JPH0442542Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a gear pump mainly used for pumping high-viscosity fluid, such as high-temperature molten resin, at high pressure.

[Conventional technology]

A typical gear pump is an internal gear drive type that has a driving gear and a driven gear built into a casing, and sucks in and discharges fluid while transmitting power from the driving gear to the driven gear. In addition, if it is not possible to satisfy power transmission and suction/discharge performance with the same gear in such a general gear pump, an external power transmission part is installed separately from the pair of internal gears that suck and discharge fluid. In other words, the rotating shafts of the pair of gears inside the casing are extended to the outside of the casing through the shaft seal, and each of the extended rotating shafts is provided with a pair of external gears for the sole purpose of transmitting power, that is, a driving gear and a driven gear. An external gear-driven gear pump with a shaft attached to the pump is used.

[Problem that the invention attempts to solve]

By the way, when pumping a highly viscous fluid such as high-temperature molten resin at high pressure, a large rotational force is required and in order to satisfy the specified suction and discharge requirements, the gear strength, gear specifications, and It is difficult to use the internal gear drive type gear pump due to the material. For this reason, the external gear drive type gear pump is used, but since the external gear is attached to the rotating shaft of the internal gear, it is limited to the same specifications as the internal gear. In addition to not reducing the power transmission, when pumping high-temperature, high-viscosity fluids, etc., the power transmission part comes close to the casing, which becomes hot, so good means cannot be used to lubricate the power transmission part. There were other problems.

This invention is an improvement of the external gear drive type gear pump among the conventional gear pumps mentioned above, and it is possible to reduce the transmission force by eliminating the need to be close to the casing housing the internal gear that performs the pumping action. The object of the present invention is to provide a gear pump suitable for pumping highly viscous fluid.

[Means for solving problems]

In order to achieve the above-mentioned problems, this invention has a gear pump configured as follows.

In other words, the gear pump, which is the premise of this invention, has a pair of gears that mesh with each other with a predetermined distance between the shafts housed in a casing that has a fluid suction port and a fluid discharge port, and rotates the rotational axes of each gear in the same direction. The pump body has a pair of extension shafts projecting to the outside, a transmission drive gear that rotates by the rotational driving force of a drive source, and a transmission driven gear that rotates in mesh with the transmission drive gear. This configuration includes a power transmission section that transmits the rotational driving force of the source to each of the extension shafts. In such a gear pump, this invention makes the distance between the shafts of the transmission gear and the driven transmission gear of the power transmission section larger than the distance between the shafts of the pair of gears of the pump body, and the drive shaft of the transmission drive gear. and a gear pump characterized in that the driven shafts of the transmission driven gears are respectively connected to the respective extension shafts of the pump body via shaft joints that allow for misalignment and achieve constant rotation.

[Effect]

In the gear pump according to the invention configured as described above, the rotational driving force transmitted from the drive source is transmitted to the drive shaft of the transmission drive gear, and is also transmitted to the driven shaft via the transmission driven gear that meshes with the transmission drive gear. communicated. Since the transmission drive gear and the transmission driven gear are gears of the same size, the rotation of the drive shaft and the rotation of the driven shaft are the same number of rotations, and this is transmitted to the rotation shaft of each gear of the pump body via the shaft coupling part. , the respective gears rotate in a meshed state without transmitting power to each other, and suck fluid from the fluid suction port and discharge it from the fluid discharge port. In this case, since the distance between the shafts of the transmission drive gear and the transmission driven gear is larger than the distance between the shafts of each gear in the casing of the pump body, the tooth surface of the transmission drive gear and the transmission driven gear The applied force is reduced, and the power transmission section is located away from the pump body via the shaft coupling section.

〔Example〕

An embodiment of the gear pump according to this invention will be described with reference to the drawings.

The drawings show a schematic diagram of the configuration of one embodiment of the gear pump according to the present invention, in which FIG. 1 is a schematic cross-sectional diagram along the axial direction, and FIG. 2 is a cross-sectional diagram taken along the axial direction.

The gear pump according to this invention shown in this embodiment includes a pump body 1, a shaft coupling portion 2, and a drive transmission portion 3.
The drive transmission section 3 is composed of a deceleration drive source 5 via a flexible joint 4. The pump body 1 includes a first gear 10 integrally formed with a first rotating shaft 9 and a second gear 10 integrally formed with a second rotating shaft 11 in a casing 8 in which a fluid suction port 6 and a fluid discharge port 7 are formed. Two identical gears of the gear 12 have a predetermined shaft-to-shaft dimension C and are configured so that their tooth surfaces do not contact each other, so that their respective shaft ends are attached to the bearing 1.
3 and 13', and the front and rear of the casing 8 are closed by a rear cover 14 and a front cover 15, and one end of each of the first rotating shaft 9 and the second rotating shaft 11 is connected to the front cover. The extension shafts 16, 16' extend through the shaft 15 with a shaft sealing structure. As the shaft sealing structure, for example, a gland packing or a mechanical seal is employed. In the drive transmission section 3, a drive shaft 20 and a driven shaft 21 are mounted in a gear box 17 using a bearing 18 with an inter-axle dimension D larger than an inter-axle dimension C of each gear of the pump body 1, and one end is connected to the drive shaft 20 and the driven shaft 21. are extended to the side where the extension shafts 16, 16' of the pump main body 1 are located to form joint shaft portions 19, 19'. A transmission drive gear 22 and a transmission driven gear 23, which are gears of the same size, are attached to the drive shaft 20 and the driven shaft 21, and the other end of the drive shaft 20 and the transmission shaft 24 of the deceleration drive source 5 are connected to each other. They are connected by a flexible joint 4.

The shaft joint portion 2 includes a transmission path that connects one end of the connecting shaft 25 to one extension shaft 16 with a universal joint 26 and the other end of the connecting shaft 25 with a joint shaft portion 19 of the drive shaft 20 with a universal joint 26', and a connecting shaft. One end of 25' is connected to the other extension shaft 16' with a universal joint 27, and the other end is connected to the joint shaft portion 19' of the driven shaft 21 with the universal joint 27.
and a transmission path connected at 7'.

Next, the operation of the gear pump configured as described above will be explained. First, the rotational driving force from the deceleration drive source 5 is transmitted through the transmission shaft 24, the flexible joint 4, and the drive shaft 21 to reach the drive transmission section 3, where it is divided into two transmission paths and is divided into the first and second transmission paths of the pump body 1. The signal is transmitted to the gear 10 and the second gear 12. One transmission path is
This is a path from the joint shaft portion 19 of the drive shaft 21 to the universal joint 26', the connecting shaft 25, the universal joint 26, the extension shaft 16, and the first gear 10.
1, the transmission drive gear 22 is connected to the driven shaft 21 via the transmission driven gear 23, and this driven shaft 2
1 joint shaft part 19' to universal joint 27', connecting shaft 2
5', universal joint 27, extension shaft 16', second gear 11
This is the route that leads to. First gear 10 and second gear 12
The A gear 10 and the B gear 10 rotate in opposite directions to each other as shown by the arrows, and are in a direction in which the fluid flowing in from the fluid suction port 6 is sent along the inner circumferential wall of the casing 8 to the fluid discharge port 7. The tooth surfaces of the gear 12 are preferably not in contact with each other,
The fluid is gradually increased in pressure from the fluid suction port 6 and sent to the fluid discharge port 7, where it is discharged. In this case, the transmission driving gear 22 and the transmission driven gear 23 are located at a position away from the pump body portion 1 and at a distance D between the shafts that is larger than the distance C between the shafts of both the first and second gears of the pump body portion 1. Since the transmission part 3 in which the 1st , not only improves the durability of the second gear, but also reduces the transmission force in the drive transmission part 3, and also makes it possible to use a free lubrication method with less thermal influence even when pumping high-temperature fluid, making it smoother. This makes it possible to transmit rotational motion. In the embodiment, a case has been described in which the drive transmission section is independent from the deceleration drive source, but the drive transmission section may be incorporated into a part of the deceleration drive source. It goes without saying that the invention is not limited to universal joints, but also includes ball joints and other joints that allow for misalignment and achieve constant rotation.

[Effect of idea]

As described above, according to the gear pump of this invention, the power transmission part for transmitting power to the two gears inside the pump body is installed at a remote location outside the pump body, between the axes of the two gears. Since the shafts are arranged with a dimension larger than the dimensions, and are connected by a shaft coupling means that allows for misalignment and obtains constant rotation, the transmission force applied to the gears in the power transmission part is reduced, and the lubrication means is It is now possible to freely adopt suitable means without being affected by the high temperature ratio of the pump body, and it is possible to improve the friction resistance and strength resistance of the gears of the power transmission part, and to improve the friction resistance and strength resistance of the gears of the power transmission part. We can provide gear pumps that are ideal for pumping high-viscosity fluids.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of a gear pump that is an embodiment of this invention, and Fig. 2 is a -
It is a line cut sectional view. 1... Pump body, 2... Shaft joint part, 3...
Drive transmission unit, 5... Deceleration drive source, 6... Fluid suction port, 7... Fluid discharge port, 8... Casing,
9...First rotating shaft, 10...First gear, 11...
Second rotating shaft, 12... Second gear, 16, 16'...
...Extension shaft, 17...Gear box, 19,19...
...Vertical shaft portion, 20... Drive shaft, 21... Driven shaft, 2
2...Transmission drive gear, 23...Transmission driven gear, 2
4...Transmission shaft, 25, 25'...Connection shaft, 26,
26', 27, 27'...Universal joint, C, D...Dimension between shafts.

Claims (1)

[Scope of utility model registration request] A pair of gears that mesh with each other with a predetermined center-to-axis dimension are housed in a casing that has a fluid suction port and a fluid discharge port, and a pair of extension shafts that extend the rotational axes of the gears in the same direction are provided to the outside. The pump body has a protruding pump body, a transmission drive gear that rotates as the drive source rotates, and a transmission driven gear that meshes with and rotates with the transmission drive gear, and transmits the rotational driving force of the drive source to the extension shaft, respectively. In a gear pump having a power transmission section, the distance between the shafts of the transmission drive gear and the transmission driven gear of the power transmission section is made larger than the distance between the shafts of the pair of gears of the pump body, and A gear pump characterized in that a drive shaft and a driven shaft of the transmission driven gear are respectively connected to each extension shaft of the pump body through a shaft longitudinal arm that allows for misalignment and achieves constant rotation.