JPH0348451Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a mechanical seal, and particularly to one equipped with a friction torque/contact load detection jig for detecting friction torque and contact load.

[Conventional technology]

As a conventional method for detecting friction torque due to sliding, there is a method as shown in FIG. Reference numeral 101 in FIG. 6 is a motor, and rotation from this motor 101 is transmitted to a drive shaft 105 via a belt 103. A mechanical seal 107 is attached to the drive shaft 105, and a seal ring serving as a fixed ring of the mechanical seal 107 is fixed to the housing 111 via a rotatable bearing 109. A shaft 113 is formed at the left end of the housing 111 in the drawing, and the housing 111
is supported by bearings 115 and 117 via this shaft 113. Inside the housing 111 is a liquid 1.
19 is included.

Further, a torque detection plate spring 121 is connected to the housing 111, and friction torque is detected by measuring minute deformations of the torque detection plate spring 121 using a strain gauge (not shown). Note that measurement may be performed using a load cell (load meter).

Further, there is another method as shown in FIG. This is measured via the rotating ring of the mechanical seal. Reference numeral 131 in the figure is a motor, and a drive shaft 133 rotated by this motor 131 has a double seal type mechanical seal 1.
35 is installed. This mechanical seal 1
35 is a pair of retainers 137, 137, springs 139, 139, mating ring 141,
141, seal rings 143, 143, etc.

Further, a torque meter 145 is interposed between the motor 131 and the drive shaft 133. This torque meter 145 detects torque via the mating ring 141 as a rotating ring.

In addition to these methods, there is also a method of detection using, for example, the electric power or current of the drive motor.

[The problem that the idea attempts to solve]

The conventional configuration described above has the following problems.

First, as shown in Fig. 6, when torque is detected through the fixed ring side, normally the housing 1
11 is equipped with various devices for temperature measurement in addition to torque detection, such as thermocouples, and piping for circulating the liquid 119. Therefore, there was a problem that it was difficult to maintain balance and the measurement accuracy was poor.

In addition, a vibration system is constructed between the mass (moment of inertia) of the rotatable part including the seal ring and the leaf spring 121 for torque detection, and as a result, a relatively low natural frequency exists, reducing measurement accuracy. There were also problems.

In addition, as shown in Figure 7, in the case of detection on the drive side, mechanical seals are often used as a double seal type as shown in the figure, and in such cases, the Therefore, there was a problem that it was difficult to measure each individual torque.

Also, in this case, a vibration system is formed between the moment of inertia of rotating parts such as the shaft 133, the rotor of the motor 131, the coupling, etc., and the torque meter 145, and the measurement accuracy is reduced due to its natural frequency. There was a problem.

In addition, in general mechanical devices, most of the drive torque is consumed by loads other than mechanical seals, so the torque meter 1 depends on the diameter of the drive shaft 133.
If you select 45, the sensitivity will be insufficient and the measurement accuracy will drop, and conversely, the sensitivity will cause the torque meter 14
When 5 was selected, there was a problem that the rigidity was insufficient.

Furthermore, there is no way to measure the contact load during operation, and the only way to find it is through theoretical calculations based on fluid pressure based on dimensions or theoretical calculations based on spring loads. At that time, the load will vary depending on the assumption of the distribution of fluid pressure between the sealing surfaces, but since there is no means to measure the load during operation, there is no way to confirm the above assumption.

The present invention was developed based on these points, and its purpose is to develop a mechanical seal that is capable of detecting friction torque with high precision and also has a mechanism that can measure contact loads during operation. Our goal is to provide the following.

[Means to solve the problem]

In order to achieve the above object, the mechanical seal according to the present invention is installed between the shaft and the equipment housing within the shaft hole formed in the equipment housing, and includes a fixed ring and a rotating ring that is placed in contact with the fixed ring. , a mechanical seal comprising an elastic member that applies a pressing load to the stationary ring or the rotating ring to bring the stationary ring and the rotating ring into pressure contact, and a shaft packing, which is installed between the device housing and the stationary ring. , having a pair of large diameter parts for fixing to the housing and a pair of small diameter parts formed between the pair of large diameter parts and not in contact with the equipment housing, the large diameter parts being the large diameter part and the small diameter part. A notch passing through in the axial direction is formed on a line connecting the boundary between the large diameter part and the small diameter part, and a torque detection sensor is provided at the boundary between the large diameter part and the small diameter part, and the large diameter part is the large diameter part. A through hole is formed on the line connecting the boundary between the part and the small diameter part so as not to intersect with the notch, and a friction torque/contact load detection jig equipped with a contact load detection sensor is installed outside the through hole. It is characterized by the provision of a tool.

[Effect]

The torque detection jig is fixed to the device housing via a pair of large diameter parts. In addition, a notch is formed in the large diameter part on a line connecting the boundary between the large diameter part and the small diameter part, and as a result, the rigidity against torsional moments at the boundary between the large diameter part and the small diameter part is reduced. is decreasing. A torque detection sensor is attached to the boundary where the rigidity is reduced, and friction torque is detected via this torque detection sensor.
On the other hand, a through hole is formed in the large diameter part so as not to intersect with the notch on a line connecting the boundary between the large diameter part and the small diameter part, and the part of this through hole extends in the axial direction (load direction). On the other hand, the rigidity is reduced. Therefore, a contact load detection sensor is attached to the outside of this through hole to detect the contact load.

〔Example〕

The first part of the present invention will be described below with reference to FIGS. 1 and 2.
An example will be explained. This first embodiment is an internal flow type (leakage goes from the outer circumference to the inner circumference of the sealed end face).
The present invention is applied to a rotary mechanical seal (one in which an elastic member rotates).

FIG. 1 is a sectional view showing the structure of a mechanical seal according to this embodiment, in which reference numeral 1 is a shaft and reference numeral 3 is a device housing. A seal ring 5 as a fixed ring is attached to the outer periphery of the shaft 1, and a mating ring 7 as a rotating ring is placed in contact with this seal ring 5. This mating ring 7 is pressed against the seal ring 5 by an elastic member (not shown). Reference numeral 9 in the figure is an O-ring.

A friction torque/contact load detection jig 11 is installed between the seal ring 5 and the device housing 3. As shown in FIG. 2, this friction torque/contact load detection jig 11 is provided with large diameter portions 13, 13 at symmetrical positions. This large diameter portion 13
It is formed in a range of 90 degrees, and holes 15, 15 for bolt penetration are formed at both ends thereof. The friction torque/contact load detection jig 11 is inserted into the hole 15 mentioned above.
It is fixed to the device housing 3 with a fixing bolt 17 via.

On the other hand, the friction torque/contact load detection jig 11 is formed with small diameter portions 19, 19, and these small diameter portions 19 are in a non-contact relationship with the device housing 3 in the radial direction. Furthermore, as shown in FIG. 1, the small diameter portion 19 is also in a non-contact relationship with the device housing 3 in the axial direction.

The large diameter portion 13 includes a large diameter portion 13 and a small diameter portion 19.
A groove 21 penetrating in the axial direction is formed on a line connecting the boundary portion (indicated by reference numeral a in the figure) with the groove 21, and holes 23, 23 are formed at both ends of the groove 21. With this configuration, the boundary portion a between the large diameter portion 13 and the small diameter portion 19 has a structure in which the rigidity is locally reduced against torsional moments.
Note that the rigidity does not decrease in the thickness direction. Four strain gauges 25 as torque detection sensors are installed at the boundary part a. Verification is performed by applying a known torsional torque to these strain gauges 25. Thereby, the friction torque is measured quantitatively.

On the other hand, on the inner peripheral side of the groove 21 of the large diameter portion 13, there is a through hole 27 that penetrates in the boundary direction (a-a direction).
is formed, and the rigidity of the through hole 27 portion is low in the axial direction (load direction).
Four strain gauges 29 are attached to this portion as sensors for detecting contact load. By applying a known load to these strain gauges 29, the contact load can be measured quantitatively.

According to this embodiment, the following effects can be achieved.

First, there are no problems with conventional methods, such as a decrease in accuracy due to difficulty in achieving balance, or a decrease in accuracy due to the natural frequency of the vibration system, and it is possible to perform highly accurate measurements. I can do it. In particular, since the small diameter portion 19 is in a non-contact relationship with the equipment housing 3, the accuracy will not be reduced due to influence via the equipment housing 3.

Further, by installing the detection jig 11 for each mechanical seal, it is possible to measure each mechanical seal even for double seal type ones.

Further, since the O-ring 25 is installed, there is no fear of leakage, and the configuration is simple.

Furthermore, in the case of this embodiment, the contact load, which could conventionally only be determined theoretically, can be actually measured via the strain sensor 29. Therefore, in combination with the detection of friction torque, it is possible to accurately grasp the state of the mechanical seal.

Next, second to fourth embodiments will be described with reference to FIGS. 3 to 5. First, there is a second embodiment shown in FIG. 3, in which the present invention is applied to an internal flow type, stationary type (one in which the elastic member does not rotate) mechanical seal. axis 31
An internal flow type and stationary mechanical seal 35 is installed between the device housing 33 and the device housing 33.
A friction torque/contact load detection jig 37 is attached to the outer circumferential side thereof.

Next is the third embodiment, in which the present invention is applied to a rotary mechanical seal that is an external flow type (leakage goes from the inner circumference to the outer circumference of the sealed end face) as shown in Fig. 4. It is something. An external flow type rotary mechanical seal 45 is installed between the shaft 41 and the equipment housing 43, and a friction torque/contact load detection jig is installed between the mechanical seal 45 and the equipment housing 43. 47 is attached.

Furthermore, in the fourth embodiment, as shown in FIG. 5, the present invention is also applied to an external flow type and stationary mechanical seal. An external flow type and stationary mechanical seal 55 is installed between the shaft 51 and the equipment housing 53, and a friction torque/contact load detection jig is installed between the mechanical seal 55 and the equipment housing 53. 57 is installed.

The respective friction torque/contact load detection jigs 37, 47, 57 in these second to fourth embodiments are the same as the torque detection jig 11 of the first embodiment, and are therefore the same as the torque detection jig 11 of the first embodiment. The same effects as in the embodiment can be achieved.

[Effect of idea]

As detailed above, according to the mechanical seal according to the present invention, friction torque and contact load can be measured with high accuracy with a simple configuration and without impairing the original function of the mechanical seal.

[Brief explanation of drawings]

1 and 2 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is a half-cut sectional view of a mechanical seal, FIG. 2 is a plan view of a torque detection jig, and FIG. 4 is a half-cut sectional view of the mechanical seal according to the third embodiment, FIG. 5 is a half-cut sectional view of the mechanical seal according to the fourth embodiment, FIG. 7th
The figure is a sectional view showing a conventional friction torque detection method. 1... Shaft, 3... Equipment housing, 5... Seal ring (fixed ring), 7... Mating ring (rotating ring), 11... Friction torque/contact load detection jig, 13... Large diameter Part, 19...Small diameter part, 21...
... Groove (notch), 25 ... Strain sensor (torque detection sensor), 27 ... Through hole, 29 ... Strain sensor (contact load detection sensor).

Claims (1)

[Scope of utility model registration request] A fixed ring, a rotating ring arranged in contact with the fixed ring, and a pressing load applied to the fixed ring or the rotating ring, are installed in the shaft hole formed in the equipment housing and between the shaft and the equipment housing. A mechanical seal comprising an elastic member that brings a fixed ring and a rotating ring into pressure contact with each other, and a shaft packing, a pair of large diameter parts installed between the device housing and the fixed ring and fixed to the housing; A pair of small diameter parts are formed between the pair of large diameter parts and do not contact the equipment housing, and the large diameter parts penetrate in the axial direction on the line connecting the boundary between the large diameter part and the small diameter part. A notch is formed in the large diameter part, and a torque detection sensor is provided at the boundary between the large diameter part and the small diameter part, and a notch is provided in the large diameter part on a line connecting the boundary between the large diameter part and the small diameter part. A mechanical seal characterized in that a through hole is formed so as not to intersect with the notch, and a friction torque/contact load detection jig equipped with a contact load detection sensor is provided outside the through hole.