Tag Archives: gear drive motor

China factory High precise Planetary gearbox DRN Series Torque Planetary Gearbox Harmonic Drive Helical Gear Motor Reducer worm gear winch

Warranty: 1 years
Applicable Industries: Manufacturing Plant, Machinery Repair Shops, Food & Beverage Factory, Retail, Food Shop, Printing Shops, Energy & Mining, Food & Beverage Shops, High performance yeduc planetary gearbox harmonic drive speed reducer Other
Weight (KG): 3 KG
Customized support: OEM, ODM
Gearing Arrangement: Harmonic
Output Torque: 2.6-1760N.m
Input Speed: 750~3500rpm
Output Speed: 14-280rpm
Product name: Planetary reduction gearbox
Installation method: Any
Average life: 2000h
Protection level: 65IP
Maximum output radial force: Fr=300N
Maximum output axial force: Fa=100N
Backlash: ≥10arcmin
Rated output torque: TN
Fault stop torque: 2TN
Full load efficiency: 90%~94%
Packaging Details: plastic packaging bag & standard packing

PRODUCT DESCRIPTION

Product nameDRN Series Torque Planetary Gearbox Harmonic Drive Helical Gear Motor Reducer
Reduction ratioSingle-stage:4/5/7/10 Bipolar:15/20/25/30/35/40/50/70
Rated output torque/ NmTN
Fault stop torque/ Nm2TN
Rated input speed/ min3000MIN-1
Input speed/ min3000MIN-1
Installation methodAny
Installation method/ H2000h
Maximum output radial force/ NFr=300N
Maximum output axial force/ NFa=100N
Full load efficiency/ %90%–94%
Lubrication methodLong term effectiveness
Protection level/ IP65
Backlash/ armin≥10
Operating temperature/ ℃-10℃~80℃
PRODUCT PICTURES PRODUCT DIMENSIONS COMPANY INTRODUCTION HangZhou Guanghong Automation Equipment Co., Ltd. is a collection of R & D, design, manufacturing, sales and service as 1 of the professional servo electric cylinder, High Power R1SF300 12000rmp 33Kg Electric Car Conversion Kit Reducer Gearbox for 2 to 4 ton Vehicle servo press equipment, etc. development and production of modern enterprises. The company has a professional design team, processing team, assembly team, sales and after-sales service team.The company mainly develops and produces servo cylinder, servo pressing machine, electric push rod, electric sliding platform, High end unique concrete mixer gearboxtypes of gear box multi-degree-of-freedom platform and other servo pressing equipment. WHY CHOOSE US EXHIBITION EVENTS PACKING & DELIVERY FAQ

Types of Bevel Gears

Bevel Gears are used in a number of industries. They are used in wheeled excavators, dredges, conveyor belts, mill actuators, and rail transmissions. A bevel gear’s spiral or angled bevel can make it suitable for confined spaces. It is also used in robotics and vertical supports of rolling mills. You can use bevel gears in food processing processes. For more information on bevel gears, read on.
gear

Spiral bevel gear

Spiral bevel gears are used to transmit power between two shafts in a 90-degree orientation. They have curved or oblique teeth and can be fabricated from various metals. Bestagear is one manufacturer specializing in medium to large spiral bevel gears. They are used in the mining, metallurgical, marine, and oil fields. Spiral bevel gears are usually made from steel, aluminum, or phenolic materials.
Spiral bevel gears have many advantages. Their mesh teeth create a less abrupt force transfer. They are incredibly durable and are designed to last a long time. They are also less expensive than other right-angle gears. They also tend to last longer, because they are manufactured in pairs. The spiral bevel gear also reduces noise and vibration from its counterparts. Therefore, if you are in need of a new gear set, spiral bevel gears are the right choice.
The contact between spiral bevel gear teeth occurs along the surface of the gear tooth. The contact follows the Hertz theory of elastic contact. This principle holds for small significant dimensions of the contact area and small relative radii of curvature of the surfaces. In this case, strains and friction are negligible. A spiral bevel gear is a common example of an inverted helical gear. This gear is commonly used in mining equipment.
Spiral bevel gears also have a backlash-absorbing feature. This feature helps secure the thickness of the oil film on the gear surface. The shaft axis, mounting distance, and angle errors all affect the tooth contact on a spiral bevel gear. Adjusting backlash helps to correct these problems. The tolerances shown above are common for bevel gears. In some cases, manufacturers make slight design changes late in the production process, which minimizes the risk to OEMs.

Straight bevel gear

Straight bevel gears are among the easiest types of gears to manufacture. The earliest method used to manufacture straight bevel gears was to use a planer equipped with an indexing head. However, improvements have been made in manufacturing methods after the introduction of the Revacycle system and the Coniflex. The latest technology allows for even more precise manufacturing. Both of these manufacturing methods are used by CZPT. Here are some examples of straight bevel gear manufacturing.
A straight bevel gear is manufactured using two kinds of bevel surfaces, namely, the Gleason method and the Klingelnberg method. Among the two, the Gleason method is the most common. Unlike other types of gear, the CZPT method is not a universal standard. The Gleason system has higher quality gears, since its adoption of tooth crowning is the most effective way to make gears that tolerate even small assembly errors. It also eliminates the stress concentration in the bevelled edges of the teeth.
The gear’s composition depends on the application. When durability is required, a gear is made of cast iron. The pinion is usually three times harder than the gear, which helps balance wear. Other materials, such as carbon steel, are cheaper, but are less resistant to corrosion. Inertia is another critical factor to consider, since heavier gears are more difficult to reverse and stop. Precision requirements may include the gear pitch and diameter, as well as the pressure angle.
Involute geometry of a straight bevel gear is often computed by varying the surface’s normal to the surface. Involute geometry is computed by incorporating the surface coordinates and the theoretical tooth thickness. Using the CMM, the spherical involute surface can be used to determine tooth contact patterns. This method is useful when a roll tester tooling is unavailable, because it can predict the teeth’ contact pattern.
gear

Hypoid bevel gear

Hypoid bevel gears are an efficient and versatile speed reduction solution. Their compact size, high efficiency, low noise and heat generation, and long life make them a popular choice in the power transmission and motion control industries. The following are some of the benefits of hypoid gearing and why you should use it. Listed below are some of the key misperceptions and false assumptions of this gear type. These assumptions may seem counterintuitive at first, but will help you understand what this gear is all about.
The basic concept of hypoid gears is that they use two non-intersecting shafts. The smaller gear shaft is offset from the larger gear shaft, allowing them to mesh without interference and support each other securely. The resulting torque transfer is improved when compared to conventional gear sets. A hypoid bevel gear is used to drive the rear axle of an automobile. It increases the flexibility of machine design and allows the axes to be freely adjusted.
In the first case, the mesh of the two bodies is obtained by fitting the hyperboloidal cutter to the desired gear. Its geometric properties, orientation, and position determine the desired gear. The latter is used if the desired gear is noise-free or is required to reduce vibrations. A hyperboloidal cutter, on the other hand, meshes with two toothed bodies. It is the most efficient option for modeling hypoid gears with noise concerns.
The main difference between hypoid and spiral bevel gears is that the hypoid bevel gear has a larger diameter than its counterparts. They are usually found in 1:1 and 2:1 applications, but some manufacturers also provide higher ratios. A hypoid gearbox can achieve speeds of three thousand rpm. This makes it the preferred choice in a variety of applications. So, if you’re looking for a gearbox with a high efficiency, this is the gear for you.

Addendum and dedendum angles

The addendum and dedendum angles of a bevel gear are used to describe the shape and depth of the teeth of the gear. Each tooth of the gear has a slightly tapered surface that changes in depth. These angles are defined by their addendum and dedendum distances. Addendum angle is the distance between the top land and the bottom surface of the teeth, while dedendum angle is the distance between the pitch surface and the bottom surface of the teeth.
The pitch angle is the angle formed by the apex point of the gear’s pitch cone with the pitch line of the gear shaft. The dedendum angle, on the other hand, is the depth of the tooth space below the pitch line. Both angles are used to measure the shape of a bevel gear. The addendum and dedendum angles are important for gear design.
The dedendum and addendum angles of a bevel gear are determined by the base contact ratio (Mc) of the two gears. The involute curve is not allowed to extend within the base diameter of the bevel gear. The base diameter is also a critical measurement for the design of a gear. It is possible to reduce the involute curve to match the involute curve, but it must be tangential to the involute curve.
The most common application of a bevel gear is the automotive differential. They are used in many types of vehicles, including cars, trucks, and even construction equipment. They are also used in the marine industry and aviation. Aside from these two common uses, there are many other uses for bevel gears. And they are still growing in popularity. But they’re a valuable part of automotive and industrial gearing systems.
gear

Applications of bevel gears

Bevel gears are used in a variety of applications. They are made of various materials depending on their weight, load, and application. For high-load applications, ferrous metals such as grey cast iron are used. These materials have excellent wear resistance and are inexpensive. For lower-weight applications, steel or non-metals such as plastics are used. Some bevel gear materials are considered noiseless. Here are some of their most common uses.
Straight bevel gears are the easiest to manufacture. The earliest method of manufacturing them was with a planer with an indexing head. Modern manufacturing methods introduced the Revacycle and Coniflex systems. For industrial gear manufacturing, the CZPT uses the Revacycle system. However, there are many types of bevel gears. This guide will help you choose the right material for your next project. These materials can withstand high rotational speeds and are very strong.
Bevel gears are most common in automotive and industrial machinery. They connect the driveshaft to the wheels. Some even have a 45-degree bevel. These gears can be placed on a bevel surface and be tested for their transmission capabilities. They are also used in testing applications to ensure proper motion transmission. They can reduce the speed of straight shafts. Bevel gears can be used in many industries, from marine to aviation.
The simplest type of bevel gear is the miter gear, which has a 1:1 ratio. It is used to change the axis of rotation. The shafts of angular miter bevel gears can intersect at any angle, from 45 degrees to 120 degrees. The teeth on the bevel gear can be straight, spiral, or Zerol. And as with the rack and pinion gears, there are different types of bevel gears.

China factory High precise Planetary gearbox DRN Series Torque Planetary Gearbox Harmonic Drive Helical Gear Motor Reducer     worm gear winchChina factory High precise Planetary gearbox DRN Series Torque Planetary Gearbox Harmonic Drive Helical Gear Motor Reducer     worm gear winch

in Surat India sales price shop near me near me shop factory supplier Precision Modelgear. Motor Gear. Micro Drive Gear manufacturer best Cost Custom Cheap wholesaler

  in Surat India  sales   price   shop   near me   near me shop   factory   supplier Precision Modelgear. Motor Gear. Micro Drive Gear manufacturer   best   Cost   Custom   Cheap   wholesaler

Our business pays specific focus to customers’ requirements, listening to the specific specifications of each and every client and guaranteeing complete fulfillment. The new products contain a sequence of substantial-tech and high good quality chains and sprockets and gears, this kind of as chains and gearboxes for agricultural machineries, metallurgical chains, escalator stage-chains, higher-speed tooth chains, timing chains, self-lubrication chains, amid which have variety high velocity tooth chain for automobile department dynamic box and aerial chains fill in the blanks of chain in China. With numerous years’ knowledge in these lines, we have been distinguished from other suppliers in China by our benefits in competitive pricing, on-time supply, prompt responses, on-hand engineering assistance and good after-sales providers. EPT design EPT.motor EPT.micro EPT EPT
Standard Info:

Manufacture HangEPT zongEPTT EPT merchandise EPTT, Ltd
Expert group over15years encounter in metallic fabrication
Component Dimension EPTT
EPT Tungsten Carbide,Stainless metal,EPTT Alloy,Brass Alloy,EPTT Metal / Die Metal / Spring Steel etc
Tolerance can be /-.001mm,high accuracy
AXiHu (West EPT) Dis.ality .002mm
Roundness .015mm
Surface roughness Ra .571mm
straightness .002mm
Hardness EPTC20-94
Payment Expression T/T, Western EPT, PayPal
Floor Mirro poEPTTd,EPTnical PoEPTTd,Mildew EPT texture, Nitriding ,plating ,VDI texture ect
Delivery 7-fifteen daEPTTafter payment
Shipment Air cargo
QC Method one hundred% inspection just before shipment
EPT CNC lathe, CNC machining,EPTT lathe,Grinder, Drilling EPTTs,
floor grinder, table lathe, parks EPTT ect
QC Method 100% inspection before shipment
Cavity One-cavity ,Multi-cavity
MOQ 1pcs
DRW Format DWG, PDF, STEPT, DRW, etc…
EPT Terms EXW
Transport Package Full thought of useful circumstance: foam/picket box, anti-rust paper,carton
little box and carton, and so on.
Shipping way DHL,UPS,FEDEX
EPT Capability 20000 pieces/Month
Our Benefits Trustworthy EPTT
Aggressive Price tag
EPT precision, substantial top quality, tigEPTT tolerance
Continuous EPTTrovement
Defect-Free EPT
On-Time Delivery
Customer Gratification
Excellent Right after-EPT Provider
For a lot more details you should contact us.

About Us:
HangEPT zongEPTT EPT items EPTT, Ltd. is situated in HangEPT EPTT, ZheJiang Province of EPTT. We has really handy transportation conditions.

EstabEPTTd in 2014, our business now addresses an region of far more than8000 square meters, and have above a hundred full time workers.
We are a skilled maker and have five several years knowledge in specifically production and processing EPTTry parts and elements, eEPTTly precision CNC EPTTd objects.
We has over one hundred twenty units of producing equipments, incXiHu (West EPT) Dis.Hu (West EPT) Dis. CNC lathes, EPTT cEPTTrs, grinding EPTTs, etc. We can offer precision machining providers, these kinds of as CNC milling, turning, drilling, tapping, stamping, anodizing, knurling, die casting, sand casting, and forging.
We can EPTT numerous types of resources, incXiHu (West EPT) Dis.Hu (West EPT) Dis. carbon steel, stainless metal, EPT, brass, bronze, Iron, plastic, and so forth.
With EPTd EPT assistance and management ideas, zongEPTT has deveXiHu (West EPT) Dis.Hu (West EPT) Dis.ed steadily and quickly. Considering that establishment, we have been cooperating with several domestic and overEPTT EPTTrprises. Most of our goods are delivered to international clientele. At current, we have EPTT-term clients from United states of america, Europe, Middle EPT, Africa, Japan and Korea. With 1st-class EPT, aggressive pricing, outstanding good quality, reliable on-time shipping and delivery, and outstXiHu (West EPT) Dis.Hu (West EPT) Dis. consumer services, we have gained the full recognition and large appreciation from our consumers.
EPT Demonstrate:

Surface end :

  in Surat India  sales   price   shop   near me   near me shop   factory   supplier Precision Modelgear. Motor Gear. Micro Drive Gear manufacturer   best   Cost   Custom   Cheap   wholesaler

  in Surat India  sales   price   shop   near me   near me shop   factory   supplier Precision Modelgear. Motor Gear. Micro Drive Gear manufacturer   best   Cost   Custom   Cheap   wholesaler

in Konya Turkey sales price shop near me near me shop factory supplier Cycloidal Gearbox Cyclo Speed Drive Planetary Gear Motor Sumitomo Pins Planetary Bwd Xwed Cycloid Gearbox Robot Reducer Stainless Steel manufacturer best Cost Custom Cheap wholesaler

  in Konya Turkey  sales   price   shop   near me   near me shop   factory   supplier Cycloidal Gearbox Cyclo Speed Drive Planetary Gear Motor Sumitomo Pins Planetary Bwd Xwed Cycloid Gearbox Robot Reducer Stainless Steel manufacturer   best   Cost   Custom   Cheap   wholesaler

Having accumulated treasured knowledge in cooperating with international buyers, EPG is a expert manufacturer and exporter that is involved with the design and style, improvement and creation. The new products incorporate a series of higher-tech and high high quality chains and sprockets and gears, such as chains and gearboxes for agricultural machineries, metallurgical chains, escalator step-chains, large-pace tooth chains, timing chains, self-lubrication chains, amongst which have variety large speed tooth chain for vehicle branch dynamic box and aerial chains fill in the blanks of chain in China.
Cycloidal EPT cyclo velocity generate planetary equipment motor sumitomo pins planetary bwd xwed cycloid EPT robot EPT stainless steel

  in Konya Turkey  sales   price   shop   near me   near me shop   factory   supplier Cycloidal Gearbox Cyclo Speed Drive Planetary Gear Motor Sumitomo Pins Planetary Bwd Xwed Cycloid Gearbox Robot Reducer Stainless Steel manufacturer   best   Cost   Custom   Cheap   wholesaler

  in Konya Turkey  sales   price   shop   near me   near me shop   factory   supplier Cycloidal Gearbox Cyclo Speed Drive Planetary Gear Motor Sumitomo Pins Planetary Bwd Xwed Cycloid Gearbox Robot Reducer Stainless Steel manufacturer   best   Cost   Custom   Cheap   wholesaler

in Tirunelveli India sales price shop near me near me shop factory supplier Planetary Gearbox Gear Speed Reducer Motor Winch Track Wheel Drive System Reduction Transmission Epicyclic Inline Precision Precision NEMA 34 Gearbox manufacturer best Cost Custom Cheap wholesaler

  in Tirunelveli India  sales   price   shop   near me   near me shop   factory   supplier Planetary Gearbox Gear Speed Reducer Motor Winch Track Wheel Drive System Reduction Transmission Epicyclic Inline Precision Precision NEMA 34 Gearbox manufacturer   best   Cost   Custom   Cheap   wholesaler

Due to our wide product selection and abundant encounters in this business, Our merchandise are used in many fields. In addition, WE CAN Generate Custom-made VARIATORS, GEARED MOTORS, Electric MOTORS AND OTHER HYDRAULIC Merchandise In accordance TO CUSTOMERS’ DRAWINGS.
Planetary EPT equipment pace EPT motor winch keep track of wheel drive method reduction EPT epicyclic inline precision precision nema 34 EPT

  in Tirunelveli India  sales   price   shop   near me   near me shop   factory   supplier Planetary Gearbox Gear Speed Reducer Motor Winch Track Wheel Drive System Reduction Transmission Epicyclic Inline Precision Precision NEMA 34 Gearbox manufacturer   best   Cost   Custom   Cheap   wholesaler

  in Tirunelveli India  sales   price   shop   near me   near me shop   factory   supplier Planetary Gearbox Gear Speed Reducer Motor Winch Track Wheel Drive System Reduction Transmission Epicyclic Inline Precision Precision NEMA 34 Gearbox manufacturer   best   Cost   Custom   Cheap   wholesaler

in Montreal Canada sales price shop near me near me shop factory supplier Worm Wheel Gearbox Speed Reducer Jack Worm Agricultural Planetary Helical Bevel Steering Gear Drive Motor Speed Nmrv Good Quantity Durableworm Gear Reducers manufacturer best Cost Custom Cheap wholesaler

  in Montreal Canada  sales   price   shop   near me   near me shop   factory   supplier Worm Wheel Gearbox Speed Reducer Jack Worm Agricultural Planetary Helical Bevel Steering Gear Drive Motor Speed Nmrv Good Quantity Durableworm Gear Reducers manufacturer   best   Cost   Custom   Cheap   wholesaler

We will give ideal providers and large high quality merchandise with all sincerity. EPG will usually adhere to it business spirit of getting practical, revolutionary, productive and outstanding to make the leading worldwide transmission drive. Keeping in brain that very good support is the key to cooperating with clients, we attempt to satisfy substantial top quality requirements, provide aggressive charges and make certain prompt supply.

Worm Wheel EPT Velocity EPT Jack Worm Agricultural Planetary Helical EPTl Steering Equipment Generate EPT Pace Nmrv Good quantity DurableWorm Gear EPTs

How does a worm gear perform?
How Worm Gears Operate. An electrical motor or engine applies rotational EPT by way of to the worm. EPT worm rotates towards the wheel, and the screw experience pushes on the enamel of the wheel. EPT wheel is pushed against the load.

Can a worm gear go each instructions?
Worm drives can go possibly route, but they want to be created for it. As you can envision, turning the worm shaft unEPTload will create a thrust aEPT the aXiHu (West Lake) Dis.s of the screw. Nonetheless, if you reverse the course the route of thrust will reverse as nicely.

EPT fundamental structure of the worm gear EPT is primarily composed of the worm equipment, the shaft, the bearing, the box body and its components. Can be divided into a few basic structural elements: box, worm gear, bearing and shaft mix. EPT box is the foundation of all the add-ons in the worm equipment EPT. It is an EPTant part that supports the fixed shaft parts, ensures the proper relative position of the EPT elements and supports the load performing on the EPT. EPT major perform of the worm gear is to transmit the movement and EPT between the two staggered shafts.

  in Montreal Canada  sales   price   shop   near me   near me shop   factory   supplier Worm Wheel Gearbox Speed Reducer Jack Worm Agricultural Planetary Helical Bevel Steering Gear Drive Motor Speed Nmrv Good Quantity Durableworm Gear Reducers manufacturer   best   Cost   Custom   Cheap   wholesaler

  in Montreal Canada  sales   price   shop   near me   near me shop   factory   supplier Worm Wheel Gearbox Speed Reducer Jack Worm Agricultural Planetary Helical Bevel Steering Gear Drive Motor Speed Nmrv Good Quantity Durableworm Gear Reducers manufacturer   best   Cost   Custom   Cheap   wholesaler

in Larkana Pakistan sales price shop near me near me shop factory supplier Worm Gear Reducer Box Speed Reducer Jack Worm Agricultural Planetary Helical Bevel Steering Gear Drive Motor Speed Nmrv Good Quantity Durableworm Gear Reducers manufacturer best Cost Custom Cheap wholesaler

  in Larkana Pakistan  sales   price   shop   near me   near me shop   factory   supplier Worm Gear Reducer Box Speed Reducer Jack Worm Agricultural Planetary Helical Bevel Steering Gear Drive Motor Speed Nmrv Good Quantity Durableworm Gear Reducers manufacturer   best   Cost   Custom   Cheap   wholesaler

We are aiming to meet the calls for of the consumers about the world.. If you need to have any information or samples, make sure you get in touch with us and you will have our soon reply. With several years’ knowledge in these traces, we have been distinguished from other suppliers in China by our advantages in aggressive pricing, on-time supply, prompt responses, on-hand engineering support and very good right after-income solutions.

Worm Gear EPT EPTox Pace EPT Jack Worm Agricultural Planetary Helical EPTl Steering Gear Drive Motor Pace Nmrv Very good quantity DurableWorm Gear EPTs

  in Larkana Pakistan  sales   price   shop   near me   near me shop   factory   supplier Worm Gear Reducer Box Speed Reducer Jack Worm Agricultural Planetary Helical Bevel Steering Gear Drive Motor Speed Nmrv Good Quantity Durableworm Gear Reducers manufacturer   best   Cost   Custom   Cheap   wholesaler

  in Larkana Pakistan  sales   price   shop   near me   near me shop   factory   supplier Worm Gear Reducer Box Speed Reducer Jack Worm Agricultural Planetary Helical Bevel Steering Gear Drive Motor Speed Nmrv Good Quantity Durableworm Gear Reducers manufacturer   best   Cost   Custom   Cheap   wholesaler

in Genoa Italy sales price shop near me near me shop factory supplier Gear Reducer Box Gearbox Reducer Speed Drive Reduction Electric Motor Good Price Transmission Prices Variator Sumitomo Excavator High Rpm China Gear Reducer Box manufacturer best Cost Custom Cheap wholesaler

  in Genoa Italy  sales   price   shop   near me   near me shop   factory   supplier Gear Reducer Box Gearbox Reducer Speed Drive Reduction Electric Motor Good Price Transmission Prices Variator Sumitomo Excavator High Rpm China Gear Reducer Box manufacturer   best   Cost   Custom   Cheap   wholesaler

Furthermore, WE CAN Make Customized VARIATORS, GEARED MOTORS, Electric MOTORS AND OTHER HYDRAULIC Products According TO CUSTOMERS’ DRAWINGS. We are aiming to satisfy the needs of the clients close to the globe.. In this way, our merchandise have continued to obtain industry acceptance and buyers gratification in excess of the earlier couple of a long time.

Equipment EPT EPTox EPT EPT Pace Generate Reduction Electric powered Motor Very good Cost EPT Charges Variator Sumitomo Excavator High Rpm EPT Gear EPT EPTox

  in Genoa Italy  sales   price   shop   near me   near me shop   factory   supplier Gear Reducer Box Gearbox Reducer Speed Drive Reduction Electric Motor Good Price Transmission Prices Variator Sumitomo Excavator High Rpm China Gear Reducer Box manufacturer   best   Cost   Custom   Cheap   wholesaler

  in Genoa Italy  sales   price   shop   near me   near me shop   factory   supplier Gear Reducer Box Gearbox Reducer Speed Drive Reduction Electric Motor Good Price Transmission Prices Variator Sumitomo Excavator High Rpm China Gear Reducer Box manufacturer   best   Cost   Custom   Cheap   wholesaler