JP3384866B2 - Shaft sealing device for concrete mixer - Google Patents

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 manufacturing 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.

Conventionally, as shown in FIG. 4, the shaft sealing portion of the kneading shaft of this concrete mixer is a seal housing which is a rotating part on the kneading shaft 1 side and a non-rotating part mounted on the side wall 3 of the kneading tank. 4, a gap 5 is formed between them and various seal mechanisms 6 such as a mechanical seal and a gland packing are adopted in the gap 5 to prevent foreign matter such as sand, cement and mortar from entering during kneading. Has been done.

Further, in order to further enhance the sealing function, as described in Japanese Utility Model Laid-Open No. 61-909, compressed air or cleaning water is supplied to the gap between the rotating portion and the non-rotating portion of the shaft sealing portion. Thus, there is one in which the gap is cleaned or foreign matter that enters is pushed out.

[0005]

However, when compressed air or cleaning water is supplied to the gap between the rotating portion and the non-rotating portion of the shaft sealing portion in order to enhance the sealing function of the shaft sealing portion, lubrication of the shaft sealing portion is performed. The grease that is supplied for this purpose will also be pushed out, and the lubricating effect may be reduced if it is somewhat.

Therefore, a method of dropping oil having a low viscosity into the gap can be considered, but it is difficult to cover the amount of the drop, and if the amount is too small, the oil is not sufficiently distributed in the gap, and if too much, it is uneconomical. Become.

In view of the above points, an object of the present invention is to provide a concrete mixer shaft sealing device capable of lubricating a shaft sealing portion which employs a sealing mechanism with compressed air or cleaning water with a small amount of oil. .

[0008]

In order to achieve the above object, the present invention provides a concrete mixer shaft sealing device according to claim 1, wherein a kneading shaft having a plurality of kneading blades is provided between opposing side walls of a kneading tank. In a concrete mixer which is penetrated through and supported by a shaft, an air passage communicating with a gap between a rotating portion and a non-rotating portion of a shaft sealing portion of a kneading shaft that penetrates a side wall of a kneading tank is formed, and a compression passage is formed in the air passage. The compressed air supply pipe connected to the air source is connected, and the compressed air supply pipe is provided with an oiler for mixing oil mist with the compressed air supplied.

According to a second aspect of the present invention, there is provided a concrete mixer shaft sealing device in which a kneading shaft having a plurality of kneading blades is penetrated between opposing side walls of a kneading tank to support the kneading shaft. An air passage communicating with the gap between the rotating portion and the non-rotating portion of the shaft-sealing portion of the kneading shaft is formed, and a compressed air supply pipe connected to a compressed air source is connected to the air passage, An air mist is added to the compressed air supplied to the compressed air supply pipe while the cleaning water supply pipe in which a pressure pump is arranged is connected to the air passage and the other end of the pipe is connected to a water supply source. The feature is that an oiler for mixing is provided.

[0010]

According to the shaft sealing device for a concrete mixer according to claim 1 of the present invention, the foreign matter that is supplied with the compressed air into the gap between the rotating portion and the non-rotating portion of the shaft sealing portion and tries to enter the gap. The shaft seal portion can be lubricated because the mist-like oil is mixed with the compressed air through the oiler while pushing out. Since the oiler can easily adjust the amount of oil to be mist, the amount of oil mist in the compressed air can be easily adjusted to an appropriate value.

Further, according to the shaft sealing device for a concrete mixer as claimed in claim 2 of the present invention, compressed air is supplied to the gap between the rotating part and the non-rotating part of the shaft sealing part by way of the Euler. Push out foreign matter that tries to enter the gap of the
The mist-like oil mixed in the compressed air can lubricate the shaft-sealing part, and can also supply the cleaning water to the gap between the rotating part and the non-rotating part of the shaft-sealing part. Foreign matters such as sand and cement that could not be extruded with compressed air can be washed and extruded, thereby further reducing wear of the shaft seal portion.

[0012]

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

FIG. 1 shows an embodiment of the present invention, and the same reference numerals as those in FIG. 4 denote the same components.

In FIG. 1, a seal housing 4 of a non-rotating portion is fixed to a side wall 3 of a kneading tank via a mounting ring 20, and is fitted to a kneading shaft 1 to allow a rotatable collar 2 and the seal housing 4. A gap 5 that allows the kneading shaft 1 to rotate is provided between them.

A lantern ring 21 is mounted on the side of the kneading tank in the gap 5, and a gland packing 22 is mounted on the outside thereof. As shown in FIG. 2, the lantern ring 21 has an inner annular groove 24 and an outer annular groove 25 formed in an inner peripheral portion and an outer peripheral portion of a ring body 23, and connects the inner annular groove 24 and the outer annular groove 25 to each other. A communication hole 26 is formed.

The gland packing 22 is a string-shaped sealing material having a rectangular cross section, is cut appropriately according to the outer peripheral size of the collar 2, is wound around several layers on the outer periphery of the collar 2, and is sealed by a packing retainer 27. The part 5 is pushed in so as to be filled.

Reference numeral 28 denotes an air passage formed in the seal housing 4, the end portion of which is opened and communicated with the lantern ring 21 of the gap portion 5, and the other end portion of which is outward from the seal housing 4. It is open.

A compressed air supply source 29 is connected to a compressed air supply pipe 30, and the tip of the compressed air supply pipe 30 is connected to the air passage 28.
Is connected to the external opening via the socket 31.

Reference numeral 32 is a water measuring tank for measuring kneading water, and a wash water supply pipe 34 for taking out a part of the measured water is branched and connected to the lower water discharge pipe 33. The tip of the supply pipe 34 is connected to the middle of the air passage 28. In addition, a pressure-feeding pump 35 for feeding the measured water toward the air passage 28 under pressure is provided in the middle of the washing water supply pipe 34.

A control valve 36 for controlling the supply of compressed air is attached to the compressed air supply pipe 30, and a control valve 3 for controlling the supply of cleaning water is attached to the cleaning water supply pipe 34.
7 is attached. Further, an oiler 38 for atomizing and mixing oil into the compressed air to be supplied is attached to the compressed air supply pipe 30.

As shown in FIG. 3, the oiler 38 comprises a bowl 39 for containing lubricating oil such as turbine oil and a lid 40, and a lid 40 has a pipe connection port 41 for connecting the compressed air supply pipe 30. , A mist forming section 42 for atomizing the oil into a mist, and an oil dropping chamber 43 for supplying oil to the mist forming section 42 above the mist forming section 42.
Is equipped with. The oil dropping chamber 43 and the bowl portion 39
The siphon section 44 is connected to the muffle forming section 42, and a needle valve 45 for adjusting the amount of oil sent to the mist forming section 42 is provided in the middle of the siphon section 44. Further, the lid 40 is provided with an oil supply part 46 that supplies oil to the bowl part 39.

However, when concrete is kneaded and manufactured, a predetermined amount of materials such as gravel, sand, cement, water, and an admixture are weighed, and sand, water (the admixture is often added to water before), cement, and gravel. The materials are charged into the mixer in this order. At the start of charging, the control valve 37 of the cleaning water supply pipe 34 is opened and the control valve 36 of the compressed air supply pipe 30 is closed.

A part of the metering water is taken out from the lower part of the water metering tank 32 by driving the pressure pump 35, and a part of the metering water is supplied to the air passage 28 formed in the seal housing 4 by about 10 kg / Send in with a pressure of about cm ² .

The metering water sent into the air passage 28 passes through the gap 5 between the collar 2 which is the rotating part of the shaft sealing part to which the lantern ring 21 is attached and the seal housing 4 which is the non-rotating part. The foreign matter that has entered the gap portion 5 is pushed out, and at the same time, the foreign matter on the wall surface is cleaned and moved forward to wash out the foreign matter into the mixer. The measured water used for cleaning is also collected in the mixer and used as kneading water.

When the metering water is completely charged, the drive of the pressure pump 35 is stopped and the control valve 37 of the cleaning water supply pipe 34 is closed. Then, the control valve 36 of the compressed air supply pipe 30 is opened to send compressed air into the air passage 28 to prevent foreign matter from entering the gap portion 5 washed with the measured water.

The compressed air supplied is, for example, about 0.5 kg.
If the pressure is regulated to around / cm ^2, foreign matter entering through the gap 5 can be expelled. Alternatively, compressed air may be intermittently supplied to blow off the foreign matter that has entered the gap 5. At this time, it is advisable to make the air pressure slightly higher than the above-mentioned air pressure. If it is not preferable to blow air into the green concrete during kneading, compressed air may be supplied at the time when the kneaded material is discharged from the mixer to expel foreign matter from the gap 5.

The compressed air to be supplied is passed through the oiler 38. In the euler 38, when the compressed air passes through the mist forming part 42, the upper oil drip chamber 43 of the mist forming part 42 is depressurized. As a result, the oil in the bowl portion 39 is sucked up into the oil dropping chamber 43 via the siphon portion 44 and dropped into the mist forming portion 42. The dropping amount is adjusted by rotating the needle valve 45 provided on the siphon portion 44.

The oil dripped into the mist forming portion 42 is blown away by the compressed air, becomes mist, is mixed into the compressed air, and is supplied to the gap portion 5 of the shaft sealing portion as lubricating oil. Then, the lubricating oil is misted to form the gap 5
Therefore, even if the amount of oil is small, it is possible to lubricate the rotating part evenly throughout the gap 5.

In the above embodiment, the water measuring tank 32 for measuring the kneading water is used as the washing water supply source, and
The foreign matter that has entered the gap portion 5 of the shaft sealing portion can be washed out for each batch kneading, but the present invention is not limited to this, and a water tank above the water measuring tank 32 as a water supply source (see FIG. It is also possible to use (not shown) or the like. At this time, the inside of the gap portion 5 of the shaft-sealing portion cannot be washed during kneading, but the inside of the gap portion 5 of the shaft-sealing portion can be washed at the time of washing the mixer after the kneading.

In the embodiment, the lantern ring 21 and the gland packing 22 are used to seal the kneading shaft 1, but these are made of cement or the like which enter the shaft sealing portion by compressed air or washing water. It can be used instead of the conventional mechanical seal to push out foreign matter, and by adopting these, the structure of the shaft sealing part is simplified and the seal replacement work can be performed easily. , Even if compressed air or cleaning water is supplied to the gap 5 of the shaft sealing part that uses only the conventional mechanical seal or gland packing, the foreign matter can be pushed out and the cleaning effect can be sufficiently exerted. It goes without saying that it is okay.

[0031]

As described above, according to the shaft sealing device for a concrete mixer according to claim 1 of the present invention, the air communicating with the gap portion 5 between the rotating portion and the non-rotating portion of the shaft sealing portion of the kneading shaft 1. Since the compressed air supply pipe 30 is connected to the compressed air supply pipe 28 and the oiler 38 for mixing oil mist with the compressed air is provided in the compressed air supply pipe 30, Foreign matter that enters the gap 5 of the shaft-sealing portion can be pushed out, and the shaft-sealing portion can be lubricated by the mist-like oil mixed in the compressed air to reduce wear of the shaft-sealing portion. it can.

According to the shaft sealing device for the concrete mixer of the second aspect of the present invention, the air passage 28 communicating with the gap 5 between the rotating part and the non-rotating part of the shaft sealing part of the kneading shaft 1 is formed. A compressed water supply pipe 30 is connected to the air passage 28, a pressure pump 35 is arranged in the compressed air supply pipe 30, and a cleaning water supply pipe 34 connected to a water supply source is connected. Further, since the euler 38 for mixing the oil mist into the compressed air is provided in the compressed air supply pipe 30, the compressed air pushes out the foreign substances that try to enter the gap portion 5 of the shaft sealing portion, and Lubrication of the shaft seal part can be performed with mixed mist-like oil, and further, cleaning water can be supplied to the gap part 5 of the shaft seal part and foreign matters such as sand and cement that could not be pushed out by compressed air. Can be washed away by flushing, It is possible to further reduce the wear of the shaft seal portion by Les.

[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 cutaway perspective view of an oiler.

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

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Kneading shaft 2 ... Color 3 ... Kneading tank side wall 4 ... Seal housing 5 ... Gap 21 ... Lantern ring 22 ... Gland packing 28 ... Air passage 29 ... Compressor (compressed air supply source) 30 ... Compressed air supply pipe 32 ... Water metering tank (water supply source) 34 ... Washing water supply pipe 35 ... Pressure pumps 36, 37 ...
Control valve 38 ... Euler

─────────────────────────────────────────────────── ─── Continuation of front page (56) Bibliography Flat 7-23511 (JP, U) Full-blown Sho 61-909 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B28C 5/12 B01F 15/00

Claims (2)

(57) [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. An air passage communicating with a gap between the compressed air supply pipe and a compressed air supply pipe connected to a compressed air source is connected to the compressed air supply pipe. A concrete mixer shaft sealing device comprising an oiler for mixing mist. 2. A concrete mixer in which a kneading shaft equipped with a plurality of kneading blades is penetrated between opposing side walls of a kneading tank to support the kneading shaft, the non-rotating part of the shaft sealing portion of the kneading shaft passing through the kneading tank side wall. Forming an air passage communicating with a gap between the air passage and the air passage, a compressed air supply pipe connected to a compressed air source is connected to the air passage, and a cleaning water in which a pressure pump is arranged in the air passage. A concrete mixer characterized in that an oiler for mixing oil mist with compressed air to be supplied is provided on the compressed air supply pipe while connecting a supply pipe and connecting the other end of the pipe to a water supply source. Shaft seal device.