A cold saw

Abstract

The utility model provides a cold cut saw, include: handle, casing, saw blade shield, drive arrangement and transmission mechanism, casing sets up handle front end, the casing includes drive part and transmission part, drive part and transmission part integrative as a whole, saw blade shield installs transmission part lower extreme, saw blade shield is used for containing saw blade, drive arrangement sets up drive part in, transmission mechanism sets up transmission part in, transmission mechanism drives through drive arrangement, transmission mechanism is used for driving saw blade rotation, through setting up drive part and transmission part integrative as casing, the strength of integral work piece increases, has eliminated the shortcoming of prior art, can increase the service life of machine.

Description

Technical Field

[0001] This utility model relates to the field of power tool technology, and in particular to a cold cutting saw. Background Technology

[0002] Cold cutting machines, also known as cold cutting saws or rebar cutters, are used in building construction to ensure structural safety and quality. A significant amount of steel reinforcement is used in the foundation and walls, forming a framework that is poured simultaneously with concrete to improve the building's load-bearing capacity and earthquake resistance. While large, benchtop rebar cutters are commonly used to cut rebar to fixed lengths, they are unsuitable for cutting rebar already fixed to walls or on-site. Manual hacksaws are inefficient and laborious. Therefore, electric rebar cutters have emerged, offering convenient portability and handheld operation for cutting rebar.

[0003] Existing cold-cutting saws consist of two parts: a gearbox and a handle. The gearbox and handle are connected by bolts. The handle contains a motor, which generates a lot of heat when it runs, causing the handle to deform. This deformation causes misalignment between the handle and the gearbox, resulting in a decrease in the concentricity of the rotor and stator. Consequently, the rotor rubs against the stator, causing the motor to wear and burn out. At the same time, the plastic handle also affects the motor's heat dissipation. Utility Model Content

[0004] The purpose of this utility model is to provide a cold-cutting saw that integrates the drive unit and transmission unit into a single housing, thereby increasing the overall strength of the workpiece. Existing saws connect the gearbox and handle with bolts, and the handle houses a motor. The motor generates a large amount of heat during operation, causing the handle to deform. This deformation leads to misalignment between the handle and the gearbox, resulting in decreased concentricity between the rotor and stator. Consequently, the rotor rubs against the stator, causing wear and burnout of the motor. This new design integrates the drive unit and transmission unit housing, eliminating any of the shortcomings of existing products and increasing the machine's service life.

[0005] This application provides a cold cutting saw, comprising:

[0006] handle;

[0007] A housing is disposed at the front end of the handle; the housing includes a drive unit and a transmission unit; the drive unit and the transmission unit are integrally formed as a single unit;

[0008] A saw blade guard is installed at the lower end of the transmission unit; the saw blade guard is used to accommodate the saw blade.

[0009] Drive unit; disposed within the drive unit; and

[0010] A transmission mechanism is disposed within the transmission section; the transmission mechanism is driven by the driving device; the transmission mechanism is used to drive the saw blade to rotate.

[0011] Preferably, the saw blade is disposed at the end of the transmission mechanism; the saw blade is driven by the transmission mechanism; the front end of the saw blade guard is provided with an opening, and the saw blade protrudes from the opening.

[0012] Preferably, the driving part has a transverse accommodating cavity a; the transmission part has a longitudinal accommodating cavity b; the accommodating cavity a and the accommodating cavity b are perpendicular; the driving device is disposed in the accommodating cavity a; and the transmission mechanism is disposed in the accommodating cavity b.

[0013] Preferably, the driving part is cylindrical; the outer circumference of the driving part is provided with a plurality of anti-slip grooves.

[0014] Preferably, the drive device is mounted inside the drive unit via a support frame.

[0015] Preferably, the drive unit is provided with a plurality of positioning ribs; the positioning ribs are engaged and locked with the positioning grooves on the support frame.

[0016] Preferably, the drive unit is threadedly connected to a rear cover; the rear cover is used to support the output shaft of the drive unit.

[0017] Preferably, a partition is provided inside the transmission unit; a transmission hole is provided on the partition; a gear shaft hole and an output shaft position are provided in front of the transmission hole;

[0018] The drive device is equipped with an output shaft; an output gear is mounted at the front end of the output shaft; the output gear drives the transmission mechanism.

[0019] The transmission mechanism includes a gear shaft; a bevel gear is mounted on the gear shaft; the bevel gear meshes with the output gear; a gear on the gear shaft meshes with a transmission gear; the transmission gear is mounted on a main shaft; the lower end of the main shaft passes through the saw blade guard and is connected to the saw blade; the output gear is located in the transmission hole; the gear shaft passes through the gear shaft hole; and the upper end of the main shaft is rotatably mounted in the output shaft position.

[0020] Preferably, the upper end of the transmission part is threadedly fitted with a top cover; the top cover is provided with a positioning hole; the upper end of the gear shaft of the transmission mechanism is rotatably mounted in the positioning hole.

[0021] Preferably, a heat insulation pad is provided between the transmission part and the saw blade guard.

[0022] Preferably, the heat insulation pad is provided with a baffle.

[0023] Preferably, a fan blade is installed at the front end of the output shaft; and an air outlet a is provided on the side of the drive unit.

[0024] Preferably, the saw blade guard includes a protective cover and a base plate; the protective cover is installed at the lower end of the transmission part; the base plate is installed at the lower end of the protective cover; an air outlet b is provided on the protective cover; the air outlet b cooperates with the air outlet a to discharge air.

[0025] Because this utility model adopts the above-described technical solution, it has the following advantages:

[0026] 1. This utility model integrates the drive unit and transmission unit into a single housing, increasing the overall strength of the workpiece. Existing designs connect the gearbox and handle using bolts, which generates significant heat during motor operation, causing the plastic handle to deform. This deformation leads to misalignment between the handle and the gearbox, reducing the concentricity of the rotor and stator. Consequently, the rotor rubs against the stator, resulting in motor wear and burnout. This design integrates the housing into a single unit, typically using cast aluminum, increasing structural strength and providing excellent heat dissipation, thus eliminating the shortcomings of existing products. This increases the machine's lifespan and enhances heat dissipation.

[0027] 2. By setting several anti-slip grooves on the outer circumference of the drive part, this utility model can increase the friction between the hand and the drive part, and can make the grip more secure.

[0028] 3. This utility model features a rear cover that is threadedly connected to the rear of the drive unit, with the rear cover supporting the drive output shaft of the drive device; the threaded connection has high strength, is easy to disassemble, and has high positioning concentricity.

[0029] 4. This utility model can effectively position the saw blade by placing it between the locking block and the pad block.

[0030] 5. By setting a heat insulation pad between the transmission part and the saw blade guard, this utility model can effectively prevent the heat generated by the saw blade during cutting and the heat on the saw blade guard from being transferred to the transmission part, and then to the drive part through the transmission part; thus preventing the drive part from getting too hot when the hand is holding it.

[0031] 6. This utility model has an air outlet b on the protective cover; the air outlet b works with the air outlet a to dissipate air; it can dissipate heat from the saw blade cover and the saw blade inside the saw blade cover; it prevents the saw blade cover and the saw blade from getting too hot, causing the saw blade to burn and wear. At the same time, the high-speed airflow can blow away the high-temperature residual iron filings in the saw blade disc, avoiding the problem of high-temperature residual iron filings accumulating and generating heat.

[0032] 7. By installing a screen on the air outlet b, this utility model can prevent saw blade cutting debris from entering the housing through the air outlet b and air outlet a, thus preventing damage to the device. Attached Figure Description

[0033] Figure 1This is a schematic diagram of the overall structure of a cold cutting saw according to the present invention.

[0034] Figure 2 This is an exploded structural diagram of a cold-cutting saw according to the present invention.

[0035] Figure 3 This is a schematic diagram of the controller of this utility model.

[0036] Figure 4 This is a schematic diagram of the saw blade guard structure of this utility model.

[0037] Figure 5 This is a schematic diagram of the exploded structure of the driving device of this utility model.

[0038] Figure 6 This is an exploded structural diagram of the transmission mechanism of this utility model.

[0039] Figures 7-9 This is a schematic diagram of the shell structure of this utility model.

[0040] Figure 10 This is a schematic diagram of the heat insulation pad structure of this utility model.

[0041] Figure 11 This is a schematic diagram of the air outlet b structure of this utility model.

[0042] Icon labels:

[0043] 10-Handle; 20-House; 30-Saw blade guard; 40-Saw blade; 50-Drive unit; 60-Transmission mechanism; 70-Heat insulation pad; 80-Top cover; 11-Controller; 12-Button; 21-Drive unit; 22-Transmission unit; 211-Cavity a; 212-Anti-slip groove; 213-Air outlet a; 214-Positioning rib; 221-Cavity b; 222-Partition plate; 2221-Transmission hole; 2222-Gear shaft hole; 222 3-Output shaft position; 31-Protective cover; 32-Base plate; 311-Outlet b; 312-Screen; 313-Chip outlet; 51-Drive output shaft; 52-Output gear; 53-Fan blade; 54-Support frame; 55-Rear cover; 541-Positioning groove; 61-Bevel gear; 62-Gear shaft; 63-Main shaft; 64-Transmission gear; 65-Locking block; 631-Padded block; 71-Baffle; 81-Mounting hole; 82-Conduit; 83-Guide post. Detailed Implementation

[0044] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0045] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or it can be an element placed in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0047] See Figure 1-11 To address the issue that existing gearboxes and handles are bolted together, causing vibrations during gear reduction mechanism operation that can damage the connection between the gearbox and handle, this invention provides a cold-cutting saw, comprising:

[0048] Handle 10; specifically, handle 10 is a plastic shell; controller 11 is installed inside handle 10; button 12 is provided on handle 10; button 12 is electrically connected to controller 11; air inlets are opened on both sides of handle 10; air inlets are located on both sides of controller 11; large screens are installed on air inlets; by installing large screens on air inlets, large particles can be prevented from entering handle 10 and causing damage to handle 10 when air is introduced.

[0049] A housing 20 is located at the front end of the handle 10. The housing 20 includes a drive unit 21 and a transmission unit 22. The drive unit 21 and the transmission unit 22 are integrally formed into the housing 20. By making the drive unit 21 and the transmission unit 22 integrally formed into the housing 20, the overall strength of the workpiece is increased. In the existing system, the gearbox and the handle are connected by bolts. The reduction mechanism inside the gearbox will generate vibration during movement, which will cause damage to the connection between the gearbox and the handle. This solution sets the housing 20 as an integral piece, which increases the overall strength of the workpiece. Preferably, the housing 20 is made of aluminum alloy and manufactured by casting, which is simple in manufacturing process, low in cost, and has excellent heat dissipation performance. This can increase the service life of the machine.

[0050] Saw blade guard 30; detachably installed at the lower end of transmission part 22; saw blade guard 30 is used to accommodate saw blade 40; saw blade guard 30 is provided with an opening, through which saw blade 40 protrudes; saw blade 40 protrudes from the opening and can contact the workpiece to be processed for cutting operation.

[0051] A drive unit 50 is disposed within the drive unit 21. Preferably, the drive unit 50 is a brushless motor. The brushless motor is electrically connected to the controller 11. The controller 11 controls the start and stop of the brushless motor.

[0052] A transmission mechanism 60 is located within the transmission section 22. The transmission mechanism 60 is driven by a drive device 50. The transmission mechanism 60 drives the saw blade 40 to rotate. Specifically, the saw blade 40 is located at the end of the transmission mechanism 60. The saw blade 40 is driven by the transmission mechanism 60. By integrating the drive section 21 and the transmission section 22 into a single housing 20, the overall strength of the workpiece is increased. In existing systems, the gearbox and handle are connected by bolts. The vibration generated during the movement of the gearbox mechanism can damage the connection between the gearbox and the handle. This solution integrates the housing 20 into a single unit, eliminating the shortcomings of existing products and increasing the machine's service life.

[0053] In another embodiment of this example, the drive unit 21 is provided with a transverse accommodating cavity a211; the transmission unit 22 is provided with a longitudinal accommodating cavity b221; the accommodating cavity a211 is perpendicular to the accommodating cavity b221; the drive device 50 is disposed in the accommodating cavity a211; and the transmission mechanism 60 is disposed in the accommodating cavity b221.

[0054] In another embodiment of this invention, the drive unit 21 is cylindrical; a plurality of anti-slip grooves 212 are provided on the outer circumference of the drive unit 21. The drive unit 21 can be held by hand during use; by providing a plurality of anti-slip grooves 212 on the outer circumference of the drive unit 21, the friction between the hand and the drive unit 21 can be increased; thus, it can be held more firmly.

[0055] In another embodiment of this invention, the drive device 50 is mounted inside the drive unit 21 via a support frame 54. Specifically, the drive unit 21 is provided with a plurality of positioning ribs 214; the positioning ribs 214 engage and lock with the positioning grooves 541 on the support frame 54. The support frame 54 is cylindrical; a heat dissipation hole is provided between two adjacent positioning grooves 541; by providing a heat dissipation hole between two adjacent positioning grooves 541, the drive device 50 therein can be cooled.

[0056] In another embodiment of this invention, a rear cover 55 is threadedly connected to the rear of the drive unit 21; the rear cover 55 is used to support the output shaft 51 of the drive device 50. Specifically, an internal thread is provided in the rear of the drive unit 21; an external thread is provided on the rear cover 55; the rear cover 55 is threadedly connected to the rear of the drive unit 21; by providing a threaded connection between the rear cover 55 and the rear of the drive unit 21, the output shaft 51 of the drive device 50 can be supported.

[0057] In another embodiment of this invention, a partition 222 is provided inside the transmission part 22, and a transmission hole 2221 is provided on the partition 222; a gear shaft hole 2222 and an output shaft position 2223 are provided in front of the transmission hole 2221.

[0058] In another embodiment of this invention, the drive device 50 is provided with an output shaft 51; an output gear 52 is mounted at the front end of the output shaft 51; the output gear 52 drives the transmission mechanism 60. Specifically, the drive device 51 can be a brushless motor.

[0059] In another embodiment of this invention, the transmission mechanism 60 includes a gear shaft 62; a bevel gear 61 is mounted on the gear shaft 62; the bevel gear 61 meshes with the output gear 52; the gear on the gear shaft 62 meshes with the transmission gear 64; the transmission gear 64 is mounted on the main shaft 63; the lower end of the main shaft 63 passes through the saw blade guard 30 and is connected to the saw blade 40. Specifically, the lower end of the gear shaft 62 is rotatably mounted in the gear shaft hole on the protective cover 31.

[0060] In another embodiment of this invention, the output gear 52 is located within the transmission hole 2221; the gear shaft 62 passes through the gear shaft hole 2222; and the upper end of the main shaft 63 is rotatably mounted within the output shaft position 2223. The output shaft position 2223 can be a through hole or a blind hole. Specifically, the bevel gear 61 and the output gear 52 are located on the upper part of the partition plate 222; a top cover 80 is threaded onto the upper end of the transmission part 22; the top cover 80 and the upper side of the partition plate 222 form a region within the accommodating cavity b221; the bevel gear 61 and the output gear 52 are located within this region; by placing the bevel gear 61 and the output gear 52 within this region and placing lubricant within this region, the bevel gear 61 and the output gear 52 can be effectively lubricated.

[0061] In another embodiment of this invention, a pad 631 is provided at the lower end of the spindle 63; a locking block 65 is threaded onto the lower end of the pad 631; and the saw blade 40 is located between the locking block 65 and the pad 631. By positioning the saw blade 40 between the locking block 65 and the pad 631, the saw blade 40 can be effectively positioned.

[0062] In another embodiment of this invention, the upper end of the transmission part 22 is threadedly fitted with an upper cover 80; a positioning hole is provided inside the upper cover 80; the upper end of the gear shaft 62 of the transmission mechanism 60 is rotatably mounted in the positioning hole. By rotatably mounting the upper end of the gear shaft 62 of the transmission mechanism 60 in the positioning hole, the gear shaft 62 can be effectively positioned and supported.

[0063] In another embodiment of this invention, the upper cover 80 is provided with a mounting hole 81; a guide tube 82 is installed in the mounting hole 81; a guide post 83 is slidably installed in the guide tube 82; and a spring is sleeved on the guide post 83. Specifically, a compression spring is sleeved on the guide post 83; a stop hole is provided on the bevel gear 61; by pressing the guide post 83, when the guide post 83 is located in the stop hole on the bevel gear 61, the bevel gear 61 is stopped; thereby stopping the transmission mechanism 60; and stopping the rotation of the main shaft 63 at the end of the transmission mechanism 60, thereby allowing the locking block 65 to be tightened or loosened.

[0064] In another embodiment of this invention, the saw blade guard 30 includes a protective cover 31 and a base plate 32; the protective cover 31 is installed at the lower end of the transmission part 22; the base plate 32 is installed at the lower end of the protective cover 31; and the saw blade 40 is located between the protective cover 31 and the base plate 32. By positioning the saw blade 40 between the protective cover 31 and the base plate 32, the saw blade 40 can be effectively covered.

[0065] In another embodiment of this invention, a heat insulation pad 70 is provided between the transmission unit 22 and the saw blade guard 30. By providing the heat insulation pad 70 between the transmission unit 22 and the saw blade guard 30, the heat generated by the saw blade 40 during cutting and the heat on the saw blade guard 30 can be effectively prevented from being transferred to the transmission unit 22, and then transferred to the drive unit 21 through the transmission unit 22; thereby preventing the drive unit 21 from getting too hot when held by hand.

[0066] In another embodiment of this invention, a baffle 71 is provided on the heat insulation pad 70. Specifically, the baffle 71 covers the gear and transmission gear 64 on the gear shaft 62; the lower side of the baffle 71, the protective cover 31, and the partition 222 forms another area within the accommodating cavity b221; the gear and transmission gear 64 on the gear shaft 62 are located in this area; by placing lubricant in this area, the gear and transmission gear 64 on the gear shaft 62 can be effectively lubricated; at the same time, the amount of lubricant can be saved.

[0067] In another embodiment of this invention, a fan blade 53 is mounted on the front end of the output shaft 51; an air outlet a213 is provided at the front of the drive unit 21; the air outlet a213 is located at the lower part of the fan blade 53. By mounting a fan blade 53 on the front end of the output shaft 51 and having the air outlet a213 located at the lower part of the fan blade 53, exhaust air can be provided at the front.

[0068] In another embodiment of this invention, the saw blade guard 30 includes a protective cover 31 and a base plate 32. The protective cover 31 is installed at the lower end of the transmission part 22. The base plate 32 is installed at the lower end of the protective cover 31. An air outlet b311 is provided on the protective cover 31. The air outlet b311 cooperates with the air outlet a213 to discharge air. By providing an air outlet b311 on the protective cover 31 and cooperating with the air outlet a213 to discharge air, cold air blown into the saw blade guard 30 can directly cool the saw blade inside the saw blade guard 30. This prevents the saw blade guard 30 and the saw blade from overheating, causing the saw blade to burn and wear. At the same time, the high-speed airflow can blow away the high-temperature residual iron filings inside the saw blade guard 30, avoiding the problem of high-temperature residual iron filings accumulating and generating heat. This solves the problem of the saw blade and head shell overheating due to the large amount of heat generated during cutting in the existing cold-cutting saw head shell.

[0069] In another embodiment of this invention, a screen 312 is provided on the air outlet b311. By providing a screen 312 on the air outlet b311, it is possible to prevent the debris from the saw blade 40 during cutting from entering the housing 20 through the air outlet b311 and the air outlet a213, thus preventing damage to the device.

[0070] This utility model also includes at least the following advantages:

[0071] This invention integrates the drive unit 21 and transmission unit 22 into a single housing 20, increasing the overall strength of the workpiece. In existing systems, the gearbox and handle are connected by bolts; the vibration generated during the gearbox's movement can damage the connection between the gearbox and handle. This design, by making the housing 20 a single unit, increases the overall strength of the workpiece. Preferably, the housing 20 is made of aluminum alloy using a casting method, resulting in a simple manufacturing process, low cost, and excellent heat dissipation. This extends the machine's service life.

[0072] The drive unit 21 has several anti-slip grooves 212 on its outer circumference. The drive unit 21 can be held by hand during use; by providing several anti-slip grooves 212 on the outer circumference of the drive unit 21, the friction between the hand and the drive unit 21 can be increased, and the grip can be more secure.

[0073] By providing a rear cover 55 that is threadedly connected to the rear of the drive unit 21, the output shaft 51 of the drive unit 50 can be supported.

[0074] By positioning the saw blade 40 between the locking block 65 and the pad block 631, the saw blade 40 can be effectively positioned. By setting the heat insulation pad 70 between the transmission part 22 and the saw blade guard 30, the heat generated by the saw blade 40 during cutting and the heat on the saw blade guard 30 can be effectively prevented from being transferred to the transmission part 22, and then transferred to the drive part 21 through the transmission part 22; thus preventing the drive part 21 from getting too hot when held by hand. By providing an air outlet b311 on the protective cover 31, and by cooperating with the air outlet a213 to deliver air, the cold air blown into the saw blade cover 30 can directly cool the saw blade inside the saw blade cover 30, preventing the saw blade cover 30 and the saw blade from overheating and causing the saw blade to burn and wear. At the same time, the high-speed airflow can blow away the high-temperature residual iron filings inside the saw blade cover 30, avoiding the problem of high-temperature residual iron filings accumulating and generating heat, and solving the problem of the saw blade and head shell overheating due to the large amount of heat generated during cutting in the existing cold-cutting saw head shell.

[0075] By installing a screen 312 on the air outlet b311, it is possible to prevent the debris from the saw blade 40 from entering the housing 20 through the air outlet b311 and the air outlet a213, thus preventing damage to the device.

[0076] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0077] The above description is merely an embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of the claims of this utility model.

Claims

1. A cold-cutting saw, characterized in that, include: Handle (10); A housing (20) is disposed at the front end of the handle (10); the housing (20) includes a drive unit (21) and a transmission unit (22); the drive unit (21) and the transmission unit (22) are integrally formed into a single unit; Saw blade guard (30); installed at the lower end of the transmission part (22); the saw blade guard (30) is used to accommodate the saw blade (40). Drive unit (50); disposed within the drive unit (21); and Transmission mechanism (60); disposed within the transmission part (22); the transmission mechanism (60) is driven by the driving device (50); the transmission mechanism (60) is used to drive the saw blade (40) to rotate.

2. The cold-cutting saw according to claim 1, characterized in that, The saw blade (40) is disposed at the end of the transmission mechanism (60); the saw blade (40) is driven by the transmission mechanism (60); the front end of the saw blade guard (30) is provided with an opening, and the saw blade (40) protrudes from the opening.

3. The cold-cutting saw according to claim 1, characterized in that, The drive unit (21) has a transverse accommodating cavity a (211); the transmission unit (22) has a longitudinal accommodating cavity b (221); the accommodating cavity a (211) is perpendicular to the accommodating cavity b (221); the drive device (50) is disposed in the accommodating cavity a (211); the transmission mechanism (60) is disposed in the accommodating cavity b (221).

4. The cold-cutting saw according to claim 1 or 3, characterized in that, The driving part (21) is cylindrical; the outer circumference of the driving part (21) is provided with a number of anti-slip grooves (212).

5. The cold-cutting saw according to claim 1, characterized in that, The drive unit (50) is mounted inside the drive unit (21) via a support frame (54).

6. The cold-cutting saw according to claim 5, characterized in that, The drive unit (21) is provided with a number of positioning ribs (214); the positioning ribs (214) are engaged with the positioning grooves (541) on the support frame (54) and clamped together.

7. The cold-cutting saw according to claim 1, characterized in that, The drive unit (21) is threadedly connected to a rear cover (55); the rear cover (55) is used to support the output shaft (51) of the drive unit (50).

8. The cold-cutting saw according to claim 1, characterized in that, A partition (222) is provided inside the transmission part (22); a transmission hole (2221) is provided on the partition (222); a gear shaft hole (2222) and an output shaft position (2223) are provided in front of the transmission hole (2221); The drive device (50) is provided with an output shaft (51); an output gear (52) is installed at the front end of the output shaft (51); the output gear (52) drives the transmission mechanism (60). The transmission mechanism (60) includes a gear shaft (62); a bevel gear (61) is provided on the gear shaft (62); the bevel gear (61) meshes with the output gear (52); the gear on the gear shaft (62) meshes with the transmission gear (64); the transmission gear (64) is mounted on the main shaft (63); the lower end of the main shaft (63) passes through the saw blade guard (30) and is connected to the saw blade (40); the output gear (52) is located in the transmission hole (2221); the gear shaft (62) passes through the gear shaft hole (2222); the upper end of the main shaft (63) is rotatably mounted in the output shaft position (2223).

9. The cold-cutting saw according to claim 1, characterized in that, The upper end of the transmission part (22) is threadedly fitted with a cover (80); a positioning hole is provided inside the cover (80); the upper end of the gear shaft (62) of the transmission mechanism (60) is rotatably installed in the positioning hole.

10. The cold-cutting saw according to claim 1, characterized in that, A heat insulation pad (70) is provided between the transmission part (22) and the saw blade guard (30).

11. The cold-cutting saw according to claim 10, characterized in that, A baffle (71) is provided on the heat insulation pad (70).

12. The cold-cutting saw according to claim 8, characterized in that, The output shaft (51) is equipped with a fan blade (53) at its front end; the drive unit (21) has an air outlet a (213) on its side.

13. The cold-cutting saw according to claim 12, characterized in that, The saw blade guard (30) includes a protective cover (31) and a base plate (32); the protective cover (31) is installed at the lower end of the transmission part (22); the base plate (32) is installed at the lower end of the protective cover (31); an air outlet b (311) is provided on the protective cover (31); the air outlet b (311) cooperates with the air outlet a (213) to discharge air.

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