JP2015175254A - Geared pump or geared motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce disadvantages such as poor motion of equipment accompanied by reduction in performance due to re-wiping when a load overcoming an upper limit of a pump application range is applied to a high pressure port.SOLUTION: This invention relates to either a geared pump or a geared motor comprising circumscription gear pairs 2, 3; a casing including a body 11 formed with a gear storing chamber 11a storing circumscription gear pairs 2, 3 inside of it, a cover for closing the gear storing chamber 11a of the body 11 and a high pressure port 1Y and a low pressure port 1X each of which is communicated with the gear storing chamber 11a; and a seal surface 9a arranged near the low pressure port 1X in the gear storing chamber 11a, opposing against tips of the circumscription gear pairs 2, 3 and continuous to an inside surface 11a1 of the gear storing chamber 11a. This invention further comprises a configuration of a seal motion mechanism 10 for moving a seal block 9 toward the circumscription gear pairs 2, 3.

Description

  The present invention relates to a gear pump or a motor used for an industrial machine or the like.

  2. Description of the Related Art Conventionally, an industrial machine or the like having a hydraulic circuit has a gear storage chamber that stores a pair of external gears inside a body, and has a high-pressure side port and a low-pressure side port that communicate with the gear storage chamber, respectively. Gear pumps or motors are widely used. When such a gear pump or motor is used as a pump, the working fluid introduced from the low pressure side port is guided to the high pressure side port through the space between the inner wall of the gear housing chamber and the teeth of the external gear pair. (For example, see Patent Document 1).

  Here, the volumetric efficiency of the pump is greatly influenced by the amount of hydraulic fluid that leaks from the gap between the low pressure side inner wall of the gear housing chamber and the tooth tip of the external gear pair, in other words, the width of the gap. The width of the gap is determined by cutting a part of the low pressure side inner wall of the gear housing chamber at the tooth tip of the external gear pair by operating with the pressure of the high pressure side port set to the upper limit of the pump usage range before shipping. It is determined.

JP 2000-179468 A

  However, if a load exceeding the upper limit of the pump operating range is applied to the high pressure side port due to the occurrence of surge pressure, etc., the external gear pair is strongly pressed to the low pressure side, and a part of the inner wall of the gear housing chamber is caused by the tooth tip of the external gear pair. Is further cut. Then, during a subsequent operation, a phenomenon called “rewiping” occurs in which a gap between the inner wall of the gear housing chamber and the tooth tip of the external gear pair is increased, and the performance is deteriorated. Furthermore, depending on the degree of performance degradation and the type of equipment on which the gear pump (or motor) is mounted, it becomes difficult to move the equipment.

  The present invention pays attention to the above points, and an object of the present invention is to reduce problems such as difficulty in moving equipment due to performance deterioration due to rewiping when a load exceeding the upper limit of the pump usage range is applied to the high-pressure side port.

  In order to solve the above problems, a gear pump or a motor according to the present invention has a configuration as described below. That is, the gear pump or motor according to the present invention communicates with the external gear pair, the body in which the gear housing chamber for housing the external gear pair is formed, the cover for closing the gear housing chamber of the body, and the gear housing chamber. A casing having a high-pressure side port and a low-pressure side port, and a seal surface disposed in the vicinity of the low-pressure side port in the gear housing chamber, facing a tooth tip of the external gear pair and continuing to the inner surface of the gear housing chamber. And a seal moving mechanism for moving the seal block toward the external gear pair.

  If this is the case, when the performance deterioration due to rewiping occurs, the seal block is moved toward the external gear pair by the seal moving mechanism, and the clearance between the tooth tip of the external gear pair and the seal surface is increased. By reducing the size and restoring the performance, it is possible to operate at a desired performance at least until the device is moved to the repair point.

  ADVANTAGE OF THE INVENTION According to this invention, malfunctions, such as the difficulty of the movement of an apparatus accompanying the performance fall by the rewiping when the load exceeding the upper limit of a pump use range is added to the high voltage | pressure side port, can be reduced.

Schematic which shows the structure of the gear pump which concerns on one Embodiment of this invention. AA sectional drawing in FIG. The side view of the gearwheel and seal block which concern on the same embodiment.

  An embodiment of the present invention will be described below with reference to FIGS.

  As shown in FIG. 1, the gear pump P according to the present embodiment mainly includes a casing 1 having a gear housing chamber 11 a therein, and a circumscribed portion that is housed and held in the gear housing chamber 11 a of the casing 1 and meshes with each other. A gear pair, that is, a drive gear 2 and a driven gear 3, and movable side plates 6 and 6 that are in contact with both side surfaces 2 a and 3 a of the gears 2 and 3 are provided.

  The drive gear 2 and the driven gear 3 are well-known ones in which a plurality of tooth bodies are provided at predetermined intervals along the outer peripheral surface. In the present embodiment, the drive shaft 4 is integrally extended from the center of the drive gear 2 in the rotational axis direction, and the driven shaft 5 is integrally extended from the driven gear 3 in the rotational axis direction. However, the drive gear 2 and the drive shaft 4 may be configured separately, and the driven gear 3 and the driven shaft 5 may be configured separately.

  The casing 1 includes, for example, a body 11 having the gear housing chamber 11a, a front cover 12 serving as a cover for closing the opening surface of the gear housing chamber 11a, and a rear cover 13 serving as a cover for closing the opening surface of the gear housing chamber 11a. It is composed of The body 11 is formed with a gear housing chamber 11a for housing the gear pair, that is, the driving gear 2 and the driven gear 3 in an engaged state. The body 11 is opened with a low-pressure side port 1X and a high-pressure side port 1Y respectively communicating with the gear housing chamber. The front cover 12 is detachably attached to the body 11 with a bolt or the like, for example, and closes the front opening surface of the gear housing chamber 11a, and a bearing hole into which the drive shaft 4 and the driven shaft 5 can be respectively fitted. 12a and 12b are formed. A bush 7 is fitted into the bearing hole 12a near the position where the drive gear 2 is to be inserted, and one end of the drive shaft 4 is inserted into the bush 7 so as to be rotatably supported. On the other hand, a bush 7 is fitted into the bearing hole 12b near the position where the driven gear 3 is to be inserted, and one end of the driven shaft 5 is inserted into the bush 7 so as to be rotatably supported. Similarly, the rear cover 13 is also detachably attached to the body 11 with a bolt or the like and closes the rear opening surface of the gear housing chamber 11a, and the drive shaft 4 and the driven shaft 5 can be respectively inserted thereinto. Bearing holes 13a and 13b are formed. A bush 7 is fitted in the bearing hole 13a near the position where the drive gear 2 is to be inserted, and the other end of the drive shaft 4 is inserted into the bush 7 so as to be rotatably supported. On the other hand, a bush 7 is also fitted in the bearing hole 13b near the position where the driven gear 3 is to be inserted, and the other end of the driven shaft 5 is inserted into the bush 7 so as to be rotatably supported.

  As shown in FIG. 1, the movable side plate 6 is disposed at two locations so as to be brought into contact with both side surfaces 2 a and 3 a of the drive gear 2 and the driven gear 3, and the side surfaces 2 a and 3 a of the drive gear 2 and the driven gear 3. It is for sealing each. Further, a gasket groove 6y is provided on the non-sliding surface 6b of the movable side plate 6 facing away from the drive gear 2 and the driven gear 3, and the gasket 8 is fitted into the gasket groove 6y.

  In addition, in the present embodiment, as shown in FIG. 2, it is provided in the vicinity of the low-pressure side port 1X in the gear housing chamber 11a, faces the tooth tip of the drive gear 2 or the driven gear 3, and the gear housing chamber 11a. A seal block 9 having a seal surface 9a continuous with the inner surface 11a1 is disposed. Here, as shown in FIG. 3, the width dimension of the body 11, the width dimension of the seal block 9, and the tooth widths of the drive gear 2 and the driven gear 3 are set to the same value d1. Further, a seal member 91 is disposed between the back surface of the seal block 9 and the gear housing chamber 11a so as to suppress liquid leakage. Further, as shown in FIG. 2, the wiping process in which the clearance between the seal surface 9 a and the tooth tip is increased by cutting the seal surface 9 a of the seal block 9 by the tooth tip of the drive gear 2 or the driven gear 3. A seal moving mechanism 10 is also provided for moving the seal block 9 toward the drive gear 2 and the driven gear 3 when this occurs. The seal moving mechanism 10 includes a female screw hole 11x provided in the body 11 and communicating with the gear housing chamber 11a, and a wrench that is screwed into the female screw hole 11x and that has a distal end portion in contact with the seal block 9 and an operation portion at the proximal end portion. A male screw member 101 having a hole 101a and a nut 102 that can be screwed to the male screw member 101 outside the body 11 are provided. The male screw member 101 includes a first male screw portion 102b having a wrench hole 101a and screwed into the nut 102, and a second male screw portion 102c spaced axially from the first male screw portion 102b and screwed into the female screw hole 11x. And a constricted portion 104d provided between the first and second male screw portions 102b and 102c and having an outer diameter smaller than the first and second male screw portions 102b and 102c. Between the constricted portion 104d of the male screw member 101 and the female screw hole 11x, a hydraulic fluid leakage suppressing member 103 for suppressing leakage of the hydraulic fluid through the female screw hole 11x is disposed. As the hydraulic fluid leakage suppressing member 103, an O-ring or the like can be employed. Then, a hexagon wrench is inserted into the wrench hole 101a, and a rotation operation for screwing the male screw member 101 into the female screw hole 11x is applied, so that the seal block 9 is driven by the tip of the male screw member 101 with the drive gear 2 and the driven gear 3 The gap between the seal surface 9a and the tooth tip can be reduced.

  The gear pump P of the present embodiment is a gear motor that introduces hydraulic fluid from the high-pressure side port 1Y and discharges the hydraulic fluid from the low-pressure side port 1X while driving the drive gear 2 and the driven gear 3 with hydraulic fluid pressure. Can also be used.

  As described above, according to the present embodiment, when the performance deterioration due to rewiping occurs, the seal moving mechanism 10 moves the seal block 9 toward the drive gear 2 and the driven gear 3 to thereby reduce the drive gear 2. Further, by reducing the gap between the tooth tip of the driven gear 3 and the seal surface 9a and restoring the performance, it is possible to operate at a desired performance at least until the device is moved to the repair location.

  The present invention is not limited to the embodiment described above.

  For example, the seal moving mechanism is not limited to the one using the screw mechanism as described above, and a piston having a tip end abutted against the seal block, a cylinder for storing the base end portion of the piston, and an operation in the cylinder. Other configurations such as a hydraulic piston mechanism having a hydraulic pressure supply path for supplying hydraulic pressure may be used.

  Of course, the present invention may be applied to only one of the gear pump and the gear motor that can be used.

  In addition, it is desirable to set the width dimension of the seal block and the tooth widths of the drive gear and the driven gear to the same value as in the above-described embodiment, but it is not always necessary to set the same value.

  In addition, various changes may be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Casing 11a ... Gear storage chamber 11 ... Body 12, 13 ... Cover 2, 3 ... External gear pair 1X ... Low pressure side port 1Y ... High pressure side port 9 ... Seal block 10 ... Seal movement mechanism

Claims (1)

Body having a gear housing chamber in which a gear housing chamber for housing the external gear pair is formed, a cover for closing the gear housing chamber of the body, a casing having a high pressure side port and a low pressure side port respectively communicating with the gear housing chamber A seal block provided in the vicinity of the low-pressure side port in the gear housing chamber and having a seal surface facing the tooth tips of the external gear pair and continuing to the inner surface of the gear housing chamber; A gear pump or motor comprising a seal moving mechanism for moving toward a gear pair.

Images