JPH0825341A - Shaft seal device of concrete mixer - Google Patents

Abstract

PURPOSE:To enhance the sealing effect of a shaft seal part while facilitating maintenance. CONSTITUTION:A seal material is provided to the gap part 16 between the rotary part and non-rotary part of the shaft seal part of a kneading shaft 11 in the order of a gland packing 17, a lantern ring 18 and a gland packing 17 to arrange the gland packings 17 on both sides of the lantern ring 18. The air passage 24 opened to the lantern ring 18 is formed to the seal housing 15 being the non-rotary part and compressed air is supplied to the lantern ring 18 through the air passage 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete mixer for kneading and producing fresh concrete, and more particularly to a shaft sealing device for a concrete mixer in which a kneading shaft is supported by penetrating a kneading tank.

[0002]

2. Description of the Related Art For example, a biaxial concrete mixer is
Two kneading shafts supporting spirally kneading blades are passed through and supported between opposite side walls of the kneading tank, and concrete is kneaded by rotating the kneading shafts in opposite directions.

Regarding the shaft-sealing portion of the kneading shaft of this kind of concrete mixer, the present applicant has applied for a shaft-sealing device as shown in FIG. 4 (Japanese Patent Application No. 5-54807), and the shaft-sealing device is a kneading device. A gap portion 5 is formed between the collar 2 which is the rotating portion on the shaft 1 side and the seal housing 4 which is the non-rotating portion attached to the side wall 3 of the kneading tank, and the mechanical seal conventionally used in the gap portion 5 is formed. Instead, the lantern ring 6 and the gland packing 7 are mounted, and the seal housing 4 is provided with a seal mechanism in which a cleaning water passage 8 for cleaning the gap 5 is disposed toward the lantern ring 6.

[0004]

However, in the above-mentioned shaft sealing device, the lantern ring and the gland packing which are mounted in the gap portion are mounted with the lantern ring at the top.
Since the gland packing was attached behind it, mortar and concrete easily entered from the lantern ring side, and the sealing effect was somewhat weak.

In view of the above points, an object of the present invention is to provide a concrete mixer shaft sealing device in which the sealing mechanism is improved to enhance the sealing effect.

[0006]

In order to achieve the above object, the present invention provides a concrete mixer in which a kneading shaft having a plurality of kneading blades attached thereto is supported by penetrating between the opposite side walls of the kneading tank. A lantern ring is installed in the gap between the rotating part and the non-rotating part of the shaft-sealing part of the kneading shaft that penetrates the kneading shaft. The passage is formed, and the passage for compressed air is connected to a compressed air supply source through a pipe for supplying compressed air.

[0007]

According to the shaft mixer for a concrete mixer of the present invention, the grant packing mounted in front of the lantern ring prevents mortar and concrete from entering the gap, and the compressed air is supplied to the lantern ring. The internal pressure in the gap can be increased to prevent foreign matter from entering.

Further, by adopting the lantern ring and the gland packing, the structure of the seal is simple and the seal can be easily replaced.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a shaft sealing portion of a two-shaft concrete mixer, which is a non-rotating portion integrally formed with a collar 13 and a kneading side wall 14 which are fitted together with a rotating ring 12 on a kneading shaft 11 so as to be rotatable. A gap portion 16 that allows the kneading shaft 11 to rotate is provided between the seal housing 15 and the seal housing 15.

A gland packing 17 is first mounted on the side of the kneading tank in the gap 16, a lantern ring 18 is subsequently mounted, and a gland packing 17 is also mounted on the outer side thereof. It is preferable to reduce the number of gland packings 17 arranged on both sides of the lantern ring 18 on the rotating ring 12 side, that is, on the kneading tank side. Make it easy to pull out.

The gland packing 17 is a string-shaped sealing material having a rectangular cross section, is appropriately cut according to the outer peripheral dimension of the collar 13, is wound around several layers around the outer periphery of the collar 13, and is sealed by a packing presser 19. The portion 16 is pushed in so as to be filled.

As shown in FIG. 2, the lantern ring 18 has an inner annular groove 21 and an outer annular groove 22 formed in an inner peripheral portion and an outer peripheral portion of a ring main body 20, and has an inner annular groove 21 and an outer annular groove 22, respectively. A communication hole 23 that communicates with each other is formed.

Reference numeral 24 denotes an air passage formed in the seal housing 15, the end portion of which is opened and communicated with the lantern ring 18 of the gap portion 16, and the other end portion of which is directed outward from the seal housing 15. It is open.

A compressed air supply source 25 is connected to a compressed air supply pipe 26, and the compressed air supply pipe 26 has a tip end portion for the air passage 24.
A compressed air control valve 28 for controlling the supply of compressed air is provided in the middle of the compressed air supply pipe 26.

Then, in the mixer, gravel, sand, cement,
When materials such as water and an admixture are added and kneaded, the compressed air control valve 28 of the compressed air supply pipe 26 is opened to allow compressed air to pass through the air passage 24 and the lantern ring 18.
Send in. The compressed air sent to the lantern ring passes through the gap 16 of the gland packing 17 on the rotating ring 12 side, which has a smaller number of attachments, out of the gland packings 17 arranged on both sides, and the foreign matter entering the gap 16 is removed from the mixer. It also blows it away, and also prevents foreign matter from entering.

The compressed air supplied is, for example, about 0.6.
About 50 L / m of compressed air regulated to around kgf / cm ²
By supplying about in, foreign matter entering from the gap portion 16 can be expelled. Alternatively, compressed air may be intermittently supplied to blow off the foreign matter that has entered the gap 16. At this time, it is advisable to make the air pressure slightly higher than the above-mentioned air pressure.

Further, if the compressed air to be supplied is passed through an oiler (not shown), the wear of the rotating portion can be reduced by the lubricating action of the oil contained in the compressed air.

Further, not only compressed air but also cleaning water may be sent to the shaft sealing portion. In this case, as shown in FIG. A cleaning water supply pipe 30 having a control valve 29 interposed therein is connected, and a tip end thereof is connected to a water discharge pipe 32 below a measuring water tank 31, and a pump 33 for pumping pressure is arranged in the middle of the cleaning water supply pipe 30. Set up.

When the concrete is mixed and manufactured, the compressed air control valve 28 is closed and the wash water control valve 29 is opened, and the pressure pump 35 is appropriately driven to take out a part of the measured water as wash water. A part of the water is sent to the lantern ring 18 via the air passage 24. The washing water sent to the lantern ring 18 flows out into the kneading tank while washing away the foreign matter that has entered the gap 16. The measured water used for cleaning is also collected in the mixer and used as kneading water.

When the feeding of the metering water is completed, the driving of the pressure pump 33 is stopped and the flush water control valve 29 is closed. Then, the compressed air control valve 28 is opened to send the compressed air into the shaft sealing portion to prevent foreign matter from entering the gap portion 16.

In the above embodiment, the metering water is used for cleaning the shaft seal portion, but it may be supplied from a water supply source provided separately, or the mixer may be cleaned only when cleaning the mixer. Is also good.

[0023]

As described above, according to the shaft sealing device for a concrete mixer of the present invention, the gland packing 17, the lantern ring 18 are provided in the gap 16 between the rotating part and the non-rotating part of the shaft sealing part of the kneading shaft 11. The seal material is attached in order such as the gland packing 17, and the seal housing 15 which is a non-rotating portion.
Since an air passage 24 opened toward the lantern ring 18 is disposed in the air passage, and compressed air is sent into the air passage 24 to prevent foreign matter from entering, a lantern ring and a gland packing are adopted. The effect of the seal can be enhanced, and maintenance such as replacement of the seal material can be easily performed.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a perspective view showing a lantern ring.

FIG. 3 is a partially omitted cross-sectional view showing another embodiment of the present invention.

FIG. 4 is a sectional view of a shaft sealing portion of a conventional concrete mixer.

[Explanation of symbols]

11 ... Kneading shaft 13 ... Color 14 ... Kneading tank side wall 15 ... Seal housing 16 ... Gap 17 ... Gland packing 18 ... Lantern ring 24 ... Air passage 25 ... Compressor (compressed air supply source) 26 ... Compressed air supply piping

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenichi Umezawa 1st Nikko Co., Ltd., 1013 Eijima, Okubo Town, Akashi City, Hyogo Prefecture

Claims (1)

[Claims] 1. A concrete mixer in which a kneading shaft equipped with a plurality of kneading blades is supported by penetrating between opposing side walls of a kneading tank, the non-rotating part of the shaft sealing portion of the kneading shaft penetrating the kneading tank side wall. The lantern ring is mounted in the gap between the lantern ring and the gland packing, and a compressed air passage is formed toward the lantern ring, and the compressed air passage is supplied with compressed air. A concrete mixer shaft sealing device, characterized in that it is connected to a compressed air supply source via a piping for use.