China factory Customized Planet Straight Spur Gear Sun Gear for Gearbox Transmission Spare Part spiral bevel gear

Product Description


Stainless steelSS201,SS303,SS304,SS316,SS416,SS420,17-4PH,SUS440C 


Carbon steelQ235,S235JR,1571, 1015, 1571, 1571, 1030, 1035, 1040, 1045

Alloy steel40Cr,15CrMo,4140,4340,35CrMo,16MnCr5

Brass/Copper/BronzeC11000, C15710, C12000, C26000, C36000, etc.etc…

Stainless Steel (201, 302, 303, 304, 316, 420, 430) etc…

Steel (mild steel, Q235, 20#, 45#) etc…


CNC Machining, turning,milling, lathe machining, boring, grinding, drilling,broaching, stamping,etc…

Surface treatment:

Clear/color anodized; Hard anodized; Powder-coating;Sand-blasting; Painting;    

Nickel plating; Chrome plating; Zinc plating; Silver/gold plating; 

Black oxide coating, Polishing etc…

Gerenal Tolerance:(+/-mm)

Gear grade :7Gread (ISO)

Run Out:0.005mm


ID/OD Grinding: 0.002

Roughness : Ra 0.05 Rz 0.2


IATF 16949, ISO140001


16 years of  machining products

Packaging :

Standard: carton with plastic bag protecting

For large quantity: pallet or wooden box as required

Lead time :

In general:30-60days

Term of Payment:

T/T,  L/C, etc

Minimum Order:

Comply with customer’s demand

Delivery way:

Express(DHL,Fedex, UPS,TNT,EMS), By Sea, By air, or as required

Our advantage: *Specialization in CNC formulations of high precision and high quality *Independent quality control department *Control plan and process flow sheet for each batch *Quality control in all whole production *Meeting demands even for very small quantities or single units *Short delivery times *Excellent price-quality ratio *Absolute confidentiality *Various materials (stainless steel, iron, brass, aluminum, titanium, special steels, industrial plastics)

FAQ: Q1: How can I get the samples? A: If you need some samples to test, you should pay for the transportation freight of samples and our samples cost. Q2: Can we have our marking,Logo or company name to be printed on your products or package? A: Sure. Your marking,logo,or company name can be put on your products by Laser machine Q3: How to order? A: Please send us your purchase order by Email, or you can ask us to send you a Performa invoice for your order. We need to know the following information for your order. 1) Product information-Quantity, Specification ( Size, Material, Technological and Packing requirements etc.) 2) Delivery time required 3) Shipping information-Company name, Street address, Phone&Fax number, Destination sea port. 4) Forwarder’s contact details if there’s any in China. Q4: When can you get the price? We usually quote within 48 hours after we get your inquiry. If you are very urgent to get the price, please call us or tell us in your email so that we will regard your inquiry priority. Kindly note that if your inquiry is with more details then the price we quote will be more accurate .Q5: How can you get a sample to check our quality? After price confirmation, you can require for samples to check our quality .Q6: What kind of files do we accept for drawing? A: PDF, CAD,STP,STEP Q7: What about the lead time for mass production? Honestly, it depends on the order quantity and the season you place the order. Generally speaking,it would need about 30-60days to finish the sample. Q8: What is our terms of delivery? We accept EXW, FOB, CFR, CIF, DDU, DDP, etc. You can choose the 1 which is the most convenient or cost effective for you.


Shipping Cost:

Estimated freight per unit.

To be negotiated
Application: Motor, Electric Cars, Motorcycle, Machinery, Marine, Toy, Agricultural Machinery, Car
Hardness: Hardened Tooth Surface
Gear Position: Internal Gear
US$ 2.5/Piece
1 Piece(Min.Order)


Order Sample

According to requirement


Customized Request

sun gear

How does a sun gear contribute to changes in torque direction in gear systems?

A sun gear plays a crucial role in gear systems when it comes to changing the direction of torque. Let’s delve into the details of how a sun gear contributes to torque direction changes in gear systems:

  • Planetary Gear Systems:

In planetary gear systems, the sun gear is one of the primary components along with the planet gears and the ring gear. These systems consist of one or more planet gears that mesh with both the sun gear and the ring gear. The arrangement of these gears allows for various torque direction changes.

  • Torque Transmission:

The sun gear acts as a central driver in a planetary gear system. As power is applied to the sun gear, it transmits torque to the planet gears. The planet gears, in turn, engage with the ring gear, which ultimately transfers the torque to the output shaft or the desired component.

When the sun gear rotates in a specific direction, it imparts torque to the planet gears. The planet gears, due to their meshing with the stationary ring gear, distribute the torque evenly across all the gears. This torque transmission mechanism allows for the transfer of rotational force from the input (sun gear) to the output (ring gear or output shaft) of the system.

  • Direction Reversal:

The unique configuration of a planetary gear system allows for torque direction changes. By manipulating the relative sizes and arrangements of the gears, including the sun gear, it is possible to reverse the direction of the torque output.

For instance, when the sun gear serves as the input and rotates clockwise, it causes the planet gears to rotate counterclockwise. This counterclockwise rotation, in turn, causes the ring gear to rotate in the clockwise direction, resulting in a torque reversal.

Similarly, by reversing the direction of the sun gear’s rotation, the torque direction can be reversed once again. This ability to change the torque direction makes planetary gear systems versatile and applicable in various mechanical and automotive applications.

  • Torque Amplification and Reduction:

Another way the sun gear contributes to torque direction changes is through torque amplification and reduction. By incorporating different gear ratios within the planetary gear system, it is possible to alter the torque output relative to the input.

A specific arrangement of gear sizes, including the sun gear, can result in torque amplification. Torque amplification occurs when the output torque is greater than the input torque. This configuration can be beneficial in applications where increased torque is required, such as in heavy machinery or vehicles.

Conversely, torque reduction can be achieved by utilizing different gear ratios. By adjusting the sizes of the gears, including the sun gear, the output torque can be lower than the input torque. Torque reduction is useful in situations where precision control or lower torque output is necessary, such as in robotics or delicate machinery.

  • Overall Torque Control:

The sun gear’s contribution to torque direction changes in gear systems provides a means of overall torque control. By manipulating the rotation direction and gear ratios, the torque can be directed, amplified, or reduced according to the specific requirements of the application.

Engineers and designers can utilize the sun gear, along with other gears in the system, to achieve the desired torque direction, torque amplification or reduction, and mechanical power transmission within gear systems.

In conclusion, the sun gear is a critical component in gear systems for changing torque direction. It enables torque transmission, facilitates torque direction reversal, contributes to torque amplification or reduction, and provides overall torque control within planetary gear systems and other similar gear configurations.

sun gear

What is the role of a sun gear in the operation of a differential gear system?

The sun gear plays a vital role in the operation of a differential gear system, which is commonly used in vehicles to distribute power between the wheels while allowing them to rotate at different speeds. The sun gear, along with other gears in the differential, contributes to the smooth and efficient operation of the system. Here’s an explanation of the role of a sun gear in the operation of a differential gear system:

  • Power Input:

The sun gear serves as the input for the differential gear system. It receives torque from the driveshaft or propeller shaft, which transfers power from the engine or transmission to the differential. The rotation of the sun gear initiates the power flow within the differential assembly.

  • Speed Differentiation:

The primary function of the differential gear system is to allow the wheels to rotate at different speeds while distributing power between them. The sun gear, along with the other gears in the differential, enables this speed differentiation.

As the sun gear rotates, it meshes with the planet gears, which are arranged around it. The planet gears, in turn, engage with the ring gear, which is connected to the axle shafts leading to the wheels. The interaction between the sun gear, planet gears, and ring gear allows the differential to accommodate different rotational speeds of the wheels.

  • Distribution of Torque:

Another critical role of the sun gear is to distribute torque between the wheels in a differential system. The torque input from the sun gear is transmitted to the planet gears, which then transfer the torque to the ring gear and, subsequently, to the axle shafts and wheels.

As the differential operates, it adjusts the distribution of torque based on the traction and resistance encountered by each wheel. If one wheel experiences less resistance or has more traction than the other, the differential will allocate more torque to that wheel. This torque distribution helps optimize power delivery, improve traction, and enhance vehicle stability during cornering or uneven road conditions.

  • Equal Torque Split (Open Differential):

In an open differential system, which is the most common type, the sun gear plays a role in equal torque split between the wheels under normal driving conditions. When both wheels have equal traction and resistance, the sun gear distributes torque equally to the planet gears, resulting in an equal torque split between the wheels.

However, in situations where one wheel loses traction or encounters less resistance, such as during wheel slip or when one wheel is on a slippery surface, the open differential will prioritize torque delivery to the wheel with less traction, potentially reducing overall traction and performance.

  • Limited-Slip Differential:

In some differential systems, such as limited-slip differentials (LSDs), the sun gear’s role is modified to provide improved traction and torque distribution. LSDs use various mechanisms, such as clutch packs or viscous fluids, to limit the speed differentiation between the wheels and redirect torque to the wheel with more traction.

In LSDs, the sun gear’s engagement with the other gears is modified to allow for controlled torque transfer, enhancing traction and stability during challenging driving conditions.

In summary, the sun gear in a differential gear system serves as the power input and enables speed differentiation and torque distribution between the wheels. Its role is crucial for ensuring smooth power delivery, optimizing traction, and enhancing vehicle stability in various driving conditions.

sun gear

How does a sun gear affect the overall gear ratio in a system?

The presence and characteristics of a sun gear play a significant role in determining the overall gear ratio in a system. Understanding how the sun gear affects the gear ratio helps in analyzing and designing gear systems with the desired performance. Here’s an explanation of how a sun gear affects the overall gear ratio in a system:

  • Number of Teeth: The number of teeth on the sun gear influences the gear ratio. In a simple gear system, where the sun gear engages with a single gear, the gear ratio is determined by the ratio of the number of teeth on the two gears. For example, if the sun gear has 10 teeth and the other gear has 30 teeth, the gear ratio would be 1:3, meaning the output gear rotates three times slower than the sun gear.
  • Arrangement with Other Gears: In more complex gear systems, such as planetary gear configurations, the arrangement of the sun gear with other gears further influences the gear ratio. In a planetary gear set, the sun gear engages with multiple planet gears and an outer ring gear. By manipulating the sizes and arrangements of these gears, a wide range of gear ratios can be achieved. For instance, if the sun gear is fixed, the ring gear becomes the output and the gear ratio is determined by the relative sizes of the sun gear, planet gears, and ring gear.
  • Planet Gears: The number of planet gears in a planetary gear system also affects the gear ratio. Increasing or decreasing the number of planet gears alters the gear ratio by changing the load distribution and the interaction between the sun gear and the ring gear. More planet gears generally result in a higher gear ratio, while fewer planet gears tend to reduce the gear ratio.
  • Epicyclic Gear Trains: The arrangement of gears in an epicyclic gear train, which includes the sun gear, planet gears, and ring gear, allows for even more complex gear ratios. By fixing or holding certain gears while others are driven, various gear ratios can be achieved. For example, fixing the ring gear and driving the sun gear produces a different gear ratio compared to fixing the sun gear and driving the ring gear.
  • Variable Gear Ratio: In some systems, the gear ratio can be varied by changing the position or speed of the sun gear. This can be achieved using mechanisms such as adjustable clutches or continuously variable transmissions (CVTs). By modifying the engagement between the sun gear and other gears, the gear ratio can be adjusted to optimize performance for different operating conditions.

In summary, the presence and characteristics of a sun gear, including the number of teeth, its arrangement with other gears, the presence of planet gears, and the overall gear system configuration, all contribute to the determination of the gear ratio. Understanding these factors allows for the design and control of gear systems with specific gear ratios to meet the requirements of various mechanical applications.

China factory Customized Planet Straight Spur Gear Sun Gear for Gearbox Transmission Spare Part spiral bevel gearChina factory Customized Planet Straight Spur Gear Sun Gear for Gearbox Transmission Spare Part spiral bevel gear
editor by CX 2023-09-14