Patent Description:
As a garden tool, a pole chain saw can be used for trimming branches and performing a cutting operation on an object at a high or distant position. The connecting rod of the chain saw is usually designed to be longer, and an electric motor, a chain, a guide plate, and the like are disposed at the front end of the connecting rod. On the market, most pole chain saws use plastic gearboxes and have a poor heat dissipation effect and low assembly accuracy, greatly shortening the service life of the gearbox and the transmission mechanism. <CIT> discloses a pole chain saw as per the preamble of appended claim <NUM>.

An object of the present application is to solve or at least alleviate some or all of the preceding problems. For this reason, an object of the present application is to provide a pole chain saw that can enhance the heat dissipation effect of a gearbox and increase the service life of a transmission mechanism.

To achieve the preceding object, the present application provides a pole chain saw comprising the combination of features of appended claim <NUM>.

Preferred embodiments are disclosed by the dependent claims.

In some examples, the front end assembly further includes a front end housing for supporting the connecting rod, where the front end housing includes a first housing and a second housing, where a first accommodation chamber and a second accommodation chamber are formed between the first housing and the second housing.

In some examples, the first accommodation chamber is used for accommodating the electric motor, and the second accommodation chamber is used for accommodating the gearbox.

In some examples, a front end housing is formed with at least one air inlet and at least one air outlet, and an airflow flowing into the front end housing from the at least one air inlet flows through the gearbox and the electric motor in sequence and then flows out from the at least one air outlet.

In some examples, the at least one air inlet is located at the rear side of the gearbox, and the at least one air outlet is located radially outside a fan.

In some examples, an air hole is formed on a front end housing at a position relative to the gearbox.

In some examples, the gearbox includes a first box lid and a second box lid, where after being mounted, the first box lid and the second box lid form an accommodation space to accommodate at least part of the transmission assembly.

In some examples, a transmission mechanism includes a first transmission gear, a second transmission gear, where a motor shaft of the electric motor drives the first transmission gear to rotate, the first transmission gear meshes with the second transmission gear to drive the second transmission gear to rotate, the second transmission gear drives the output shaft to rotate.

In some examples, the extension direction of the motor shaft is perpendicular to the extension direction of the output shaft.

In some examples, the oil fill hole is further formed on a front end housing, where the oil fill hole extends from the front end housing to a meshing point of the first transmission gear and the second transmission gear.

In some examples, a transmission mechanism further includes a bearing sleeved on an output shaft, and an outer race of the bearing has an interference fit with the gearbox.

In some examples, an inner race of the bearing has a clearance fit with the output shaft. In some examples, at least part of the gearbox is integrally formed with a front end housing.

In this application, the terms "up", "down", "left", "right", "front", and "rear" " and other directional words are described based on the orientation or positional relationship shown in the drawings, and should not be understood as limitations to the examples of this application. In addition, in this context, it also needs to be understood that when it is mentioned that an element is connected "above" or "under" another element, it can not only be directly connected "above" or "under" the other element, but can also be indirectly connected "above" or "under" the other element through an intermediate element. It should also be understood that orientation words such as upper side, lower side, left side, right side, front side, and rear side do not only represent perfect orientations, but can also be understood as lateral orientations. For example, lower side may include directly below, bottom left, bottom right, front bottom, and rear bottom. In this application, the terms "controller", "processor", "central processor", "CPU" and "MCU" are interchangeable. Where a unit "controller", "processor", "central processing", "CPU", or "MCU" is used to perform a specific function, the specific function may be implemented by a single aforementioned unit or a plurality of the aforementioned unit.

In this application, the term "device", "module" or "unit" may be implemented in the form of hardware or software to achieve specific functions.

In this application, the terms "computing", "judging", "controlling", "determining", "recognizing" and the like refer to the operations and processes of a computer system or similar electronic computing device (e.g., controller, processor, etc.).

As shown in <FIG>, a pole chain saw <NUM> disclosed in the present application is a commonly used garden tool and may be used for trimming branches and the like. The pole chain saw <NUM> may be operated and controlled by a user to trim branches. In this specification, a front and rear direction, a left and right direction, and an up and down direction are described as directions shown in <FIG>. Specifically, when the user operates the pole chain saw <NUM>, it is defined that a direction which the user faces is the front, a direction which the user faces away from is the rear, a direction on the left-hand side of the user is the left, a direction on the right-hand side of the user is the right, a direction facing the ground is the down, and a direction facing away from the ground is the up.

The pole chain saw <NUM> includes a front end assembly <NUM> and a connecting rod <NUM>. The front end assembly <NUM> is used for outputting and operating and is disposed at the front end of the connecting rod <NUM>.

The front end assembly <NUM> includes an electric motor <NUM>, an output device <NUM>, and a front end housing <NUM>. The output device <NUM> includes a guide plate <NUM> and a chain <NUM> wound around the guide plate <NUM>. The electric motor <NUM> includes a motor shaft <NUM> rotatable about a first axis <NUM>, and the rotational output of the motor shaft <NUM> drives the chain <NUM> to rotate, thereby performing a cutting operation. The front end housing <NUM> is disposed at the front end of the connecting rod <NUM> and is used for supporting the electric motor <NUM> and the output device <NUM>. The connecting rod <NUM> is a long rod with a certain length so that the user can send the chain <NUM> to a branch or other remote positions to perform the cutting operation.

The connecting rod <NUM> is fixed in the front end housing <NUM> and extends into a rear end housing <NUM>. The rear end housing <NUM> is formed with or connected to a coupling portion <NUM>, and a power supply device <NUM> is detachably connected to the coupling portion <NUM> to supply electrical energy to at least the electric motor <NUM>.

The pole chain saw <NUM> further includes a transmission mechanism <NUM>, and the transmission mechanism <NUM> connects the electric motor <NUM> to the output device <NUM>. The front end housing <NUM> includes a first housing <NUM> and a second housing <NUM>. A first accommodation chamber <NUM> and a second accommodation chamber <NUM> are formed between the first housing <NUM> and the second housing <NUM>. The first accommodation chamber <NUM> is used for accommodating the electric motor <NUM>, and the second accommodation chamber <NUM> is used for accommodating the transmission mechanism <NUM>. Specifically, the first housing <NUM> and the second housing <NUM> form a two-half housing structure of the front end housing <NUM>, and the first housing <NUM> engages with the second housing <NUM>, so as to limit the positions of the electric motor <NUM> and the transmission mechanism <NUM>.

Specifically, the transmission mechanism <NUM> includes a transmission assembly 14a. Specifically, the transmission assembly 14a includes a first transmission gear <NUM>, a second transmission gear <NUM>, an output shaft <NUM>, and a chainwheel <NUM>. The first transmission gear <NUM> and the second transmission gear <NUM> may be configured to be bevel gears. In some examples, the end of the motor shaft <NUM> is connected to the first transmission gear <NUM>. In some examples, the motor shaft <NUM> and the first transmission gear <NUM> are integrally formed. The motor shaft <NUM> drives the first transmission gear <NUM> to rotate, the first transmission gear <NUM> drives the second transmission gear <NUM> to rotate, the second transmission gear <NUM> drives the output shaft <NUM> to rotate synchronously, the output shaft <NUM> drives the chainwheel <NUM> to rotate, and the chain <NUM> is driven by the chainwheel <NUM> to move on the guide plate <NUM>. Of course, in some examples, the motor shaft <NUM> and the first transmission gear <NUM> are designed as separate parts, and the first transmission gear <NUM> is sleeved on the end of the motor shaft <NUM>.

In some examples, the transmission mechanism <NUM> further includes a gearbox <NUM>. The gearbox <NUM> includes a first box lid <NUM> and a second box lid <NUM>. After being mounted, the first box lid <NUM> and the second box lid <NUM> form an accommodation space (not shown in the figure). The first transmission gear <NUM>, the second transmission gear <NUM>, and the output shaft <NUM> are disposed in the preceding accommodation space. Specifically, the gearbox <NUM> is made of metal The transmission mechanism <NUM> further includes a bearing <NUM> sleeved on the output shaft <NUM>. Specifically, an outer race of the bearing <NUM> abuts against and has an interference fit with the gearbox <NUM>. An inner ring of the bearing <NUM> has a clearance fit with the output shaft <NUM>, thereby ensuring that the output shaft <NUM> is rotatable relative to the bearing <NUM>.

In this manner, on the one hand, a gearbox made of metal is used so that the machining accuracy can be improved and the fit between the bearing, the front end housing, and the output shaft can be ensured. On the other hand, the preceding metal gearbox is used so that the heat dissipation effect can be enhanced and the service life of the gearbox can be increased.

To verify the technical effect of the technical solution adopted by the chain saw in the present application, a comparison test is conducted between the chain saw in the present application and a chain saw using a traditional plastic gearbox. The test method is: to remove the chain and the guide plate, connect the machine to a <NUM>. 4V voltage regulator, and apply resistance to the output shaft of the machine through a load device to simulate the actual cutting condition of the machine. The actual test process is: to run with no load for <NUM>, run with a 15A load for <NUM>, run with a 20A load for <NUM>, run with a 15A load for <NUM>, and run with no load for <NUM>. The preceding process is repeated. Table <NUM> below is the data of the comparison test between the service life of the transmission mechanism of the chain saw in the present application and the service life of the transmission mechanism of the chain saw using the plastic gearbox.

The chain saw in the present application uses the metal gearbox, while Comparison <NUM>, Comparison <NUM>, and Comparison <NUM> use plastic gearboxes. As can be seen from Table <NUM> above, the service life of the transmission mechanism of the chain saw in the present application can be increased by at least <NUM>% compared to the service life of the transmission mechanism of the chain saw using the plastic gearbox.

Of course, at least part of the preceding gearbox <NUM> is integrally formed with the front end housing <NUM>. It is to be understood that part of the front end housing for supporting the transmission mechanism <NUM> is made of metal.

In some examples, the first box lid <NUM> of the gearbox <NUM> and the first housing <NUM> of the front end housing <NUM> are integrally formed. The second box lid <NUM> of the gearbox <NUM> and the second housing <NUM> of the front end housing <NUM> are integrally formed. In this manner, after the first housing <NUM> and the second housing <NUM> are assembled, the gearbox accommodating the transmission mechanism <NUM> is formed. Specifically, the first housing <NUM> and the second housing <NUM> are made of metal.

In some examples, the first box lid <NUM> of the gearbox <NUM> and the first housing <NUM> of the front end housing <NUM> are integrally formed. The second box lid <NUM> of the gearbox <NUM> and the second housing <NUM> of the front end housing <NUM> are provided separately. Specifically, the first housing <NUM> and the second box lid <NUM> are made of metal.

In some examples, the first box lid <NUM> of the gearbox <NUM> and the first housing <NUM> of the front end housing <NUM> are provided separately. The second box lid <NUM> of the gearbox <NUM> and the second housing <NUM> of the front end housing <NUM> are integrally formed. The first box lid <NUM> and the second housing <NUM> are made of metal.

In this manner, at least part of the gearbox <NUM> is integrally formed with the front end housing <NUM> so that while the service life of the transmission mechanism <NUM> can be increased, the number of components can be reduced and the assembly difficulty can be reduced.

As shown in <FIG>, to lubricate the transmission mechanism <NUM>, an oil fill hole <NUM> is disposed on the front end housing. Specifically, the oil fill hole <NUM> is disposed on the gearbox <NUM>. Lubricating oil is injected through the oil fill hole <NUM> into the meshing point of the first transmission gear <NUM> and the second transmission gear <NUM>, so as to reduce the friction between the first transmission gear <NUM> and the second transmission gear <NUM> and improve the service life of the first transmission gear <NUM> and the second transmission gear <NUM>. Specifically, the oil fill hole <NUM> may be closed by a bolt.

The oil fill hole <NUM> is disposed on the gearbox <NUM>. The gearbox <NUM> is provided with a pillar forming the oil fill hole <NUM>, and the post extends to the front end housing <NUM> to enable a user to input lubricating oil into the oil fill hole <NUM>. In other examples, the oil fill hole may be further formed on the front end housing. The front end housing is formed with a pillar, which provides the oil fill hole. The pillar extends into the meshing point of the first transmission gear and the second transmission gear so that the oil fill hole extends to the meshing point of the first transmission gear and the second transmission gear.

Referring to <FIG>, <FIG>, and <FIG>, the pole chain saw <NUM> further includes a fan <NUM> disposed behind the electric motor <NUM>, and the fan <NUM> rotates about a fan axis. The front end housing <NUM> of the pole chain saw <NUM> is further formed with an air inlet and an air outlet. The fan <NUM> is used for generating a heat dissipation airflow that enters from the air inlet and flows out from the air outlet. In this example, the air inlet includes a first air inlet <NUM> disposed in front of the gearbox <NUM>. The air outlet includes a first air outlet <NUM> and a second air outlet <NUM>. Specifically, the first air outlet <NUM> and the second air outlet <NUM> are disposed radially outside the fan <NUM>. In this manner, when the electric motor <NUM> is started, the fan <NUM> is driven to rotate, and the airflow enters the front end housing <NUM> from the first air inlet <NUM>, flows through the gearbox <NUM> and the electric motor <NUM>, and then flows out from the first air outlet <NUM> and the second air outlet <NUM>, thereby taking away the heat generated on the electric motor <NUM> and the gearbox <NUM>.

In this manner, the positions and number of the air inlets and air outlets are reasonably set, and the heat from the gearbox <NUM> is effectively dissipated through the airflow, thereby improving the service life of the gearbox.

In some examples, as shown in <FIG>, to further dissipate the heat from the gearbox <NUM>, an air hole <NUM> is formed on the first housing <NUM>. The air hole <NUM> is opposite to the gearbox <NUM>. In this manner, in the working process of the pole chain saw <NUM>, the heat generated on the gearbox <NUM> can be dissipated from the preceding air hole <NUM>.

As shown in <FIG> and <FIG>, the pole chain saw <NUM> further includes a chain tensioning assembly <NUM>. The chain tensioning assembly <NUM> can automatically adjust a gap between the chain <NUM> and the guide plate <NUM>, thereby improving the adaptability of the chain <NUM> and the guide plate <NUM> and improving the cutting efficiency. It is to be understood that during daily use of the pole chain saw <NUM>, the chain <NUM> is prone to loosening due to work wear. The user adjusts the distance between the guide plate <NUM> and the chainwheel <NUM> through the chain tensioning assembly <NUM> to tension the chain <NUM>. Next, the structure and working principle of the chain tensioning assembly <NUM> are introduced in detail.

Specifically, the chain tensioning assembly <NUM> includes at least a transmission component and a tensioning nut <NUM>. The tensioning nut <NUM> can drive the transmission component to rotate synchronously. The transmission component includes a first gear <NUM>, a second gear <NUM>, and a transmission shaft <NUM>. The first gear <NUM> is formed or sleeved on the tensioning nut <NUM>, the second gear <NUM> is sleeved on an end of the transmission shaft <NUM>, and the other end of the transmission shaft <NUM> is connected to the guide plate <NUM>. The first gear <NUM> meshes with the second gear <NUM>. When the user rotates the tensioning nut <NUM>, the tensioning nut <NUM> drives the first gear <NUM> to rotate, the first gear <NUM> drives the second gear <NUM> to rotate, and the second gear <NUM> drives the transmission shaft <NUM> to move along the extension direction of the guide plate <NUM>, thereby driving the guide plate <NUM> to move along the extension direction to adjust the tension of the chain <NUM>.

As shown in <FIG>, the pole chain saw <NUM> further includes an oil supply assembly. The oil supply assembly includes an oil pot <NUM>, an oil pump <NUM>, and an oil pipe <NUM>. The oil pot <NUM> is used for storing engine oil for lubricating the chain <NUM> or the guide plate <NUM>. The front end housing <NUM> further includes a fixing portion <NUM> for fixing the oil pot <NUM>. The oil pipe <NUM> connects the oil pot <NUM> to the oil pump <NUM>. Through the oil pipe <NUM>, the oil pump <NUM> pumps the engine oil in the oil pot <NUM> and transports the engine oil to the chain <NUM> or the guide plate <NUM>, so as to lubricate the chain <NUM> and the guide plate <NUM>.

Claim 1:
A pole chain saw (<NUM>), comprising:
a connecting rod (<NUM>); and
a front end assembly (<NUM>) disposed at a front end of the connecting rod;
wherein the front end assembly comprises:
an electric motor (<NUM>);
an output device (<NUM>) comprising a guide plate (<NUM>) and a chain (<NUM>) wound around the guide plate;
a transmission assembly (14a) connecting the electric motor to the output device,
wherein the transmission assembly comprises an output shaft (<NUM>) and a chainwheel (<NUM>), wherein a motor shaft (<NUM>) of the electric motor drives the output shaft to rotate, and wherein the output shaft drives the chainwheel to rotate to drive the chain to rotate; and
a gearbox (<NUM>) supporting and accommodating at least part of the transmission assembly, characterized in that, at least part of the gearbox is made of metal, and an oil fill hole (<NUM>) is formed on the gearbox.