JPS61144543A - Mechanical seal tester - Google Patents

Abstract

PURPOSE:To increase accuracy with enabling the load measurement in the axial direction of mechanical seal so as to make the surface pressure of the sliding part of the mechanical seal of sample body adjustable by changing the relative screwing position of the bolt for load adjustment and retainer. CONSTITUTION:The shaft end of the rotary shaft 4 connected to rotary driving mechanism via torque detector is inserted freely turnably into the shaft aperture of bottomed cylindrical retainer 11 and also the end part of the bolt 18 for load adjustment screwed to the rear end of the retainer 11 is brought into contact with the detection end part of load cell 17. One end of the sample body mechanical seal 30 is then held on the end face of the retainer 11 and the other end is held by one part of the supporting base 1 which is fixed on the shaft periphery and it is made so as to detect the load in the axial direction by the load cell 17. Because of the surface pressure of the sliding part of the mechanical seal 30 being adjustable and the surface pressure being detectable at all times by the load cell 17 in case of the relative screwing position of the bolt 18 and retainer 11 being changed more correct data is obtainable.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is used to test the wear resistance and sealing properties of mechanical seals used in shaft sealing devices, in particular to investigate load reduction due to creep that occurs during long-term shaft rotation. This article relates to a mechanical seal testing machine for testing effects.

[Conventional technology]

As one of the characteristics of mechanical seals, it is important to know the coefficient of friction f and the dimensionless characteristic number G. These coefficients are: f = W, G = LI W: Load applied to the sliding surface (Kg) R : Center diameter of sliding part (C■) T : Torque (Kg・am) : Absolute viscosity of liquid near sliding part (cps) N : Rotational speed (RP) P : Surface pressure of sliding surface ( It is given in Kg/c.

Therefore, when conducting operational tests on mechanical seals,
It is extremely important to detect the axial load (surface pressure) related to W and P values, but in conventional mechanical seal testers that test the wear resistance and sealing properties of mechanical seals, Before attaching the seal to the shaft, the mechanical seal was measured in advance with a spring load measuring device in order to determine the installation length that would result in a fixed installation load value within a certain range, and the mechanical seal was set on the shaft based on that installation length.

[Problem that the invention seeks to solve]

Therefore, in this type of mechanical seal testing machine, once the test state is entered, the mounting position in the axial direction cannot be changed, so it is impossible to control the surface pressure from the outside, and the axial load on the mechanical seal cannot be changed. It was not possible to carry out various tests on the

In view of the above-mentioned problems, the present invention constitutes a mechanical seal testing machine that can fluctuate and measure the surface pressure from the outside after the mechanical seal is attached to the shaft. The object of the present invention is to provide a mechanical seal testing machine that can detect the influence of load reduction due to creep of members.

[Means for solving problems]

The present invention has a structure of a mechanical seal testing machine that achieves the above object, and the shaft end of a rotating shaft connected to a rotational drive mechanism such as a motor through a torque detector for detecting torque is connected to a cylindrical retainer with a bottom. The retainer is rotatably inserted into the shaft hole of the retainer, and the end of the load adjustment bolt screwed into the rear end of the retainer is brought into contact with the detection shaft end of the load cell, and the retainer is inserted into the rotary ring. A specimen mechanical seal made by sliding a floating sheet on a seal ring. One end of the mechanical seal was supported on the end face of the retainer, the other end was supported on a part of a support fixed around the shaft, and an axial load was applied using a load cell. It is designed to be detected.

[For production]

In the mechanical seal testing machine with the above configuration, the mechanical seal to be tested is arranged in series on the rotating shaft and is in contact with the detection shaft end of the load cell via a retainer and a load adjustment bolt that is screwed into the retainer. By changing the relative screwing position of the load adjustment bolt and the retainer, the surface pressure of the specimen mechanical seal sliding part can be adjusted, and this surface pressure is detected by a load cell.

〔Example〕

An embodiment of the mechanical seal testing machine of the present invention will be described below with reference to the drawings. As shown in Figure 1, the mounting state of the specimen mechanical seal, the support stand (1) of the test machine consists of a front plate (2) and a rear plate (3) that stand opposite each other.
A rotation shaft (0 end of which is connected between the plates (2) and (3) through the through hole (2a) through a rotational drive source such as a motor (not shown) and a torque detection mechanism (not shown) is inserted. Install the shaft. Code (5)
) is the specimen case supported between the above plates (2) and (3), and the front cover is airtightly fitted to the front and rear ends of the outer cylinder (8) through sealing materials such as O-rings. (7) and the rear cover (8) are fixed poles screwed and erected on the front plate (2) and rear plate (3), respectively. (9) (to) The ends are pressed and supported. The shaft hole (8) of the rear cover (8)
In a), the cylindrical shaft portion (ll) of the bottomed cylindrical body retainer (11) is shown.
a) is an O-ring (12) fitted into the inner diameter of the shaft hole (8a)
A dowel pin (13
) is engaged with a knock pin (14) protruding from the rear cover (8) to prevent rotation. The acid screw (15) screwed onto the rear end of the retainer (11) has an adjustment screw at the end of the detection shaft (17a) of the load cell (17) fixed to the rear plate (3) via a bolt (18). The rear end of the knob (18) is in contact with the axial load adjustment bolt (18), and the rotation shaft (0 end is The snap ring (22) is inserted into the shaft hole (20) of the retainer (11), and a shell (21) for supporting a floating seam (31), which will be described later, is fitted onto the outer periphery of the tip of the retainer (11). ) to create a structure that fits.

For example, a bellows (33) is used for a seal ring (32).
) The specimen mechanical seal (30) is of the type that slides into contact with a floating sheet (34) fixed to one end of the specimen.

Collar (35) fixed to the other end of the bellows (33)
is extrapolated onto the rotation shaft (4), and the front cover (7
) is airtightly fixed to the inner surface of the floating seat (30) via an O-ring.
32) is formed by engaging a key groove (32a) formed on the inner diameter with a key (37) protruding from the rotary ring (0) so as to be able to freely slide in the axial direction.The rear end of the seal ring (34) The floating seat (31) carried by the shell (21) is brought into close contact with the front end of the retainer (11), and the adjustment knob (18) is rotated to adjust the load adjustment port (18) and the retainer (11). Adjust the screw position.

The pressure load in the axial direction is read by a load cell (17).

The mechanical seal tester with the above configuration has a rear cover (8).
With the floating seam (31) supported on the retainer (11) and the shaft hole (8) of the rear cover (8)
After inserting the retainer (11) into a), insert the rotating shaft (0 end into the shaft hole (2o) of the retainer (11) so that the floating seat (38) is in close contact with the seal ring (34) and fix it. Assemble the specimen case (5) by tightening the bolts (1) (to), and connect the rear end of the load adjustment bolt (18) protruding from the rear end of the retainer (11) to the detection axis of the load cell (17). (17a) While in contact with the end,
The rotary shaft (4) is rotated by the rotary drive source to test the wear resistance and sealing performance of the mechanical seal, and the sealing fluid at an appropriate internal pressure is placed in the hollow part (A) of the specimen case (5). It can also be filled with.

In the rotation test of the above mechanical seal specimen, the axial load is directly detected by the load cell (17), so by displaying this detected value on, for example, a digital indicator, the adjustment knob (19) can be rotated. It is possible to easily set the mechanical seal to a set load value.

In addition, since the load cell (17) always detects the load value in the axial direction, the rubber generated during the long-term rotation test,
It is also possible to investigate the effect of load reduction due to creep on mechanical seal members such as springs.

Next, FIG. 2 shows another embodiment of the present invention, in which the retainer (11) is connected to the shaft hole (8) of the rear cover (8).
The shaft was inserted into 8a) via the O-ring (12), but
This is particularly the case when the O-ring (12) is deformed by hydraulic pressure and hardened by heat, thereby affecting the axial sliding movement of the retainer (11). That is, the retainer (11
) between the rear end of the rear cover (8) and the inner surface of the rear cover (8).
At the same time, the load adjustment pole I-(18) is screwed to the rear end of the retainer (11) by penetrating the shaft hole (8a) of the rear cover (8) and adjusting the load. (for use)
The rear end of the adjustment knob (18) of (18) is in contact with the end of the detection shaft (17a) of the load cell, and is used to support and test the mechanical seal (30) as the specimen in the same manner as in the previous example. .

The mechanical seal tester having the configuration described in 1 is arranged in series on the bellows (33), floating seat (30, seal ring (32) and floating seat (31) e rotating wheel (4) of the mechanical seal (3G) under test, The detection shaft (1
7a) Since it is in contact with the end, the above load adjustment pole)
(18) and the retainer (11), the surface pressure on the sliding part of the mechanical seal (30) is adjusted, and the surface pressure is directly detected by the load cell (17). . In addition, the above load adjustment port)
The adjustment knob (19) of (18) is located at a position protruding from the rear/<- (8), and can be adjusted freely after setting the mechanical seal (30) under test. It is possible to adjust even inside.

Therefore, regarding the specimen mechanical seal (30),
The load W (Kg) applied to the sliding surface and the surface pressure (
Kg/cni'') can be detected, and the characteristics of mechanical seals such as friction coefficient f=T/WR and dimensionless characteristic number G=end・N/P can be tested.

In addition, during long-term high-temperature tests, it is possible to investigate changes in surface pressure over time due to creep deformation of each component such as the rubber seal of a mechanical seal or a coil spring, and the relationship between rotational conditions and leakage amount. It is.

〔Effect of the invention〕

As described above, the mechanical seal testing machine of the present invention can adjust the surface pressure of the sliding part after setting the specimen mechanical seal, and can constantly detect the surface pressure using the load cell. Therefore, more accurate data can be obtained in mechanical seal characteristic tests.

[Brief explanation of drawings]

The drawings show embodiments of the mechanical seal testing machine of the present invention. Figure 1 is a front cross-sectional view of the first embodiment with a mechanical seal attached, and Figure 2 shows another embodiment. FIG. 3 is an enlarged cross-sectional view of main parts. (1) Support stand (4) Swivel ring (5) Specimen case (?) (8) Cover (11) Retainer (!5
) Female screw (17) Load cell (17a) Detection shaft (1
8) Load adjustment pole) (19) Adjustment knob (23)
(33) Bellows

Claims (1)

[Claims] The shaft end of a rotating shaft connected via a rotational drive mechanism and a torque detection mechanism is rotatably inserted into the shaft hole of a bottomed cylindrical retainer, and a load is screwed onto the rear end of the retainer. one end of a specimen mechanical seal formed by contacting the end of the adjustment bolt with the detection shaft end of the load cell and sliding a floating sheet on a seal ring fitted onto the rotation shaft, supported on the end face of the retainer; A mechanical seal testing machine characterized in that the other end is supported on a part of a support stand fixed around the shaft, and the load in the axial direction is detected by a load cell.