Patent Description:
A compressor is a kind of fluid machinery which boosts low-pressure gas into high-pressure gas. It sucks low-temperature and low-pressure refrigerant gas from the air suction pipe, boosts it by driving the impeller through motor operation, and discharges high-temperature and high-pressure refrigerant gas from the air exhaust pipe, so as to provide power for the refrigeration cycle.

The locking structure of a compressor impeller is an important component inside the compressor, which includes a lock nut <NUM>, an impeller <NUM> and a nose piece <NUM>. The impeller <NUM> (also referred to as the running wheel) is sleeved on the end of a rotary shaft <NUM>, and it is the only component inside the compressor that applies work to the air flow. In the prior art, the nose piece <NUM> is in threaded connection with the rotary shaft <NUM>, so the nose piece <NUM> is generally designed to be thicker and its weight cannot be reduced. In addition, the lock nut <NUM> is mounted on the rotary shaft <NUM> by means of a threaded connection. Therefore, in addition to designing the right-hand threads for the lock nut <NUM>, the rotary shaft <NUM> also has to additionally design the left-hand threads for the nose piece <NUM>, thus resulting in a more complex processing method for the rotary shaft <NUM>. On the other hand, the operating personnel need to drill a hole <NUM> in the installation site to secure the nose piece <NUM> to the lock nut <NUM>, which brings a lot of difficulties to on-site installation and maintenance.

<CIT> discloses a compressor impeller wheel lock in a drive assembly, the drive assembly including a shaft having a shaft mounting portion to receive the compressor impeller wheel; wherein a retaining nut is threaded onto the shaft mounting portion for retaining the compressor impeller wheel on the shaft; and wherein a nose portion of the compressor impeller wheel, adjacent the retaining nut, is covered by a fixed nose cone.

In view of the above, according to a first aspect of the present invention, a locking structure of a compressor impeller is provided, which effectively solves or at least partially solves the above problems and problems in other aspects existing in the prior art. The locking structure for a compressor impeller according to the first aspect of the present invention comprises:.

The waist-shaped holes may comprise elongate holes or slot holes that extend in the circumferential direction of the lock nut. For example, the waist-shaped holes may comprise arcuate or curved elongate holes or slot holes. Each waist-shaped hole may extend partially around the lock nut in the circumferential direction thereof. That is, each waist-shape hole may be a partially circumferentially extending hole.

Optionally, the plurality of threaded holes are provided and are arranged at equal intervals along the circumferential direction of the impeller; the plurality of through holes are provided and are arranged at equal intervals along the circumferential direction of the nose piece; and the plurality of waist-shaped holes are provided and are arranged at equal intervals along the circumferential direction of the lock nut.

Optionally, the number of the through holes is the same as the number of the waist-shaped holes, and the number of the threaded holes is twice the number of the waist-shaped holes.

Optionally, the number of the through holes and the number of the waist-shaped holes are four, five, six, seven or eight.

Optionally, the end of the rotary shaft is provided with a shoulder, wherein the inner side of the lock nut abuts against the shoulder, and the impeller is sleeved on the shoulder of the rotary shaft.

Optionally, a center line of the bolt (e.g. one or more or each of the bolts) is parallel to the axis of the rotary shaft.

Optionally, the impeller and the nose piece are made of aluminum alloys.

Optionally, an inner wall of the nose piece is not in contact with the end of the rotary shaft.

In addition, according to a second aspect of the present invention, a centrifugal compressor is further provided, wherein the centrifugal compressor of the second aspect is provided with the aforementioned locking structure of a compressor impeller according to the first aspect. The centrifugal compressor of the second aspect may include any one or more or all of the optional features described above in respect of the first aspect.

Furthermore, according to a third aspect of the present invention, a refrigeration system is further provided, wherein the refrigeration system of the third aspect is configured with the aforementioned centrifugal compressor according to the second aspect.

Still further, according to a fourth aspect of the present invention, an installation method for the locking structure of a compressor impeller according to the first aspect is further provided, which comprises:.

It can be appreciated that the locking structure of a compressor impeller according to the present invention can avoid drilling holes in the installation site, thus facilitating on-site installation and maintenance. In addition, since there is no need for a threaded connection between the nose piece and the rotary shaft of the locking structure of a compressor impeller, the nose piece can be designed to be as thin as possible, thereby greatly reducing the weight of the nose piece.

Certain exemplary embodiments of the present invention will be described in further detail below by way of example only in conjunction with the accompanying drawings, in which:.

Some embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that orientation terms such as upper, lower, left, right, front, rear, inner side, outer side, top, bottom, etc. mentioned or possibly mentioned in this specification are defined relative to the configurations illustrated in the respective drawings. They are relative concepts, so they may change accordingly according to their different locations and different states of use. Therefore, these and other orientation terms shall not be construed as restrictive terms.

<FIG> schematically illustrates in general the structure of a locking structure of a compressor impeller according to the claimed invention.

As can be explicitly seen from <FIG>, the locking structure of a compressor impeller is composed of a rotary shaft <NUM>, a lock nut <NUM>, an impeller <NUM>, a nose piece <NUM>, bolts <NUM> and other components. The lock nut <NUM> is arranged on the end of the rotary shaft <NUM> by means of a threaded connection, and the lock nut <NUM> is provided with waist-shaped holes <NUM> extending along its circumferential direction. The impeller <NUM> is sleeved on the end of the rotary shaft <NUM>, and it is the only component inside the compressor that is in contact with and applies work to the air. Since the impeller <NUM> needs to operate continuously at the high speed of over a thousand revolutions per minute for several hours, it therefore needs to be made of high-strength materials such as aluminum alloys. As shown in the figures, the impeller <NUM> is located on the inner side of the lock nut <NUM> and is provided with threaded holes <NUM> that are in communication with the waist-shaped holes <NUM> of the lock nut <NUM>. The nose piece <NUM> is located on the outer side of the lock nut <NUM>, so as to help the impeller <NUM> to maintain balance and reduce aerodynamic resistance. The nose piece <NUM> is provided with through holes <NUM> that are in communication with the waist-shaped holes <NUM> of the lock nut <NUM>. The bolts <NUM> pass through the through holes <NUM> and the waist-shaped holes <NUM> in turn into the threaded holes <NUM>, thereby fixing the nose piece <NUM>, the lock nut <NUM> and the impeller <NUM> together. It should be noted that during assembly, the lock nut <NUM> is prone to circumferential rotation, so the lock nut <NUM> is designed with waist-shaped holes to reserve sufficient positions for installation, so that the threaded holes <NUM> and the through holes <NUM> can be aligned when the lock nut <NUM> is rotated in a circumferential direction.

Referring also to <FIG>, a plurality of threaded holes <NUM> are provided, which are arranged at equal intervals along the circumferential direction of the impeller <NUM>. A plurality of through holes <NUM> are provided, which are arranged at equal intervals along the circumferential direction of the nose piece <NUM>. A plurality of waist-shaped holes <NUM> are provided, which are arranged at equal intervals along the circumferential direction of the lock nut <NUM>. That is, the centers of the plurality of threaded holes <NUM>, the centers of the plurality of through holes <NUM>, and the centers of the plurality of waist-shaped holes <NUM> shall be arranged on a concentric circle centered at the axis of the rotary shaft <NUM>, so that the threaded holes <NUM> and the through holes <NUM> can be aligned during installation. For example, the center line of the bolt <NUM> is parallel to the axis of the rotary shaft <NUM>. In addition, it is easy to understand by those skilled in the art that the number of the through holes <NUM> may be the same as the number of the waist-shaped holes <NUM>, and that the number of the threaded holes <NUM> is twice the number of the waist-shaped holes <NUM>. Further, the number of the through holes <NUM> and the number of the waist-shaped holes <NUM> can be four, five, six, seven or eight.

In conjunction with the above embodiment, in other preferred embodiments, the end of the rotary shaft <NUM> is provided with a shoulder, wherein the inner side of the lock nut <NUM> abuts against the shoulder, and the impeller <NUM> is sleeved on the shoulder of the rotary shaft <NUM> to facilitate installation.

It should be noted that the inner wall of the nose piece <NUM> is not in contact with the end of the rotary shaft <NUM>. That is, there is a certain space between the inner wall of the nose piece <NUM> and the end of the rotary shaft <NUM>, so that the nose piece <NUM> can be designed as thin as possible, thereby greatly reducing the weight of the nose piece <NUM>. In addition, since the rotary shaft <NUM> does not need to be in threaded connection with the nose piece <NUM>, the processing method of the rotary shaft <NUM> becomes simpler. Furthermore, similar to the impeller <NUM>, the nose piece <NUM> can also be made of high-strength materials such as aluminum alloys.

In addition, the present invention also provides a centrifugal compressor configured with a locking structure of a compressor impeller according to the various embodiments. Furthermore, the present invention further provides a refrigeration system configured with the aforementioned centrifugal compressor. The refrigeration system may comprise a cooling tower, a water chiller, a pump assembly, and the like connected through pipelines, wherein the water chiller is composed of a centrifugal compressor, a condenser, a throttling assembly, an evaporator, and the like. As noted earlier, the installation can be significantly simplified and the maintenance costs be greatly reduced by installing the centrifugal compressor mentioned above. Therefore, it is highly recommended that the aforementioned centrifugal compressors be widely applied to various refrigeration systems.

Furthermore, the present invention further proposes an installation method for the aforementioned locking structure of a compressor impeller, which comprises:.

In summary, the locking structure of a compressor impeller and the installation method therefor according to the present invention can avoid drilling holes in the installation site, thus facilitating on-site installation and maintenance. In addition, the nose piece of the locking structure of a compressor impeller can be designed to be as thin as possible, thereby greatly reducing its weight.

Claim 1:
A locking structure of a compressor impeller, comprising:
a rotary shaft (<NUM>);
a lock nut (<NUM>), arranged on an end of the rotary shaft (<NUM>) by means of a threaded connection and provided with waist-shaped holes (<NUM>) extending along a circumferential direction thereof;
an impeller (<NUM>), sleeved on the end of the rotary shaft (<NUM>) and located on an inner side of the lock nut (<NUM>), wherein the impeller (<NUM>) is provided with threaded holes (<NUM>) in communication with the waist-shaped holes (<NUM>) of the lock nut (<NUM>);
a nose piece (<NUM>), located on an outer side of the lock nut (<NUM>) and provided with through holes (<NUM>) in communication with the waist-shaped holes (<NUM>) of the lock nut (<NUM>); and
bolts (<NUM>), passing through the through holes (<NUM>) and the waist-shaped holes (<NUM>) in turn into the threaded holes (<NUM>), thereby fixing the nose piece (<NUM>), the lock nut (<NUM>) and the impeller (<NUM>) together.