JPH0417813Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field of the Invention) This invention relates to an improvement in a drive device for a reciprocating pump, which performs a pumping operation by reciprocating a pump section called a metering pump.

(Technical background of the invention and its problems) In general, in metering pumps, the driving force transmission means for the pumping action of the diaphragm constituting the pump section, that is, the rotational motion of the output shaft of the drive motor that has been decelerated, is converted into reciprocating motion. Eccentric cams are widely used as a converting mechanism.

Conventional metering pump drive devices of this type have a configuration in which an eccentric cam attached to the output shaft of the drive motor is usually installed on the same axis as the drive shaft (plunger) of the pump section. .

However, in such a conventional driving force transmission means for pumping operation in a pump unit, an abutment member that abuts and regulates the amount of reciprocating movement (travel) of the drive shaft unit for adjusting the stroke length of the pump unit, It is located offset from the center axis of the drive shaft of the pump section, and the bearing of the drive shaft section of the pump section is only at one location, sandwiched between the tip of the pump section and the input shaft. is the current situation.

Therefore, when the stroke length of the drive shaft of the pump section is being adjusted, stress in a direction other than the axial direction is applied to the drive shaft of the pump section, and this causes a local load on the bearing. As a result, uneven wear and wear at the end of the bearing tend to occur, which not only adversely affects the durability life and lowers reliability, but also makes it impossible to make the entire device compact.

(Purpose of the invention) This invention was made under the above circumstances, and its purpose is to easily adjust the stroke length of the pump part, and to make it possible to easily adjust the stroke length of the pump part, and to It is an object of the present invention to provide a reciprocating pump drive device that prevents the effects of stress other than those described above, increases reliability and durability, and can be made more compact.

(Summary of the invention) In order to achieve the above purpose, this invention:
The rotational drive of the output shaft of the drive motor is transmitted to the drive shaft section via an eccentric cam mechanism having a camshaft, causing the drive shaft section to reciprocate along the axial direction, and one end of the drive shaft section is a stroke having an abutment member that abuts against the drive shaft portion to perform a pumping operation in the pump portion through the pump portion, regulate the amount of reciprocating movement of the drive shaft portion, and adjust the stroke length of the pump portion; Assuming that the reciprocating pump is equipped with a length adjustment mechanism, the other end of the drive shaft portion opposite to the one end portion is positioned corresponding to the abutment member on the central axis of the drive shaft portion, and the drive A pair of sliding contact surfaces are formed at symmetrical positions with respect to the central axis of the drive shaft at intermediate portions between one end and the other end of the shaft, and the drive shaft is in sliding contact with these sliding surfaces. The eccentric cam mechanism is provided with a pair of eccentric cam members mounted on the camshaft so as to transmit power to the eccentric cam mechanism, and a pair of eccentric cam members are formed on the drive shaft portion surrounding the eccentric cam mechanism and on the other end thereof. The present invention proposes a reciprocating pump drive device characterized by a configuration in which connected loop-shaped connecting portions are provided.

(Function) That is, according to the reciprocating pump drive device of this invention, the loop-shaped connecting portion formed in the drive shaft portion surrounding the eccentric cam mechanism allows the other end of the drive shaft portion to be connected to its center. Since the structure is such that it is positioned on the axis and corresponds to the abutment member of the stroke length adjustment mechanism, the loop-shaped connecting part is configured to surround the eccentric cam mechanism, and the drive shaft can be moved without interfering with the operating area of the eccentric cam mechanism. The drive shaft can be reciprocated, and a force can be applied from the abutting member to the drive shaft along its central axis. In addition, since a pair of sliding surfaces are provided on the drive shaft portion at symmetrical positions with respect to the central axis, and a pair of eccentric cam members of the eccentric cam mechanism are made to correspond to these sliding surfaces, there is no contact between the eccentric cam mechanism and the drive shaft portion. Force transmission can be applied along the central axis from dispersed positions, and the force acting from both the eccentric cam mechanism and the stroke length adjustment mechanism is also along the central axis of the drive shaft, so the axis relative to the drive shaft is By eliminating the effects of stress in directions other than directions, the durability and reliability of the drive device can be improved.

(Embodiment) Hereinafter, the present invention will be described in detail with reference to an illustrated embodiment.

As shown in FIGS. 1 and 2, reference numeral 1 in the figures is a reciprocating pump main body, which is equipped with a pump head 2 constituting a pump section on the tip side, and this pump head 2 has the following features:
It has a suction port 3 and a discharge port 4, and each of the suction port 3 and discharge port 4 is provided with ball valves 5, 6. Further, a diaphragm 8 is provided in the pump chamber 7 in the pump head 2,
A drive shaft portion 9 is connected to the diaphragm 8 and is biased in the axial direction by a return spring 10, which is reciprocated by a power transmission means to be described later. This drive shaft portion 9 is formed by pumping the diaphragm 8, and by the pumping action of the diaphragm 8, the pumped fluid introduced from the suction port 3 is discharged in fixed amounts from the discharge port 4. ing. The discharge amount of the pumped fluid corresponds to the stroke amount of the drive shaft portion 9, and the adjustment of this stroke amount is performed as described below, in which the range of reciprocating motion of the drive shaft portion 9 is abutted and restricted. This is performed by a stroke length adjustment mechanism having an abutment member that allows the stroke length to be adjusted.

That is, the power transmission means allows the pump-side tip 9a of the drive shaft 9 to slide freely along the central axis of the drive shaft 9 within the casing 11 to which the pump head 2 is connected, and the return spring 10. The casing 1 is supported by being biased in the axial direction by the biasing force of
A sliding portion 12 extending toward the rear end of the drive shaft portion 9 is slidably supported along the central axis of the drive shaft portion 9, and a U-shaped cross section is formed midway through the drive shaft portion 9. A pair of sliding surfaces 91 and 92 formed at symmetrical positions with respect to the central axis of the drive shaft section 9 are symmetrically spaced apart by a cam shaft 14 forming an eccentric cam mechanism 13. Eccentric cams 15 and 16 constituting an eccentric cam member consisting of a pair of bearings supported by
By meshing the worm wheel 17 provided on the camshaft 14 with the worm 20 provided on the output shaft 19 of the drive motor 18 facing from the outer upper part of the casing 11, the rotation of the output shaft 19 of the drive motor 18 causes an eccentric cam to be generated. A pair of eccentric cams 15 and 16 of the mechanism 13 are eccentrically rotated to cause the drive shaft portion 9 to reciprocate.

In addition, 21 in the figure is the drive shaft portion stroke amount S
With this adjustment mechanism, an abutment member 22 is movably disposed on a sliding portion 12 extending to the rear end side of the casing 11, and a tip end 22a of this abutment member 22 is placed behind the drive shaft portion 9. The abutment member 22 is positioned correspondingly to the end portion 9b side along the central axis of the drive shaft portion 9.
The amount of movement can be adjusted by a rotation adjustment body 23 screwed onto the rear end side of the sliding portion 11a of 1. A display scale a is attached that allows for identification. That is, such a stroke length adjustment mechanism 21 adjusts the amount of movement of the abutting member 22 by rotating the rotation adjustment body 23, and adjusts the movement amount of the abutting member 22 to adjust the movement of the drive shaft portion 9.
The range of reciprocating motion can be regulated by abutment. Further, an eccentric cam mechanism is interposed with respect to the pump part side tip part 9a which is one end part of the drive shaft part 9, and the other end part which is the shaft-shaped rear end part 9b is located on the opposite side or rear end side. In order to position the drive shaft portion 9 along the central axis, the drive shaft portion 9 includes a loop-shaped connecting portion 9c formed to surround the eccentric cam mechanism 13, as shown in FIG. provided integrally, whereas the rear end portion 9
b are connected together. With this configuration, the drive shaft portion 9 can reciprocate without interfering with the rotational movement area of the eccentric cam mechanism 13. In addition, since the connecting portion 9c has a loop shape, sufficient strength can be obtained, and the front end portion 9a is supported at one end, and the rear end portion 9b is supported at the other end, so that the drive shaft is supported along the central axis. The portion 9 can perform stable reciprocating motion.

Further, reference numeral 24 in the figure is a set screw for fixing the moving position of the abutment member 22, so that the stroke amount can be maintained stably.

Note that the present invention is not limited to the above-described embodiments, and the drive device of the present invention can be applied to, for example, a bellows-type pump structure.

In addition, it goes without saying that the present invention can be modified in various ways without departing from the gist of the invention.

(Effects of the invention) As is clear from the above explanation, according to the invention, the drive shaft part that reciprocates by the eccentric cam mechanism,
A pair of sliding surfaces are provided at symmetrical positions with respect to this central axis, and the eccentric cam members on the camshaft are made to correspond to these, and the drive shaft portion is extended rearward by a loop-shaped connecting portion. and a rear end corresponding to the abutment member of the stroke length adjustment mechanism is integrally provided at a position along the central axis, so that the eccentric cam mechanism and the stroke length adjustment mechanism act on the drive shaft. All forces are directed along the central axis, eliminating the biased force acting on the drive shaft, improving the durability and reliability of the drive device.Moreover, due to the above-mentioned loop-shaped connection structure, the drive shaft The reciprocating movement of can be performed without any interference with the operation of the eccentric cam mechanism,
Since the loop-shaped connecting portion is also integrally connected to the drive shaft portion in a loop-like manner, sufficient strength can be obtained, and the above effects can be achieved with a simple configuration.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view taken along the line shown in Fig. 2, which shows an embodiment of the drive device for a reciprocating pump according to the present invention; FIG. 3 is a cross-sectional view of the transmission portion. DESCRIPTION OF SYMBOLS 1... Pump body, 2... Pump head (pump part), 9... Drive shaft part, 10... Return spring, 12... Sliding part, 13... Eccentric cam mechanism, 14... Camshaft, 15, 16...Eccentric cam,
17... Worm wheel, 18... Drive motor, 19... Output shaft, 20... Worm, 21...
...Stroke length adjustment mechanism, 22...Abutment member, 2
3... Rotation adjustment body, S... Stroke length.

Claims (1)

[Claims for Utility Model Registration] The rotational drive of the output shaft 19 of the drive motor 18 is transmitted to the drive shaft section 9 via the eccentric cam mechanism 13 having the camshaft 14 to reciprocate along the drive shaft section in the axial direction. The pump unit 2 performs a pumping operation in the pump unit 2 through one end 9a of the drive shaft, and regulates the amount of reciprocating movement of the drive shaft to adjust the stroke length of the pump unit. In a reciprocating pump equipped with a stroke length adjustment mechanism 21 having an abutment member 22 that abuts against the drive shaft, the other end 9b of the drive shaft on the opposite side from the one end 9a is connected to the drive shaft. a pair of sliding contact surfaces located symmetrically with respect to the central axis of the drive shaft portion at intermediate portions between one end and the other end of the drive shaft portion; 91,9
A pair of eccentric cam members 15 and 16 are attached to the eccentric cam mechanism 13 and are mounted on the camshaft 14 so as to slide on these sliding surfaces and transmit power to the drive shaft. A reciprocating pump drive device, characterized in that the drive shaft portion is provided with a loop-shaped connecting portion 9c that is formed surrounding the eccentric cam mechanism 13 and connected to the other end portion 9b.