Hydrostatic variator K16 5,5-7,5kW - KACPEREK (2024)

CONSTRUCTION AND OPERATION

Construction of a hydrostatic variator with radial pistons:
– variable displacement main pump (A)
– second pump with constant capacity (B)
– auxiliary pump
– separation roller

The main pump, driven by an electric motor, has a variable displacement, regulated by changing the external position
bearings – A.
In the middle position, the pistons have no stroke during rotation.
When the eccentricity is modified, the pistons send oil under
oil under pressure to the second pump, which starts to rotate (output shaft).

Each K series variator is equipped with an adjustable maximum torque valve (one for each direction of rotation at the output). The torque setting must be verified manually by checking the actual torque on the output shaft during operation. To measure torque, it is necessary to include the device code MM of the dual pressure inlet and pressure gauge.

In hydraulic variators, the output torque is directly proportional to the pressure in the main circuit. Using the MM pressure inlet code and a pressure gauge you can check what the pressure (torque) is on the output shaft. Using a pressure switch or transducer, an alarm or electrical signal can be set to remotely sense torque.

Auxiliary circuit
The electric motor also activates, inside the variator, an auxiliary circuit consisting of a roller pump (oil flow at low pressure 6-8 bar), which is necessary to feed oil to the main circuit. Oil flow from the auxiliary pump is also used to power the electro-hydraulic controls.

Auxiliary circuit relief valve.
On the left side of the variators there is an auxiliary pump relief valve that keeps the auxiliary circuit pressurized. Excess oil is discharged through the valve to the variator housing.

Speed ​​Controller Types:
1. Mechanical (knob code 00, with lever code 02)
2. Electric (with a 3-phase electric motor 230/400 – 50 Hz or single-phase 220 – 50 Hz)
3. Pneumatic (to control a 0,2÷1 bar signal, for one direction of output rotation)
4. Electrohydraulic (with 2 speeds or adjustable in the entire range of 1400-0-1400 rpm, with or
without zeroing device)
5. Electronic (for speed regulation via 4-20mA, 0-10V or potentiometer etc.)
Device types:
1. Speed ​​sensor code 8 and speed indicator (for reading the output speed of the variator using an analog or digital indicator)
2. Micro switches code 9 (for electrical control code 20)
3. Pressure inlet code MM (for detecting the main pressure of the variator)
4. Oil cooler (used in high temperature environments)

Control lever code 02
Very easy to install and use, allowing instant speed adjustment. Useful in self-propelled machines, where it replaces the gearbox for the engine and allows you to obtain infinitely variable speed without a clutch.

Constant power control code 06
In this case, the knob is used to change the output power of the variator. Used in winding applications, the variator automatically reduces speed by increasing torque, maintaining constant linear speed.

Electrical control code 20
Control code 20 allows remote adjustment of the output speed of the variators in both directions of rotation. When used with variable displacement pumps, this control allows for remote regulation of oil flow from the pump.

Electrical control code 49
It is similar to electric control code 20, with the addition of a hydraulic device for automatic progressive start. This device sets the variator to zero revolutions each time the engine is stopped and starts gradually at the set speed with an adjustable ramp. It works in one direction of output rotation.

Pneumatic control code 52
This control allows speed adjustment via a 0,2 -1 bar pneumatic signal. It works in one direction of output rotation. Particularly suitable for Ex zones.

Electrohydraulic control code 68
It is a hydraulic control that allows speed regulation, in both directions of output rotation, using a valve with 2 electromagnets (one to increase the speed, the other to reduce it). It also has a second valve for quickly reaching zero speed.

Device with code 8 – speed sensor
Code 8 is a sensor mounted on the output side of the variator and detecting the actual rotational speed of the output shaft. There are 3 different types of sensors available:
– 0-10 V generator
– namur 2 wires (ON/OFF frequency)
– 3-wire proximity (NPN or PNP)

Hydrostatic transmissions
Consists of:
– Variable displacement pump
- Hydraulic engine
The compact dimensions of the hydraulic motor make this solution particularly suitable where space is a problem or access is difficult.

Variable displacement pump
Variable displacement pump with radial pistons that can be used in:
– open circuit
– closed circuit
The capacity range starts from 3,85 cc to 3 cc, with a built-in maximum pressure limiter. IEC or NEMA input size. Particularly indicated in applications where precise regulation of oil flow is necessary, with various types of controls to regulate it. It can be combined with various types of hydraulic motors.

Hydraulic motors
Hydraulic motor with radial pistons with a displacement range from 3,85 cm3 to 19,91 cm3. Particularly useful as it is equipped with an IEC or NEMA output flange, suitable for connection to all major gear types available on the market.
Other features:
– works in any position
– dynamic brake
– reversible (bidirectional output rotation).

APPLICATION

PUMPS
screw, metering, dispensing, mono, cavity, cam, peristaltic
Main advantages:
– speed range,
– torque at low speed,
- reset,
– difficult conditions (aggressive atmosphere or weather),
– explosive environment,
– initial speed setting with the engine turned off,
– starting from zero under load,
– remote control (4-20 mA or pneumatic),
– closed loop circuit (with feedback).

PETROCHEMICAL AND GAS INDUSTRY
Pumps, conveyors, pellet mills, mixers
Main advantages:
– cheap and simple installation in an explosive environment,
– suitable for work in difficult (aggressive) conditions,
– speed range,
– torque at low speed,
– remote control (4-20 mA or pneumatic),
– closed loop circuit (with feedback).

AGRICULTURE
Main advantages:
– precise speed regulation (variator speed regulation replaces the gearbox),
– suitable for various types of environments,
- resilience,
– high torque at low speed,
– bidirectional output rotation,
– not subject to electromagnetic interference.

SCREW MIXERS AND FEEDERS
Chemical, food and pharmaceutical industries
Main advantages:
– appropriate to the type of environment (aggressive),
– for explosive environments (Atex),
– high torque at low speed,
– wide speed range,
– remote control (4-20 mA or pneumatic),
– closed loop circuit (with feedback).

STONE INDUSTRY
Stone mining and polishing machines.
Main advantages:
– appropriate to the type of environment (dust, water),
- resilience,
– high torque at low speed,
– bidirectional output rotation,
– torque limiter,
– speed range,
– precise and accurate speed regulation.

WOOD INDUSTRY
Preliminary and finishing processing.
Main advantages:
– suitable for the type of environment (dust),
– saving for long life,
– quick change of direction of rotation,
– load resistance,
– speed range,
– ease of installation,
– torque limiter,
– load monitoring.

WINDERS
Textile / Paper / Cable industry
Main advantages:
– easy power regulation,
– long life of the variator guaranteeing savings,
– automatic speed reduction and torque increase (as the material diameter increases).

REPLACEMENT FOR INVERTERS

Hydrostatic variators are an excellent replacement for inverters when:

1. A wider speed range is needed.
The hydraulic variator has an output speed range of 1/30 (min. 50/60 rpm, max. 1500 rpm with the possibility of, with appropriate displacements, also reaching up to 2000 rpm).

2. Higher torque is required at low speeds.
Taking into account the nominal torque at maximum speed, the speed of the hydraulic variator is reduced
increases the available torque to 3 times the nominal torque.

3. IP65 protection rating for humid environments is required
The hydraulic variator has a sealed structure, especially suitable for humid or dusty environments. In such cases, the unit is supplied with a vent plug without a non-return valve to prevent water and powder from entering.

4. A simple workaround is required.
In the event of a failure, the customer needs a quick and simple way to replace the faulty device to avoid production downtime and does not want to make the electrical connection or program a new inverter.

5. A solution free from electrical noise is required.
Inverters cause electromagnetic and harmonic interference. To eliminate them, it is necessary to use anti-interference devices. The inverter also causes faster wear of the electric motor bearings.

6. A durable and reliable device is required.
Hydraulic variators are characterized by a long service life (up to 20-25 years), which is a necessary condition for strategic production, where the devices take part in key processes, working 24 hours a day, 365 days a year.

7. A simple device for work in an explosive environment (Atex) is required.
The hydraulic variator requires simple adjustments to obtain the Atex certificate: a special vent plug with a non-return valve, Viton seals, and in the case of more stringent Atex cat. 2 T4 requirements, PTC thermal protection is mounted on the variator housing.

8. A solution is required to work with an electric endothermic generator.
When there is no power line available, only an endothermic electrical generator, the power supply is not as constant, which poses a problem for the operation of the inverters. Moreover, in some applications, the endothermic engine provides movement and the hydraulic variator can be well connected to the power take-off.

REPLACEMENT FOR MECHANICAL VARIANTS

Hydrostatic variators are an excellent replacement for mechanical variators when:

1. A wider speed range is required.
Mechanical variators are able to regulate speeds in the range from 200 to 1000 rpm, while hydrostatic variators cover the range from 0 to 1500 rpm.

2. No rotation is required with the engine running.

3. Fast change of direction of rotation at the output is required.
The use of hydrostatic variators allows you to change the direction of rotation at the output by using control (mechanical and electro-hydraulic) or by changing the direction of rotation at the input.

4. There is a need to adjust the speed with the engine turned off.
Hydrostatic variators enable speed regulation with the engine turned off, without damaging the variator. Mechanical variators cannot be adjusted with the engine stopped.

5. Minimal and repeatable speed control is required.
There is often a need to repeat precise speed regulation even several years after installation, which is possible thanks to the use of a hydraulic variator.

6. A reliable and durable device is required.
The long service life of hydrostatic variators is ensured by always lubricated parts that are not subject to friction.

7. Output torque adjustment is required.
Hydrostatic variators are suitable for applications that require variable, adjustable speed and torque control.

8. Speed ​​regulation is required using different types of control.
The following controls are available: mechanical, pneumatic, hydraulic, electric, electronic.

9. Power range of hydrostatic variators from 0,37 kW to 22 kW.

REPLACEMENT FOR HYDRAULIC DRIVES

Hydrostatic variators are an excellent replacement for hydraulic drives when:

1. The application must avoid tank and pipeline connections.
Traditional hydraulic transmissions require tanks for large amounts of oil, pipes to connect pumps and motors, etc.
In the case of hydrostatic variators, the oil tank, with a small amount of oil, is located in the variator itself.

2. A compact device is required.
Hydrostatic variators are used when there is no space in the machine to place a variable displacement pump, hydraulic motor and pipes.