able to perform stable liquid sending with very little change in the discharge pressure and the filament outer diameter.

[0017]

[Table 1]

Example 2 An experiment was performed under the same conditions as in Table 1 by changing the driven gear and the driven shaft to the driven gear 2 and the driven shaft 4 'as shown in FIG. Results were obtained. Comparative Example 1 As shown in FIG. 9, a filament was obtained in the same manner as in Example 1 except that a conventional gear type metering pump with a rated end of 0.15 cc / rev having a gear end face formed on a single plane was used. The outer diameter and discharge pressure of the filament were measured.

In the conventional pump having the gap between the gear end face and the side plate as shown in Experiment Nos. 5 to 8 in Table 2, if the gap between the gear end face and the side plate is small, a pump stop trouble occurs. Further, when the gap between the gear end face and the side plate was increased, the trouble of stopping the pump did not occur, but the discharge pressure and the outer diameter of the filament became large, and stable liquid feeding could not be performed.

[0020]

[Table 2]

COMPARATIVE EXAMPLE 2 A pump having the same structure as that of Example 1 was used except that a rated 0.15 cc / rev pump having different dimensions was used. The diameter and the discharge pressure were measured.

In the pump having the recesses having the dimensions shown in Experiment Nos. 9 to 12 in Table 3, some gear stop troubles occurred, and the discharge pressure and the filament outer diameter fluctuated as compared with Embodiments 1 and 2. It increased, and it became impossible to perform sufficiently stable liquid sending.

[0023]

[Table 3]

[0024]

According to the gear metering pump of the present invention, since the gear has an annular sealing surface, it is possible to prevent the lubricant from leaking more than necessary to the axial end face of the gear. Can be prevented from decreasing and fluctuating. Further, since the gear has a concave portion and the lubricating liquid leaking to the axial end face of the gear is quickly discharged, the lubricating liquid is prevented from solidifying inside the pump such as the axial end face of the gear. And the pump is inexpensive to produce and easy to maintain.

Further, by providing a lubrication groove on the outer peripheral portion of the shaft, the slidability of the shaft in the circumferential direction can be improved. Further, by fixing the driven shaft to the side plate, the number of movable parts can be reduced, and the stable operability of the pump can be improved. In addition, by making the structure of the driven shaft and the drive shaft the same, parts can be diverted, and the cost of the pump can be reduced.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a first embodiment of a pump according to the present invention.

FIG. 2 is a side sectional view of the pump according to the first embodiment.

FIG. 3 shows the drive gear and the driven gear of the assembled pump,
FIG. 3 is a front view of only a drive shaft, a driven shaft, and a side plate as viewed from a direction III in FIG. 1.

FIG. 4 is a plan view of a drive gear.

FIG. 5 is a sectional view of the drive gear taken along line VV of FIG. 4;

FIG. 6 is a side view of the drive shaft.

FIG. 7 is an end view of the drive shaft.

FIG. 8 is an exploded perspective view of a second embodiment of the pump of the present invention.

FIG. 9 is a side sectional view of a conventional pump.

FIG. 10 is a front view of the drive gear of FIG. 9;

11 is a sectional view of the drive gear taken along line XI-XI in FIG.

[Description of Signs] 1 ... Drive gear 2 ... Driven gear 3 ... Drive shaft 4 ... Driven shaft 5, 6 ... Side plate 7 ... Casing 8 ... Suction port 9 ... Discharge port 10 ... Seal surface 11 ... Recess 12 and 13 ... Lubrication Grooves 14: Lubricant discharge pipe 15: Lubricant discharge port

Claims (6)

[Claims] 1. A fluid sucked from an inlet is conveyed to an outlet by a pair of gears rotating at a constant speed while meshing with each other.
Discharged from the discharge port at a constant flow rate, and a part of the fluid sucked from the suction port is leaked from a gap between an axial end face of the gear pair and a side plate provided opposite to the end face, In the self-lubricating enhanced gear type metering pump for lubricating gears, an axial end face of at least one of the gears in the gear pair prevents fluid from leaking from the suction port to an axial end face of the gear more than necessary. An annular sealing surface that seals between the gear and the side plate to prevent it, and a recess formed radially inward of the sealing surface to prevent the fluid from stagnating and solidifying at the axial end surface of the gear. And a flow path for discharging the fluid leaking to the axial end surfaces of the gear pair from the recess to the outside of the pump. 2. The pump according to claim 1, wherein a gap between the sealing surface and the side plate is 5 μm or less. 3. A depth of a bottom surface of the concave portion with respect to the seal surface is 50 μm or more, and a radial length from a tooth bottom of the gear to an inner peripheral edge of the seal surface is from the tooth bottom to the gear. 3. The pump according to claim 1, wherein the length is 5% or more and 10% or less of a radial length of the shaft supporting the shaft to the outer peripheral surface. 4. 4. A lubrication groove provided on an outer peripheral surface of the gear shaft for improving a sliding property of a gear shaft, wherein a flow path for discharging a fluid to the outside of the gear type metering pump is provided. The pump according to any one of claims 1 to 3, further comprising a lubricating fluid discharge pipe formed in the shaft and communicating with the outside. 5. The apparatus according to claim 1, wherein said gear pair is constituted by a drive gear and a driven gear, and a driven shaft supporting said driven gear is fixed to said side plate. A pump according to any one of the preceding claims. 6. The gear pair includes a drive gear and a driven gear, and a driven shaft supporting the driven gear is fixed to the driven gear in a circumferentially immovable manner. The pump according to claim 1.