JPH0814165A - Gear pump - Google Patents

Abstract

PURPOSE:To improve pump performance by preventing deterioration of tooth contact of helical gears with each other by finish machining of a gear side surface. CONSTITUTION:A helical gear 12 oh the side of a shaft end part is fixed free to adjust its position against a shaft 3 with a collar 5 as its coupler. The collar 5 is divided into a plural number in the circumferential direction and is constituted of first wedge elements 51, 52 and second wedge elements 53, 54, and one of the first wedge elements 51, 52 is connected to the shaft 3 and the other is connected to the helical gear 12 with keys.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear pump preferably used for transferring high molecular polymers, chemicals and the like.

[0002]

2. Description of the Related Art A helical gear is effective as a measure for preventing pulsation reduction. Since a thrust load due to a rotational force acts on the gears, it is necessary to connect a pair of gears in opposite directions to form a double helical gear if the discharge pressure is high or if lubrication on the side surface of the gears poses a problem. . In addition, since the simulaoid tooth profile has one-point contact, it is indispensable to have a double-helical structure for petrochemical applications. Due to machining and material problems, the double-helical gear pump has a shaft and left and right gears that are machined separately and fixed through a key and a key groove. In terms of pump performance, it is important that the tooth contact of both the drive shaft and the driven shaft be accurately matched, and that the clearances between each part (side surface, bearing, tooth tip) be properly managed.

[0003]

When austenitic stainless steel is used as a gear material, the gear side surface is finished after gear cutting and key groove processing. this is,
This is because stainless steel, which has high ductility, removes the processing strain on the particularly important side surface. However, due to this processing, it is difficult to accurately match the phases of the key groove and the gear, and the phases of the teeth of the helical gears 11 and 12 adjacent to each other change as shown in FIG. 7, resulting in poor tooth contact. Further, when the tooth contact becomes poor, an error d is generated in the side surface gap and causes seizure. Therefore, it is necessary to set the side surface gap (larger than an appropriate value) in consideration of this error from the beginning. However, there is no choice but to approve a certain decrease in performance from the beginning. Further, in correcting the error, since the key or the key groove is manually finished and ground, the reversibility in the rotation direction and the compatibility between parts are lost.

The present invention has been made in view of such a problem, and it is possible to reliably improve the pump performance by preventing the tooth contact between the helical gears from being deteriorated by the finishing of the side surfaces of the gears. It is an object.

[0005]

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

That is, in the gear pump according to the present invention, in which the double helical gear is supported by the drive shaft and the driven shaft, one of the gears forming the double helical gear is directly connected to the shaft through the key and the key groove. The gears are fixed gears, and the other is a position adjusting gear that is pivotally attached to the shaft through a collar. The collars are provided with a plurality of first wedge elements whose width gradually narrows toward the shaft end, and a shaft. A plurality of second wedge elements which become gradually wider toward the end and are interposed between the respective first wedge elements, and one of the first wedge elements is attached to the shaft via a key and a key groove. In addition to being connected, the other one is connected to the position adjusting gear via the key and the key groove.

[0007]

The operation will be described on the assumption that the first wedge elements and the second wedge elements have the same shape. The first wedge element and the second wedge element forming the collar are alternately arranged in the circumferential direction and are positioned in the annular gap between the shaft and the position adjusting gear. The first wedge element has a shape that gradually narrows toward the shaft end, and a gap that gradually widens toward the shaft end is formed between the first wedge elements. When the second wedge element is driven with a uniform depth, the first wedge element is fixed in the equiangular position along the circumferential direction. It is also possible to drive a part of the second wedge element shallow and conversely drive the other part deeply. In this case, the first wedge elements at the positions where the second wedge element is driven deeply push and open. As a result, the first wedge elements in the shallowly driven positions are conversely clogged, and as a result, the respective first wedge elements are fixed at the non-conformal positions. One of the first wedge elements is keyed with the shaft, the other is keyed with the position adjusting gear, and as a whole the collar acts as a joint between the shaft and the position adjusting gear, The phase of the connection between the shaft and the position adjusting gear is changed depending on whether each of the first wedge elements is fixed equiangularly or non-equically. That is,
Based on the key connection position with the shaft, the position of the position adjustment gear when the second wedge element is driven is displaced from the reference position when the second wedge element is driven evenly to the advance side or the lag side. obtain. On the other hand, since the fixed gear has a fixed shaft attachment position with respect to the shaft, it is possible to correct the deviation of the tooth contact between the fixed gear and the position adjusting gear, which is caused by machining depending on the driving method of the second wedge element.

Even when the first wedge elements or the second wedge elements do not have the same shape, the action according to the above is obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, this gear pump is constructed by supporting double helical gears 1 and 2 on a drive shaft 3 and a driven shaft 4, respectively. Since the mounting structure of the double helical gear 1 and the drive shaft 3 and the mounting structure of the double helical gear 2 and the driven shaft 4 are the same, only the former will be described below.

As shown in FIG. 2, the double helical gear 1 comprises a fixed gear 11 and a position adjusting gear 12, which are arranged adjacent to each other.

The fixed gear 11 is provided with a key 11a extending in the inner peripheral generatrix direction, and this key 11a is engaged with a key groove 31 extending in the generatrix direction provided on the outer periphery of the shaft 3 to connect in the rotational direction. To be done.

The position adjusting gear 12, as shown in FIGS. 2 to 5, is attached to the shaft 3 via a collar 5. The collar 5 includes two first wedge elements 51, which gradually become narrower toward the shaft end,
52, and two second wedge elements 53 which are gradually widened toward the shaft end and are interposed between the first wedge elements 51, 52.
And 54. One first wedge element 51 is provided with an axially extending key 51a on its inner circumference, and the other first wedge element 52 is provided with an axially extending key 52a on its outer circumference. Actually, the first wedge element 51 is further divided in the vicinity of the center, and is divided into a divided piece with the key 51a and a divided piece without the key 51a, but it can be handled as a functionally integrated piece. On the other hand, a key groove 32 extending along the generatrix direction is provided on the outer circumference of the shaft 3, and a key groove 12 extending along the generatrix direction is also provided on the inner circumference of the position adjusting gear 12.
a is provided. The key 51a on the inner circumference of the collar 5 is used for the shaft 3
By engaging the key groove 32 of the position adjusting gear 12 with the key 52a on the outer periphery of the collar 5,
The shaft 3 and the position adjusting gear 12 are connected in the rotational direction via the collar 5.

Next, the procedure for assembling this gear pump will be described. First, the fixed gear 11 is fitted on the shaft 3 by aligning the key 11a with the key groove 31. Accordingly, the fixed gear 11 is integrally rotatably fixed to the shaft 3 by the engagement of the key 11a and the key groove 31. Next, the first wedge elements 51 and 52 of the collar 5 are positioned at the opposite positions of the annular gap between the shaft 3 and the position adjusting gear 12, and the position adjusting gear 12 is loosely fitted to the outer periphery of the shaft 3. Since the first wedge elements 51, 52 are gradually narrowed toward the shaft end, both the first wedge elements 51, 52
A gap that gradually widens toward the shaft end is formed between 52. Then, the second wedge elements 53, 54 are driven into the gap. When the second wedge elements 53 and 54 are driven in at an equal depth, the wedge action causes the first wedge elements 51 and 5 to move.
The forces that urge the two in the circumferential direction cancel each other out, and the first wedge elements 51, 52 are fixed in that position, that is, in the equiangular position in the circumferential direction. However, as shown in FIG. 5, it is possible to make one second wedge element 54 shallow, and conversely, deeply drive the other second wedge element 53. In this case, the second wedge element 53 is deeply driven. At the position, the first wedge elements 51 and 52 are pushed open, and conversely, at the position where the second wedge element 54 is shallowly driven,
The wedge elements 51 and 52 are clogged, and as a result,
The first wedge elements 51, 52 are fixed at positions that are not equiangular.
The first wedge element 51 is keyed to the shaft 3, the first wedge element 52 is keyed to the position adjusting gear 12, and the collar 5 as a whole is like a joint between the shaft 3 and the position adjusting gear 12. Since it plays a role, the phase of the connection between the shaft 3 and the position adjusting gear 12 changes depending on whether the first wedge elements 51 and 52 are fixed equiangularly or non-equally. That is, if the position of the key 51a is set to the reference point 0 ° as shown in FIG. 5, the position of the key 52a is on the leading side or the trailing side of the 180 ° position when the second wedge elements 53 and 54 are evenly driven. Will be displaced. Since the fixed gear 11 does not change the position where the fixed gear 11 is attached to the shaft 3, as a result, even if the tooth contact between the fixed gear 11 and the position adjusting gear 12 is shifted as shown in FIG. The misalignment can be corrected by changing the shaft attachment position of the position adjusting gear 12 to the state shown.

When the driving of the color 5 is completed, the shaft 3 is further moved.
The auxiliary collar 6 and the lock nut 7 shown in FIGS. 2 and 6 are fitted in the annular gap between the position adjusting gear 12 and the position adjusting gear 12. The auxiliary collar 6 is provided with a beveled protrusion 61 at a part in the circumferential direction, and the difference between the second wedge elements 53 and 54 is utilized by utilizing the step between the protrusion 61 and the flat portion 62. (See FIG. 5), and the auxiliary collar 6 is attached to both the second wedge elements 53 and 54 at the same time. Then, finally, the lock nut 7 is fastened to the outer periphery of the shaft 3 to complete the attachment of all the element parts. The direction of the slope of the protrusion 61 is oriented in the direction in which the second wedge elements 53, 54 are tightened when the lock nut 7 is tightened, that is, the direction of arrow X in FIG.

In the gear pump as described above, after the gear cutting and key groove processing, the gear side surface is finished, and the tooth phase changes between the adjacent gears 11 and 12, resulting in poor tooth contact. Even so, the tooth contact can be easily corrected to an appropriate state at the assembling stage. Therefore, it is not necessary to allow for an error in the side surface gap, and it is possible to set an appropriate value to enhance volumetric efficiency and pursue maximum pump performance.
Also, because no method is used to grind and match the keys and key grooves by hand to correct the error, the gap does not widen in any rotation direction, so it can be used as a dual-rotation pump. Will be able to exhibit high performance. In addition, because hand-finishing work is eliminated, the compatibility of parts between pumps is improved, quality is stabilized, and in hand-finishing, the time required for completion differs depending on the size of the error dimension. The problem is solved, standard delivery time can be set and delivery date can be managed, and total cost can be reduced.

The present invention is not limited to the above-mentioned embodiments. For example, in the above embodiment, the number of colors is 2.
It is composed of one first wedge element and two second wedge elements, but the number thereof can be any combination within the range where the effect of the present invention can be obtained.

[0018]

As described above, according to the present invention, one of the double helical gears is directly fixed to the shaft, and the other is fixed to the shaft so that the position can be adjusted with respect to the shaft. After finishing the key groove processing, the side surface of the gear is finished and even if the tooth contact between adjacent gears changes and the tooth contact deteriorates, depending on the driving method of the second wedge element of the empty The hit can be easily corrected to a proper state. Therefore, it is not necessary to allow for an error in the side surface gap, and it is possible to set an appropriate value to enhance volumetric efficiency and pursue maximum pump performance. Also, because no method is used to grind and match the keys and key grooves by hand to correct the error, the gap does not widen in any rotation direction, so it can be used as a dual-rotation pump. Can also demonstrate high performance. In addition, it eliminates the need for hand-finishing work, improves the compatibility of parts between pumps, stabilizes quality, enables delivery control, and achieves overall cost reduction. To be done.

[Brief description of drawings]

FIG. 1 is a diagram showing a main part according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of one double helical gear of the same embodiment.

FIG. 3 is an exploded perspective view of essential parts of the embodiment.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a diagram showing the collar of the embodiment developed in a circumferential direction.

FIG. 6 is a perspective view showing an auxiliary color of the embodiment.

FIG. 7 is a diagram corresponding to FIG. 1 for explaining a conventional defect.

[Explanation of symbols]

 1, 2 ... Double helical gear 3 ... Drive shaft 4 ... Driven shaft 5 ... Collar 11 ... Fixed gear 11a ... Key 12a ... Key groove 12 ... Position adjustment gear 31 ... Key groove 32 ... Key groove 51, 52 ... First wedge element 51a, 52a ... Keys 53, 54 ... Second wedge element

Claims (1)

[Claims] 1. A gear pump in which a double helical gear is supported on a drive shaft and a driven shaft, respectively, wherein one of the gears forming the double helical gear is directly attached to the shaft via a key and a key groove to form a fixed gear. , The other is a position adjusting gear by being attached to the shaft via a collar, and the collar is provided with a plurality of first wedge elements whose width gradually narrows toward the shaft end and gradually widens toward the shaft end. And a plurality of second wedge elements interposed between the respective first wedge elements, and one of the first wedge elements is connected to the shaft via a key and a key groove, and the other one A gear pump characterized in that one is connected to a position adjusting gear via a key and a key groove.